* [PATCH v12 01/10] crypto: Add ML-DSA crypto_sig support
2026-01-15 21:50 [PATCH v12 00/10] x509, pkcs7, crypto: Add ML-DSA and RSASSA-PSS signing David Howells
@ 2026-01-15 21:50 ` David Howells
2026-01-15 21:50 ` [PATCH v12 02/10] pkcs7: Allow the signing algo to calculate the digest itself David Howells
` (8 subsequent siblings)
9 siblings, 0 replies; 20+ messages in thread
From: David Howells @ 2026-01-15 21:50 UTC (permalink / raw)
To: Lukas Wunner, Ignat Korchagin
Cc: David Howells, Jarkko Sakkinen, Herbert Xu, Eric Biggers,
Luis Chamberlain, Petr Pavlu, Daniel Gomez, Sami Tolvanen,
Jason A . Donenfeld, Ard Biesheuvel, Stephan Mueller,
linux-crypto, keyrings, linux-modules, linux-kernel
Add verify-only public key crypto support for ML-DSA so that the
X.509/PKCS#7 signature verification code, as used by module signing,
amongst other things, can make use of it through the common crypto_sig API.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Eric Biggers <ebiggers@kernel.org>
cc: Lukas Wunner <lukas@wunner.de>
cc: Ignat Korchagin <ignat@cloudflare.com>
cc: Stephan Mueller <smueller@chronox.de>
cc: Herbert Xu <herbert@gondor.apana.org.au>
cc: keyrings@vger.kernel.org
cc: linux-crypto@vger.kernel.org
---
crypto/Kconfig | 10 +++
crypto/Makefile | 2 +
crypto/mldsa.c | 201 ++++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 213 insertions(+)
create mode 100644 crypto/mldsa.c
diff --git a/crypto/Kconfig b/crypto/Kconfig
index 12a87f7cf150..8dd5c6660c5a 100644
--- a/crypto/Kconfig
+++ b/crypto/Kconfig
@@ -344,6 +344,16 @@ config CRYPTO_ECRDSA
One of the Russian cryptographic standard algorithms (called GOST
algorithms). Only signature verification is implemented.
+config CRYPTO_MLDSA
+ tristate "ML-DSA (Module-Lattice-Based Digital Signature Algorithm)"
+ select CRYPTO_SIG
+ select CRYPTO_LIB_MLDSA
+ select CRYPTO_LIB_SHA3
+ help
+ ML-DSA (Module-Lattice-Based Digital Signature Algorithm) (FIPS-204).
+
+ Only signature verification is implemented.
+
endmenu
menu "Block ciphers"
diff --git a/crypto/Makefile b/crypto/Makefile
index 23d3db7be425..267d5403045b 100644
--- a/crypto/Makefile
+++ b/crypto/Makefile
@@ -60,6 +60,8 @@ ecdsa_generic-y += ecdsa-p1363.o
ecdsa_generic-y += ecdsasignature.asn1.o
obj-$(CONFIG_CRYPTO_ECDSA) += ecdsa_generic.o
+obj-$(CONFIG_CRYPTO_MLDSA) += mldsa.o
+
crypto_acompress-y := acompress.o
crypto_acompress-y += scompress.o
obj-$(CONFIG_CRYPTO_ACOMP2) += crypto_acompress.o
diff --git a/crypto/mldsa.c b/crypto/mldsa.c
new file mode 100644
index 000000000000..2146c774b5ca
--- /dev/null
+++ b/crypto/mldsa.c
@@ -0,0 +1,201 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * crypto_sig wrapper around ML-DSA library.
+ */
+#include <linux/init.h>
+#include <linux/module.h>
+#include <crypto/internal/sig.h>
+#include <crypto/mldsa.h>
+
+struct crypto_mldsa_ctx {
+ u8 pk[MAX(MAX(MLDSA44_PUBLIC_KEY_SIZE,
+ MLDSA65_PUBLIC_KEY_SIZE),
+ MLDSA87_PUBLIC_KEY_SIZE)];
+ unsigned int pk_len;
+ enum mldsa_alg strength;
+ u8 key_set;
+};
+
+static int crypto_mldsa_sign(struct crypto_sig *tfm,
+ const void *msg, unsigned int msg_len,
+ void *sig, unsigned int sig_len)
+{
+ return -EOPNOTSUPP;
+}
+
+static int crypto_mldsa_verify(struct crypto_sig *tfm,
+ const void *sig, unsigned int sig_len,
+ const void *msg, unsigned int msg_len)
+{
+ const struct crypto_mldsa_ctx *ctx = crypto_sig_ctx(tfm);
+
+ if (unlikely(!ctx->key_set))
+ return -EINVAL;
+
+ return mldsa_verify(ctx->strength, sig, sig_len, msg, msg_len,
+ ctx->pk, ctx->pk_len);
+}
+
+static unsigned int crypto_mldsa_key_size(struct crypto_sig *tfm)
+{
+ struct crypto_mldsa_ctx *ctx = crypto_sig_ctx(tfm);
+
+ switch (ctx->strength) {
+ case MLDSA44:
+ return MLDSA44_PUBLIC_KEY_SIZE;
+ case MLDSA65:
+ return MLDSA65_PUBLIC_KEY_SIZE;
+ case MLDSA87:
+ return MLDSA87_PUBLIC_KEY_SIZE;
+ default:
+ WARN_ON_ONCE(1);
+ return 0;
+ }
+}
+
+static int crypto_mldsa_set_pub_key(struct crypto_sig *tfm,
+ const void *key, unsigned int keylen)
+{
+ struct crypto_mldsa_ctx *ctx = crypto_sig_ctx(tfm);
+ unsigned int expected_len = crypto_mldsa_key_size(tfm);
+
+ if (keylen != expected_len)
+ return -EINVAL;
+
+ ctx->pk_len = keylen;
+ memcpy(ctx->pk, key, keylen);
+ ctx->key_set = true;
+ return 0;
+}
+
+static int crypto_mldsa_set_priv_key(struct crypto_sig *tfm,
+ const void *key, unsigned int keylen)
+{
+ return -EOPNOTSUPP;
+}
+
+static unsigned int crypto_mldsa_max_size(struct crypto_sig *tfm)
+{
+ struct crypto_mldsa_ctx *ctx = crypto_sig_ctx(tfm);
+
+ switch (ctx->strength) {
+ case MLDSA44:
+ return MLDSA44_SIGNATURE_SIZE;
+ case MLDSA65:
+ return MLDSA65_SIGNATURE_SIZE;
+ case MLDSA87:
+ return MLDSA87_SIGNATURE_SIZE;
+ default:
+ WARN_ON_ONCE(1);
+ return 0;
+ }
+}
+
+static int crypto_mldsa44_alg_init(struct crypto_sig *tfm)
+{
+ struct crypto_mldsa_ctx *ctx = crypto_sig_ctx(tfm);
+
+ ctx->strength = MLDSA44;
+ ctx->key_set = false;
+ return 0;
+}
+
+static int crypto_mldsa65_alg_init(struct crypto_sig *tfm)
+{
+ struct crypto_mldsa_ctx *ctx = crypto_sig_ctx(tfm);
+
+ ctx->strength = MLDSA65;
+ ctx->key_set = false;
+ return 0;
+}
+
+static int crypto_mldsa87_alg_init(struct crypto_sig *tfm)
+{
+ struct crypto_mldsa_ctx *ctx = crypto_sig_ctx(tfm);
+
+ ctx->strength = MLDSA87;
+ ctx->key_set = false;
+ return 0;
+}
+
+static void crypto_mldsa_alg_exit(struct crypto_sig *tfm)
+{
+}
+
+static struct sig_alg crypto_mldsa_algs[] = {
+ {
+ .sign = crypto_mldsa_sign,
+ .verify = crypto_mldsa_verify,
+ .set_pub_key = crypto_mldsa_set_pub_key,
+ .set_priv_key = crypto_mldsa_set_priv_key,
+ .key_size = crypto_mldsa_key_size,
+ .max_size = crypto_mldsa_max_size,
+ .init = crypto_mldsa44_alg_init,
+ .exit = crypto_mldsa_alg_exit,
+ .base.cra_name = "mldsa44",
+ .base.cra_driver_name = "mldsa44-lib",
+ .base.cra_ctxsize = sizeof(struct crypto_mldsa_ctx),
+ .base.cra_module = THIS_MODULE,
+ .base.cra_priority = 5000,
+ }, {
+ .sign = crypto_mldsa_sign,
+ .verify = crypto_mldsa_verify,
+ .set_pub_key = crypto_mldsa_set_pub_key,
+ .set_priv_key = crypto_mldsa_set_priv_key,
+ .key_size = crypto_mldsa_key_size,
+ .max_size = crypto_mldsa_max_size,
+ .init = crypto_mldsa65_alg_init,
+ .exit = crypto_mldsa_alg_exit,
+ .base.cra_name = "mldsa65",
+ .base.cra_driver_name = "mldsa65-lib",
+ .base.cra_ctxsize = sizeof(struct crypto_mldsa_ctx),
+ .base.cra_module = THIS_MODULE,
+ .base.cra_priority = 5000,
+ }, {
+ .sign = crypto_mldsa_sign,
+ .verify = crypto_mldsa_verify,
+ .set_pub_key = crypto_mldsa_set_pub_key,
+ .set_priv_key = crypto_mldsa_set_priv_key,
+ .key_size = crypto_mldsa_key_size,
+ .max_size = crypto_mldsa_max_size,
+ .init = crypto_mldsa87_alg_init,
+ .exit = crypto_mldsa_alg_exit,
+ .base.cra_name = "mldsa87",
+ .base.cra_driver_name = "mldsa87-lib",
+ .base.cra_ctxsize = sizeof(struct crypto_mldsa_ctx),
+ .base.cra_module = THIS_MODULE,
+ .base.cra_priority = 5000,
+ },
+};
+
+static int __init mldsa_init(void)
+{
+ int ret, i;
+
+ for (i = 0; i < ARRAY_SIZE(crypto_mldsa_algs); i++) {
+ ret = crypto_register_sig(&crypto_mldsa_algs[i]);
+ if (ret < 0)
+ goto error;
+ }
+ return 0;
+
+error:
+ pr_err("Failed to register (%d)\n", ret);
+ for (i--; i >= 0; i--)
+ crypto_unregister_sig(&crypto_mldsa_algs[i]);
+ return ret;
+}
+module_init(mldsa_init);
+
+static void mldsa_exit(void)
+{
+ for (int i = 0; i < ARRAY_SIZE(crypto_mldsa_algs); i++)
+ crypto_unregister_sig(&crypto_mldsa_algs[i]);
+}
+module_exit(mldsa_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Crypto API support for ML-DSA signature verification");
+MODULE_ALIAS_CRYPTO("mldsa44");
+MODULE_ALIAS_CRYPTO("mldsa65");
+MODULE_ALIAS_CRYPTO("mldsa87");
^ permalink raw reply related [flat|nested] 20+ messages in thread* [PATCH v12 02/10] pkcs7: Allow the signing algo to calculate the digest itself
2026-01-15 21:50 [PATCH v12 00/10] x509, pkcs7, crypto: Add ML-DSA and RSASSA-PSS signing David Howells
2026-01-15 21:50 ` [PATCH v12 01/10] crypto: Add ML-DSA crypto_sig support David Howells
@ 2026-01-15 21:50 ` David Howells
2026-01-20 14:06 ` Ignat Korchagin
2026-01-15 21:50 ` [PATCH v12 03/10] pkcs7: Allow direct signing of data with ML-DSA David Howells
` (7 subsequent siblings)
9 siblings, 1 reply; 20+ messages in thread
From: David Howells @ 2026-01-15 21:50 UTC (permalink / raw)
To: Lukas Wunner, Ignat Korchagin
Cc: David Howells, Jarkko Sakkinen, Herbert Xu, Eric Biggers,
Luis Chamberlain, Petr Pavlu, Daniel Gomez, Sami Tolvanen,
Jason A . Donenfeld, Ard Biesheuvel, Stephan Mueller,
linux-crypto, keyrings, linux-modules, linux-kernel
The ML-DSA public key algorithm really wants to calculate the message
digest itself, rather than having the digest precalculated and fed to it
separately as RSA does[*]. The kernel's PKCS#7 parser, however, is
designed around the latter approach.
[*] ML-DSA does allow for an "external mu", but CMS doesn't yet have that
standardised.
Fix this by noting in the public_key_signature struct when the signing
algorithm is going to want this and then, rather than doing the digest of
the authenticatedAttributes ourselves and overwriting the sig->digest with
that, replace sig->digest with a copy of the contents of the
authenticatedAttributes section and adjust the digest length to match.
This will then be fed to the public key algorithm as normal which can do
what it wants with the data.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Lukas Wunner <lukas@wunner.de>
cc: Ignat Korchagin <ignat@cloudflare.com>
cc: Stephan Mueller <smueller@chronox.de>
cc: Eric Biggers <ebiggers@kernel.org>
cc: Herbert Xu <herbert@gondor.apana.org.au>
cc: keyrings@vger.kernel.org
cc: linux-crypto@vger.kernel.org
---
crypto/asymmetric_keys/pkcs7_parser.c | 4 +--
crypto/asymmetric_keys/pkcs7_verify.c | 48 ++++++++++++++++++---------
include/crypto/public_key.h | 1 +
3 files changed, 36 insertions(+), 17 deletions(-)
diff --git a/crypto/asymmetric_keys/pkcs7_parser.c b/crypto/asymmetric_keys/pkcs7_parser.c
index 423d13c47545..3cdbab3b9f50 100644
--- a/crypto/asymmetric_keys/pkcs7_parser.c
+++ b/crypto/asymmetric_keys/pkcs7_parser.c
@@ -599,8 +599,8 @@ int pkcs7_sig_note_set_of_authattrs(void *context, size_t hdrlen,
}
/* We need to switch the 'CONT 0' to a 'SET OF' when we digest */
- sinfo->authattrs = value - (hdrlen - 1);
- sinfo->authattrs_len = vlen + (hdrlen - 1);
+ sinfo->authattrs = value - hdrlen;
+ sinfo->authattrs_len = vlen + hdrlen;
return 0;
}
diff --git a/crypto/asymmetric_keys/pkcs7_verify.c b/crypto/asymmetric_keys/pkcs7_verify.c
index 6d6475e3a9bf..0f9f515b784d 100644
--- a/crypto/asymmetric_keys/pkcs7_verify.c
+++ b/crypto/asymmetric_keys/pkcs7_verify.c
@@ -70,8 +70,6 @@ static int pkcs7_digest(struct pkcs7_message *pkcs7,
* digest we just calculated.
*/
if (sinfo->authattrs) {
- u8 tag;
-
if (!sinfo->msgdigest) {
pr_warn("Sig %u: No messageDigest\n", sinfo->index);
ret = -EKEYREJECTED;
@@ -97,20 +95,40 @@ static int pkcs7_digest(struct pkcs7_message *pkcs7,
* as the contents of the digest instead. Note that we need to
* convert the attributes from a CONT.0 into a SET before we
* hash it.
+ *
+ * However, for certain algorithms, such as ML-DSA, the digest
+ * is integrated into the signing algorithm. In such a case,
+ * we copy the authattrs, modifying the tag type, and set that
+ * as the digest.
*/
- memset(sig->digest, 0, sig->digest_size);
-
- ret = crypto_shash_init(desc);
- if (ret < 0)
- goto error;
- tag = ASN1_CONS_BIT | ASN1_SET;
- ret = crypto_shash_update(desc, &tag, 1);
- if (ret < 0)
- goto error;
- ret = crypto_shash_finup(desc, sinfo->authattrs,
- sinfo->authattrs_len, sig->digest);
- if (ret < 0)
- goto error;
+ if (sig->algo_does_hash) {
+ kfree(sig->digest);
+
+ ret = -ENOMEM;
+ sig->digest = kmalloc(umax(sinfo->authattrs_len, sig->digest_size),
+ GFP_KERNEL);
+ if (!sig->digest)
+ goto error_no_desc;
+
+ sig->digest_size = sinfo->authattrs_len;
+ memcpy(sig->digest, sinfo->authattrs, sinfo->authattrs_len);
+ ((u8 *)sig->digest)[0] = ASN1_CONS_BIT | ASN1_SET;
+ ret = 0;
+ } else {
+ u8 tag = ASN1_CONS_BIT | ASN1_SET;
+
+ ret = crypto_shash_init(desc);
+ if (ret < 0)
+ goto error;
+ ret = crypto_shash_update(desc, &tag, 1);
+ if (ret < 0)
+ goto error;
+ ret = crypto_shash_finup(desc, sinfo->authattrs + 1,
+ sinfo->authattrs_len - 1,
+ sig->digest);
+ if (ret < 0)
+ goto error;
+ }
pr_devel("AADigest = [%*ph]\n", 8, sig->digest);
}
diff --git a/include/crypto/public_key.h b/include/crypto/public_key.h
index 81098e00c08f..e4ec8003a3a4 100644
--- a/include/crypto/public_key.h
+++ b/include/crypto/public_key.h
@@ -46,6 +46,7 @@ struct public_key_signature {
u8 *digest;
u32 s_size; /* Number of bytes in signature */
u32 digest_size; /* Number of bytes in digest */
+ bool algo_does_hash; /* Public key algo does its own hashing */
const char *pkey_algo;
const char *hash_algo;
const char *encoding;
^ permalink raw reply related [flat|nested] 20+ messages in thread* Re: [PATCH v12 02/10] pkcs7: Allow the signing algo to calculate the digest itself
2026-01-15 21:50 ` [PATCH v12 02/10] pkcs7: Allow the signing algo to calculate the digest itself David Howells
@ 2026-01-20 14:06 ` Ignat Korchagin
2026-01-20 16:10 ` David Howells
0 siblings, 1 reply; 20+ messages in thread
From: Ignat Korchagin @ 2026-01-20 14:06 UTC (permalink / raw)
To: David Howells
Cc: Lukas Wunner, Jarkko Sakkinen, Herbert Xu, Eric Biggers,
Luis Chamberlain, Petr Pavlu, Daniel Gomez, Sami Tolvanen,
Jason A . Donenfeld, Ard Biesheuvel, Stephan Mueller,
linux-crypto, keyrings, linux-modules, linux-kernel
Hi David,
On Thu, Jan 15, 2026 at 9:51 PM David Howells <dhowells@redhat.com> wrote:
>
> The ML-DSA public key algorithm really wants to calculate the message
> digest itself, rather than having the digest precalculated and fed to it
> separately as RSA does[*]. The kernel's PKCS#7 parser, however, is
> designed around the latter approach.
>
> [*] ML-DSA does allow for an "external mu", but CMS doesn't yet have that
> standardised.
>
> Fix this by noting in the public_key_signature struct when the signing
> algorithm is going to want this and then, rather than doing the digest of
> the authenticatedAttributes ourselves and overwriting the sig->digest with
> that, replace sig->digest with a copy of the contents of the
> authenticatedAttributes section and adjust the digest length to match.
>
> This will then be fed to the public key algorithm as normal which can do
> what it wants with the data.
>
> Signed-off-by: David Howells <dhowells@redhat.com>
> cc: Lukas Wunner <lukas@wunner.de>
> cc: Ignat Korchagin <ignat@cloudflare.com>
> cc: Stephan Mueller <smueller@chronox.de>
> cc: Eric Biggers <ebiggers@kernel.org>
> cc: Herbert Xu <herbert@gondor.apana.org.au>
> cc: keyrings@vger.kernel.org
> cc: linux-crypto@vger.kernel.org
> ---
> crypto/asymmetric_keys/pkcs7_parser.c | 4 +--
> crypto/asymmetric_keys/pkcs7_verify.c | 48 ++++++++++++++++++---------
> include/crypto/public_key.h | 1 +
> 3 files changed, 36 insertions(+), 17 deletions(-)
>
> diff --git a/crypto/asymmetric_keys/pkcs7_parser.c b/crypto/asymmetric_keys/pkcs7_parser.c
> index 423d13c47545..3cdbab3b9f50 100644
> --- a/crypto/asymmetric_keys/pkcs7_parser.c
> +++ b/crypto/asymmetric_keys/pkcs7_parser.c
> @@ -599,8 +599,8 @@ int pkcs7_sig_note_set_of_authattrs(void *context, size_t hdrlen,
> }
>
> /* We need to switch the 'CONT 0' to a 'SET OF' when we digest */
> - sinfo->authattrs = value - (hdrlen - 1);
> - sinfo->authattrs_len = vlen + (hdrlen - 1);
> + sinfo->authattrs = value - hdrlen;
> + sinfo->authattrs_len = vlen + hdrlen;
> return 0;
> }
>
> diff --git a/crypto/asymmetric_keys/pkcs7_verify.c b/crypto/asymmetric_keys/pkcs7_verify.c
> index 6d6475e3a9bf..0f9f515b784d 100644
> --- a/crypto/asymmetric_keys/pkcs7_verify.c
> +++ b/crypto/asymmetric_keys/pkcs7_verify.c
> @@ -70,8 +70,6 @@ static int pkcs7_digest(struct pkcs7_message *pkcs7,
> * digest we just calculated.
> */
> if (sinfo->authattrs) {
> - u8 tag;
> -
> if (!sinfo->msgdigest) {
> pr_warn("Sig %u: No messageDigest\n", sinfo->index);
> ret = -EKEYREJECTED;
> @@ -97,20 +95,40 @@ static int pkcs7_digest(struct pkcs7_message *pkcs7,
> * as the contents of the digest instead. Note that we need to
> * convert the attributes from a CONT.0 into a SET before we
> * hash it.
> + *
> + * However, for certain algorithms, such as ML-DSA, the digest
> + * is integrated into the signing algorithm. In such a case,
> + * we copy the authattrs, modifying the tag type, and set that
> + * as the digest.
> */
> - memset(sig->digest, 0, sig->digest_size);
> -
> - ret = crypto_shash_init(desc);
> - if (ret < 0)
> - goto error;
> - tag = ASN1_CONS_BIT | ASN1_SET;
> - ret = crypto_shash_update(desc, &tag, 1);
> - if (ret < 0)
> - goto error;
> - ret = crypto_shash_finup(desc, sinfo->authattrs,
> - sinfo->authattrs_len, sig->digest);
> - if (ret < 0)
> - goto error;
> + if (sig->algo_does_hash) {
> + kfree(sig->digest);
> +
> + ret = -ENOMEM;
> + sig->digest = kmalloc(umax(sinfo->authattrs_len, sig->digest_size),
> + GFP_KERNEL);
I'm still bothered by this "reallocation". You mentioned we need to do
some parsing for attributes, but it seems by the time this function is
called we have all the data to do something like
kmalloc(sig->algo_does_hash ? umax(sinfo->authattrs_len,
sig->digest_size) : sig->digest_size, GFP_KERNEL) during the initial
allocation. Or am I missing something?
> + if (!sig->digest)
> + goto error_no_desc;
> +
> + sig->digest_size = sinfo->authattrs_len;
> + memcpy(sig->digest, sinfo->authattrs, sinfo->authattrs_len);
> + ((u8 *)sig->digest)[0] = ASN1_CONS_BIT | ASN1_SET;
> + ret = 0;
> + } else {
> + u8 tag = ASN1_CONS_BIT | ASN1_SET;
> +
> + ret = crypto_shash_init(desc);
> + if (ret < 0)
> + goto error;
> + ret = crypto_shash_update(desc, &tag, 1);
> + if (ret < 0)
> + goto error;
> + ret = crypto_shash_finup(desc, sinfo->authattrs + 1,
> + sinfo->authattrs_len - 1,
> + sig->digest);
> + if (ret < 0)
> + goto error;
> + }
> pr_devel("AADigest = [%*ph]\n", 8, sig->digest);
> }
>
> diff --git a/include/crypto/public_key.h b/include/crypto/public_key.h
> index 81098e00c08f..e4ec8003a3a4 100644
> --- a/include/crypto/public_key.h
> +++ b/include/crypto/public_key.h
> @@ -46,6 +46,7 @@ struct public_key_signature {
> u8 *digest;
> u32 s_size; /* Number of bytes in signature */
> u32 digest_size; /* Number of bytes in digest */
> + bool algo_does_hash; /* Public key algo does its own hashing */
nit: still do not like this name, but have no better alternatives so far
> const char *pkey_algo;
> const char *hash_algo;
> const char *encoding;
>
Ignat
^ permalink raw reply [flat|nested] 20+ messages in thread* Re: [PATCH v12 02/10] pkcs7: Allow the signing algo to calculate the digest itself
2026-01-20 14:06 ` Ignat Korchagin
@ 2026-01-20 16:10 ` David Howells
0 siblings, 0 replies; 20+ messages in thread
From: David Howells @ 2026-01-20 16:10 UTC (permalink / raw)
To: Ignat Korchagin
Cc: dhowells, Lukas Wunner, Jarkko Sakkinen, Herbert Xu, Eric Biggers,
Luis Chamberlain, Petr Pavlu, Daniel Gomez, Sami Tolvanen,
Jason A . Donenfeld, Ard Biesheuvel, Stephan Mueller,
linux-crypto, keyrings, linux-modules, linux-kernel
Ignat Korchagin <ignat@cloudflare.com> wrote:
> > + sig->digest = kmalloc(umax(sinfo->authattrs_len, sig->digest_size),
> > + GFP_KERNEL);
>
> I'm still bothered by this "reallocation". You mentioned we need to do
> some parsing for attributes, but it seems by the time this function is
> called we have all the data to do something like
> kmalloc(sig->algo_does_hash ? umax(sinfo->authattrs_len,
> sig->digest_size) : sig->digest_size, GFP_KERNEL) during the initial
> allocation. Or am I missing something?
Actually, you're right, we do have that info at this point
David
^ permalink raw reply [flat|nested] 20+ messages in thread
* [PATCH v12 03/10] pkcs7: Allow direct signing of data with ML-DSA
2026-01-15 21:50 [PATCH v12 00/10] x509, pkcs7, crypto: Add ML-DSA and RSASSA-PSS signing David Howells
2026-01-15 21:50 ` [PATCH v12 01/10] crypto: Add ML-DSA crypto_sig support David Howells
2026-01-15 21:50 ` [PATCH v12 02/10] pkcs7: Allow the signing algo to calculate the digest itself David Howells
@ 2026-01-15 21:50 ` David Howells
2026-01-15 21:50 ` [PATCH v12 04/10] pkcs7, x509: Add ML-DSA support David Howells
` (6 subsequent siblings)
9 siblings, 0 replies; 20+ messages in thread
From: David Howells @ 2026-01-15 21:50 UTC (permalink / raw)
To: Lukas Wunner, Ignat Korchagin
Cc: David Howells, Jarkko Sakkinen, Herbert Xu, Eric Biggers,
Luis Chamberlain, Petr Pavlu, Daniel Gomez, Sami Tolvanen,
Jason A . Donenfeld, Ard Biesheuvel, Stephan Mueller,
linux-crypto, keyrings, linux-modules, linux-kernel
Allow the data part of a PKCS#7 or CMS messge to be passed directly to an
asymmetric cipher algorithm (e.g. ML-DSA) if it wants to do the digestion
itself. The normal digestion of the data is then skipped as that would be
ignored unless another signed info in the message has some other algorithm
that needs it.
