[PATCH v11 0/8] x509, pkcs7, crypto: Add ML-DSA and RSASSA-PSS signing

[PATCH v11 0/8] x509, pkcs7, crypto: Add ML-DSA and RSASSA-PSS signing

[David Howells]

Hi Lukas, Ignat,

[Note this is based on Eric Bigger's libcrypto-next branch].

These patches add ML-DSA module signing and RSASSA-PSS module signing.  The
first half of the set adds ML-DSA signing:

 (1) Add a crypto_sig interface for ML-DSA, verification only.

 (2) Modify PKCS#7 support to allow kernel module signatures to carry
     authenticatedAttributes as OpenSSL refuses to let them be opted out of
     for ML-DSA (CMS_NOATTR).  This adds an extra digest calculation to the
     process.

     Modify PKCS#7 to pass the authenticatedAttributes directly to the
     ML-DSA algorithm rather than passing over a digest as is done with RSA
     as ML-