This is done by setting the digest parameters to point to the data to be
verified rather than making public_key_verify_signature() access the data
directly. This is so that keyctl(KEYCTL_PKEY_VERIFY) will still work.
To test this with ML-DSA, sign-file must be built with openssl > v3.5 and
must include the following fix:
https://github.com/openssl/openssl/pull/28923
which will allow CMS_NOATTR to be used with CMS_sign() for an ML-DSA key.
sign-file will remove CMS_NOATTR if openssl is earlier than v4 and signed
attributes will be used.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Lukas Wunner <lukas@wunner.de>
cc: Ignat Korchagin <ignat@cloudflare.com>
cc: Stephan Mueller <smueller@chronox.de>
cc: Eric Biggers <ebiggers@kernel.org>
cc: Herbert Xu <herbert@gondor.apana.org.au>
cc: keyrings@vger.kernel.org
cc: linux-crypto@vger.kernel.org
---
crypto/asymmetric_keys/mscode_parser.c | 2 +-
crypto/asymmetric_keys/pkcs7_verify.c | 18 ++++++++++++++++++
crypto/asymmetric_keys/signature.c | 3 ++-
crypto/asymmetric_keys/verify_pefile.c | 3 ++-
crypto/asymmetric_keys/verify_pefile.h | 1 +
crypto/asymmetric_keys/x509_public_key.c | 1 +
include/crypto/public_key.h | 1 +
7 files changed, 26 insertions(+), 3 deletions(-)
diff --git a/crypto/asymmetric_keys/mscode_parser.c b/crypto/asymmetric_keys/mscode_parser.c
index 8aecbe4637f3..54dac17f19e2 100644
--- a/crypto/asymmetric_keys/mscode_parser.c
+++ b/crypto/asymmetric_keys/mscode_parser.c
@@ -124,6 +124,6 @@ int mscode_note_digest(void *context, size_t hdrlen,
return -ENOMEM;
ctx->digest_len = vlen;
-
+ ctx->digest_free = true;
return 0;
}
diff --git a/crypto/asymmetric_keys/pkcs7_verify.c b/crypto/asymmetric_keys/pkcs7_verify.c
index 0f9f515b784d..46eee9811023 100644
--- a/crypto/asymmetric_keys/pkcs7_verify.c
+++ b/crypto/asymmetric_keys/pkcs7_verify.c
@@ -30,6 +30,16 @@ static int pkcs7_digest(struct pkcs7_message *pkcs7,
kenter(",%u,%s", sinfo->index, sinfo->sig->hash_algo);
+ if (!sinfo->authattrs && sig->algo_does_hash) {
+ /* There's no intermediate digest and the signature algo
+ * doesn't want the data prehashing.
+ */
+ sig->digest = (void *)pkcs7->data;
+ sig->digest_size = pkcs7->data_len;
+ sig->digest_free = false;
+ return 0;
+ }
+
/* The digest was calculated already. */
if (sig->digest)
return 0;
@@ -51,6 +61,7 @@ static int pkcs7_digest(struct pkcs7_message *pkcs7,
sig->digest = kmalloc(sig->digest_size, GFP_KERNEL);
if (!sig->digest)
goto error_no_desc;
+ sig->digest_free = true;
desc = kzalloc(desc_size, GFP_KERNEL);
if (!desc)
@@ -103,6 +114,7 @@ static int pkcs7_digest(struct pkcs7_message *pkcs7,
*/
if (sig->algo_does_hash) {
kfree(sig->digest);
+ sig->digest_free = false;
ret = -ENOMEM;
sig->digest = kmalloc(umax(sinfo->authattrs_len, sig->digest_size),
@@ -110,6 +122,7 @@ static int pkcs7_digest(struct pkcs7_message *pkcs7,
if (!sig->digest)
goto error_no_desc;
+ sig->digest_free = true;
sig->digest_size = sinfo->authattrs_len;
memcpy(sig->digest, sinfo->authattrs, sinfo->authattrs_len);
((u8 *)sig->digest)[0] = ASN1_CONS_BIT | ASN1_SET;
@@ -155,6 +168,11 @@ int pkcs7_get_digest(struct pkcs7_message *pkcs7, const u8 **buf, u32 *len,
ret = pkcs7_digest(pkcs7, sinfo);
if (ret)
return ret;
+ if (!sinfo->sig->digest_free) {
+ pr_notice_once("%s: No digest available\n", __func__);
+ return -EINVAL; /* TODO: MLDSA doesn't necessarily calculate an
+ * intermediate digest. */
+ }
*buf = sinfo->sig->digest;
*len = sinfo->sig->digest_size;
diff --git a/crypto/asymmetric_keys/signature.c b/crypto/asymmetric_keys/signature.c
index 041d04b5c953..bea01cf27d0a 100644
--- a/crypto/asymmetric_keys/signature.c
+++ b/crypto/asymmetric_keys/signature.c
@@ -28,7 +28,8 @@ void public_key_signature_free(struct public_key_signature *sig)
for (i = 0; i < ARRAY_SIZE(sig->auth_ids); i++)
kfree(sig->auth_ids[i]);
kfree(sig->s);
- kfree(sig->digest);
+ if (sig->digest_free)
+ kfree(sig->digest);
kfree(sig);
}
}
diff --git a/crypto/asymmetric_keys/verify_pefile.c b/crypto/asymmetric_keys/verify_pefile.c
index 1f3b227ba7f2..30c23aea3b25 100644
--- a/crypto/asymmetric_keys/verify_pefile.c
+++ b/crypto/asymmetric_keys/verify_pefile.c
@@ -451,6 +451,7 @@ int verify_pefile_signature(const void *pebuf, unsigned pelen,
ret = pefile_digest_pe(pebuf, pelen, &ctx);
error:
- kfree_sensitive(ctx.digest);
+ if (ctx.digest_free)
+ kfree_sensitive(ctx.digest);
return ret;
}
diff --git a/crypto/asymmetric_keys/verify_pefile.h b/crypto/asymmetric_keys/verify_pefile.h
index e1628e100cde..f641437264b4 100644
--- a/crypto/asymmetric_keys/verify_pefile.h
+++ b/crypto/asymmetric_keys/verify_pefile.h
@@ -22,6 +22,7 @@ struct pefile_context {
/* PKCS#7 MS Individual Code Signing content */
const void *digest; /* Digest */
unsigned digest_len; /* Digest length */
+ bool digest_free; /* T if digest should be freed */
const char *digest_algo; /* Digest algorithm */
};
diff --git a/crypto/asymmetric_keys/x509_public_key.c b/crypto/asymmetric_keys/x509_public_key.c
index 12e3341e806b..2243add11d48 100644
--- a/crypto/asymmetric_keys/x509_public_key.c
+++ b/crypto/asymmetric_keys/x509_public_key.c
@@ -56,6 +56,7 @@ int x509_get_sig_params(struct x509_certificate *cert)
sig->digest = kmalloc(sig->digest_size, GFP_KERNEL);
if (!sig->digest)
goto error;
+ sig->digest_free = true;
desc = kzalloc(desc_size, GFP_KERNEL);
if (!desc)
diff --git a/include/crypto/public_key.h b/include/crypto/public_key.h
index e4ec8003a3a4..68899a49cd0d 100644
--- a/include/crypto/public_key.h
+++ b/include/crypto/public_key.h
@@ -46,6 +46,7 @@ struct public_key_signature {
u8 *digest;
u32 s_size; /* Number of bytes in signature */
u32 digest_size; /* Number of bytes in digest */
+ bool digest_free; /* T if digest needs freeing */
bool algo_does_hash; /* Public key algo does its own hashing */
const char *pkey_algo;
const char *hash_algo;
^ permalink raw reply related [flat|nested] 20+ messages in thread* [PATCH v12 04/10] pkcs7, x509: Add ML-DSA support
2026-01-15 21:50 [PATCH v12 00/10] x509, pkcs7, crypto: Add ML-DSA and RSASSA-PSS signing David Howells
` (2 preceding siblings ...)
2026-01-15 21:50 ` [PATCH v12 03/10] pkcs7: Allow direct signing of data with ML-DSA David Howells
@ 2026-01-15 21:50 ` David Howells
2026-01-15 21:50 ` [PATCH v12 05/10] modsign: Enable ML-DSA module signing David Howells
` (5 subsequent siblings)
9 siblings, 0 replies; 20+ messages in thread
From: David Howells @ 2026-01-15 21:50 UTC (permalink / raw)
To: Lukas Wunner, Ignat Korchagin
Cc: David Howells, Jarkko Sakkinen, Herbert Xu, Eric Biggers,
Luis Chamberlain, Petr Pavlu, Daniel Gomez, Sami Tolvanen,
Jason A . Donenfeld, Ard Biesheuvel, Stephan Mueller,
linux-crypto, keyrings, linux-modules, linux-kernel
Add support for ML-DSA keys and signatures to the PKCS#7 and X.509
implementations.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Lukas Wunner <lukas@wunner.de>
cc: Ignat Korchagin <ignat@cloudflare.com>
cc: Stephan Mueller <smueller@chronox.de>
cc: Eric Biggers <ebiggers@kernel.org>
cc: Herbert Xu <herbert@gondor.apana.org.au>
cc: keyrings@vger.kernel.org
cc: linux-crypto@vger.kernel.org
---
crypto/asymmetric_keys/pkcs7_parser.c | 15 ++++++++++++++
crypto/asymmetric_keys/public_key.c | 7 +++++++
crypto/asymmetric_keys/x509_cert_parser.c | 24 +++++++++++++++++++++++
include/linux/oid_registry.h | 5 +++++
4 files changed, 51 insertions(+)
diff --git a/crypto/asymmetric_keys/pkcs7_parser.c b/crypto/asymmetric_keys/pkcs7_parser.c
index 3cdbab3b9f50..90c36fe1b5ed 100644
--- a/crypto/asymmetric_keys/pkcs7_parser.c
+++ b/crypto/asymmetric_keys/pkcs7_parser.c
@@ -297,6 +297,21 @@ int pkcs7_sig_note_pkey_algo(void *context, size_t hdrlen,
ctx->sinfo->sig->pkey_algo = "ecrdsa";
ctx->sinfo->sig->encoding = "raw";
break;
+ case OID_id_ml_dsa_44:
+ ctx->sinfo->sig->pkey_algo = "mldsa44";
+ ctx->sinfo->sig->encoding = "raw";
+ ctx->sinfo->sig->algo_does_hash = true;
+ break;
+ case OID_id_ml_dsa_65:
+ ctx->sinfo->sig->pkey_algo = "mldsa65";
+ ctx->sinfo->sig->encoding = "raw";
+ ctx->sinfo->sig->algo_does_hash = true;
+ break;
+ case OID_id_ml_dsa_87:
+ ctx->sinfo->sig->pkey_algo = "mldsa87";
+ ctx->sinfo->sig->encoding = "raw";
+ ctx->sinfo->sig->algo_does_hash = true;
+ break;
default:
printk("Unsupported pkey algo: %u\n", ctx->last_oid);
return -ENOPKG;
diff --git a/crypto/asymmetric_keys/public_key.c b/crypto/asymmetric_keys/public_key.c
index e5b177c8e842..ed6b4b5ae4ef 100644
--- a/crypto/asymmetric_keys/public_key.c
+++ b/crypto/asymmetric_keys/public_key.c
@@ -142,6 +142,13 @@ software_key_determine_akcipher(const struct public_key *pkey,
if (strcmp(hash_algo, "streebog256") != 0 &&
strcmp(hash_algo, "streebog512") != 0)
return -EINVAL;
+ } else if (strcmp(pkey->pkey_algo, "mldsa44") == 0 ||
+ strcmp(pkey->pkey_algo, "mldsa65") == 0 ||
+ strcmp(pkey->pkey_algo, "mldsa87") == 0) {
+ if (strcmp(encoding, "raw") != 0)
+ return -EINVAL;
+ if (!hash_algo)
+ return -EINVAL;
} else {
/* Unknown public key algorithm */
return -ENOPKG;
diff --git a/crypto/asymmetric_keys/x509_cert_parser.c b/crypto/asymmetric_keys/x509_cert_parser.c
index b37cae914987..5ab5b4e5f1b4 100644
--- a/crypto/asymmetric_keys/x509_cert_parser.c
+++ b/crypto/asymmetric_keys/x509_cert_parser.c
@@ -257,6 +257,15 @@ int x509_note_sig_algo(void *context, size_t hdrlen, unsigned char tag,
case OID_gost2012Signature512:
ctx->cert->sig->hash_algo = "streebog512";
goto ecrdsa;
+ case OID_id_ml_dsa_44:
+ ctx->cert->sig->pkey_algo = "mldsa44";
+ goto ml_dsa;
+ case OID_id_ml_dsa_65:
+ ctx->cert->sig->pkey_algo = "mldsa65";
+ goto ml_dsa;
+ case OID_id_ml_dsa_87:
+ ctx->cert->sig->pkey_algo = "mldsa87";
+ goto ml_dsa;
}
rsa_pkcs1:
@@ -274,6 +283,12 @@ int x509_note_sig_algo(void *context, size_t hdrlen, unsigned char tag,
ctx->cert->sig->encoding = "x962";
ctx->sig_algo = ctx->last_oid;
return 0;
+ml_dsa:
+ ctx->cert->sig->algo_does_hash = true;
+ ctx->cert->sig->hash_algo = ctx->cert->sig->pkey_algo;
+ ctx->cert->sig->encoding = "raw";
+ ctx->sig_algo = ctx->last_oid;
+ return 0;
}
/*
@@ -524,6 +539,15 @@ int x509_extract_key_data(void *context, size_t hdrlen,
return -ENOPKG;
}
break;
+ case OID_id_ml_dsa_44:
+ ctx->cert->pub->pkey_algo = "mldsa44";
+ break;
+ case OID_id_ml_dsa_65:
+ ctx->cert->pub->pkey_algo = "mldsa65";
+ break;
+ case OID_id_ml_dsa_87:
+ ctx->cert->pub->pkey_algo = "mldsa87";
+ break;
default:
return -ENOPKG;
}
diff --git a/include/linux/oid_registry.h b/include/linux/oid_registry.h
index 6de479ebbe5d..ebce402854de 100644
--- a/include/linux/oid_registry.h
+++ b/include/linux/oid_registry.h
@@ -145,6 +145,11 @@ enum OID {
OID_id_rsassa_pkcs1_v1_5_with_sha3_384, /* 2.16.840.1.101.3.4.3.15 */
OID_id_rsassa_pkcs1_v1_5_with_sha3_512, /* 2.16.840.1.101.3.4.3.16 */
+ /* NIST FIPS-204 ML-DSA */
+ OID_id_ml_dsa_44, /* 2.16.840.1.101.3.4.3.17 */
+ OID_id_ml_dsa_65, /* 2.16.840.1.101.3.4.3.18 */
+ OID_id_ml_dsa_87, /* 2.16.840.1.101.3.4.3.19 */
+
OID__NR
};
^ permalink raw reply related [flat|nested] 20+ messages in thread* [PATCH v12 05/10] modsign: Enable ML-DSA module signing
2026-01-15 21:50 [PATCH v12 00/10] x509, pkcs7, crypto: Add ML-DSA and RSASSA-PSS signing David Howells
` (3 preceding siblings ...)
2026-01-15 21:50 ` [PATCH v12 04/10] pkcs7, x509: Add ML-DSA support David Howells
@ 2026-01-15 21:50 ` David Howells
2026-01-15 21:50 ` [PATCH v12 06/10] crypto: Add supplementary info param to asymmetric key signature verification David Howells
` (4 subsequent siblings)
9 siblings, 0 replies; 20+ messages in thread
From: David Howells @ 2026-01-15 21:50 UTC (permalink / raw)
To: Lukas Wunner, Ignat Korchagin
Cc: David Howells, Jarkko Sakkinen, Herbert Xu, Eric Biggers,
Luis Chamberlain, Petr Pavlu, Daniel Gomez, Sami Tolvanen,
Jason A . Donenfeld, Ard Biesheuvel, Stephan Mueller,
linux-crypto, keyrings, linux-modules, linux-kernel
Allow ML-DSA module signing to be enabled.
Note that openssl's CMS_*() function suite does not, as of openssl-3.5.1,
support the use of CMS_NOATTR with ML-DSA, so the prohibition against using
authenticatedAttributes with module signing has to be removed. The
selected digest then applies only to the algorithm used to calculate the
digest stored in the messageDigest attribute.
The ML-DSA algorithm uses its own internal choice of digest (SHAKE256)
without regard to what's specified in the CMS message. This is, in theory,
configurable, but there's currently no hook in the crypto_sig API to do
that, though possibly it could be done by parameterising the name of the
algorithm, e.g. ("mldsa87(sha512)").
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Eric Biggers <ebiggers@kernel.org>
cc: Lukas Wunner <lukas@wunner.de>
cc: Ignat Korchagin <ignat@cloudflare.com>
cc: Stephan Mueller <smueller@chronox.de>
cc: Herbert Xu <herbert@gondor.apana.org.au>
cc: keyrings@vger.kernel.org
cc: linux-crypto@vger.kernel.org
---
Documentation/admin-guide/module-signing.rst | 16 +++++----
certs/Kconfig | 21 ++++++++++++
certs/Makefile | 3 ++
crypto/asymmetric_keys/pkcs7_verify.c | 4 ---
scripts/sign-file.c | 34 +++++++++++++++-----
5 files changed, 59 insertions(+), 19 deletions(-)
diff --git a/Documentation/admin-guide/module-signing.rst b/Documentation/admin-guide/module-signing.rst
index a8667a777490..7f2f127dc76f 100644
--- a/Documentation/admin-guide/module-signing.rst
+++ b/Documentation/admin-guide/module-signing.rst
@@ -28,10 +28,12 @@ trusted userspace bits.
This facility uses X.509 ITU-T standard certificates to encode the public keys
involved. The signatures are not themselves encoded in any industrial standard
-type. The built-in facility currently only supports the RSA & NIST P-384 ECDSA
-public key signing standard (though it is pluggable and permits others to be
-used). The possible hash algorithms that can be used are SHA-2 and SHA-3 of
-sizes 256, 384, and 512 (the algorithm is selected by data in the signature).
+type. The built-in facility currently only supports the RSA, NIST P-384 ECDSA
+and NIST FIPS-204 ML-DSA public key signing standards (though it is pluggable
+and permits others to be used). For RSA and ECDSA, the possible hash
+algorithms that can be used are SHA-2 and SHA-3 of sizes 256, 384, and 512 (the
+algorithm is selected by data in the signature); ML-DSA does its own hashing,
+but is allowed to be used with a SHA512 hash for signed attributes.
==========================
@@ -146,9 +148,9 @@ into vmlinux) using parameters in the::
file (which is also generated if it does not already exist).
-One can select between RSA (``MODULE_SIG_KEY_TYPE_RSA``) and ECDSA
-(``MODULE_SIG_KEY_TYPE_ECDSA``) to generate either RSA 4k or NIST
-P-384 keypair.
+One can select between RSA (``MODULE_SIG_KEY_TYPE_RSA``), ECDSA
+(``MODULE_SIG_KEY_TYPE_ECDSA``) and ML-DSA (``MODULE_SIG_KEY_TYPE_MLDSA_*``) to
+generate an RSA 4k, a NIST P-384 keypair or an ML-DSA 44, 65 or 87 keypair.
It is strongly recommended that you provide your own x509.genkey file.
diff --git a/certs/Kconfig b/certs/Kconfig
index 78307dc25559..67a5786423b5 100644
--- a/certs/Kconfig
+++ b/certs/Kconfig
@@ -39,6 +39,27 @@ config MODULE_SIG_KEY_TYPE_ECDSA
Note: Remove all ECDSA signing keys, e.g. certs/signing_key.pem,
when falling back to building Linux 5.14 and older kernels.
+config MODULE_SIG_KEY_TYPE_MLDSA_44
+ bool "ML-DSA-44"
+ select CRYPTO_MLDSA
+ help
+ Use an ML-DSA-44 key (NIST FIPS 204) for module signing
+ with a SHAKE256 'hash' of the authenticatedAttributes.
+
+config MODULE_SIG_KEY_TYPE_MLDSA_65
+ bool "ML-DSA-65"
+ select CRYPTO_MLDSA
+ help
+ Use an ML-DSA-65 key (NIST FIPS 204) for module signing
+ with a SHAKE256 'hash' of the authenticatedAttributes.
+
+config MODULE_SIG_KEY_TYPE_MLDSA_87
+ bool "ML-DSA-87"
+ select CRYPTO_MLDSA
+ help
+ Use an ML-DSA-87 key (NIST FIPS 204) for module signing
+ with a SHAKE256 'hash' of the authenticatedAttributes.
+
endchoice
config SYSTEM_TRUSTED_KEYRING
diff --git a/certs/Makefile b/certs/Makefile
index f6fa4d8d75e0..3ee1960f9f4a 100644
--- a/certs/Makefile
+++ b/certs/Makefile
@@ -43,6 +43,9 @@ targets += x509_certificate_list
ifeq ($(CONFIG_MODULE_SIG_KEY),certs/signing_key.pem)
keytype-$(CONFIG_MODULE_SIG_KEY_TYPE_ECDSA) := -newkey ec -pkeyopt ec_paramgen_curve:secp384r1
+keytype-$(CONFIG_MODULE_SIG_KEY_TYPE_MLDSA_44) := -newkey ml-dsa-44
+keytype-$(CONFIG_MODULE_SIG_KEY_TYPE_MLDSA_65) := -newkey ml-dsa-65
+keytype-$(CONFIG_MODULE_SIG_KEY_TYPE_MLDSA_87) := -newkey ml-dsa-87
quiet_cmd_gen_key = GENKEY $@
cmd_gen_key = openssl req -new -nodes -utf8 -$(CONFIG_MODULE_SIG_HASH) -days 36500 \
diff --git a/crypto/asymmetric_keys/pkcs7_verify.c b/crypto/asymmetric_keys/pkcs7_verify.c
index 46eee9811023..3896e24423f9 100644
--- a/crypto/asymmetric_keys/pkcs7_verify.c
+++ b/crypto/asymmetric_keys/pkcs7_verify.c
@@ -442,10 +442,6 @@ int pkcs7_verify(struct pkcs7_message *pkcs7,
pr_warn("Invalid module sig (not pkcs7-data)\n");
return -EKEYREJECTED;
}
- if (pkcs7->have_authattrs) {
- pr_warn("Invalid module sig (has authattrs)\n");
- return -EKEYREJECTED;
- }
break;
case VERIFYING_FIRMWARE_SIGNATURE:
if (pkcs7->data_type != OID_data) {
diff --git a/scripts/sign-file.c b/scripts/sign-file.c
index 7070245edfc1..547b97097230 100644
--- a/scripts/sign-file.c
+++ b/scripts/sign-file.c
@@ -315,18 +315,36 @@ int main(int argc, char **argv)
ERR(!digest_algo, "EVP_get_digestbyname");
#ifndef USE_PKCS7
+
+ unsigned int flags =
+ CMS_NOCERTS |
+ CMS_PARTIAL |
+ CMS_BINARY |
+ CMS_DETACHED |
+ CMS_STREAM |
+ CMS_NOSMIMECAP |
+ CMS_NO_SIGNING_TIME |
+ use_keyid;
+
+ if ((EVP_PKEY_is_a(private_key, "ML-DSA-44") ||
+ EVP_PKEY_is_a(private_key, "ML-DSA-65") ||
+ EVP_PKEY_is_a(private_key, "ML-DSA-87")) &&
+ OPENSSL_VERSION_MAJOR < 4) {
+ /* ML-DSA + CMS_NOATTR is not supported in openssl-3.5
+ * and before.
+ */
+ use_signed_attrs = 0;
+ }
+
+ flags |= use_signed_attrs;
+
/* Load the signature message from the digest buffer. */
- cms = CMS_sign(NULL, NULL, NULL, NULL,
- CMS_NOCERTS | CMS_PARTIAL | CMS_BINARY |
- CMS_DETACHED | CMS_STREAM);
+ cms = CMS_sign(NULL, NULL, NULL, NULL, flags);
ERR(!cms, "CMS_sign");
- ERR(!CMS_add1_signer(cms, x509, private_key, digest_algo,
- CMS_NOCERTS | CMS_BINARY |
- CMS_NOSMIMECAP | use_keyid |
- use_signed_attrs),
+ ERR(!CMS_add1_signer(cms, x509, private_key, digest_algo, flags),
"CMS_add1_signer");
- ERR(CMS_final(cms, bm, NULL, CMS_NOCERTS | CMS_BINARY) != 1,
+ ERR(CMS_final(cms, bm, NULL, flags) != 1,
"CMS_final");
#else
^ permalink raw reply related [flat|nested] 20+ messages in thread* [PATCH v12 06/10] crypto: Add supplementary info param to asymmetric key signature verification
2026-01-15 21:50 [PATCH v12 00/10] x509, pkcs7, crypto: Add ML-DSA and RSASSA-PSS signing David Howells
` (4 preceding siblings ...)
2026-01-15 21:50 ` [PATCH v12 05/10] modsign: Enable ML-DSA module signing David Howells
@ 2026-01-15 21:50 ` David Howells
2026-01-20 22:03 ` Eric Biggers
2026-01-15 21:50 ` [PATCH v12 07/10] crypto: Add RSASSA-PSS support David Howells
` (3 subsequent siblings)
9 siblings, 1 reply; 20+ messages in thread
From: David Howells @ 2026-01-15 21:50 UTC (permalink / raw)
To: Lukas Wunner, Ignat Korchagin
Cc: David Howells, Jarkko Sakkinen, Herbert Xu, Eric Biggers,
Luis Chamberlain, Petr Pavlu, Daniel Gomez, Sami Tolvanen,
Jason A . Donenfeld, Ard Biesheuvel, Stephan Mueller,
linux-crypto, keyrings, linux-modules, linux-kernel,
David S. Miller
Add a supplementary information parameter to the asymmetric key signature
verification API, in particular crypto_sig_verify() and sig_alg::verify.
This takes the form of a printable string containing of key=val elements.
This is needed as some algorithms require additional metadata
(e.g. RSASSA-PSS) and this extra metadata is included in the X.509
certificates and PKCS#7 messages. Furthermore, keyctl(KEYCTL_PKEY_VERIFY)
already allows for this to be passed to the kernel, as do the _SIGN,
_ENCRYPT and _DECRYPT keyctls.
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Ignat Korchagin <ignat@cloudflare.com>
cc: Herbert Xu <herbert@gondor.apana.org.au>
cc: "David S. Miller" <davem@davemloft.net>
cc: Lukas Wunner <lukas@wunner.de>
cc: keyrings@vger.kernel.org
cc: linux-crypto@vger.kernel.org
---
crypto/asymmetric_keys/asymmetric_type.c | 1 +
crypto/asymmetric_keys/public_key.c | 2 +-
crypto/asymmetric_keys/signature.c | 1 +
crypto/ecdsa-p1363.c | 5 +++--
crypto/ecdsa-x962.c | 5 +++--
crypto/ecdsa.c | 3 ++-
crypto/ecrdsa.c | 3 ++-
crypto/mldsa.c | 3 ++-
crypto/rsassa-pkcs1.c | 3 ++-
crypto/sig.c | 3 ++-
crypto/testmgr.c | 2 +-
crypto/testmgr.h | 1 +
include/crypto/public_key.h | 1 +
include/crypto/sig.h | 9 ++++++---
14 files changed, 28 insertions(+), 14 deletions(-)
diff --git a/crypto/asymmetric_keys/asymmetric_type.c b/crypto/asymmetric_keys/asymmetric_type.c
index 348966ea2175..dad4f0edfa25 100644
--- a/crypto/asymmetric_keys/asymmetric_type.c
+++ b/crypto/asymmetric_keys/asymmetric_type.c
@@ -596,6 +596,7 @@ static int asymmetric_key_verify_signature(struct kernel_pkey_params *params,
.digest_size = params->in_len,
.encoding = params->encoding,
.hash_algo = params->hash_algo,
+ .info = params->info,
.digest = (void *)in,
.s = (void *)in2,
};
diff --git a/crypto/asymmetric_keys/public_key.c b/crypto/asymmetric_keys/public_key.c
index ed6b4b5ae4ef..61dc4f626620 100644
--- a/crypto/asymmetric_keys/public_key.c
+++ b/crypto/asymmetric_keys/public_key.c
@@ -433,7 +433,7 @@ int public_key_verify_signature(const struct public_key *pkey,
goto error_free_key;
ret = crypto_sig_verify(tfm, sig->s, sig->s_size,
- sig->digest, sig->digest_size);
+ sig->digest, sig->digest_size, sig->info);
error_free_key:
kfree_sensitive(key);
diff --git a/crypto/asymmetric_keys/signature.c b/crypto/asymmetric_keys/signature.c
index bea01cf27d0a..30ba50eb44af 100644
--- a/crypto/asymmetric_keys/signature.c
+++ b/crypto/asymmetric_keys/signature.c
@@ -30,6 +30,7 @@ void public_key_signature_free(struct public_key_signature *sig)
kfree(sig->s);
if (sig->digest_free)
kfree(sig->digest);
+ kfree(sig->info);
kfree(sig);
}
}
diff --git a/crypto/ecdsa-p1363.c b/crypto/ecdsa-p1363.c
index e0c55c64711c..fa987dba1213 100644
--- a/crypto/ecdsa-p1363.c
+++ b/crypto/ecdsa-p1363.c
@@ -18,7 +18,8 @@ struct ecdsa_p1363_ctx {
static int ecdsa_p1363_verify(struct crypto_sig *tfm,
const void *src, unsigned int slen,
- const void *digest, unsigned int dlen)
+ const void *digest, unsigned int dlen,
+ const char *info)
{
struct ecdsa_p1363_ctx *ctx = crypto_sig_ctx(tfm);
unsigned int keylen = DIV_ROUND_UP_POW2(crypto_sig_keysize(ctx->child),
@@ -32,7 +33,7 @@ static int ecdsa_p1363_verify(struct crypto_sig *tfm,
ecc_digits_from_bytes(src, keylen, sig.r, ndigits);
ecc_digits_from_bytes(src + keylen, keylen, sig.s, ndigits);
- return crypto_sig_verify(ctx->child, &sig, sizeof(sig), digest, dlen);
+ return crypto_sig_verify(ctx->child, &sig, sizeof(sig), digest, dlen, info);
}
static unsigned int ecdsa_p1363_key_size(struct crypto_sig *tfm)
diff --git a/crypto/ecdsa-x962.c b/crypto/ecdsa-x962.c
index ee71594d10a0..5d7f1078989c 100644
--- a/crypto/ecdsa-x962.c
+++ b/crypto/ecdsa-x962.c
@@ -75,7 +75,8 @@ int ecdsa_get_signature_s(void *context, size_t hdrlen, unsigned char tag,
static int ecdsa_x962_verify(struct crypto_sig *tfm,
const void *src, unsigned int slen,
- const void *digest, unsigned int dlen)
+ const void *digest, unsigned int dlen,
+ const char *info)
{
struct ecdsa_x962_ctx *ctx = crypto_sig_ctx(tfm);
struct ecdsa_x962_signature_ctx sig_ctx;
@@ -89,7 +90,7 @@ static int ecdsa_x962_verify(struct crypto_sig *tfm,
return err;
return crypto_sig_verify(ctx->child, &sig_ctx.sig, sizeof(sig_ctx.sig),
- digest, dlen);
+ digest, dlen, info);
}
static unsigned int ecdsa_x962_key_size(struct crypto_sig *tfm)
diff --git a/crypto/ecdsa.c b/crypto/ecdsa.c
index ce8e4364842f..144fd6b9168b 100644
--- a/crypto/ecdsa.c
+++ b/crypto/ecdsa.c
@@ -65,7 +65,8 @@ static int _ecdsa_verify(struct ecc_ctx *ctx, const u64 *hash, const u64 *r, con
*/
static int ecdsa_verify(struct crypto_sig *tfm,
const void *src, unsigned int slen,
- const void *digest, unsigned int dlen)
+ const void *digest, unsigned int dlen,
+ const char *info)
{
struct ecc_ctx *ctx = crypto_sig_ctx(tfm);
size_t bufsize = ctx->curve->g.ndigits * sizeof(u64);
diff --git a/crypto/ecrdsa.c b/crypto/ecrdsa.c
index 2c0602f0cd40..59f2d5bb3be4 100644
--- a/crypto/ecrdsa.c
+++ b/crypto/ecrdsa.c
@@ -69,7 +69,8 @@ static const struct ecc_curve *get_curve_by_oid(enum OID oid)
static int ecrdsa_verify(struct crypto_sig *tfm,
const void *src, unsigned int slen,
- const void *digest, unsigned int dlen)
+ const void *digest, unsigned int dlen,
+ const char *info)
{
struct ecrdsa_ctx *ctx = crypto_sig_ctx(tfm);
unsigned int ndigits = dlen / sizeof(u64);
diff --git a/crypto/mldsa.c b/crypto/mldsa.c
index 2146c774b5ca..ba071d030ab0 100644
--- a/crypto/mldsa.c
+++ b/crypto/mldsa.c
@@ -25,7 +25,8 @@ static int crypto_mldsa_sign(struct crypto_sig *tfm,
static int crypto_mldsa_verify(struct crypto_sig *tfm,
const void *sig, unsigned int sig_len,
- const void *msg, unsigned int msg_len)
+ const void *msg, unsigned int msg_len,
+ const char *info)
{
const struct crypto_mldsa_ctx *ctx = crypto_sig_ctx(tfm);
diff --git a/crypto/rsassa-pkcs1.c b/crypto/rsassa-pkcs1.c
index 94fa5e9600e7..6283050e609a 100644
--- a/crypto/rsassa-pkcs1.c
+++ b/crypto/rsassa-pkcs1.c
@@ -215,7 +215,8 @@ static int rsassa_pkcs1_sign(struct crypto_sig *tfm,
static int rsassa_pkcs1_verify(struct crypto_sig *tfm,
const void *src, unsigned int slen,
- const void *digest, unsigned int dlen)
+ const void *digest, unsigned int dlen,
+ const char *info)
{
struct sig_instance *inst = sig_alg_instance(tfm);
struct rsassa_pkcs1_inst_ctx *ictx = sig_instance_ctx(inst);
diff --git a/crypto/sig.c b/crypto/sig.c
index beba745b6405..c56fea3a53ae 100644
--- a/crypto/sig.c
+++ b/crypto/sig.c
@@ -92,7 +92,8 @@ static int sig_default_sign(struct crypto_sig *tfm,
static int sig_default_verify(struct crypto_sig *tfm,
const void *src, unsigned int slen,
- const void *dst, unsigned int dlen)
+ const void *dst, unsigned int dlen,
+ const char *info)
{
return -ENOSYS;
}
diff --git a/crypto/testmgr.c b/crypto/testmgr.c
index 5df204d9c9dd..51f76b15f134 100644
--- a/crypto/testmgr.c
+++ b/crypto/testmgr.c
@@ -3969,7 +3969,7 @@ static int test_sig_one(struct crypto_sig *tfm, const struct sig_testvec *vecs)
* (which does not require a private key)
*/
err = crypto_sig_verify(tfm, vecs->c, vecs->c_size,
- vecs->m, vecs->m_size);
+ vecs->m, vecs->m_size, vecs->verify_info);
if (err) {
pr_err("alg: sig: verify test failed: err %d\n", err);
return err;
diff --git a/crypto/testmgr.h b/crypto/testmgr.h
index 1a3329e1c325..305adad2f2d0 100644
--- a/crypto/testmgr.h
+++ b/crypto/testmgr.h
@@ -146,6 +146,7 @@ struct akcipher_testvec {
struct sig_testvec {
const unsigned char *key;
+ const unsigned char *verify_info;
const unsigned char *params;
const unsigned char *m;
const unsigned char *c;
diff --git a/include/crypto/public_key.h b/include/crypto/public_key.h
index 68899a49cd0d..b6f2f2218aae 100644
--- a/include/crypto/public_key.h
+++ b/include/crypto/public_key.h
@@ -48,6 +48,7 @@ struct public_key_signature {
u32 digest_size; /* Number of bytes in digest */
bool digest_free; /* T if digest needs freeing */
bool algo_does_hash; /* Public key algo does its own hashing */
+ char *info; /* Supplementary parameters */
const char *pkey_algo;
const char *hash_algo;
const char *encoding;
diff --git a/include/crypto/sig.h b/include/crypto/sig.h
index fa6dafafab3f..885fa6487780 100644
--- a/include/crypto/sig.h
+++ b/include/crypto/sig.h
@@ -56,7 +56,8 @@ struct sig_alg {
void *dst, unsigned int dlen);
int (*verify)(struct crypto_sig *tfm,
const void *src, unsigned int slen,
- const void *digest, unsigned int dlen);
+ const void *digest, unsigned int dlen,
+ const char *info);
int (*set_pub_key)(struct crypto_sig *tfm,
const void *key, unsigned int keylen);
int (*set_priv_key)(struct crypto_sig *tfm,
@@ -209,16 +210,18 @@ static inline int crypto_sig_sign(struct crypto_sig *tfm,
* @slen: source length
* @digest: digest
* @dlen: digest length
+ * @info: Additional parameters as a set of k=v
*
* Return: zero on verification success; error code in case of error.
*/
static inline int crypto_sig_verify(struct crypto_sig *tfm,
const void *src, unsigned int slen,
- const void *digest, unsigned int dlen)
+ const void *digest, unsigned int dlen,
+ const char *info)
{
struct sig_alg *alg = crypto_sig_alg(tfm);
- return alg->verify(tfm, src, slen, digest, dlen);
+ return alg->verify(tfm, src, slen, digest, dlen, info);
}
/**
^ permalink raw reply related [flat|nested] 20+ messages in thread* Re: [PATCH v12 06/10] crypto: Add supplementary info param to asymmetric key signature verification
2026-01-15 21:50 ` [PATCH v12 06/10] crypto: Add supplementary info param to asymmetric key signature verification David Howells
@ 2026-01-20 22:03 ` Eric Biggers
2026-01-20 23:39 ` David Howells
2026-01-25 14:19 ` Jarkko Sakkinen
0 siblings, 2 replies; 20+ messages in thread
From: Eric Biggers @ 2026-01-20 22:03 UTC (permalink / raw)
To: David Howells
Cc: Lukas Wunner, Ignat Korchagin, Jarkko Sakkinen, Herbert Xu,
Luis Chamberlain, Petr Pavlu, Daniel Gomez, Sami Tolvanen,
Jason A . Donenfeld, Ard Biesheuvel, Stephan Mueller,
linux-crypto, keyrings, linux-modules, linux-kernel,
David S. Miller
On Thu, Jan 15, 2026 at 09:50:48PM +0000, David Howells wrote:
> Add a supplementary information parameter to the asymmetric key signature
> verification API, in particular crypto_sig_verify() and sig_alg::verify.
> This takes the form of a printable string containing of key=val elements.
As I'm sure you're aware, C has native support for function parameters.
No need to serialize to a string on the caller side and then deserialize
in the callee.
This is yet another example of a case where trying to fit different
algorithms into a generic API doesn't work well.
We should just have a library API for each signature algorithm, with
each algorithm taking the parameters it needs.
- Eric
^ permalink raw reply [flat|nested] 20+ messages in thread
* Re: [PATCH v12 06/10] crypto: Add supplementary info param to asymmetric key signature verification
2026-01-20 22:03 ` Eric Biggers
@ 2026-01-20 23:39 ` David Howells
2026-01-21 0:06 ` Eric Biggers
2026-01-25 14:19 ` Jarkko Sakkinen
1 sibling, 1 reply; 20+ messages in thread
From: David Howells @ 2026-01-20 23:39 UTC (permalink / raw)
To: Eric Biggers
Cc: dhowells, Lukas Wunner, Ignat Korchagin, Jarkko Sakkinen,
Herbert Xu, Luis Chamberlain, Petr Pavlu, Daniel Gomez,
Sami Tolvanen, Jason A . Donenfeld, Ard Biesheuvel,
Stephan Mueller, linux-crypto, keyrings, linux-modules,
linux-kernel, David S. Miller
Eric Biggers <ebiggers@kernel.org> wrote:
> As I'm sure you're aware, C has native support for function parameters.
And we have a syscall interface to honour that takes a parameter string *for
this very purpose*. It just wasn't threaded into the akcipher API.
> This is yet another example of a case where trying to fit different
> algorithms into a generic API doesn't work well.
Well enough.
> We should just have a library API for each signature algorithm, with
> each algorithm taking the parameters it needs.
No, we shouldn't. We have a library that allows demand loadable modules. We
should use that.
David
^ permalink raw reply [flat|nested] 20+ messages in thread
* Re: [PATCH v12 06/10] crypto: Add supplementary info param to asymmetric key signature verification
2026-01-20 23:39 ` David Howells
@ 2026-01-21 0:06 ` Eric Biggers
0 siblings, 0 replies; 20+ messages in thread
From: Eric Biggers @ 2026-01-21 0:06 UTC (permalink / raw)
To: David Howells
Cc: Lukas Wunner, Ignat Korchagin, Jarkko Sakkinen, Herbert Xu,
Luis Chamberlain, Petr Pavlu, Daniel Gomez, Sami Tolvanen,
Jason A . Donenfeld, Ard Biesheuvel, Stephan Mueller,
linux-crypto, keyrings, linux-modules, linux-kernel,
David S. Miller
On Tue, Jan 20, 2026 at 11:39:46PM +0000, David Howells wrote:
> Eric Biggers <ebiggers@kernel.org> wrote:
>
> > As I'm sure you're aware, C has native support for function parameters.
>
> And we have a syscall interface to honour that takes a parameter string *for
> this very purpose*. It just wasn't threaded into the akcipher API.
This seems to be more of a bug than a feature, though. It seems the
actual goals of this patchset are to add ML-DSA and RSASSA-PSS support
to kernel module signing. But because of how the code is organized, as
a side effect it ended up extending the KEYCTL_PKEY_* UAPIs as well.
Linux's UAPI stability guarantee holds for these UAPIs; anything that we
add to them, including these ad-hoc and undocumented parameter strings,
will likely have to be supported forever.
Unless these keyctl UAPI extensions are well-justified and come with
documentation and tests, we should just hold off on them for now.
What's the hurry?
BTW, we got hit by this when there was an attempt to remove SHA-1
support from module signing. Due to the design defect where the signing
is also exposed through KEYCTL_PKEY_*, it caused a UAPI regression as
well and had to be reverted.
- Eric
^ permalink raw reply [flat|nested] 20+ messages in thread
* Re: [PATCH v12 06/10] crypto: Add supplementary info param to asymmetric key signature verification
2026-01-20 22:03 ` Eric Biggers
2026-01-20 23:39 ` David Howells
@ 2026-01-25 14:19 ` Jarkko Sakkinen
1 sibling, 0 replies; 20+ messages in thread
From: Jarkko Sakkinen @ 2026-01-25 14:19 UTC (permalink / raw)
To: Eric Biggers
Cc: David Howells, Lukas Wunner, Ignat Korchagin, Herbert Xu,
Luis Chamberlain, Petr Pavlu, Daniel Gomez, Sami Tolvanen,
Jason A . Donenfeld, Ard Biesheuvel, Stephan Mueller,
linux-crypto, keyrings, linux-modules, linux-kernel,
David S. Miller
On Tue, Jan 20, 2026 at 02:03:21PM -0800, Eric Biggers wrote:
> On Thu, Jan 15, 2026 at 09:50:48PM +0000, David Howells wrote:
> > Add a supplementary information parameter to the asymmetric key signature
> > verification API, in particular crypto_sig_verify() and sig_alg::verify.
> > This takes the form of a printable string containing of key=val elements.
>
> As I'm sure you're aware, C has native support for function parameters.
> No need to serialize to a string on the caller side and then deserialize
> in the callee.
>
> This is yet another example of a case where trying to fit different
> algorithms into a generic API doesn't work well.
>
> We should just have a library API for each signature algorithm, with
> each algorithm taking the parameters it needs.
This would be a great idea IMHO. I'm looking into renewing my TPM2
asymmetric keys patch set some day, and e.g., for that such primitives
would be more ergonomic fit.
>
> - Eric
BR, Jarkko
^ permalink raw reply [flat|nested] 20+ messages in thread
* [PATCH v12 07/10] crypto: Add RSASSA-PSS support
2026-01-15 21:50 [PATCH v12 00/10] x509, pkcs7, crypto: Add ML-DSA and RSASSA-PSS signing David Howells
` (5 preceding siblings ...)
2026-01-15 21:50 ` [PATCH v12 06/10] crypto: Add supplementary info param to asymmetric key signature verification David Howells
@ 2026-01-15 21:50 ` David Howells
2026-01-20 14:26 ` Ignat Korchagin
2026-01-15 21:50 ` [PATCH v12 08/10] pkcs7, x509: " David Howells
` (2 subsequent siblings)
9 siblings, 1 reply; 20+ messages in thread
From: David Howells @ 2026-01-15 21:50 UTC (permalink / raw)
To: Lukas Wunner, Ignat Korchagin
Cc: David Howells, Jarkko Sakkinen, Herbert Xu, Eric Biggers,
Luis Chamberlain, Petr Pavlu, Daniel Gomez, Sami Tolvanen,
Jason A . Donenfeld, Ard Biesheuvel, Stephan Mueller,
linux-crypto, keyrings, linux-modules, linux-kernel,
Tadeusz Struk, David S. Miller
Add support for RSASSA-PSS [RFC8017 sec 8.1] signature verification support
to the RSA driver in crypto/. Note that signing support is not provided.
The verification function requires an info string formatted as a
space-separated list of key=value pairs. The following parameters need to
be provided:
(1) sighash=<algo>
The hash algorithm to be used to digest the data.
(2) pss_mask=<type>,...
The mask generation function (MGF) and its parameters.
(3) pss_salt=<len>
The length of the salt used.
The only MGF currently supported is "mgf1". This takes an additional
parameter indicating the mask-generating hash (which need not be the same
as the data hash). E.g.:
"sighash=sha256 pss_mask=mgf1,sha256 pss_salt=32"
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Tadeusz Struk <tadeusz.struk@intel.com>
cc: Herbert Xu <herbert@gondor.apana.org.au>
cc: David S. Miller <davem@davemloft.net>
cc: Lukas Wunner <lukas@wunner.de>
cc: Ignat Korchagin <ignat@cloudflare.com>
cc: keyrings@vger.kernel.org
cc: linux-crypto@vger.kernel.org
---
crypto/Makefile | 1 +
crypto/rsa.c | 8 +
crypto/rsassa-pss.c | 384 ++++++++++++++++++++++++++++++++++
include/crypto/hash.h | 3 +
include/crypto/internal/rsa.h | 2 +
5 files changed, 398 insertions(+)
create mode 100644 crypto/rsassa-pss.c
diff --git a/crypto/Makefile b/crypto/Makefile
index 267d5403045b..5c91440d1751 100644
--- a/crypto/Makefile
+++ b/crypto/Makefile
@@ -50,6 +50,7 @@ rsa_generic-y += rsa.o
rsa_generic-y += rsa_helper.o
rsa_generic-y += rsa-pkcs1pad.o
rsa_generic-y += rsassa-pkcs1.o
+rsa_generic-y += rsassa-pss.o
obj-$(CONFIG_CRYPTO_RSA) += rsa_generic.o
$(obj)/ecdsasignature.asn1.o: $(obj)/ecdsasignature.asn1.c $(obj)/ecdsasignature.asn1.h
diff --git a/crypto/rsa.c b/crypto/rsa.c
index 6c7734083c98..189a09d54c16 100644
--- a/crypto/rsa.c
+++ b/crypto/rsa.c
@@ -10,6 +10,7 @@
#include <linux/mpi.h>
#include <crypto/internal/rsa.h>
#include <crypto/internal/akcipher.h>
+#include <crypto/internal/sig.h>
#include <crypto/akcipher.h>
#include <crypto/algapi.h>
@@ -414,8 +415,14 @@ static int __init rsa_init(void)
if (err)
goto err_unregister_rsa_pkcs1pad;
+ err = crypto_register_sig(&rsassa_pss_alg);
+ if (err)
+ goto err_rsassa_pss;
+
return 0;
+err_rsassa_pss:
+ crypto_unregister_template(&rsassa_pkcs1_tmpl);
err_unregister_rsa_pkcs1pad:
crypto_unregister_template(&rsa_pkcs1pad_tmpl);
err_unregister_rsa:
@@ -425,6 +432,7 @@ static int __init rsa_init(void)
static void __exit rsa_exit(void)
{
+ crypto_unregister_sig(&rsassa_pss_alg);
crypto_unregister_template(&rsassa_pkcs1_tmpl);
crypto_unregister_template(&rsa_pkcs1pad_tmpl);
crypto_unregister_akcipher(&rsa);
diff --git a/crypto/rsassa-pss.c b/crypto/rsassa-pss.c
new file mode 100644
index 000000000000..c12ffa3813df
--- /dev/null
+++ b/crypto/rsassa-pss.c
@@ -0,0 +1,384 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * RSA Signature Scheme combined with EMSA-PSS encoding (RFC 8017 sec 8.2)
+ *
+ * https://www.rfc-editor.org/rfc/rfc8017#section-8.1
+ *
+ * Copyright (c) 2025 Red Hat
+ */
+
+#define pr_fmt(fmt) "RSAPSS: "fmt
+#include <linux/ctype.h>
+#include <linux/module.h>
+#include <linux/oid_registry.h>
+#include <linux/parser.h>
+#include <linux/scatterlist.h>
+#include <crypto/akcipher.h>
+#include <crypto/algapi.h>
+#include <crypto/hash.h>
+#include <crypto/sig.h>
+#include <crypto/internal/akcipher.h>
+#include <crypto/internal/rsa.h>
+#include <crypto/internal/sig.h>
+
+struct rsassa_pss_ctx {
+ struct crypto_akcipher *rsa;
+ unsigned int key_size;
+ unsigned int salt_len;
+ char *pss_hash;
+ char *mgf1_hash;
+};
+
+enum {
+ rsassa_pss_verify_hash_algo,
+ rsassa_pss_verify_pss_mask,
+ rsassa_pss_verify_pss_salt,
+};
+
+static const match_table_t rsassa_pss_verify_params = {
+ { rsassa_pss_verify_hash_algo, "sighash=%s" },
+ { rsassa_pss_verify_pss_mask, "pss_mask=%s" },
+ { rsassa_pss_verify_pss_salt, "pss_salt=%u" },
+ {}
+};
+
+/*
+ * Parse the signature parameters out of the info string.
+ */
+static int rsassa_pss_vinfo_parse(struct rsassa_pss_ctx *ctx,
+ char *info)
+{
+ substring_t args[MAX_OPT_ARGS];
+ char *p;
+
+ ctx->pss_hash = NULL;
+ ctx->mgf1_hash = NULL;
+ ctx->salt_len = 0;
+
+ while ((p = strsep(&info, " \t"))) {
+ if (*p == '\0' || *p == ' ' || *p == '\t')
+ continue;
+
+ switch (match_token(p, rsassa_pss_verify_params, args)) {
+ case rsassa_pss_verify_hash_algo:
+ *args[0].to = 0;
+ ctx->pss_hash = args[0].from;
+ break;
+ case rsassa_pss_verify_pss_mask:
+ if (memcmp(args[0].from, "mgf1", 4) != 0)
+ return -ENOPKG;
+ if (args[0].from[4] != ',')
+ return -EINVAL;
+ args[0].from += 5;
+ if (args[0].from >= args[0].to)
+ return -EINVAL;
+ *args[0].to = 0;
+ ctx->mgf1_hash = args[0].from;
+ break;
+ case rsassa_pss_verify_pss_salt:
+ if (match_uint(&args[0], &ctx->salt_len) < 0)
+ return -EINVAL;
+ break;
+ default:
+ pr_debug("Unknown info param\n");
+ return -EINVAL; /* Ignoring it might be better. */
+ }
+ }
+
+ if (!ctx->pss_hash ||
+ !ctx->mgf1_hash ||
+ !ctx->salt_len)
+ return -EINVAL;
+ return 0;
+}
+
+/*
+ * Perform mask = MGF1(mgfSeed, masklen) - RFC8017 appendix B.2.1.
+ */
+static int MGF1(struct rsassa_pss_ctx *ctx,
+ const u8 *mgfSeed, unsigned int mgfSeed_len,
+ u8 *mask, unsigned int maskLen)
+{
+ unsigned int counter, count_to, hLen, T_len;
+ __be32 *C;
+ int err;
+ u8 *T, *t, *to_hash;
+
+ struct crypto_shash *hash_tfm __free(crypto_free_shash) =
+ crypto_alloc_shash(ctx->mgf1_hash, 0, 0);
+ if (IS_ERR(hash_tfm))
+ return PTR_ERR(hash_tfm);
+
+ hLen = crypto_shash_digestsize(hash_tfm);
+ count_to = DIV_ROUND_UP(maskLen, hLen);
+ T_len = hLen * count_to;
+
+ struct shash_desc *Hash __free(kfree) =
+ kmalloc(roundup(sizeof(struct shash_desc) +
+ crypto_shash_descsize(hash_tfm), 64) +
+ roundup(T_len, 64) + /* T */
+ roundup(mgfSeed_len + 4, 64), /* mgfSeed||C */
+ GFP_KERNEL);
+ if (!Hash)
+ return -ENOMEM;
+
+ Hash->tfm = hash_tfm;
+
+ /* 2: Let T be the empty octet string. */
+ T = (void *)Hash +
+ roundup(sizeof(struct shash_desc) +
+ crypto_shash_descsize(hash_tfm), 64);
+
+ /* 3: Generate the mask. */
+ to_hash = T + roundup(T_len, 64);
+ memcpy(to_hash, mgfSeed, mgfSeed_len);
+ C = (__be32 *)(to_hash + mgfSeed_len);
+
+ t = T;
+ for (counter = 0; counter < count_to; counter++) {
+ /* 3A: C = I2OSP(counter, 4). */
+ put_unaligned_be32(counter, C);
+
+ /* 3B: T = T || Hash(mgfSeed || C). */
+ err = crypto_shash_digest(Hash, to_hash, mgfSeed_len + 4, t);
+ if (err < 0)
+ return err;
+
+ t += hLen;
+ }
+
+ /* 4: Output T to mask */
+ memcpy(mask, T, maskLen);
+ return 0;
+}
+
+/*
+ * Perform EMSA-PSS-VERIFY(M, EM, emBits) - RFC8017 sec 9.1.2.
+ */
+static int emsa_pss_verify(struct rsassa_pss_ctx *ctx,
+ const u8 *M, unsigned int M_len,
+ const u8 *EM, unsigned int emLen)
+{
+ unsigned int emBits, hLen, sLen, DB_len;
+ const u8 *maskedDB, *H;
+ u8 *mHash, *dbMask, *DB, *salt, *Mprime, *Hprime;
+ int err, i;
+
+ emBits = 8 - fls(EM[0]);
+ emBits = emLen * 8 - emBits;
+
+ struct crypto_shash *hash_tfm __free(crypto_free_shash) =
+ crypto_alloc_shash(ctx->pss_hash, 0, 0);
+ if (IS_ERR(hash_tfm))
+ return PTR_ERR(hash_tfm);
+
+ hLen = crypto_shash_digestsize(hash_tfm);
+ sLen = ctx->salt_len;
+
+ if (sLen > 65536 ||
+ emBits < 8 * (hLen + sLen) + 9)
+ return -EBADMSG;
+
+ DB_len = emLen - hLen - 1;
+
+ struct shash_desc *Hash __free(kfree) =
+ kmalloc(roundup(sizeof(struct shash_desc) +
+ crypto_shash_descsize(hash_tfm), 64) +
+ roundup(hLen, 64) + /* mHash */
+ roundup(DB_len, 64) + /* DB and dbMask */
+ roundup(8 + hLen + sLen, 64) + /* M' */
+ roundup(hLen, 64), /* H' */
+ GFP_KERNEL);
+ if (!Hash)
+ return -ENOMEM;
+
+ Hash->tfm = hash_tfm;
+
+ mHash = (void *)Hash +
+ roundup(sizeof(struct shash_desc) +
+ crypto_shash_descsize(hash_tfm), 64);
+ DB = dbMask = mHash + roundup(hLen, 64);
+ Mprime = dbMask + roundup(DB_len, 64);
+ Hprime = Mprime + roundup(8 + hLen + sLen, 64);
+
+ /* 1. Check len M against hash input limitation. */
+ /* The standard says ~2EiB for SHA1, so I think we can ignore this. */
+
+ /* 2. mHash = Hash(M).
+ * In theory, we would do:
+ * err = crypto_shash_digest(Hash, M, M_len, mHash);
+ * but the caller is assumed to already have done that for us.
+ */
+ if (M_len != hLen)
+ return -EINVAL;
+ memcpy(mHash, M, hLen);
+
+ /* 3. Check emLen against hLen + sLen + 2. */
+ if (emLen < hLen + sLen + 2)
+ return -EBADMSG;
+
+ /* 4. Validate EM. */
+ if (EM[emLen - 1] != 0xbc)
+ return -EKEYREJECTED;
+
+ /* 5. Pick maskedDB and H. */
+ maskedDB = EM;
+ H = EM + DB_len;
+
+ /* 6. Check leftmost 8emLen-emBits bits of maskedDB are 0. */
+ /* Can only find emBits by counting the zeros on the Left. */
+
+ /* 7. Let dbMask = MGF(H, emLen - hLen - 1). */
+ err = MGF1(ctx, H, hLen, dbMask, DB_len);
+ if (err < 0)
+ return err;
+
+ /* 8. Let DB = maskedDB XOR dbMask. */
+ for (i = 0; i < DB_len; i++)
+ DB[i] = maskedDB[i] ^ dbMask[i];
+
+ /* 9. Set leftmost bits in DB to zero. */
+ int z = 8 * emLen - emBits;
+
+ if (z > 0) {
+ if (z >= 8) {
+ DB[0] = 0;
+ } else {
+ z = 8 - z;
+ DB[0] &= (1 << z) - 1;
+ }
+ }
+
+ /* 10. Check the left part of DB is {0,0,...,1}. */
+ for (i = 0; i < emLen - hLen - sLen - 2; i++)
+ if (DB[i] != 0)
+ return -EKEYREJECTED;
+ if (DB[i] != 0x01)
+ return -EKEYREJECTED;
+
+ /* 11. Let salt be the last sLen octets of DB. */
+ salt = DB + DB_len - sLen;
+
+ /* 12. Let M' be 00 00 00 00 00 00 00 00 || mHash || salt. */
+ memset(Mprime, 0, 8);
+ memcpy(Mprime + 8, mHash, hLen);
+ memcpy(Mprime + 8 + hLen, salt, sLen);
+
+ /* 13. Let H' = Hash(M'). */
+ err = crypto_shash_digest(Hash, Mprime, 8 + hLen + sLen, Hprime);
+ if (err < 0)
+ return err;
+
+ /* 14. Check H = H'. */
+ if (memcmp(H, Hprime, hLen) != 0)
+ return -EKEYREJECTED;
+ return 0;
+}
+
+/*
+ * Perform RSASSA-PSS-VERIFY((n,e),M,S) - RFC8017 sec 8.1.2.
+ */
+static int rsassa_pss_verify(struct crypto_sig *tfm,
+ const void *src, unsigned int slen,
+ const void *digest, unsigned int dlen,
+ const char *info)
+{
+ struct rsassa_pss_ctx *ctx = crypto_sig_ctx(tfm);
+ struct crypto_wait cwait;
+ struct scatterlist sg;
+ unsigned int rsa_reqsize = crypto_akcipher_reqsize(ctx->rsa);
+ u8 *EM;
+ int err;
+
+ if (!info)
+ return -EINVAL;
+
+ char *str __free(kfree) = kstrdup(info, GFP_KERNEL);
+ if (!str)
+ return -ENOMEM;
+
+ err = rsassa_pss_vinfo_parse(ctx, str);
+ if (err < 0)
+ return err;
+
+ /* RFC8017 sec 8.1.2 step 1 - length checking */
+ if (!ctx->key_size || slen != ctx->key_size)
+ return -EINVAL;
+
+ /* RFC8017 sec 8.1.2 step 2 - RSA verification */
+ struct akcipher_request *rsa_req __free(kfree) =
+ kmalloc(sizeof(*rsa_req) + rsa_reqsize + ctx->key_size,
+ GFP_KERNEL);
+ if (!rsa_req)
+ return -ENOMEM;
+
+ EM = (u8 *)(rsa_req + 1) + rsa_reqsize;
+ memcpy(EM, src, slen);
+
+ crypto_init_wait(&cwait);
+ sg_init_one(&sg, EM, slen);
+ akcipher_request_set_tfm(rsa_req, ctx->rsa);
+ akcipher_request_set_crypt(rsa_req, &sg, &sg, slen, slen);
+ akcipher_request_set_callback(rsa_req, CRYPTO_TFM_REQ_MAY_SLEEP,
+ crypto_req_done, &cwait);
+
+ err = crypto_akcipher_encrypt(rsa_req);
+ err = crypto_wait_req(err, &cwait);
+ if (err)
+ return err;
+
+ /* RFC 8017 sec 8.1.2 step 3 - EMSA-PSS(M, EM, modbits-1) */
+ return emsa_pss_verify(ctx, digest, dlen, EM, slen);
+}
+
+static unsigned int rsassa_pss_key_size(struct crypto_sig *tfm)
+{
+ struct rsassa_pss_ctx *ctx = crypto_sig_ctx(tfm);
+
+ return ctx->key_size * BITS_PER_BYTE;
+}
+
+static int rsassa_pss_set_pub_key(struct crypto_sig *tfm,
+ const void *key, unsigned int keylen)
+{
+ struct rsassa_pss_ctx *ctx = crypto_sig_ctx(tfm);
+
+ return rsa_set_key(ctx->rsa, &ctx->key_size, RSA_PUB, key, keylen);
+}
+
+static int rsassa_pss_init_tfm(struct crypto_sig *tfm)
+{
+ struct crypto_akcipher *rsa;
+ struct rsassa_pss_ctx *ctx = crypto_sig_ctx(tfm);
+
+ rsa = crypto_alloc_akcipher("rsa", 0, 0);
+ if (IS_ERR(rsa))
+ return PTR_ERR(rsa);
+
+ ctx->rsa = rsa;
+ return 0;
+}
+
+static void rsassa_pss_exit_tfm(struct crypto_sig *tfm)
+{
+ struct rsassa_pss_ctx *ctx = crypto_sig_ctx(tfm);
+
+ crypto_free_akcipher(ctx->rsa);
+}
+
+struct sig_alg rsassa_pss_alg = {
+ .verify = rsassa_pss_verify,
+ .set_pub_key = rsassa_pss_set_pub_key,
+ .key_size = rsassa_pss_key_size,
+ .init = rsassa_pss_init_tfm,
+ .exit = rsassa_pss_exit_tfm,
+ .base = {
+ .cra_name = "rsassa-pss",
+ .cra_driver_name = "rsassa-pss-generic",
+ .cra_priority = 100,
+ .cra_module = THIS_MODULE,
+ .cra_ctxsize = sizeof(struct rsassa_pss_ctx),
+ },
+};
+
+MODULE_ALIAS_CRYPTO("rsassa-pss");
diff --git a/include/crypto/hash.h b/include/crypto/hash.h
index 586700332c73..49b1ea5cf78d 100644
--- a/include/crypto/hash.h
+++ b/include/crypto/hash.h
@@ -779,6 +779,9 @@ static inline void crypto_free_shash(struct crypto_shash *tfm)
crypto_destroy_tfm(tfm, crypto_shash_tfm(tfm));
}
+DEFINE_FREE(crypto_free_shash, struct crypto_shash*,
+ if (!IS_ERR_OR_NULL(_T)) { crypto_free_shash(_T); });
+
static inline const char *crypto_shash_alg_name(struct crypto_shash *tfm)
{
return crypto_tfm_alg_name(crypto_shash_tfm(tfm));
diff --git a/include/crypto/internal/rsa.h b/include/crypto/internal/rsa.h
index 071a1951b992..d7f38a273949 100644
--- a/include/crypto/internal/rsa.h
+++ b/include/crypto/internal/rsa.h
@@ -83,4 +83,6 @@ static inline int rsa_set_key(struct crypto_akcipher *child,
extern struct crypto_template rsa_pkcs1pad_tmpl;
extern struct crypto_template rsassa_pkcs1_tmpl;
+extern struct sig_alg rsassa_pss_alg;
+
#endif
^ permalink raw reply related [flat|nested] 20+ messages in thread* Re: [PATCH v12 07/10] crypto: Add RSASSA-PSS support
2026-01-15 21:50 ` [PATCH v12 07/10] crypto: Add RSASSA-PSS support David Howells
@ 2026-01-20 14:26 ` Ignat Korchagin
0 siblings, 0 replies; 20+ messages in thread
From: Ignat Korchagin @ 2026-01-20 14:26 UTC (permalink / raw)
To: David Howells
Cc: Lukas Wunner, Jarkko Sakkinen, Herbert Xu, Eric Biggers,
Luis Chamberlain, Petr Pavlu, Daniel Gomez, Sami Tolvanen,
Jason A . Donenfeld, Ard Biesheuvel, Stephan Mueller,
linux-crypto, keyrings, linux-modules, linux-kernel,
Tadeusz Struk, David S. Miller
On Thu, Jan 15, 2026 at 9:51 PM David Howells <dhowells@redhat.com> wrote:
>
> Add support for RSASSA-PSS [RFC8017 sec 8.1] signature verification support
> to the RSA driver in crypto/. Note that signing support is not provided.
>
> The verification function requires an info string formatted as a
> space-separated list of key=value pairs. The following parameters need to
> be provided:
>
> (1) sighash=<algo>
>
> The hash algorithm to be used to digest the data.
>
> (2) pss_mask=<type>,...
>
> The mask generation function (MGF) and its parameters.
>
> (3) pss_salt=<len>
>
> The length of the salt used.
>
> The only MGF currently supported is "mgf1". This takes an additional
> parameter indicating the mask-generating hash (which need not be the same
> as the data hash). E.g.:
>
> "sighash=sha256 pss_mask=mgf1,sha256 pss_salt=32"
>
> Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Ignat Korchagin <ignat@cloudflare.com>
> cc: Tadeusz Struk <tadeusz.struk@intel.com>
> cc: Herbert Xu <herbert@gondor.apana.org.au>
> cc: David S. Miller <davem@davemloft.net>
> cc: Lukas Wunner <lukas@wunner.de>
> cc: Ignat Korchagin <ignat@cloudflare.com>
> cc: keyrings@vger.kernel.org
> cc: linux-crypto@vger.kernel.org
> ---
> crypto/Makefile | 1 +
> crypto/rsa.c | 8 +
> crypto/rsassa-pss.c | 384 ++++++++++++++++++++++++++++++++++
> include/crypto/hash.h | 3 +
> include/crypto/internal/rsa.h | 2 +
> 5 files changed, 398 insertions(+)
> create mode 100644 crypto/rsassa-pss.c
>
> diff --git a/crypto/Makefile b/crypto/Makefile
> index 267d5403045b..5c91440d1751 100644
> --- a/crypto/Makefile
> +++ b/crypto/Makefile
> @@ -50,6 +50,7 @@ rsa_generic-y += rsa.o
> rsa_generic-y += rsa_helper.o
> rsa_generic-y += rsa-pkcs1pad.o
> rsa_generic-y += rsassa-pkcs1.o
> +rsa_generic-y += rsassa-pss.o
> obj-$(CONFIG_CRYPTO_RSA) += rsa_generic.o
>
> $(obj)/ecdsasignature.asn1.o: $(obj)/ecdsasignature.asn1.c $(obj)/ecdsasignature.asn1.h
> diff --git a/crypto/rsa.c b/crypto/rsa.c
> index 6c7734083c98..189a09d54c16 100644
> --- a/crypto/rsa.c
> +++ b/crypto/rsa.c
> @@ -10,6 +10,7 @@
> #include <linux/mpi.h>
> #include <crypto/internal/rsa.h>
> #include <crypto/internal/akcipher.h>
> +#include <crypto/internal/sig.h>
> #include <crypto/akcipher.h>
> #include <crypto/algapi.h>
>
> @@ -414,8 +415,14 @@ static int __init rsa_init(void)
> if (err)
> goto err_unregister_rsa_pkcs1pad;
>
> + err = crypto_register_sig(&rsassa_pss_alg);
> + if (err)
> + goto err_rsassa_pss;
> +
> return 0;
>
> +err_rsassa_pss:
> + crypto_unregister_template(&rsassa_pkcs1_tmpl);
> err_unregister_rsa_pkcs1pad:
> crypto_unregister_template(&rsa_pkcs1pad_tmpl);
> err_unregister_rsa:
> @@ -425,6 +432,7 @@ static int __init rsa_init(void)
>
> static void __exit rsa_exit(void)
> {
> + crypto_unregister_sig(&rsassa_pss_alg);
> crypto_unregister_template(&rsassa_pkcs1_tmpl);
> crypto_unregister_template(&rsa_pkcs1pad_tmpl);
> crypto_unregister_akcipher(&rsa);
> diff --git a/crypto/rsassa-pss.c b/crypto/rsassa-pss.c
> new file mode 100644
> index 000000000000..c12ffa3813df
> --- /dev/null
> +++ b/crypto/rsassa-pss.c
> @@ -0,0 +1,384 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * RSA Signature Scheme combined with EMSA-PSS encoding (RFC 8017 sec 8.2)
> + *
> + * https://www.rfc-editor.org/rfc/rfc8017#section-8.1
> + *
> + * Copyright (c) 2025 Red Hat
> + */
> +
> +#define pr_fmt(fmt) "RSAPSS: "fmt
> +#include <linux/ctype.h>
> +#include <linux/module.h>
> +#include <linux/oid_registry.h>
> +#include <linux/parser.h>
> +#include <linux/scatterlist.h>
> +#include <crypto/akcipher.h>
> +#include <crypto/algapi.h>
> +#include <crypto/hash.h>
> +#include <crypto/sig.h>
> +#include <crypto/internal/akcipher.h>
> +#include <crypto/internal/rsa.h>
> +#include <crypto/internal/sig.h>
> +
> +struct rsassa_pss_ctx {
> + struct crypto_akcipher *rsa;
> + unsigned int key_size;
> + unsigned int salt_len;
> + char *pss_hash;
> + char *mgf1_hash;
> +};
> +
> +enum {
> + rsassa_pss_verify_hash_algo,
> + rsassa_pss_verify_pss_mask,
> + rsassa_pss_verify_pss_salt,
> +};
> +
> +static const match_table_t rsassa_pss_verify_params = {
> + { rsassa_pss_verify_hash_algo, "sighash=%s" },
> + { rsassa_pss_verify_pss_mask, "pss_mask=%s" },
> + { rsassa_pss_verify_pss_salt, "pss_salt=%u" },
> + {}
> +};
> +
> +/*
> + * Parse the signature parameters out of the info string.
> + */
> +static int rsassa_pss_vinfo_parse(struct rsassa_pss_ctx *ctx,
> + char *info)
> +{
> + substring_t args[MAX_OPT_ARGS];
> + char *p;
> +
> + ctx->pss_hash = NULL;
> + ctx->mgf1_hash = NULL;
> + ctx->salt_len = 0;
> +
> + while ((p = strsep(&info, " \t"))) {
> + if (*p == '\0' || *p == ' ' || *p == '\t')
> + continue;
> +
> + switch (match_token(p, rsassa_pss_verify_params, args)) {
> + case rsassa_pss_verify_hash_algo:
> + *args[0].to = 0;
> + ctx->pss_hash = args[0].from;
> + break;
> + case rsassa_pss_verify_pss_mask:
> + if (memcmp(args[0].from, "mgf1", 4) != 0)
> + return -ENOPKG;
> + if (args[0].from[4] != ',')
> + return -EINVAL;
> + args[0].from += 5;
> + if (args[0].from >= args[0].to)
> + return -EINVAL;
> + *args[0].to = 0;
> + ctx->mgf1_hash = args[0].from;
> + break;
> + case rsassa_pss_verify_pss_salt:
> + if (match_uint(&args[0], &ctx->salt_len) < 0)
> + return -EINVAL;
> + break;
> + default:
> + pr_debug("Unknown info param\n");
> + return -EINVAL; /* Ignoring it might be better. */
> + }
> + }
> +
> + if (!ctx->pss_hash ||
> + !ctx->mgf1_hash ||
> + !ctx->salt_len)
> + return -EINVAL;
> + return 0;
> +}
> +
> +/*
> + * Perform mask = MGF1(mgfSeed, masklen) - RFC8017 appendix B.2.1.
> + */
> +static int MGF1(struct rsassa_pss_ctx *ctx,
> + const u8 *mgfSeed, unsigned int mgfSeed_len,
> + u8 *mask, unsigned int maskLen)
> +{
> + unsigned int counter, count_to, hLen, T_len;
> + __be32 *C;
> + int err;
> + u8 *T, *t, *to_hash;
> +
> + struct crypto_shash *hash_tfm __free(crypto_free_shash) =
> + crypto_alloc_shash(ctx->mgf1_hash, 0, 0);
> + if (IS_ERR(hash_tfm))
> + return PTR_ERR(hash_tfm);
> +
> + hLen = crypto_shash_digestsize(hash_tfm);
> + count_to = DIV_ROUND_UP(maskLen, hLen);
> + T_len = hLen * count_to;
> +
> + struct shash_desc *Hash __free(kfree) =
> + kmalloc(roundup(sizeof(struct shash_desc) +
> + crypto_shash_descsize(hash_tfm), 64) +
> + roundup(T_len, 64) + /* T */
> + roundup(mgfSeed_len + 4, 64), /* mgfSeed||C */
> + GFP_KERNEL);
> + if (!Hash)
> + return -ENOMEM;
> +
> + Hash->tfm = hash_tfm;
> +
> + /* 2: Let T be the empty octet string. */
> + T = (void *)Hash +
> + roundup(sizeof(struct shash_desc) +
> + crypto_shash_descsize(hash_tfm), 64);
> +
> + /* 3: Generate the mask. */
> + to_hash = T + roundup(T_len, 64);
> + memcpy(to_hash, mgfSeed, mgfSeed_len);
> + C = (__be32 *)(to_hash + mgfSeed_len);
> +
> + t = T;
> + for (counter = 0; counter < count_to; counter++) {
> + /* 3A: C = I2OSP(counter, 4). */
> + put_unaligned_be32(counter, C);
> +
> + /* 3B: T = T || Hash(mgfSeed || C). */
> + err = crypto_shash_digest(Hash, to_hash, mgfSeed_len + 4, t);
> + if (err < 0)
> + return err;
> +
> + t += hLen;
> + }
> +
> + /* 4: Output T to mask */
> + memcpy(mask, T, maskLen);
> + return 0;
> +}
> +
> +/*
> + * Perform EMSA-PSS-VERIFY(M, EM, emBits) - RFC8017 sec 9.1.2.
> + */
> +static int emsa_pss_verify(struct rsassa_pss_ctx *ctx,
> + const u8 *M, unsigned int M_len,
> + const u8 *EM, unsigned int emLen)
> +{
> + unsigned int emBits, hLen, sLen, DB_len;
> + const u8 *maskedDB, *H;
> + u8 *mHash, *dbMask, *DB, *salt, *Mprime, *Hprime;
> + int err, i;
> +
> + emBits = 8 - fls(EM[0]);
> + emBits = emLen * 8 - emBits;
> +
> + struct crypto_shash *hash_tfm __free(crypto_free_shash) =
> + crypto_alloc_shash(ctx->pss_hash, 0, 0);
> + if (IS_ERR(hash_tfm))
> + return PTR_ERR(hash_tfm);
> +
> + hLen = crypto_shash_digestsize(hash_tfm);
> + sLen = ctx->salt_len;
> +
> + if (sLen > 65536 ||
> + emBits < 8 * (hLen + sLen) + 9)
> + return -EBADMSG;
> +
> + DB_len = emLen - hLen - 1;
> +
> + struct shash_desc *Hash __free(kfree) =
> + kmalloc(roundup(sizeof(struct shash_desc) +
> + crypto_shash_descsize(hash_tfm), 64) +
> + roundup(hLen, 64) + /* mHash */
> + roundup(DB_len, 64) + /* DB and dbMask */
> + roundup(8 + hLen + sLen, 64) + /* M' */
> + roundup(hLen, 64), /* H' */
> + GFP_KERNEL);
> + if (!Hash)
> + return -ENOMEM;
> +
> + Hash->tfm = hash_tfm;
> +
> + mHash = (void *)Hash +
> + roundup(sizeof(struct shash_desc) +
> + crypto_shash_descsize(hash_tfm), 64);
> + DB = dbMask = mHash + roundup(hLen, 64);
> + Mprime = dbMask + roundup(DB_len, 64);
> + Hprime = Mprime + roundup(8 + hLen + sLen, 64);
> +
> + /* 1. Check len M against hash input limitation. */
> + /* The standard says ~2EiB for SHA1, so I think we can ignore this. */
> +
> + /* 2. mHash = Hash(M).
> + * In theory, we would do:
> + * err = crypto_shash_digest(Hash, M, M_len, mHash);
> + * but the caller is assumed to already have done that for us.
> + */
> + if (M_len != hLen)
> + return -EINVAL;
> + memcpy(mHash, M, hLen);
> +
> + /* 3. Check emLen against hLen + sLen + 2. */
> + if (emLen < hLen + sLen + 2)
> + return -EBADMSG;
> +
> + /* 4. Validate EM. */
> + if (EM[emLen - 1] != 0xbc)
> + return -EKEYREJECTED;
> +
> + /* 5. Pick maskedDB and H. */
> + maskedDB = EM;
> + H = EM + DB_len;
> +
> + /* 6. Check leftmost 8emLen-emBits bits of maskedDB are 0. */
> + /* Can only find emBits by counting the zeros on the Left. */
> +
> + /* 7. Let dbMask = MGF(H, emLen - hLen - 1). */
> + err = MGF1(ctx, H, hLen, dbMask, DB_len);
> + if (err < 0)
> + return err;
> +
> + /* 8. Let DB = maskedDB XOR dbMask. */
> + for (i = 0; i < DB_len; i++)
> + DB[i] = maskedDB[i] ^ dbMask[i];
> +
> + /* 9. Set leftmost bits in DB to zero. */
> + int z = 8 * emLen - emBits;
> +
> + if (z > 0) {
> + if (z >= 8) {
> + DB[0] = 0;
> + } else {
> + z = 8 - z;
> + DB[0] &= (1 << z) - 1;
> + }
> + }
> +
> + /* 10. Check the left part of DB is {0,0,...,1}. */
> + for (i = 0; i < emLen - hLen - sLen - 2; i++)
> + if (DB[i] != 0)
> + return -EKEYREJECTED;
> + if (DB[i] != 0x01)
> + return -EKEYREJECTED;
> +
> + /* 11. Let salt be the last sLen octets of DB. */
> + salt = DB + DB_len - sLen;
> +
> + /* 12. Let M' be 00 00 00 00 00 00 00 00 || mHash || salt. */
> + memset(Mprime, 0, 8);
> + memcpy(Mprime + 8, mHash, hLen);
> + memcpy(Mprime + 8 + hLen, salt, sLen);
> +
> + /* 13. Let H' = Hash(M'). */
> + err = crypto_shash_digest(Hash, Mprime, 8 + hLen + sLen, Hprime);
> + if (err < 0)
> + return err;
> +
> + /* 14. Check H = H'. */
> + if (memcmp(H, Hprime, hLen) != 0)
> + return -EKEYREJECTED;
> + return 0;
> +}
> +
> +/*
> + * Perform RSASSA-PSS-VERIFY((n,e),M,S) - RFC8017 sec 8.1.2.
> + */
> +static int rsassa_pss_verify(struct crypto_sig *tfm,
> + const void *src, unsigned int slen,
> + const void *digest, unsigned int dlen,
> + const char *info)
> +{
> + struct rsassa_pss_ctx *ctx = crypto_sig_ctx(tfm);
> + struct crypto_wait cwait;
> + struct scatterlist sg;
> + unsigned int rsa_reqsize = crypto_akcipher_reqsize(ctx->rsa);
> + u8 *EM;
> + int err;
> +
> + if (!info)
> + return -EINVAL;
> +
> + char *str __free(kfree) = kstrdup(info, GFP_KERNEL);
> + if (!str)
> + return -ENOMEM;
> +
> + err = rsassa_pss_vinfo_parse(ctx, str);
> + if (err < 0)
> + return err;
> +
> + /* RFC8017 sec 8.1.2 step 1 - length checking */
> + if (!ctx->key_size || slen != ctx->key_size)
> + return -EINVAL;
> +
> + /* RFC8017 sec 8.1.2 step 2 - RSA verification */
> + struct akcipher_request *rsa_req __free(kfree) =
> + kmalloc(sizeof(*rsa_req) + rsa_reqsize + ctx->key_size,
> + GFP_KERNEL);
> + if (!rsa_req)
> + return -ENOMEM;
> +
> + EM = (u8 *)(rsa_req + 1) + rsa_reqsize;
> + memcpy(EM, src, slen);
> +
> + crypto_init_wait(&cwait);
> + sg_init_one(&sg, EM, slen);
> + akcipher_request_set_tfm(rsa_req, ctx->rsa);
> + akcipher_request_set_crypt(rsa_req, &sg, &sg, slen, slen);
> + akcipher_request_set_callback(rsa_req, CRYPTO_TFM_REQ_MAY_SLEEP,
> + crypto_req_done, &cwait);
> +
> + err = crypto_akcipher_encrypt(rsa_req);
> + err = crypto_wait_req(err, &cwait);
> + if (err)
> + return err;
> +
> + /* RFC 8017 sec 8.1.2 step 3 - EMSA-PSS(M, EM, modbits-1) */
> + return emsa_pss_verify(ctx, digest, dlen, EM, slen);
> +}
> +
> +static unsigned int rsassa_pss_key_size(struct crypto_sig *tfm)
> +{
> + struct rsassa_pss_ctx *ctx = crypto_sig_ctx(tfm);
> +
> + return ctx->key_size * BITS_PER_BYTE;
> +}
> +
> +static int rsassa_pss_set_pub_key(struct crypto_sig *tfm,
> + const void *key, unsigned int keylen)
> +{
> + struct rsassa_pss_ctx *ctx = crypto_sig_ctx(tfm);
> +
> + return rsa_set_key(ctx->rsa, &ctx->key_size, RSA_PUB, key, keylen);
> +}
> +
> +static int rsassa_pss_init_tfm(struct crypto_sig *tfm)
> +{
> + struct crypto_akcipher *rsa;
> + struct rsassa_pss_ctx *ctx = crypto_sig_ctx(tfm);
> +
> + rsa = crypto_alloc_akcipher("rsa", 0, 0);
> + if (IS_ERR(rsa))
> + return PTR_ERR(rsa);
> +
> + ctx->rsa = rsa;
> + return 0;
> +}
> +
> +static void rsassa_pss_exit_tfm(struct crypto_sig *tfm)
> +{
> + struct rsassa_pss_ctx *ctx = crypto_sig_ctx(tfm);
> +
> + crypto_free_akcipher(ctx->rsa);
> +}
> +
> +struct sig_alg rsassa_pss_alg = {
> + .verify = rsassa_pss_verify,
> + .set_pub_key = rsassa_pss_set_pub_key,
> + .key_size = rsassa_pss_key_size,
> + .init = rsassa_pss_init_tfm,
> + .exit = rsassa_pss_exit_tfm,
> + .base = {
> + .cra_name = "rsassa-pss",
> + .cra_driver_name = "rsassa-pss-generic",
> + .cra_priority = 100,
> + .cra_module = THIS_MODULE,
> + .cra_ctxsize = sizeof(struct rsassa_pss_ctx),
> + },
> +};
> +
> +MODULE_ALIAS_CRYPTO("rsassa-pss");
> diff --git a/include/crypto/hash.h b/include/crypto/hash.h
> index 586700332c73..49b1ea5cf78d 100644
> --- a/include/crypto/hash.h
> +++ b/include/crypto/hash.h
> @@ -779,6 +779,9 @@ static inline void crypto_free_shash(struct crypto_shash *tfm)
> crypto_destroy_tfm(tfm, crypto_shash_tfm(tfm));
> }
>
> +DEFINE_FREE(crypto_free_shash, struct crypto_shash*,
> + if (!IS_ERR_OR_NULL(_T)) { crypto_free_shash(_T); });
> +
> static inline const char *crypto_shash_alg_name(struct crypto_shash *tfm)
> {
> return crypto_tfm_alg_name(crypto_shash_tfm(tfm));
> diff --git a/include/crypto/internal/rsa.h b/include/crypto/internal/rsa.h
> index 071a1951b992..d7f38a273949 100644
> --- a/include/crypto/internal/rsa.h
> +++ b/include/crypto/internal/rsa.h
> @@ -83,4 +83,6 @@ static inline int rsa_set_key(struct crypto_akcipher *child,
>
> extern struct crypto_template rsa_pkcs1pad_tmpl;
> extern struct crypto_template rsassa_pkcs1_tmpl;
> +extern struct sig_alg rsassa_pss_alg;
> +
> #endif
>
^ permalink raw reply [flat|nested] 20+ messages in thread
* [PATCH v12 08/10] pkcs7, x509: Add RSASSA-PSS support
2026-01-15 21:50 [PATCH v12 00/10] x509, pkcs7, crypto: Add ML-DSA and RSASSA-PSS signing David Howells
` (6 preceding siblings ...)
2026-01-15 21:50 ` [PATCH v12 07/10] crypto: Add RSASSA-PSS support David Howells
@ 2026-01-15 21:50 ` David Howells
2026-01-20 14:39 ` Ignat Korchagin
2026-01-15 21:50 ` [PATCH v12 09/10] modsign: Enable RSASSA-PSS module signing David Howells
2026-01-15 21:50 ` [PATCH v12 10/10] x509, pkcs7: Limit crypto combinations that may be used for " David Howells
9 siblings, 1 reply; 20+ messages in thread
From: David Howells @ 2026-01-15 21:50 UTC (permalink / raw)
To: Lukas Wunner, Ignat Korchagin
Cc: David Howells, Jarkko Sakkinen, Herbert Xu, Eric Biggers,
Luis Chamberlain, Petr Pavlu, Daniel Gomez, Sami Tolvanen,
Jason A . Donenfeld, Ard Biesheuvel, Stephan Mueller,
linux-crypto, keyrings, linux-modules, linux-kernel
Add support for RSASSA-PSS keys and signatures to the PKCS#7 and X.509
implementations. This requires adding support for algorithm parameters for
keys and signatures as RSASSA-PSS needs metadata. The ASN.1 encoded data
is converted into a printable key=value list string and passed to the
verification code.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Lukas Wunner <lukas@wunner.de>
cc: Ignat Korchagin <ignat@cloudflare.com>
cc: Herbert Xu <herbert@gondor.apana.org.au>
cc: keyrings@vger.kernel.org
cc: linux-crypto@vger.kernel.org
---
crypto/asymmetric_keys/Makefile | 12 +-
crypto/asymmetric_keys/mgf1_params.asn1 | 12 ++
crypto/asymmetric_keys/pkcs7.asn1 | 2 +-
crypto/asymmetric_keys/pkcs7_parser.c | 114 +++++-----
crypto/asymmetric_keys/public_key.c | 10 +
crypto/asymmetric_keys/rsassa_params.asn1 | 25 +++
crypto/asymmetric_keys/rsassa_parser.c | 240 ++++++++++++++++++++++
crypto/asymmetric_keys/rsassa_parser.h | 25 +++
crypto/asymmetric_keys/x509.asn1 | 2 +-
crypto/asymmetric_keys/x509_cert_parser.c | 100 ++++-----
crypto/asymmetric_keys/x509_parser.h | 45 +++-
crypto/asymmetric_keys/x509_public_key.c | 36 +++-
include/linux/oid_registry.h | 2 +
13 files changed, 503 insertions(+), 122 deletions(-)
create mode 100644 crypto/asymmetric_keys/mgf1_params.asn1
create mode 100644 crypto/asymmetric_keys/rsassa_params.asn1
create mode 100644 crypto/asymmetric_keys/rsassa_parser.c
create mode 100644 crypto/asymmetric_keys/rsassa_parser.h
diff --git a/crypto/asymmetric_keys/Makefile b/crypto/asymmetric_keys/Makefile
index bc65d3b98dcb..c5aed382ee8a 100644
--- a/crypto/asymmetric_keys/Makefile
+++ b/crypto/asymmetric_keys/Makefile
@@ -21,7 +21,11 @@ x509_key_parser-y := \
x509_akid.asn1.o \
x509_cert_parser.o \
x509_loader.o \
- x509_public_key.o
+ x509_public_key.o \
+ rsassa_params.asn1.o \
+ rsassa_parser.o \
+ mgf1_params.asn1.o
+
obj-$(CONFIG_FIPS_SIGNATURE_SELFTEST) += x509_selftest.o
x509_selftest-y += selftest.o
x509_selftest-$(CONFIG_FIPS_SIGNATURE_SELFTEST_RSA) += selftest_rsa.o
@@ -31,8 +35,14 @@ $(obj)/x509_cert_parser.o: \
$(obj)/x509.asn1.h \
$(obj)/x509_akid.asn1.h
+$(obj)/rsassa_parser.o: \
+ $(obj)/rsassa_params.asn1.h \
+ $(obj)/mgf1_params.asn1.h
+
$(obj)/x509.asn1.o: $(obj)/x509.asn1.c $(obj)/x509.asn1.h
$(obj)/x509_akid.asn1.o: $(obj)/x509_akid.asn1.c $(obj)/x509_akid.asn1.h
+$(obj)/rsassa_params.asn1.o: $(obj)/rsassa_params.asn1.c $(obj)/rsassa_params.asn1.h
+$(obj)/mgf1_params.asn1.o: $(obj)/mgf1_params.asn1.c $(obj)/mgf1_params.asn1.h
#
# PKCS#8 private key handling
diff --git a/crypto/asymmetric_keys/mgf1_params.asn1 b/crypto/asymmetric_keys/mgf1_params.asn1
new file mode 100644
index 000000000000..c3bc4643e72c
--- /dev/null
+++ b/crypto/asymmetric_keys/mgf1_params.asn1
@@ -0,0 +1,12 @@
+-- SPDX-License-Identifier: BSD-3-Clause
+--
+-- Copyright (C) 2009 IETF Trust and the persons identified as authors
+-- of the code
+--
+--
+-- https://datatracker.ietf.org/doc/html/rfc4055 Section 6.
+
+AlgorithmIdentifier ::= SEQUENCE {
+ algorithm OBJECT IDENTIFIER ({ mgf1_note_OID }),
+ parameters ANY OPTIONAL
+}
diff --git a/crypto/asymmetric_keys/pkcs7.asn1 b/crypto/asymmetric_keys/pkcs7.asn1
index 28e1f4a41c14..03c2248f23bc 100644
--- a/crypto/asymmetric_keys/pkcs7.asn1
+++ b/crypto/asymmetric_keys/pkcs7.asn1
@@ -124,7 +124,7 @@ UnauthenticatedAttribute ::= SEQUENCE {
DigestEncryptionAlgorithmIdentifier ::= SEQUENCE {
algorithm OBJECT IDENTIFIER ({ pkcs7_note_OID }),
- parameters ANY OPTIONAL
+ parameters ANY OPTIONAL ({ pkcs7_sig_note_algo_params })
}
EncryptedDigest ::= OCTET STRING ({ pkcs7_sig_note_signature })
diff --git a/crypto/asymmetric_keys/pkcs7_parser.c b/crypto/asymmetric_keys/pkcs7_parser.c
index 90c36fe1b5ed..47d3c1920e8f 100644
--- a/crypto/asymmetric_keys/pkcs7_parser.c
+++ b/crypto/asymmetric_keys/pkcs7_parser.c
@@ -14,6 +14,7 @@
#include <linux/oid_registry.h>
#include <crypto/public_key.h>
#include "pkcs7_parser.h"
+#include "rsassa_parser.h"
#include "pkcs7.asn1.h"
MODULE_DESCRIPTION("PKCS#7 parser");
@@ -28,14 +29,16 @@ struct pkcs7_parse_context {
struct x509_certificate **ppcerts;
unsigned long data; /* Start of data */
enum OID last_oid; /* Last OID encountered */
- unsigned x509_index;
- unsigned sinfo_index;
+ unsigned int x509_index;
+ unsigned int sinfo_index;
+ unsigned int algo_params_size;
+ const void *algo_params;
const void *raw_serial;
- unsigned raw_serial_size;
- unsigned raw_issuer_size;
+ unsigned int raw_serial_size;
+ unsigned int raw_issuer_size;
const void *raw_issuer;
const void *raw_skid;
- unsigned raw_skid_size;
+ unsigned int raw_skid_size;
bool expect_skid;
};
@@ -225,45 +228,29 @@ int pkcs7_sig_note_digest_algo(void *context, size_t hdrlen,
const void *value, size_t vlen)
{
struct pkcs7_parse_context *ctx = context;
+ const char *algo;
- switch (ctx->last_oid) {
- case OID_sha1:
- ctx->sinfo->sig->hash_algo = "sha1";
- break;
- case OID_sha256:
- ctx->sinfo->sig->hash_algo = "sha256";
- break;
- case OID_sha384:
- ctx->sinfo->sig->hash_algo = "sha384";
- break;
- case OID_sha512:
- ctx->sinfo->sig->hash_algo = "sha512";
- break;
- case OID_sha224:
- ctx->sinfo->sig->hash_algo = "sha224";
- break;
- case OID_sm3:
- ctx->sinfo->sig->hash_algo = "sm3";
- break;
- case OID_gost2012Digest256:
- ctx->sinfo->sig->hash_algo = "streebog256";
- break;
- case OID_gost2012Digest512:
- ctx->sinfo->sig->hash_algo = "streebog512";
- break;
- case OID_sha3_256:
- ctx->sinfo->sig->hash_algo = "sha3-256";
- break;
- case OID_sha3_384:
- ctx->sinfo->sig->hash_algo = "sha3-384";
- break;
- case OID_sha3_512:
- ctx->sinfo->sig->hash_algo = "sha3-512";
- break;
- default:
- printk("Unsupported digest algo: %u\n", ctx->last_oid);
+ algo = oid_to_hash(ctx->last_oid);
+ if (!algo) {
+ pr_notice("Unsupported digest algo: %u\n", ctx->last_oid);
return -ENOPKG;
}
+
+ ctx->sinfo->sig->hash_algo = algo;
+ return 0;
+}
+
+/*
+ * Note the parameters for the signature.
+ */
+int pkcs7_sig_note_algo_params(void *context, size_t hdrlen,
+ unsigned char tag,
+ const void *value, size_t vlen)
+{
+ struct pkcs7_parse_context *ctx = context;
+
+ ctx->algo_params = value - hdrlen;
+ ctx->algo_params_size = vlen + hdrlen;
return 0;
}
@@ -275,11 +262,21 @@ int pkcs7_sig_note_pkey_algo(void *context, size_t hdrlen,
const void *value, size_t vlen)
{
struct pkcs7_parse_context *ctx = context;
+ struct public_key_signature *sig = ctx->sinfo->sig;
+ int err;
switch (ctx->last_oid) {
case OID_rsaEncryption:
- ctx->sinfo->sig->pkey_algo = "rsa";
- ctx->sinfo->sig->encoding = "pkcs1";
+ sig->pkey_algo = "rsa";
+ sig->encoding = "pkcs1";
+ break;
+ case OID_id_rsassa_pss:
+ err = rsassa_parse_sig_params(sig, ctx->algo_params,
+ ctx->algo_params_size);
+ if (err < 0)
+ return err;
+ sig->pkey_algo = "rsa";
+ sig->encoding = "emsa-pss";
break;
case OID_id_ecdsa_with_sha1:
case OID_id_ecdsa_with_sha224:
@@ -289,33 +286,36 @@ int pkcs7_sig_note_pkey_algo(void *context, size_t hdrlen,
case OID_id_ecdsa_with_sha3_256:
case OID_id_ecdsa_with_sha3_384:
case OID_id_ecdsa_with_sha3_512:
- ctx->sinfo->sig->pkey_algo = "ecdsa";
- ctx->sinfo->sig->encoding = "x962";
+ sig->pkey_algo = "ecdsa";
+ sig->encoding = "x962";
break;
case OID_gost2012PKey256:
case OID_gost2012PKey512:
- ctx->sinfo->sig->pkey_algo = "ecrdsa";
- ctx->sinfo->sig->encoding = "raw";
+ sig->pkey_algo = "ecrdsa";
+ sig->encoding = "raw";
break;
case OID_id_ml_dsa_44:
- ctx->sinfo->sig->pkey_algo = "mldsa44";
- ctx->sinfo->sig->encoding = "raw";
- ctx->sinfo->sig->algo_does_hash = true;
+ sig->pkey_algo = "mldsa44";
+ sig->encoding = "raw";
+ sig->algo_does_hash = true;
break;
case OID_id_ml_dsa_65:
- ctx->sinfo->sig->pkey_algo = "mldsa65";
- ctx->sinfo->sig->encoding = "raw";
- ctx->sinfo->sig->algo_does_hash = true;
+ sig->pkey_algo = "mldsa65";
+ sig->encoding = "raw";
+ sig->algo_does_hash = true;
break;
case OID_id_ml_dsa_87:
- ctx->sinfo->sig->pkey_algo = "mldsa87";
- ctx->sinfo->sig->encoding = "raw";
- ctx->sinfo->sig->algo_does_hash = true;
+ sig->pkey_algo = "mldsa87";
+ sig->encoding = "raw";
+ sig->algo_does_hash = true;
break;
default:
- printk("Unsupported pkey algo: %u\n", ctx->last_oid);
+ pr_notice("Unsupported pkey algo: %u\n", ctx->last_oid);
return -ENOPKG;
}
+
+ ctx->algo_params = NULL;
+ ctx->algo_params_size = 0;
return 0;
}
diff --git a/crypto/asymmetric_keys/public_key.c b/crypto/asymmetric_keys/public_key.c
index 61dc4f626620..13a5616becaa 100644
--- a/crypto/asymmetric_keys/public_key.c
+++ b/crypto/asymmetric_keys/public_key.c
@@ -100,6 +100,16 @@ software_key_determine_akcipher(const struct public_key *pkey,
}
return n >= CRYPTO_MAX_ALG_NAME ? -EINVAL : 0;
}
+ if (strcmp(encoding, "emsa-pss") == 0) {
+ if (op != kernel_pkey_sign &&
+ op != kernel_pkey_verify)
+ return -EINVAL;
+ *sig = true;
+ if (!hash_algo)
+ hash_algo = "none";
+ n = snprintf(alg_name, CRYPTO_MAX_ALG_NAME, "rsassa-pss");
+ return n >= CRYPTO_MAX_ALG_NAME ? -EINVAL : 0;
+ }
if (strcmp(encoding, "raw") != 0)
return -EINVAL;
/*
diff --git a/crypto/asymmetric_keys/rsassa_params.asn1 b/crypto/asymmetric_keys/rsassa_params.asn1
new file mode 100644
index 000000000000..95a4e5f0dcd5
--- /dev/null
+++ b/crypto/asymmetric_keys/rsassa_params.asn1
@@ -0,0 +1,25 @@
+-- SPDX-License-Identifier: BSD-3-Clause
+--
+-- Copyright (C) 2009 IETF Trust and the persons identified as authors
+-- of the code
+--
+--
+-- https://datatracker.ietf.org/doc/html/rfc4055 Section 6.
+
+RSASSA-PSS-params ::= SEQUENCE {
+ hashAlgorithm [0] HashAlgorithm,
+ maskGenAlgorithm [1] MaskGenAlgorithm,
+ saltLength [2] INTEGER ({ rsassa_note_salt_length }),
+ trailerField [3] TrailerField OPTIONAL
+}
+
+TrailerField ::= INTEGER ({ rsassa_note_trailer })
+-- { trailerFieldBC(1) }
+
+HashAlgorithm ::= AlgorithmIdentifier ({ rsassa_note_hash_algo })
+MaskGenAlgorithm ::= AlgorithmIdentifier ({ rsassa_note_maskgen_algo })
+
+AlgorithmIdentifier ::= SEQUENCE {
+ algorithm OBJECT IDENTIFIER ({ rsassa_note_OID }),
+ parameters ANY OPTIONAL ({ rsassa_note_params })
+}
diff --git a/crypto/asymmetric_keys/rsassa_parser.c b/crypto/asymmetric_keys/rsassa_parser.c
new file mode 100644
index 000000000000..b80720fa94be
--- /dev/null
+++ b/crypto/asymmetric_keys/rsassa_parser.c
@@ -0,0 +1,240 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* RSASSA-PSS ASN.1 parameter parser
+ *
+ * Copyright (C) 2025 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#define pr_fmt(fmt) "RSASSA-PSS: "fmt
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/err.h>
+#include <linux/asn1.h>
+#include <crypto/hash.h>
+#include <crypto/hash_info.h>
+#include <crypto/public_key.h>
+#include "x509_parser.h"
+#include "rsassa_parser.h"
+#include "rsassa_params.asn1.h"
+#include "mgf1_params.asn1.h"
+
+struct rsassa_parse_context {
+ struct rsassa_parameters *rsassa; /* The parsed parameters */
+ unsigned long data; /* Start of data */
+ const void *params; /* Algo parameters */
+ unsigned int params_len; /* Length of algo parameters */
+ enum OID last_oid; /* Last OID encountered */
+ enum OID mgf1_last_oid; /* Last OID encountered in MGF1 */
+};
+
+/*
+ * Parse an RSASSA parameter block.
+ */
+struct rsassa_parameters *rsassa_params_parse(const void *data, size_t datalen)
+{
+ struct rsassa_parse_context ctx = {};
+ long ret;
+
+ struct rsassa_parameters *rsassa __free(kfree) =
+ kzalloc(sizeof(*rsassa), GFP_KERNEL);
+ if (!rsassa)
+ return ERR_PTR(-ENOMEM);
+
+ ctx.rsassa = rsassa;
+ ctx.data = (unsigned long)data;
+
+ /* Attempt to decode the parameters */
+ ret = asn1_ber_decoder(&rsassa_params_decoder, &ctx, data, datalen);
+ if (ret < 0) {
+ pr_debug("RSASSA parse failed %ld\n", ret);
+ return ERR_PTR(ret);
+ }
+
+ return no_free_ptr(rsassa);
+}
+
+/*
+ * Note an OID when we find one for later processing when we know how
+ * to interpret it.
+ */
+int rsassa_note_OID(void *context, size_t hdrlen, unsigned char tag,
+ const void *value, size_t vlen)
+{
+ struct rsassa_parse_context *ctx = context;
+
+ ctx->last_oid = look_up_OID(value, vlen);
+ if (ctx->last_oid == OID__NR) {
+ char buffer[56];
+
+ sprint_oid(value, vlen, buffer, sizeof(buffer));
+ pr_debug("Unknown OID: %s\n", buffer);
+ }
+ return 0;
+}
+
+/*
+ * Parse trailerField. We only accept trailerFieldBC.
+ */
+int rsassa_note_trailer(void *context, size_t hdrlen, unsigned char tag,
+ const void *value, size_t vlen)
+{
+ if (vlen != 1 || *(u8 *)value != 0x01) {
+ pr_debug("Unknown trailerField\n");
+ return -EINVAL;
+ }
+ return 0;
+}
+
+int rsassa_note_hash_algo(void *context, size_t hdrlen, unsigned char tag,
+ const void *value, size_t vlen)
+{
+ struct rsassa_parse_context *ctx = context;
+
+ ctx->rsassa->hash_algo = ctx->last_oid;
+ pr_debug("HASH-ALGO %u %u\n", ctx->rsassa->hash_algo, ctx->params_len);
+ ctx->params = NULL;
+ return 0;
+}
+
+int rsassa_note_maskgen_algo(void *context, size_t hdrlen, unsigned char tag,
+ const void *value, size_t vlen)
+{
+ struct rsassa_parse_context *ctx = context;
+ int ret;
+
+ ctx->rsassa->maskgen_algo = ctx->last_oid;
+ pr_debug("MGF-ALGO %u %u\n", ctx->rsassa->maskgen_algo, ctx->params_len);
+
+ switch (ctx->rsassa->maskgen_algo) {
+ case OID_id_mgf1:
+ if (!vlen) {
+ pr_debug("MGF1 missing parameters\n");
+ return -EBADMSG;
+ }
+
+ ret = asn1_ber_decoder(&mgf1_params_decoder, ctx,
+ ctx->params, ctx->params_len);
+ if (ret < 0) {
+ pr_debug("MGF1 parse failed %d\n", ret);
+ return ret;
+ }
+ ctx->rsassa->maskgen_hash = ctx->mgf1_last_oid;
+ break;
+
+ default:
+ pr_debug("Unsupported MaskGenAlgorithm %d\n", ret);
+ return -ENOPKG;
+ }
+
+ ctx->params = NULL;
+ return 0;
+}
+
+int rsassa_note_salt_length(void *context, size_t hdrlen, unsigned char tag,
+ const void *value, size_t vlen)
+{
+ struct rsassa_parse_context *ctx = context;
+ u32 salt_len = 0;
+
+ if (!vlen) {
+ pr_debug("Salt len bad integer\n");
+ return -EBADMSG;
+ }
+ if (vlen > 4) {
+ pr_debug("Salt len too long %zu\n", vlen);
+ return -EBADMSG;
+ }
+ if (((u8 *)value)[0] & 0x80) {
+ pr_debug("Salt len negative\n");
+ return -EBADMSG;
+ }
+
+ for (size_t i = 0; i < vlen; i++) {
+ salt_len <<= 8;
+ salt_len |= ((u8 *)value)[i];
+ }
+
+ ctx->rsassa->salt_len = salt_len;
+ pr_debug("Salt-Len %u\n", salt_len);
+ return 0;
+}
+
+/*
+ * Extract arbitrary parameters.
+ */
+int rsassa_note_params(void *context, size_t hdrlen, unsigned char tag,
+ const void *value, size_t vlen)
+{
+ struct rsassa_parse_context *ctx = context;
+
+ ctx->params = value - hdrlen;
+ ctx->params_len = vlen + hdrlen;
+ return 0;
+}
+
+/*
+ * Note an OID when we find one for later processing when we know how to
+ * interpret it.
+ */
+int mgf1_note_OID(void *context, size_t hdrlen, unsigned char tag,
+ const void *value, size_t vlen)
+{
+ struct rsassa_parse_context *ctx = context;
+
+ ctx->mgf1_last_oid = look_up_OID(value, vlen);
+ if (ctx->mgf1_last_oid == OID__NR) {
+ char buffer[56];
+
+ sprint_oid(value, vlen, buffer, sizeof(buffer));
+ pr_debug("Unknown MGF1 OID: %s\n", buffer);
+ }
+ return 0;
+}
+
+/*
+ * Parse the signature parameter block and generate a suitable info string from
+ * it.
+ */
+int rsassa_parse_sig_params(struct public_key_signature *sig,
+ const u8 *sig_params, unsigned int sig_params_size)
+{
+ const char *mf, *mh;
+
+ if (!sig_params || !sig_params_size) {
+ pr_debug("sig algo without parameters\n");
+ return -EBADMSG;
+ }
+
+ struct rsassa_parameters *rsassa __free(rsassa_params_free) =
+ rsassa_params_parse(sig_params, sig_params_size);
+ if (IS_ERR(rsassa))
+ return PTR_ERR(rsassa);
+
+ sig->hash_algo = oid_to_hash(rsassa->hash_algo);
+ if (!sig->hash_algo) {
+ pr_notice("Unsupported hash: %u\n", rsassa->hash_algo);
+ return -ENOPKG;
+ }
+
+ switch (rsassa->maskgen_algo) {
+ case OID_id_mgf1:
+ mf = "mgf1";
+ break;
+ default:
+ pr_notice("Unsupported maskgen algo: %u\n", rsassa->maskgen_algo);
+ return -ENOPKG;
+ }
+
+ mh = oid_to_hash(rsassa->maskgen_hash);
+ if (!mh) {
+ pr_notice("Unsupported MGF1 hash: %u\n", rsassa->maskgen_hash);
+ return -ENOPKG;
+ }
+
+ sig->info = kasprintf(GFP_KERNEL, "sighash=%s pss_mask=%s,%s pss_salt=%u",
+ sig->hash_algo, mf, mh, rsassa->salt_len);
+ if (!sig->info)
+ return -ENOMEM;
+ pr_debug("Info string: %s\n", sig->info);
+ return 0;
+}
diff --git a/crypto/asymmetric_keys/rsassa_parser.h b/crypto/asymmetric_keys/rsassa_parser.h
new file mode 100644
index 000000000000..b80401a3de8f
--- /dev/null
+++ b/crypto/asymmetric_keys/rsassa_parser.h
@@ -0,0 +1,25 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/* RSASSA-PSS parameter parsing context
+ *
+ * Copyright (C) 2025 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#include <linux/oid_registry.h>
+
+struct rsassa_parameters {
+ enum OID hash_algo; /* Hash algorithm identifier */
+ enum OID maskgen_algo; /* Mask gen algorithm identifier */
+ enum OID maskgen_hash; /* Mask gen hash algorithm identifier */
+ u32 salt_len;
+};
+
+struct rsassa_parameters *rsassa_params_parse(const void *data, size_t datalen);
+int rsassa_parse_sig_params(struct public_key_signature *sig,
+ const u8 *sig_params, unsigned int sig_params_size);
+
+static inline void rsassa_params_free(struct rsassa_parameters *params)
+{
+ kfree(params);
+}
+DEFINE_FREE(rsassa_params_free, struct rsassa_parameters*, rsassa_params_free(_T))
diff --git a/crypto/asymmetric_keys/x509.asn1 b/crypto/asymmetric_keys/x509.asn1
index feb9573cacce..453b72eba1fe 100644
--- a/crypto/asymmetric_keys/x509.asn1
+++ b/crypto/asymmetric_keys/x509.asn1
@@ -29,7 +29,7 @@ CertificateSerialNumber ::= INTEGER
AlgorithmIdentifier ::= SEQUENCE {
algorithm OBJECT IDENTIFIER ({ x509_note_OID }),
- parameters ANY OPTIONAL ({ x509_note_params })
+ parameters ANY OPTIONAL ({ x509_note_algo_id_params })
}
Name ::= SEQUENCE OF RelativeDistinguishedName
diff --git a/crypto/asymmetric_keys/x509_cert_parser.c b/crypto/asymmetric_keys/x509_cert_parser.c
index 5ab5b4e5f1b4..a4b848628e37 100644
--- a/crypto/asymmetric_keys/x509_cert_parser.c
+++ b/crypto/asymmetric_keys/x509_cert_parser.c
@@ -15,28 +15,7 @@
#include "x509_parser.h"
#include "x509.asn1.h"
#include "x509_akid.asn1.h"
-
-struct x509_parse_context {
- struct x509_certificate *cert; /* Certificate being constructed */
- unsigned long data; /* Start of data */
- const void *key; /* Key data */
- size_t key_size; /* Size of key data */
- const void *params; /* Key parameters */
- size_t params_size; /* Size of key parameters */
- enum OID key_algo; /* Algorithm used by the cert's key */
- enum OID last_oid; /* Last OID encountered */
- enum OID sig_algo; /* Algorithm used to sign the cert */
- u8 o_size; /* Size of organizationName (O) */
- u8 cn_size; /* Size of commonName (CN) */
- u8 email_size; /* Size of emailAddress */
- u16 o_offset; /* Offset of organizationName (O) */
- u16 cn_offset; /* Offset of commonName (CN) */
- u16 email_offset; /* Offset of emailAddress */
- unsigned raw_akid_size;
- const void *raw_akid; /* Raw authorityKeyId in ASN.1 */
- const void *akid_raw_issuer; /* Raw directoryName in authorityKeyId */
- unsigned akid_raw_issuer_size;
-};
+#include "rsassa_parser.h"
/*
* Free an X.509 certificate
@@ -60,12 +39,11 @@ EXPORT_SYMBOL_GPL(x509_free_certificate);
*/
struct x509_certificate *x509_cert_parse(const void *data, size_t datalen)
{
- struct x509_certificate *cert __free(x509_free_certificate) = NULL;
- struct x509_parse_context *ctx __free(kfree) = NULL;
struct asymmetric_key_id *kid;
long ret;
- cert = kzalloc(sizeof(struct x509_certificate), GFP_KERNEL);
+ struct x509_certificate *cert __free(x509_free_certificate) =
+ kzalloc(sizeof(struct x509_certificate), GFP_KERNEL);
if (!cert)
return ERR_PTR(-ENOMEM);
cert->pub = kzalloc(sizeof(struct public_key), GFP_KERNEL);
@@ -74,7 +52,9 @@ struct x509_certificate *x509_cert_parse(const void *data, size_t datalen)
cert->sig = kzalloc(sizeof(struct public_key_signature), GFP_KERNEL);
if (!cert->sig)
return ERR_PTR(-ENOMEM);
- ctx = kzalloc(sizeof(struct x509_parse_context), GFP_KERNEL);
+
+ struct x509_parse_context *ctx __free(kfree) =
+ kzalloc(sizeof(struct x509_parse_context), GFP_KERNEL);
if (!ctx)
return ERR_PTR(-ENOMEM);
@@ -104,15 +84,15 @@ struct x509_certificate *x509_cert_parse(const void *data, size_t datalen)
cert->pub->keylen = ctx->key_size;
- cert->pub->params = kmemdup(ctx->params, ctx->params_size, GFP_KERNEL);
+ cert->pub->params = kmemdup(ctx->key_params, ctx->key_params_size, GFP_KERNEL);
if (!cert->pub->params)
return ERR_PTR(-ENOMEM);
- cert->pub->paramlen = ctx->params_size;
+ cert->pub->paramlen = ctx->key_params_size;
cert->pub->algo = ctx->key_algo;
/* Grab the signature bits */
- ret = x509_get_sig_params(cert);
+ ret = x509_get_sig_params(cert, ctx);
if (ret < 0)
return ERR_PTR(ret);
@@ -146,7 +126,7 @@ int x509_note_OID(void *context, size_t hdrlen,
ctx->last_oid = look_up_OID(value, vlen);
if (ctx->last_oid == OID__NR) {
- char buffer[50];
+ char buffer[56];
sprint_oid(value, vlen, buffer, sizeof(buffer));
pr_debug("Unknown OID: [%lu] %s\n",
(unsigned long)value - ctx->data, buffer);
@@ -179,6 +159,7 @@ int x509_note_sig_algo(void *context, size_t hdrlen, unsigned char tag,
const void *value, size_t vlen)
{
struct x509_parse_context *ctx = context;
+ int err;
pr_debug("PubKey Algo: %u\n", ctx->last_oid);
@@ -210,6 +191,9 @@ int x509_note_sig_algo(void *context, size_t hdrlen, unsigned char tag,
ctx->cert->sig->hash_algo = "sha1";
goto ecdsa;
+ case OID_id_rsassa_pss:
+ goto rsassa_pss;
+
case OID_id_rsassa_pkcs1_v1_5_with_sha3_256:
ctx->cert->sig->hash_algo = "sha3-256";
goto rsa_pkcs1;
@@ -268,6 +252,19 @@ int x509_note_sig_algo(void *context, size_t hdrlen, unsigned char tag,
goto ml_dsa;
}
+rsassa_pss:
+ err = rsassa_parse_sig_params(ctx->cert->sig,
+ ctx->algo_params, ctx->algo_params_size);
+ if (err < 0)
+ return err;
+
+ ctx->cert->sig->pkey_algo = "rsa";
+ ctx->cert->sig->encoding = "emsa-pss";
+ ctx->sig_algo = ctx->last_oid;
+ ctx->algo_params = NULL;
+ ctx->algo_params_size = 0;
+ return 0;
+
rsa_pkcs1:
ctx->cert->sig->pkey_algo = "rsa";
ctx->cert->sig->encoding = "pkcs1";
@@ -324,8 +321,8 @@ int x509_note_signature(void *context, size_t hdrlen,
vlen--;
}
- ctx->cert->raw_sig = value;
- ctx->cert->raw_sig_size = vlen;
+ ctx->sig = value;
+ ctx->sig_size = vlen;
return 0;
}
@@ -479,23 +476,16 @@ int x509_note_subject(void *context, size_t hdrlen,
}
/*
- * Extract the parameters for the public key
+ * Extract the parameters for an AlgorithmIdentifier.
*/
-int x509_note_params(void *context, size_t hdrlen,
- unsigned char tag,
- const void *value, size_t vlen)
+int x509_note_algo_id_params(void *context, size_t hdrlen,
+ unsigned char tag,
+ const void *value, size_t vlen)
{
struct x509_parse_context *ctx = context;
- /*
- * AlgorithmIdentifier is used three times in the x509, we should skip
- * first and ignore third, using second one which is after subject and
- * before subjectPublicKey.
- */
- if (!ctx->cert->raw_subject || ctx->key)
- return 0;
- ctx->params = value - hdrlen;
- ctx->params_size = vlen + hdrlen;
+ ctx->algo_params = value - hdrlen;
+ ctx->algo_params_size = vlen + hdrlen;
return 0;
}
@@ -514,12 +504,28 @@ int x509_extract_key_data(void *context, size_t hdrlen,
case OID_rsaEncryption:
ctx->cert->pub->pkey_algo = "rsa";
break;
+ case OID_id_rsassa_pss:
+ /* Parameters are optional for the key itself. */
+ if (ctx->algo_params_size) {
+ ctx->key_params = ctx->algo_params;
+ ctx->key_params_size = ctx->algo_params_size;
+ ctx->algo_params = NULL;
+ ctx->algo_params_size = 0;
+
+ struct rsassa_parameters *params __free(rsassa_params_free) =
+ rsassa_params_parse(ctx->key_params, ctx->key_params_size);
+ if (IS_ERR(params))
+ return PTR_ERR(params);
+ break;
+ }
+ ctx->cert->pub->pkey_algo = "rsa";
+ break;
case OID_gost2012PKey256:
case OID_gost2012PKey512:
ctx->cert->pub->pkey_algo = "ecrdsa";
break;
case OID_id_ecPublicKey:
- if (parse_OID(ctx->params, ctx->params_size, &oid) != 0)
+ if (parse_OID(ctx->algo_params, ctx->algo_params_size, &oid) != 0)
return -EBADMSG;
switch (oid) {
@@ -557,6 +563,8 @@ int x509_extract_key_data(void *context, size_t hdrlen,
return -EBADMSG;
ctx->key = value + 1;
ctx->key_size = vlen - 1;
+ ctx->algo_params = NULL;
+ ctx->algo_params_size = 0;
return 0;
}
diff --git a/crypto/asymmetric_keys/x509_parser.h b/crypto/asymmetric_keys/x509_parser.h
index 0688c222806b..578de49c37bc 100644
--- a/crypto/asymmetric_keys/x509_parser.h
+++ b/crypto/asymmetric_keys/x509_parser.h
@@ -22,18 +22,16 @@ struct x509_certificate {
time64_t valid_from;
time64_t valid_to;
const void *tbs; /* Signed data */
- unsigned tbs_size; /* Size of signed data */
- unsigned raw_sig_size; /* Size of signature */
- const void *raw_sig; /* Signature data */
+ unsigned int tbs_size; /* Size of signed data */
const void *raw_serial; /* Raw serial number in ASN.1 */
- unsigned raw_serial_size;
- unsigned raw_issuer_size;
+ unsigned int raw_serial_size;
+ unsigned int raw_issuer_size;
const void *raw_issuer; /* Raw issuer name in ASN.1 */
const void *raw_subject; /* Raw subject name in ASN.1 */
- unsigned raw_subject_size;
- unsigned raw_skid_size;
+ unsigned int raw_subject_size;
+ unsigned int raw_skid_size;
const void *raw_skid; /* Raw subjectKeyId in ASN.1 */
- unsigned index;
+ unsigned int index;
bool seen; /* Infinite recursion prevention */
bool verified;
bool self_signed; /* T if self-signed (check unsupported_sig too) */
@@ -41,6 +39,34 @@ struct x509_certificate {
bool blacklisted;
};
+struct x509_parse_context {
+ struct x509_certificate *cert; /* Certificate being constructed */
+ unsigned long data; /* Start of data */
+ const void *key; /* Key data */
+ size_t key_size; /* Size of key data */
+ const void *algo_params; /* AlgorithmIdentifier: parameters */
+ size_t algo_params_size; /* AlgorithmIdentifier: parameters size */
+ const void *key_params; /* Key parameters */
+ size_t key_params_size; /* Size of key parameters */
+ const void *sig_params; /* Signature parameters */
+ unsigned int sig_params_size; /* Size of sig parameters */
+ unsigned int sig_size; /* Size of signature */
+ const void *sig; /* Signature data */
+ enum OID key_algo; /* Algorithm used by the cert's key */
+ enum OID last_oid; /* Last OID encountered */
+ enum OID sig_algo; /* Algorithm used to sign the cert */
+ u8 o_size; /* Size of organizationName (O) */
+ u8 cn_size; /* Size of commonName (CN) */
+ u8 email_size; /* Size of emailAddress */
+ u16 o_offset; /* Offset of organizationName (O) */
+ u16 cn_offset; /* Offset of commonName (CN) */
+ u16 email_offset; /* Offset of emailAddress */
+ unsigned int raw_akid_size;
+ const void *raw_akid; /* Raw authorityKeyId in ASN.1 */
+ const void *akid_raw_issuer; /* Raw directoryName in authorityKeyId */
+ unsigned int akid_raw_issuer_size;
+};
+
/*
* x509_cert_parser.c
*/
@@ -55,5 +81,6 @@ extern int x509_decode_time(time64_t *_t, size_t hdrlen,
/*
* x509_public_key.c
*/
-extern int x509_get_sig_params(struct x509_certificate *cert);
+extern const char *oid_to_hash(enum OID oid);
+extern int x509_get_sig_params(struct x509_certificate *cert, struct x509_parse_context *parse);
extern int x509_check_for_self_signed(struct x509_certificate *cert);
diff --git a/crypto/asymmetric_keys/x509_public_key.c b/crypto/asymmetric_keys/x509_public_key.c
index 2243add11d48..4490cfa368a3 100644
--- a/crypto/asymmetric_keys/x509_public_key.c
+++ b/crypto/asymmetric_keys/x509_public_key.c
@@ -17,11 +17,32 @@
#include "asymmetric_keys.h"
#include "x509_parser.h"
+/*
+ * Translate OIDs to hash algorithm names.
+ */
+const char *oid_to_hash(enum OID oid)
+{
+ switch (oid) {
+ case OID_sha1: return "sha1";
+ case OID_sha256: return "sha256";
+ case OID_sha384: return "sha384";
+ case OID_sha512: return "sha512";
+ case OID_sha224: return "sha224";
+ case OID_sm3: return "sm3";
+ case OID_gost2012Digest256: return "streebog256";
+ case OID_gost2012Digest512: return "streebog512";
+ case OID_sha3_256: return "sha3-256";
+ case OID_sha3_384: return "sha3-384";
+ case OID_sha3_512: return "sha3-512";
+ default: return NULL;
+ }
+}
+
/*
* Set up the signature parameters in an X.509 certificate. This involves
* digesting the signed data and extracting the signature.
*/
-int x509_get_sig_params(struct x509_certificate *cert)
+int x509_get_sig_params(struct x509_certificate *cert, struct x509_parse_context *parse)
{
struct public_key_signature *sig = cert->sig;
struct crypto_shash *tfm;
@@ -31,11 +52,11 @@ int x509_get_sig_params(struct x509_certificate *cert)
pr_devel("==>%s()\n", __func__);
- sig->s = kmemdup(cert->raw_sig, cert->raw_sig_size, GFP_KERNEL);
+ sig->s = kmemdup(parse->sig, parse->sig_size, GFP_KERNEL);
if (!sig->s)
return -ENOMEM;
- sig->s_size = cert->raw_sig_size;
+ sig->s_size = parse->sig_size;
/* Allocate the hashing algorithm we're going to need and find out how
* big the hash operational data will be.
@@ -43,6 +64,7 @@ int x509_get_sig_params(struct x509_certificate *cert)
tfm = crypto_alloc_shash(sig->hash_algo, 0, 0);
if (IS_ERR(tfm)) {
if (PTR_ERR(tfm) == -ENOENT) {
+ pr_debug("Unsupported hash %s\n", sig->hash_algo);
cert->unsupported_sig = true;
return 0;
}
@@ -149,13 +171,12 @@ int x509_check_for_self_signed(struct x509_certificate *cert)
*/
static int x509_key_preparse(struct key_preparsed_payload *prep)
{
- struct x509_certificate *cert __free(x509_free_certificate) = NULL;
- struct asymmetric_key_ids *kids __free(kfree) = NULL;
char *p, *desc __free(kfree) = NULL;
const char *q;
size_t srlen, sulen;
- cert = x509_cert_parse(prep->data, prep->datalen);
+ struct x509_certificate *cert __free(x509_free_certificate) =
+ x509_cert_parse(prep->data, prep->datalen);
if (IS_ERR(cert))
return PTR_ERR(cert);
@@ -198,7 +219,8 @@ static int x509_key_preparse(struct key_preparsed_payload *prep)
p = bin2hex(p, q, srlen);
*p = 0;
- kids = kmalloc(sizeof(struct asymmetric_key_ids), GFP_KERNEL);
+ struct asymmetric_key_ids *kids __free(kfree) =
+ kmalloc(sizeof(struct asymmetric_key_ids), GFP_KERNEL);
if (!kids)
return -ENOMEM;
kids->id[0] = cert->id;
diff --git a/include/linux/oid_registry.h b/include/linux/oid_registry.h
index ebce402854de..7fe168f54a6c 100644
--- a/include/linux/oid_registry.h
+++ b/include/linux/oid_registry.h
@@ -31,6 +31,8 @@ enum OID {
/* PKCS#1 {iso(1) member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs-1(1)} */
OID_rsaEncryption, /* 1.2.840.113549.1.1.1 */
OID_sha1WithRSAEncryption, /* 1.2.840.113549.1.1.5 */
+ OID_id_mgf1, /* 1.2.840.113549.1.1.8 */
+ OID_id_rsassa_pss, /* 1.2.840.113549.1.1.10 */
OID_sha256WithRSAEncryption, /* 1.2.840.113549.1.1.11 */
OID_sha384WithRSAEncryption, /* 1.2.840.113549.1.1.12 */
OID_sha512WithRSAEncryption, /* 1.2.840.113549.1.1.13 */
^ permalink raw reply related [flat|nested] 20+ messages in thread* Re: [PATCH v12 08/10] pkcs7, x509: Add RSASSA-PSS support
2026-01-15 21:50 ` [PATCH v12 08/10] pkcs7, x509: " David Howells
@ 2026-01-20 14:39 ` Ignat Korchagin
2026-01-20 15:28 ` David Howells
0 siblings, 1 reply; 20+ messages in thread
From: Ignat Korchagin @ 2026-01-20 14:39 UTC (permalink / raw)
To: David Howells
Cc: Lukas Wunner, Jarkko Sakkinen, Herbert Xu, Eric Biggers,
Luis Chamberlain, Petr Pavlu, Daniel Gomez, Sami Tolvanen,
Jason A . Donenfeld, Ard Biesheuvel, Stephan Mueller,
linux-crypto, keyrings, linux-modules, linux-kernel
Hi David,
On Thu, Jan 15, 2026 at 9:52 PM David Howells <dhowells@redhat.com> wrote:
>
> Add support for RSASSA-PSS keys and signatures to the PKCS#7 and X.509
> implementations. This requires adding support for algorithm parameters for
> keys and signatures as RSASSA-PSS needs metadata. The ASN.1 encoded data
> is converted into a printable key=value list string and passed to the
> verification code.
>
> Signed-off-by: David Howells <dhowells@redhat.com>
> cc: Lukas Wunner <lukas@wunner.de>
> cc: Ignat Korchagin <ignat@cloudflare.com>
> cc: Herbert Xu <herbert@gondor.apana.org.au>
> cc: keyrings@vger.kernel.org
> cc: linux-crypto@vger.kernel.org
> ---
> crypto/asymmetric_keys/Makefile | 12 +-
> crypto/asymmetric_keys/mgf1_params.asn1 | 12 ++
> crypto/asymmetric_keys/pkcs7.asn1 | 2 +-
> crypto/asymmetric_keys/pkcs7_parser.c | 114 +++++-----
> crypto/asymmetric_keys/public_key.c | 10 +
> crypto/asymmetric_keys/rsassa_params.asn1 | 25 +++
> crypto/asymmetric_keys/rsassa_parser.c | 240 ++++++++++++++++++++++
> crypto/asymmetric_keys/rsassa_parser.h | 25 +++
> crypto/asymmetric_keys/x509.asn1 | 2 +-
> crypto/asymmetric_keys/x509_cert_parser.c | 100 ++++-----
> crypto/asymmetric_keys/x509_parser.h | 45 +++-
> crypto/asymmetric_keys/x509_public_key.c | 36 +++-
> include/linux/oid_registry.h | 2 +
> 13 files changed, 503 insertions(+), 122 deletions(-)
> create mode 100644 crypto/asymmetric_keys/mgf1_params.asn1
> create mode 100644 crypto/asymmetric_keys/rsassa_params.asn1
> create mode 100644 crypto/asymmetric_keys/rsassa_parser.c
> create mode 100644 crypto/asymmetric_keys/rsassa_parser.h
>
> diff --git a/crypto/asymmetric_keys/Makefile b/crypto/asymmetric_keys/Makefile
> index bc65d3b98dcb..c5aed382ee8a 100644
> --- a/crypto/asymmetric_keys/Makefile
> +++ b/crypto/asymmetric_keys/Makefile
> @@ -21,7 +21,11 @@ x509_key_parser-y := \
> x509_akid.asn1.o \
> x509_cert_parser.o \
> x509_loader.o \
> - x509_public_key.o
> + x509_public_key.o \
> + rsassa_params.asn1.o \
> + rsassa_parser.o \
> + mgf1_params.asn1.o
> +
> obj-$(CONFIG_FIPS_SIGNATURE_SELFTEST) += x509_selftest.o
> x509_selftest-y += selftest.o
> x509_selftest-$(CONFIG_FIPS_SIGNATURE_SELFTEST_RSA) += selftest_rsa.o
> @@ -31,8 +35,14 @@ $(obj)/x509_cert_parser.o: \
> $(obj)/x509.asn1.h \
> $(obj)/x509_akid.asn1.h
>
> +$(obj)/rsassa_parser.o: \
> + $(obj)/rsassa_params.asn1.h \
> + $(obj)/mgf1_params.asn1.h
> +
> $(obj)/x509.asn1.o: $(obj)/x509.asn1.c $(obj)/x509.asn1.h
> $(obj)/x509_akid.asn1.o: $(obj)/x509_akid.asn1.c $(obj)/x509_akid.asn1.h
> +$(obj)/rsassa_params.asn1.o: $(obj)/rsassa_params.asn1.c $(obj)/rsassa_params.asn1.h
> +$(obj)/mgf1_params.asn1.o: $(obj)/mgf1_params.asn1.c $(obj)/mgf1_params.asn1.h
>
> #
> # PKCS#8 private key handling
> diff --git a/crypto/asymmetric_keys/mgf1_params.asn1 b/crypto/asymmetric_keys/mgf1_params.asn1
> new file mode 100644
> index 000000000000..c3bc4643e72c
> --- /dev/null
> +++ b/crypto/asymmetric_keys/mgf1_params.asn1
> @@ -0,0 +1,12 @@
> +-- SPDX-License-Identifier: BSD-3-Clause
> +--
> +-- Copyright (C) 2009 IETF Trust and the persons identified as authors
> +-- of the code
> +--
> +--
> +-- https://datatracker.ietf.org/doc/html/rfc4055 Section 6.
> +
> +AlgorithmIdentifier ::= SEQUENCE {
> + algorithm OBJECT IDENTIFIER ({ mgf1_note_OID }),
> + parameters ANY OPTIONAL
> +}
> diff --git a/crypto/asymmetric_keys/pkcs7.asn1 b/crypto/asymmetric_keys/pkcs7.asn1
> index 28e1f4a41c14..03c2248f23bc 100644
> --- a/crypto/asymmetric_keys/pkcs7.asn1
> +++ b/crypto/asymmetric_keys/pkcs7.asn1
> @@ -124,7 +124,7 @@ UnauthenticatedAttribute ::= SEQUENCE {
>
> DigestEncryptionAlgorithmIdentifier ::= SEQUENCE {
> algorithm OBJECT IDENTIFIER ({ pkcs7_note_OID }),
> - parameters ANY OPTIONAL
> + parameters ANY OPTIONAL ({ pkcs7_sig_note_algo_params })
> }
>
> EncryptedDigest ::= OCTET STRING ({ pkcs7_sig_note_signature })
> diff --git a/crypto/asymmetric_keys/pkcs7_parser.c b/crypto/asymmetric_keys/pkcs7_parser.c
> index 90c36fe1b5ed..47d3c1920e8f 100644
> --- a/crypto/asymmetric_keys/pkcs7_parser.c
> +++ b/crypto/asymmetric_keys/pkcs7_parser.c
> @@ -14,6 +14,7 @@
> #include <linux/oid_registry.h>
> #include <crypto/public_key.h>
> #include "pkcs7_parser.h"
> +#include "rsassa_parser.h"
> #include "pkcs7.asn1.h"
>
> MODULE_DESCRIPTION("PKCS#7 parser");
> @@ -28,14 +29,16 @@ struct pkcs7_parse_context {
> struct x509_certificate **ppcerts;
> unsigned long data; /* Start of data */
> enum OID last_oid; /* Last OID encountered */
> - unsigned x509_index;
> - unsigned sinfo_index;
> + unsigned int x509_index;
> + unsigned int sinfo_index;
> + unsigned int algo_params_size;
> + const void *algo_params;
> const void *raw_serial;
> - unsigned raw_serial_size;
> - unsigned raw_issuer_size;
> + unsigned int raw_serial_size;
> + unsigned int raw_issuer_size;
> const void *raw_issuer;
> const void *raw_skid;
> - unsigned raw_skid_size;
> + unsigned int raw_skid_size;
> bool expect_skid;
> };
>
> @@ -225,45 +228,29 @@ int pkcs7_sig_note_digest_algo(void *context, size_t hdrlen,
> const void *value, size_t vlen)
> {
> struct pkcs7_parse_context *ctx = context;
> + const char *algo;
>
> - switch (ctx->last_oid) {
> - case OID_sha1:
> - ctx->sinfo->sig->hash_algo = "sha1";
> - break;
> - case OID_sha256:
> - ctx->sinfo->sig->hash_algo = "sha256";
> - break;
> - case OID_sha384:
> - ctx->sinfo->sig->hash_algo = "sha384";
> - break;
> - case OID_sha512:
> - ctx->sinfo->sig->hash_algo = "sha512";
> - break;
> - case OID_sha224:
> - ctx->sinfo->sig->hash_algo = "sha224";
> - break;
> - case OID_sm3:
> - ctx->sinfo->sig->hash_algo = "sm3";
> - break;
> - case OID_gost2012Digest256:
> - ctx->sinfo->sig->hash_algo = "streebog256";
> - break;
> - case OID_gost2012Digest512:
> - ctx->sinfo->sig->hash_algo = "streebog512";
> - break;
> - case OID_sha3_256:
> - ctx->sinfo->sig->hash_algo = "sha3-256";
> - break;
> - case OID_sha3_384:
> - ctx->sinfo->sig->hash_algo = "sha3-384";
> - break;
> - case OID_sha3_512:
> - ctx->sinfo->sig->hash_algo = "sha3-512";
> - break;
> - default:
> - printk("Unsupported digest algo: %u\n", ctx->last_oid);
> + algo = oid_to_hash(ctx->last_oid);
> + if (!algo) {
> + pr_notice("Unsupported digest algo: %u\n", ctx->last_oid);
> return -ENOPKG;
> }
> +
> + ctx->sinfo->sig->hash_algo = algo;
> + return 0;
> +}
> +
> +/*
> + * Note the parameters for the signature.
> + */
> +int pkcs7_sig_note_algo_params(void *context, size_t hdrlen,
> + unsigned char tag,
> + const void *value, size_t vlen)
> +{
> + struct pkcs7_parse_context *ctx = context;
> +
> + ctx->algo_params = value - hdrlen;
> + ctx->algo_params_size = vlen + hdrlen;
> return 0;
> }
>
> @@ -275,11 +262,21 @@ int pkcs7_sig_note_pkey_algo(void *context, size_t hdrlen,
> const void *value, size_t vlen)
> {
> struct pkcs7_parse_context *ctx = context;
> + struct public_key_signature *sig = ctx->sinfo->sig;
> + int err;
>
> switch (ctx->last_oid) {
> case OID_rsaEncryption:
> - ctx->sinfo->sig->pkey_algo = "rsa";
> - ctx->sinfo->sig->encoding = "pkcs1";
> + sig->pkey_algo = "rsa";
> + sig->encoding = "pkcs1";
> + break;
> + case OID_id_rsassa_pss:
> + err = rsassa_parse_sig_params(sig, ctx->algo_params,
> + ctx->algo_params_size);
> + if (err < 0)
> + return err;
> + sig->pkey_algo = "rsa";
> + sig->encoding = "emsa-pss";
> break;
> case OID_id_ecdsa_with_sha1:
> case OID_id_ecdsa_with_sha224:
> @@ -289,33 +286,36 @@ int pkcs7_sig_note_pkey_algo(void *context, size_t hdrlen,
> case OID_id_ecdsa_with_sha3_256:
> case OID_id_ecdsa_with_sha3_384:
> case OID_id_ecdsa_with_sha3_512:
> - ctx->sinfo->sig->pkey_algo = "ecdsa";
> - ctx->sinfo->sig->encoding = "x962";
> + sig->pkey_algo = "ecdsa";
> + sig->encoding = "x962";
> break;
> case OID_gost2012PKey256:
> case OID_gost2012PKey512:
> - ctx->sinfo->sig->pkey_algo = "ecrdsa";
> - ctx->sinfo->sig->encoding = "raw";
> + sig->pkey_algo = "ecrdsa";
> + sig->encoding = "raw";
> break;
> case OID_id_ml_dsa_44:
> - ctx->sinfo->sig->pkey_algo = "mldsa44";
> - ctx->sinfo->sig->encoding = "raw";
> - ctx->sinfo->sig->algo_does_hash = true;
> + sig->pkey_algo = "mldsa44";
> + sig->encoding = "raw";
> + sig->algo_does_hash = true;
> break;
> case OID_id_ml_dsa_65:
> - ctx->sinfo->sig->pkey_algo = "mldsa65";
> - ctx->sinfo->sig->encoding = "raw";
> - ctx->sinfo->sig->algo_does_hash = true;
> + sig->pkey_algo = "mldsa65";
> + sig->encoding = "raw";
> + sig->algo_does_hash = true;
> break;
> case OID_id_ml_dsa_87:
> - ctx->sinfo->sig->pkey_algo = "mldsa87";
> - ctx->sinfo->sig->encoding = "raw";
> - ctx->sinfo->sig->algo_does_hash = true;
> + sig->pkey_algo = "mldsa87";
> + sig->encoding = "raw";
> + sig->algo_does_hash = true;
> break;
> default:
> - printk("Unsupported pkey algo: %u\n", ctx->last_oid);
> + pr_notice("Unsupported pkey algo: %u\n", ctx->last_oid);
> return -ENOPKG;
> }
> +
> + ctx->algo_params = NULL;
> + ctx->algo_params_size = 0;
> return 0;
> }
>
> diff --git a/crypto/asymmetric_keys/public_key.c b/crypto/asymmetric_keys/public_key.c
> index 61dc4f626620..13a5616becaa 100644
> --- a/crypto/asymmetric_keys/public_key.c
> +++ b/crypto/asymmetric_keys/public_key.c
> @@ -100,6 +100,16 @@ software_key_determine_akcipher(const struct public_key *pkey,
> }
> return n >= CRYPTO_MAX_ALG_NAME ? -EINVAL : 0;
> }
> + if (strcmp(encoding, "emsa-pss") == 0) {
> + if (op != kernel_pkey_sign &&
> + op != kernel_pkey_verify)
> + return -EINVAL;
> + *sig = true;
> + if (!hash_algo)
> + hash_algo = "none";
> + n = snprintf(alg_name, CRYPTO_MAX_ALG_NAME, "rsassa-pss");
> + return n >= CRYPTO_MAX_ALG_NAME ? -EINVAL : 0;
> + }
> if (strcmp(encoding, "raw") != 0)
> return -EINVAL;
> /*
> diff --git a/crypto/asymmetric_keys/rsassa_params.asn1 b/crypto/asymmetric_keys/rsassa_params.asn1
> new file mode 100644
> index 000000000000..95a4e5f0dcd5
> --- /dev/null
> +++ b/crypto/asymmetric_keys/rsassa_params.asn1
> @@ -0,0 +1,25 @@
> +-- SPDX-License-Identifier: BSD-3-Clause
> +--
> +-- Copyright (C) 2009 IETF Trust and the persons identified as authors
> +-- of the code
> +--
> +--
> +-- https://datatracker.ietf.org/doc/html/rfc4055 Section 6.
> +
> +RSASSA-PSS-params ::= SEQUENCE {
> + hashAlgorithm [0] HashAlgorithm,
> + maskGenAlgorithm [1] MaskGenAlgorithm,
> + saltLength [2] INTEGER ({ rsassa_note_salt_length }),
> + trailerField [3] TrailerField OPTIONAL
> +}
> +
> +TrailerField ::= INTEGER ({ rsassa_note_trailer })
> +-- { trailerFieldBC(1) }
> +
> +HashAlgorithm ::= AlgorithmIdentifier ({ rsassa_note_hash_algo })
> +MaskGenAlgorithm ::= AlgorithmIdentifier ({ rsassa_note_maskgen_algo })
> +
> +AlgorithmIdentifier ::= SEQUENCE {
> + algorithm OBJECT IDENTIFIER ({ rsassa_note_OID }),
> + parameters ANY OPTIONAL ({ rsassa_note_params })
> +}
> diff --git a/crypto/asymmetric_keys/rsassa_parser.c b/crypto/asymmetric_keys/rsassa_parser.c
> new file mode 100644
> index 000000000000..b80720fa94be
> --- /dev/null
> +++ b/crypto/asymmetric_keys/rsassa_parser.c
> @@ -0,0 +1,240 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/* RSASSA-PSS ASN.1 parameter parser
> + *
> + * Copyright (C) 2025 Red Hat, Inc. All Rights Reserved.
> + * Written by David Howells (dhowells@redhat.com)
> + */
> +
> +#define pr_fmt(fmt) "RSASSA-PSS: "fmt
> +#include <linux/kernel.h>
> +#include <linux/slab.h>
> +#include <linux/err.h>
> +#include <linux/asn1.h>
> +#include <crypto/hash.h>
> +#include <crypto/hash_info.h>
> +#include <crypto/public_key.h>
> +#include "x509_parser.h"
> +#include "rsassa_parser.h"
> +#include "rsassa_params.asn1.h"
> +#include "mgf1_params.asn1.h"
> +
> +struct rsassa_parse_context {
> + struct rsassa_parameters *rsassa; /* The parsed parameters */
> + unsigned long data; /* Start of data */
> + const void *params; /* Algo parameters */
> + unsigned int params_len; /* Length of algo parameters */
> + enum OID last_oid; /* Last OID encountered */
> + enum OID mgf1_last_oid; /* Last OID encountered in MGF1 */
> +};
> +
> +/*
> + * Parse an RSASSA parameter block.
> + */
> +struct rsassa_parameters *rsassa_params_parse(const void *data, size_t datalen)
> +{
> + struct rsassa_parse_context ctx = {};
> + long ret;
> +
> + struct rsassa_parameters *rsassa __free(kfree) =
Did you mean to use the newly added rsassa_params_free() here?
> + kzalloc(sizeof(*rsassa), GFP_KERNEL);
> + if (!rsassa)
> + return ERR_PTR(-ENOMEM);
> +
> + ctx.rsassa = rsassa;
> + ctx.data = (unsigned long)data;
> +
> + /* Attempt to decode the parameters */
> + ret = asn1_ber_decoder(&rsassa_params_decoder, &ctx, data, datalen);
> + if (ret < 0) {
> + pr_debug("RSASSA parse failed %ld\n", ret);
> + return ERR_PTR(ret);
> + }
> +
> + return no_free_ptr(rsassa);
> +}
> +
> +/*
> + * Note an OID when we find one for later processing when we know how
> + * to interpret it.
> + */
> +int rsassa_note_OID(void *context, size_t hdrlen, unsigned char tag,
> + const void *value, size_t vlen)
> +{
> + struct rsassa_parse_context *ctx = context;
> +
> + ctx->last_oid = look_up_OID(value, vlen);
> + if (ctx->last_oid == OID__NR) {
> + char buffer[56];
> +
> + sprint_oid(value, vlen, buffer, sizeof(buffer));
> + pr_debug("Unknown OID: %s\n", buffer);
> + }
> + return 0;
> +}
> +
> +/*
> + * Parse trailerField. We only accept trailerFieldBC.
> + */
> +int rsassa_note_trailer(void *context, size_t hdrlen, unsigned char tag,
> + const void *value, size_t vlen)
> +{
> + if (vlen != 1 || *(u8 *)value != 0x01) {
> + pr_debug("Unknown trailerField\n");
> + return -EINVAL;
> + }
> + return 0;
> +}
> +
> +int rsassa_note_hash_algo(void *context, size_t hdrlen, unsigned char tag,
> + const void *value, size_t vlen)
> +{
> + struct rsassa_parse_context *ctx = context;
> +
> + ctx->rsassa->hash_algo = ctx->last_oid;
> + pr_debug("HASH-ALGO %u %u\n", ctx->rsassa->hash_algo, ctx->params_len);
> + ctx->params = NULL;
> + return 0;
> +}
> +
> +int rsassa_note_maskgen_algo(void *context, size_t hdrlen, unsigned char tag,
> + const void *value, size_t vlen)
> +{
> + struct rsassa_parse_context *ctx = context;
> + int ret;
> +
> + ctx->rsassa->maskgen_algo = ctx->last_oid;
> + pr_debug("MGF-ALGO %u %u\n", ctx->rsassa->maskgen_algo, ctx->params_len);
> +
> + switch (ctx->rsassa->maskgen_algo) {
> + case OID_id_mgf1:
> + if (!vlen) {
> + pr_debug("MGF1 missing parameters\n");
> + return -EBADMSG;
> + }
> +
> + ret = asn1_ber_decoder(&mgf1_params_decoder, ctx,
> + ctx->params, ctx->params_len);
> + if (ret < 0) {
> + pr_debug("MGF1 parse failed %d\n", ret);
> + return ret;
> + }
> + ctx->rsassa->maskgen_hash = ctx->mgf1_last_oid;
> + break;
> +
> + default:
> + pr_debug("Unsupported MaskGenAlgorithm %d\n", ret);
> + return -ENOPKG;
> + }
> +
> + ctx->params = NULL;
> + return 0;
> +}
> +
> +int rsassa_note_salt_length(void *context, size_t hdrlen, unsigned char tag,
> + const void *value, size_t vlen)
> +{
> + struct rsassa_parse_context *ctx = context;
> + u32 salt_len = 0;
> +
> + if (!vlen) {
> + pr_debug("Salt len bad integer\n");
> + return -EBADMSG;
> + }
> + if (vlen > 4) {
> + pr_debug("Salt len too long %zu\n", vlen);
> + return -EBADMSG;
> + }
> + if (((u8 *)value)[0] & 0x80) {
> + pr_debug("Salt len negative\n");
> + return -EBADMSG;
> + }
> +
> + for (size_t i = 0; i < vlen; i++) {
> + salt_len <<= 8;
> + salt_len |= ((u8 *)value)[i];
> + }
> +
> + ctx->rsassa->salt_len = salt_len;
> + pr_debug("Salt-Len %u\n", salt_len);
> + return 0;
> +}
> +
> +/*
> + * Extract arbitrary parameters.
> + */
> +int rsassa_note_params(void *context, size_t hdrlen, unsigned char tag,
> + const void *value, size_t vlen)
> +{
> + struct rsassa_parse_context *ctx = context;
> +
> + ctx->params = value - hdrlen;
> + ctx->params_len = vlen + hdrlen;
> + return 0;
> +}
> +
> +/*
> + * Note an OID when we find one for later processing when we know how to
> + * interpret it.
> + */
> +int mgf1_note_OID(void *context, size_t hdrlen, unsigned char tag,
> + const void *value, size_t vlen)
> +{
> + struct rsassa_parse_context *ctx = context;
> +
> + ctx->mgf1_last_oid = look_up_OID(value, vlen);
> + if (ctx->mgf1_last_oid == OID__NR) {
> + char buffer[56];
> +
> + sprint_oid(value, vlen, buffer, sizeof(buffer));
> + pr_debug("Unknown MGF1 OID: %s\n", buffer);
> + }
> + return 0;
> +}
> +
> +/*
> + * Parse the signature parameter block and generate a suitable info string from
> + * it.
> + */
> +int rsassa_parse_sig_params(struct public_key_signature *sig,
> + const u8 *sig_params, unsigned int sig_params_size)
> +{
> + const char *mf, *mh;
> +
> + if (!sig_params || !sig_params_size) {
> + pr_debug("sig algo without parameters\n");
> + return -EBADMSG;
> + }
> +
> + struct rsassa_parameters *rsassa __free(rsassa_params_free) =
> + rsassa_params_parse(sig_params, sig_params_size);
> + if (IS_ERR(rsassa))
> + return PTR_ERR(rsassa);
> +
> + sig->hash_algo = oid_to_hash(rsassa->hash_algo);
> + if (!sig->hash_algo) {
> + pr_notice("Unsupported hash: %u\n", rsassa->hash_algo);
> + return -ENOPKG;
> + }
> +
> + switch (rsassa->maskgen_algo) {
> + case OID_id_mgf1:
> + mf = "mgf1";
> + break;
> + default:
> + pr_notice("Unsupported maskgen algo: %u\n", rsassa->maskgen_algo);
> + return -ENOPKG;
> + }
> +
> + mh = oid_to_hash(rsassa->maskgen_hash);
> + if (!mh) {
> + pr_notice("Unsupported MGF1 hash: %u\n", rsassa->maskgen_hash);
> + return -ENOPKG;
> + }
> +
> + sig->info = kasprintf(GFP_KERNEL, "sighash=%s pss_mask=%s,%s pss_salt=%u",
> + sig->hash_algo, mf, mh, rsassa->salt_len);
> + if (!sig->info)
> + return -ENOMEM;
> + pr_debug("Info string: %s\n", sig->info);
> + return 0;
> +}
> diff --git a/crypto/asymmetric_keys/rsassa_parser.h b/crypto/asymmetric_keys/rsassa_parser.h
> new file mode 100644
> index 000000000000..b80401a3de8f
> --- /dev/null
> +++ b/crypto/asymmetric_keys/rsassa_parser.h
> @@ -0,0 +1,25 @@
> +/* SPDX-License-Identifier: GPL-2.0-or-later */
> +/* RSASSA-PSS parameter parsing context
> + *
> + * Copyright (C) 2025 Red Hat, Inc. All Rights Reserved.
> + * Written by David Howells (dhowells@redhat.com)
> + */
> +
> +#include <linux/oid_registry.h>
> +
> +struct rsassa_parameters {
> + enum OID hash_algo; /* Hash algorithm identifier */
> + enum OID maskgen_algo; /* Mask gen algorithm identifier */
> + enum OID maskgen_hash; /* Mask gen hash algorithm identifier */
> + u32 salt_len;
> +};
> +
> +struct rsassa_parameters *rsassa_params_parse(const void *data, size_t datalen);
> +int rsassa_parse_sig_params(struct public_key_signature *sig,
> + const u8 *sig_params, unsigned int sig_params_size);
> +
> +static inline void rsassa_params_free(struct rsassa_parameters *params)
> +{
> + kfree(params);
> +}
> +DEFINE_FREE(rsassa_params_free, struct rsassa_parameters*, rsassa_params_free(_T))
So you use plain kfree() in one instance and this custom free
definition in another. We should probably pick one. What is the idea
behind this custom rsassa_params_free(), if it just calls into
kfree()?
> diff --git a/crypto/asymmetric_keys/x509.asn1 b/crypto/asymmetric_keys/x509.asn1
> index feb9573cacce..453b72eba1fe 100644
> --- a/crypto/asymmetric_keys/x509.asn1
> +++ b/crypto/asymmetric_keys/x509.asn1
> @@ -29,7 +29,7 @@ CertificateSerialNumber ::= INTEGER
>
> AlgorithmIdentifier ::= SEQUENCE {
> algorithm OBJECT IDENTIFIER ({ x509_note_OID }),
> - parameters ANY OPTIONAL ({ x509_note_params })
> + parameters ANY OPTIONAL ({ x509_note_algo_id_params })
> }
>
> Name ::= SEQUENCE OF RelativeDistinguishedName
> diff --git a/crypto/asymmetric_keys/x509_cert_parser.c b/crypto/asymmetric_keys/x509_cert_parser.c
> index 5ab5b4e5f1b4..a4b848628e37 100644
> --- a/crypto/asymmetric_keys/x509_cert_parser.c
> +++ b/crypto/asymmetric_keys/x509_cert_parser.c
> @@ -15,28 +15,7 @@
> #include "x509_parser.h"
> #include "x509.asn1.h"
> #include "x509_akid.asn1.h"
> -
> -struct x509_parse_context {
> - struct x509_certificate *cert; /* Certificate being constructed */
> - unsigned long data; /* Start of data */
> - const void *key; /* Key data */
> - size_t key_size; /* Size of key data */
> - const void *params; /* Key parameters */
> - size_t params_size; /* Size of key parameters */
> - enum OID key_algo; /* Algorithm used by the cert's key */
> - enum OID last_oid; /* Last OID encountered */
> - enum OID sig_algo; /* Algorithm used to sign the cert */
> - u8 o_size; /* Size of organizationName (O) */
> - u8 cn_size; /* Size of commonName (CN) */
> - u8 email_size; /* Size of emailAddress */
> - u16 o_offset; /* Offset of organizationName (O) */
> - u16 cn_offset; /* Offset of commonName (CN) */
> - u16 email_offset; /* Offset of emailAddress */
> - unsigned raw_akid_size;
> - const void *raw_akid; /* Raw authorityKeyId in ASN.1 */
> - const void *akid_raw_issuer; /* Raw directoryName in authorityKeyId */
> - unsigned akid_raw_issuer_size;
> -};
> +#include "rsassa_parser.h"
>
> /*
> * Free an X.509 certificate
> @@ -60,12 +39,11 @@ EXPORT_SYMBOL_GPL(x509_free_certificate);
> */
> struct x509_certificate *x509_cert_parse(const void *data, size_t datalen)
> {
> - struct x509_certificate *cert __free(x509_free_certificate) = NULL;
> - struct x509_parse_context *ctx __free(kfree) = NULL;
Thank you for fixing this.
> struct asymmetric_key_id *kid;
> long ret;
>
> - cert = kzalloc(sizeof(struct x509_certificate), GFP_KERNEL);
> + struct x509_certificate *cert __free(x509_free_certificate) =
> + kzalloc(sizeof(struct x509_certificate), GFP_KERNEL);
> if (!cert)
> return ERR_PTR(-ENOMEM);
> cert->pub = kzalloc(sizeof(struct public_key), GFP_KERNEL);
> @@ -74,7 +52,9 @@ struct x509_certificate *x509_cert_parse(const void *data, size_t datalen)
> cert->sig = kzalloc(sizeof(struct public_key_signature), GFP_KERNEL);
> if (!cert->sig)
> return ERR_PTR(-ENOMEM);
> - ctx = kzalloc(sizeof(struct x509_parse_context), GFP_KERNEL);
> +
> + struct x509_parse_context *ctx __free(kfree) =
> + kzalloc(sizeof(struct x509_parse_context), GFP_KERNEL);
> if (!ctx)
> return ERR_PTR(-ENOMEM);
>
> @@ -104,15 +84,15 @@ struct x509_certificate *x509_cert_parse(const void *data, size_t datalen)
>
> cert->pub->keylen = ctx->key_size;
>
> - cert->pub->params = kmemdup(ctx->params, ctx->params_size, GFP_KERNEL);
> + cert->pub->params = kmemdup(ctx->key_params, ctx->key_params_size, GFP_KERNEL);
> if (!cert->pub->params)
> return ERR_PTR(-ENOMEM);
>
> - cert->pub->paramlen = ctx->params_size;
> + cert->pub->paramlen = ctx->key_params_size;
> cert->pub->algo = ctx->key_algo;
>
> /* Grab the signature bits */
> - ret = x509_get_sig_params(cert);
> + ret = x509_get_sig_params(cert, ctx);
> if (ret < 0)
> return ERR_PTR(ret);
>
> @@ -146,7 +126,7 @@ int x509_note_OID(void *context, size_t hdrlen,
>
> ctx->last_oid = look_up_OID(value, vlen);
> if (ctx->last_oid == OID__NR) {
> - char buffer[50];
> + char buffer[56];
> sprint_oid(value, vlen, buffer, sizeof(buffer));
> pr_debug("Unknown OID: [%lu] %s\n",
> (unsigned long)value - ctx->data, buffer);
> @@ -179,6 +159,7 @@ int x509_note_sig_algo(void *context, size_t hdrlen, unsigned char tag,
> const void *value, size_t vlen)
> {
> struct x509_parse_context *ctx = context;
> + int err;
>
> pr_debug("PubKey Algo: %u\n", ctx->last_oid);
>
> @@ -210,6 +191,9 @@ int x509_note_sig_algo(void *context, size_t hdrlen, unsigned char tag,
> ctx->cert->sig->hash_algo = "sha1";
> goto ecdsa;
>
> + case OID_id_rsassa_pss:
> + goto rsassa_pss;
> +
> case OID_id_rsassa_pkcs1_v1_5_with_sha3_256:
> ctx->cert->sig->hash_algo = "sha3-256";
> goto rsa_pkcs1;
> @@ -268,6 +252,19 @@ int x509_note_sig_algo(void *context, size_t hdrlen, unsigned char tag,
> goto ml_dsa;
> }
>
> +rsassa_pss:
> + err = rsassa_parse_sig_params(ctx->cert->sig,
> + ctx->algo_params, ctx->algo_params_size);
> + if (err < 0)
> + return err;
> +
> + ctx->cert->sig->pkey_algo = "rsa";
> + ctx->cert->sig->encoding = "emsa-pss";
> + ctx->sig_algo = ctx->last_oid;
> + ctx->algo_params = NULL;
> + ctx->algo_params_size = 0;
> + return 0;
> +
> rsa_pkcs1:
> ctx->cert->sig->pkey_algo = "rsa";
> ctx->cert->sig->encoding = "pkcs1";
> @@ -324,8 +321,8 @@ int x509_note_signature(void *context, size_t hdrlen,
> vlen--;
> }
>
> - ctx->cert->raw_sig = value;
> - ctx->cert->raw_sig_size = vlen;
> + ctx->sig = value;
> + ctx->sig_size = vlen;
> return 0;
> }
>
> @@ -479,23 +476,16 @@ int x509_note_subject(void *context, size_t hdrlen,
> }
>
> /*
> - * Extract the parameters for the public key
> + * Extract the parameters for an AlgorithmIdentifier.
> */
> -int x509_note_params(void *context, size_t hdrlen,
> - unsigned char tag,
> - const void *value, size_t vlen)
> +int x509_note_algo_id_params(void *context, size_t hdrlen,
> + unsigned char tag,
> + const void *value, size_t vlen)
> {
> struct x509_parse_context *ctx = context;
>
> - /*
> - * AlgorithmIdentifier is used three times in the x509, we should skip
> - * first and ignore third, using second one which is after subject and
> - * before subjectPublicKey.
> - */
> - if (!ctx->cert->raw_subject || ctx->key)
> - return 0;
> - ctx->params = value - hdrlen;
> - ctx->params_size = vlen + hdrlen;
> + ctx->algo_params = value - hdrlen;
> + ctx->algo_params_size = vlen + hdrlen;
> return 0;
> }
>
> @@ -514,12 +504,28 @@ int x509_extract_key_data(void *context, size_t hdrlen,
> case OID_rsaEncryption:
> ctx->cert->pub->pkey_algo = "rsa";
> break;
> + case OID_id_rsassa_pss:
> + /* Parameters are optional for the key itself. */
> + if (ctx->algo_params_size) {
> + ctx->key_params = ctx->algo_params;
> + ctx->key_params_size = ctx->algo_params_size;
> + ctx->algo_params = NULL;
> + ctx->algo_params_size = 0;
> +
> + struct rsassa_parameters *params __free(rsassa_params_free) =
> + rsassa_params_parse(ctx->key_params, ctx->key_params_size);
> + if (IS_ERR(params))
> + return PTR_ERR(params);
> + break;
> + }
> + ctx->cert->pub->pkey_algo = "rsa";
> + break;
> case OID_gost2012PKey256:
> case OID_gost2012PKey512:
> ctx->cert->pub->pkey_algo = "ecrdsa";
> break;
> case OID_id_ecPublicKey:
> - if (parse_OID(ctx->params, ctx->params_size, &oid) != 0)
> + if (parse_OID(ctx->algo_params, ctx->algo_params_size, &oid) != 0)
> return -EBADMSG;
>
> switch (oid) {
> @@ -557,6 +563,8 @@ int x509_extract_key_data(void *context, size_t hdrlen,
> return -EBADMSG;
> ctx->key = value + 1;
> ctx->key_size = vlen - 1;
> + ctx->algo_params = NULL;
> + ctx->algo_params_size = 0;
> return 0;
> }
>
> diff --git a/crypto/asymmetric_keys/x509_parser.h b/crypto/asymmetric_keys/x509_parser.h
> index 0688c222806b..578de49c37bc 100644
> --- a/crypto/asymmetric_keys/x509_parser.h
> +++ b/crypto/asymmetric_keys/x509_parser.h
> @@ -22,18 +22,16 @@ struct x509_certificate {
> time64_t valid_from;
> time64_t valid_to;
> const void *tbs; /* Signed data */
> - unsigned tbs_size; /* Size of signed data */
> - unsigned raw_sig_size; /* Size of signature */
> - const void *raw_sig; /* Signature data */
> + unsigned int tbs_size; /* Size of signed data */
> const void *raw_serial; /* Raw serial number in ASN.1 */
> - unsigned raw_serial_size;
> - unsigned raw_issuer_size;
> + unsigned int raw_serial_size;
> + unsigned int raw_issuer_size;
> const void *raw_issuer; /* Raw issuer name in ASN.1 */
> const void *raw_subject; /* Raw subject name in ASN.1 */
> - unsigned raw_subject_size;
> - unsigned raw_skid_size;
> + unsigned int raw_subject_size;
> + unsigned int raw_skid_size;
> const void *raw_skid; /* Raw subjectKeyId in ASN.1 */
> - unsigned index;
> + unsigned int index;
> bool seen; /* Infinite recursion prevention */
> bool verified;
> bool self_signed; /* T if self-signed (check unsupported_sig too) */
> @@ -41,6 +39,34 @@ struct x509_certificate {
> bool blacklisted;
> };
>
> +struct x509_parse_context {
> + struct x509_certificate *cert; /* Certificate being constructed */
> + unsigned long data; /* Start of data */
> + const void *key; /* Key data */
> + size_t key_size; /* Size of key data */
> + const void *algo_params; /* AlgorithmIdentifier: parameters */
> + size_t algo_params_size; /* AlgorithmIdentifier: parameters size */
> + const void *key_params; /* Key parameters */
> + size_t key_params_size; /* Size of key parameters */
> + const void *sig_params; /* Signature parameters */
> + unsigned int sig_params_size; /* Size of sig parameters */
> + unsigned int sig_size; /* Size of signature */
> + const void *sig; /* Signature data */
> + enum OID key_algo; /* Algorithm used by the cert's key */
> + enum OID last_oid; /* Last OID encountered */
> + enum OID sig_algo; /* Algorithm used to sign the cert */
> + u8 o_size; /* Size of organizationName (O) */
> + u8 cn_size; /* Size of commonName (CN) */
> + u8 email_size; /* Size of emailAddress */
> + u16 o_offset; /* Offset of organizationName (O) */
> + u16 cn_offset; /* Offset of commonName (CN) */
> + u16 email_offset; /* Offset of emailAddress */
> + unsigned int raw_akid_size;
> + const void *raw_akid; /* Raw authorityKeyId in ASN.1 */
> + const void *akid_raw_issuer; /* Raw directoryName in authorityKeyId */
> + unsigned int akid_raw_issuer_size;
> +};
> +
> /*
> * x509_cert_parser.c
> */
> @@ -55,5 +81,6 @@ extern int x509_decode_time(time64_t *_t, size_t hdrlen,
> /*
> * x509_public_key.c
> */
> -extern int x509_get_sig_params(struct x509_certificate *cert);
> +extern const char *oid_to_hash(enum OID oid);
> +extern int x509_get_sig_params(struct x509_certificate *cert, struct x509_parse_context *parse);
> extern int x509_check_for_self_signed(struct x509_certificate *cert);
> diff --git a/crypto/asymmetric_keys/x509_public_key.c b/crypto/asymmetric_keys/x509_public_key.c
> index 2243add11d48..4490cfa368a3 100644
> --- a/crypto/asymmetric_keys/x509_public_key.c
> +++ b/crypto/asymmetric_keys/x509_public_key.c
> @@ -17,11 +17,32 @@
> #include "asymmetric_keys.h"
> #include "x509_parser.h"
>
> +/*
> + * Translate OIDs to hash algorithm names.
> + */
> +const char *oid_to_hash(enum OID oid)
> +{
> + switch (oid) {
> + case OID_sha1: return "sha1";
> + case OID_sha256: return "sha256";
> + case OID_sha384: return "sha384";
> + case OID_sha512: return "sha512";
> + case OID_sha224: return "sha224";
> + case OID_sm3: return "sm3";
> + case OID_gost2012Digest256: return "streebog256";
> + case OID_gost2012Digest512: return "streebog512";
> + case OID_sha3_256: return "sha3-256";
> + case OID_sha3_384: return "sha3-384";
> + case OID_sha3_512: return "sha3-512";
> + default: return NULL;
> + }
> +}
> +
> /*
> * Set up the signature parameters in an X.509 certificate. This involves
> * digesting the signed data and extracting the signature.
> */
> -int x509_get_sig_params(struct x509_certificate *cert)
> +int x509_get_sig_params(struct x509_certificate *cert, struct x509_parse_context *parse)
> {
> struct public_key_signature *sig = cert->sig;
> struct crypto_shash *tfm;
> @@ -31,11 +52,11 @@ int x509_get_sig_params(struct x509_certificate *cert)
>
> pr_devel("==>%s()\n", __func__);
>
> - sig->s = kmemdup(cert->raw_sig, cert->raw_sig_size, GFP_KERNEL);
> + sig->s = kmemdup(parse->sig, parse->sig_size, GFP_KERNEL);
> if (!sig->s)
> return -ENOMEM;
>
> - sig->s_size = cert->raw_sig_size;
> + sig->s_size = parse->sig_size;
>
> /* Allocate the hashing algorithm we're going to need and find out how
> * big the hash operational data will be.
> @@ -43,6 +64,7 @@ int x509_get_sig_params(struct x509_certificate *cert)
> tfm = crypto_alloc_shash(sig->hash_algo, 0, 0);
> if (IS_ERR(tfm)) {
> if (PTR_ERR(tfm) == -ENOENT) {
> + pr_debug("Unsupported hash %s\n", sig->hash_algo);
> cert->unsupported_sig = true;
> return 0;
> }
> @@ -149,13 +171,12 @@ int x509_check_for_self_signed(struct x509_certificate *cert)
> */
> static int x509_key_preparse(struct key_preparsed_payload *prep)
> {
> - struct x509_certificate *cert __free(x509_free_certificate) = NULL;
> - struct asymmetric_key_ids *kids __free(kfree) = NULL;
> char *p, *desc __free(kfree) = NULL;
> const char *q;
> size_t srlen, sulen;
>
> - cert = x509_cert_parse(prep->data, prep->datalen);
> + struct x509_certificate *cert __free(x509_free_certificate) =
> + x509_cert_parse(prep->data, prep->datalen);
> if (IS_ERR(cert))
> return PTR_ERR(cert);
>
> @@ -198,7 +219,8 @@ static int x509_key_preparse(struct key_preparsed_payload *prep)
> p = bin2hex(p, q, srlen);
> *p = 0;
>
> - kids = kmalloc(sizeof(struct asymmetric_key_ids), GFP_KERNEL);
> + struct asymmetric_key_ids *kids __free(kfree) =
> + kmalloc(sizeof(struct asymmetric_key_ids), GFP_KERNEL);
> if (!kids)
> return -ENOMEM;
> kids->id[0] = cert->id;
> diff --git a/include/linux/oid_registry.h b/include/linux/oid_registry.h
> index ebce402854de..7fe168f54a6c 100644
> --- a/include/linux/oid_registry.h
> +++ b/include/linux/oid_registry.h
> @@ -31,6 +31,8 @@ enum OID {
> /* PKCS#1 {iso(1) member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs-1(1)} */
> OID_rsaEncryption, /* 1.2.840.113549.1.1.1 */
> OID_sha1WithRSAEncryption, /* 1.2.840.113549.1.1.5 */
> + OID_id_mgf1, /* 1.2.840.113549.1.1.8 */
> + OID_id_rsassa_pss, /* 1.2.840.113549.1.1.10 */
> OID_sha256WithRSAEncryption, /* 1.2.840.113549.1.1.11 */
> OID_sha384WithRSAEncryption, /* 1.2.840.113549.1.1.12 */
> OID_sha512WithRSAEncryption, /* 1.2.840.113549.1.1.13 */
>
Ignat
^ permalink raw reply [flat|nested] 20+ messages in thread* Re: [PATCH v12 08/10] pkcs7, x509: Add RSASSA-PSS support
2026-01-20 14:39 ` Ignat Korchagin
@ 2026-01-20 15:28 ` David Howells
0 siblings, 0 replies; 20+ messages in thread
From: David Howells @ 2026-01-20 15:28 UTC (permalink / raw)
To: Ignat Korchagin
Cc: dhowells, Lukas Wunner, Jarkko Sakkinen, Herbert Xu, Eric Biggers,
Luis Chamberlain, Petr Pavlu, Daniel Gomez, Sami Tolvanen,
Jason A . Donenfeld, Ard Biesheuvel, Stephan Mueller,
linux-crypto, keyrings, linux-modules, linux-kernel
Ignat Korchagin <ignat@cloudflare.com> wrote:
> > + struct rsassa_parameters *rsassa __free(kfree) =
>
> Did you mean to use the newly added rsassa_params_free() here?
Err, yes, I should have done.
> > +DEFINE_FREE(rsassa_params_free, struct rsassa_parameters*, rsassa_params_free(_T))
>
> So you use plain kfree() in one instance and this custom free definition in
> another. We should probably pick one.
Yeah, both should have used the custom one.
> What is the idea behind this custom rsassa_params_free(), if it just calls
> into kfree()?
In case in future something freeable is added to it, it seems like a good idea
to have a destructor[*]. Other mask functions are theoretically possible, for
example.
[*] (Since we seem to be reinventing C++ ;-)
David
^ permalink raw reply [flat|nested] 20+ messages in thread
* [PATCH v12 09/10] modsign: Enable RSASSA-PSS module signing
2026-01-15 21:50 [PATCH v12 00/10] x509, pkcs7, crypto: Add ML-DSA and RSASSA-PSS signing David Howells
` (7 preceding siblings ...)
2026-01-15 21:50 ` [PATCH v12 08/10] pkcs7, x509: " David Howells
@ 2026-01-15 21:50 ` David Howells
2026-01-15 21:50 ` [PATCH v12 10/10] x509, pkcs7: Limit crypto combinations that may be used for " David Howells
9 siblings, 0 replies; 20+ messages in thread
From: David Howells @ 2026-01-15 21:50 UTC (permalink / raw)
To: Lukas Wunner, Ignat Korchagin
Cc: David Howells, Jarkko Sakkinen, Herbert Xu, Eric Biggers,
Luis Chamberlain, Petr Pavlu, Daniel Gomez, Sami Tolvanen,
Jason A . Donenfeld, Ard Biesheuvel, Stephan Mueller,
linux-crypto, keyrings, linux-modules, linux-kernel
Add support for RSASSA-PSS signatures (RFC8017) for use with module signing
and other public key cryptography done by the kernel.
Note that only signature verification is supported by the kernel.
Note further that this alters some of the same code as the MLDSA support,
so that needs to be applied first to avoid conflicts.
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Ignat Korchagin <ignat@cloudflare.com>
cc: Lukas Wunner <lukas@wunner.de>
cc: Herbert Xu <herbert@gondor.apana.org.au>
cc: keyrings@vger.kernel.org
cc: linux-crypto@vger.kernel.org
---
Documentation/admin-guide/module-signing.rst | 5 ++-
certs/Kconfig | 6 +++
certs/Makefile | 1 +
scripts/sign-file.c | 39 +++++++++++++++++++-
4 files changed, 47 insertions(+), 4 deletions(-)
diff --git a/Documentation/admin-guide/module-signing.rst b/Documentation/admin-guide/module-signing.rst
index 7f2f127dc76f..aa24715cd2d8 100644
--- a/Documentation/admin-guide/module-signing.rst
+++ b/Documentation/admin-guide/module-signing.rst
@@ -32,8 +32,9 @@ type. The built-in facility currently only supports the RSA, NIST P-384 ECDSA
and NIST FIPS-204 ML-DSA public key signing standards (though it is pluggable
and permits others to be used). For RSA and ECDSA, the possible hash
algorithms that can be used are SHA-2 and SHA-3 of sizes 256, 384, and 512 (the
-algorithm is selected by data in the signature); ML-DSA does its own hashing,
-but is allowed to be used with a SHA512 hash for signed attributes.
+algorithm is selected by data in the signature); RSASSA-PSS is allowed to use
+SHA512 only; ML-DSA does its own hashing, but is allowed to be used with a
+SHA512 hash for signed attributes.
==========================
diff --git a/certs/Kconfig b/certs/Kconfig
index 67a5786423b5..524d1747c541 100644
--- a/certs/Kconfig
+++ b/certs/Kconfig
@@ -27,6 +27,12 @@ config MODULE_SIG_KEY_TYPE_RSA
help
Use an RSA key for module signing.
+config MODULE_SIG_KEY_TYPE_RSASSA_PSS
+ bool "RSASSA-PSS"
+ select CRYPTO_RSA
+ help
+ Use an RSASSA-PSS key for module signing.
+
config MODULE_SIG_KEY_TYPE_ECDSA
bool "ECDSA"
select CRYPTO_ECDSA
diff --git a/certs/Makefile b/certs/Makefile
index 3ee1960f9f4a..3b5a3a303f4c 100644
--- a/certs/Makefile
+++ b/certs/Makefile
@@ -42,6 +42,7 @@ targets += x509_certificate_list
# boolean option and we unfortunately can't make it depend on !RANDCONFIG.
ifeq ($(CONFIG_MODULE_SIG_KEY),certs/signing_key.pem)
+keytype-$(CONFIG_MODULE_SIG_KEY_TYPE_RSASSA_PSS) := -newkey rsassa-pss
keytype-$(CONFIG_MODULE_SIG_KEY_TYPE_ECDSA) := -newkey ec -pkeyopt ec_paramgen_curve:secp384r1
keytype-$(CONFIG_MODULE_SIG_KEY_TYPE_MLDSA_44) := -newkey ml-dsa-44
keytype-$(CONFIG_MODULE_SIG_KEY_TYPE_MLDSA_65) := -newkey ml-dsa-65
diff --git a/scripts/sign-file.c b/scripts/sign-file.c
index 547b97097230..800e2e2e36c3 100644
--- a/scripts/sign-file.c
+++ b/scripts/sign-file.c
@@ -233,6 +233,7 @@ int main(int argc, char **argv)
EVP_PKEY *private_key;
#ifndef USE_PKCS7
CMS_ContentInfo *cms = NULL;
+ CMS_SignerInfo *signer;
unsigned int use_keyid = 0;
#else
PKCS7 *pkcs7 = NULL;
@@ -338,12 +339,46 @@ int main(int argc, char **argv)
flags |= use_signed_attrs;
+ if (EVP_PKEY_is_a(private_key, "RSASSA-PSS")) {
+ EVP_PKEY_CTX *pkctx;
+ char mdname[1024] = {};
+
+ pkctx = EVP_PKEY_CTX_new(private_key, NULL);
+
+ ERR(!EVP_PKEY_sign_init(pkctx), "EVP_PKEY_sign_init");
+ ERR(!EVP_PKEY_CTX_set_rsa_padding(pkctx, RSA_PKCS1_PSS_PADDING),
+ "EVP_PKEY_CTX_set_rsa_padding");
+ ERR(!EVP_PKEY_CTX_set_rsa_mgf1_md_name(pkctx, hash_algo, NULL),
+ "EVP_PKEY_CTX_set_rsa_mgf1_md_name");
+
+ ERR(!EVP_PKEY_CTX_get_rsa_mgf1_md_name(pkctx, mdname, sizeof(mdname)),
+ "EVP_PKEY_CTX_get_rsa_mgf1_md_name");
+ printf("RSASSA-PSS %s\n", mdname);
+ flags |= CMS_KEY_PARAM;
+ }
+
/* Load the signature message from the digest buffer. */
cms = CMS_sign(NULL, NULL, NULL, NULL, flags);
ERR(!cms, "CMS_sign");
- ERR(!CMS_add1_signer(cms, x509, private_key, digest_algo, flags),
- "CMS_add1_signer");
+ signer = CMS_add1_signer(cms, x509, private_key, digest_algo, flags);
+ ERR(!signer, "CMS_add1_signer");
+
+ if (EVP_PKEY_is_a(private_key, "RSASSA-PSS")) {
+ EVP_PKEY_CTX *pkctx;
+ char mdname[1024] = {};
+
+ pkctx = CMS_SignerInfo_get0_pkey_ctx(signer);
+ ERR(!EVP_PKEY_CTX_set_rsa_padding(pkctx, RSA_PKCS1_PSS_PADDING),
+ "EVP_PKEY_CTX_set_rsa_padding");
+ ERR(!EVP_PKEY_CTX_set_rsa_mgf1_md_name(pkctx, hash_algo, NULL),
+ "EVP_PKEY_CTX_set_rsa_mgf1_md_name");
+
+ ERR(!EVP_PKEY_CTX_get_rsa_mgf1_md_name(pkctx, mdname, sizeof(mdname)),
+ "EVP_PKEY_CTX_get_rsa_mgf1_md_name");
+ printf("RSASSA-PSS %s\n", mdname);
+ }
+
ERR(CMS_final(cms, bm, NULL, flags) != 1,
"CMS_final");
^ permalink raw reply related [flat|nested] 20+ messages in thread* [PATCH v12 10/10] x509, pkcs7: Limit crypto combinations that may be used for module signing
2026-01-15 21:50 [PATCH v12 00/10] x509, pkcs7, crypto: Add ML-DSA and RSASSA-PSS signing David Howells
` (8 preceding siblings ...)
2026-01-15 21:50 ` [PATCH v12 09/10] modsign: Enable RSASSA-PSS module signing David Howells
@ 2026-01-15 21:50 ` David Howells
9 siblings, 0 replies; 20+ messages in thread
From: David Howells @ 2026-01-15 21:50 UTC (permalink / raw)
To: Lukas Wunner, Ignat Korchagin
Cc: David Howells, Jarkko Sakkinen, Herbert Xu, Eric Biggers,
Luis Chamberlain, Petr Pavlu, Daniel Gomez, Sami Tolvanen,
Jason A . Donenfeld, Ard Biesheuvel, Stephan Mueller,
linux-crypto, keyrings, linux-modules, linux-kernel
Limit the set of crypto combinations that may be used for module signing as
no indication of hash algorithm used for signing is added to the hash of
the data, so in theory a data blob hashed with a different algorithm can be
substituted provided it has the same hash output.
This also rejects the use of less secure algorithms.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Lukas Wunner <lukas@wunner.de>
cc: Ignat Korchagin <ignat@cloudflare.com>
cc: Stephan Mueller <smueller@chronox.de>
cc: Eric Biggers <ebiggers@kernel.org>
cc: Herbert Xu <herbert@gondor.apana.org.au>
cc: keyrings@vger.kernel.org
cc: linux-crypto@vger.kernel.org
---
crypto/asymmetric_keys/public_key.c | 51 +++++++++++++++++++++++++++--
1 file changed, 49 insertions(+), 2 deletions(-)
diff --git a/crypto/asymmetric_keys/public_key.c b/crypto/asymmetric_keys/public_key.c
index 13a5616becaa..78e1194de71c 100644
--- a/crypto/asymmetric_keys/public_key.c
+++ b/crypto/asymmetric_keys/public_key.c
@@ -24,6 +24,48 @@ MODULE_DESCRIPTION("In-software asymmetric public-key subtype");
MODULE_AUTHOR("Red Hat, Inc.");
MODULE_LICENSE("GPL");
+struct public_key_restriction {
+ const char *pkey_algo; /* Signing algorithm (e.g. "rsa") */
+ const char *pkey_enc; /* Signature encoding (e.g. "pkcs1") */
+ const char *hash_algo; /* Content hash algorithm (e.g. "sha256") */
+};
+
+static const struct public_key_restriction public_key_restrictions[] = {
+ /* algo encoding hash */
+ { "rsa", "pkcs1", "sha256" },
+ { "rsa", "pkcs1", "sha384" },
+ { "rsa", "pkcs1", "sha512" },
+ { "rsa", "emsa-pss", "sha512" },
+ { "ecdsa", "x962", "sha512" },
+ { "ecrdsa", "raw", "sha512" },
+ { "mldsa44", "raw", "sha512" },
+ { "mldsa65", "raw", "sha512" },
+ { "mldsa87", "raw", "sha512" },
+ /* ML-DSA may also do its own hashing over the entire message. */
+ { "mldsa44", "raw", "-" },
+ { "mldsa65", "raw", "-" },
+ { "mldsa87", "raw", "-" },
+};
+
+/*
+ * Determine if a particular key/hash combination is allowed.
+ */
+static int is_public_key_sig_allowed(const struct public_key_signature *sig)
+{
+ for (int i = 0; i < ARRAY_SIZE(public_key_restrictions); i++) {
+ if (strcmp(public_key_restrictions[i].pkey_algo, sig->pkey_algo) != 0)
+ continue;
+ if (strcmp(public_key_restrictions[i].pkey_enc, sig->encoding) != 0)
+ continue;
+ if (strcmp(public_key_restrictions[i].hash_algo, sig->hash_algo) != 0)
+ continue;
+ return 0;
+ }
+ pr_warn_once("Public key signature combo (%s,%s,%s) rejected\n",
+ sig->pkey_algo, sig->encoding, sig->hash_algo);
+ return -EKEYREJECTED;
+}
+
/*
* Provide a part of a description of the key for /proc/keys.
*/
@@ -391,12 +433,17 @@ int public_key_verify_signature(const struct public_key *pkey,
bool issig;
int ret;
- pr_devel("==>%s()\n", __func__);
-
BUG_ON(!pkey);
BUG_ON(!sig);
BUG_ON(!sig->s);
+ ret = is_public_key_sig_allowed(sig);
+ if (ret < 0)
+ return ret;
+
+ pr_devel("==>%s(%s,%s,%s)\n",
+ __func__, sig->pkey_algo, sig->encoding, sig->hash_algo);
+
/*
* If the signature specifies a public key algorithm, it *must* match
* the key's actual public key algorithm.
^ permalink raw reply related [flat|nested] 20+ messages in thread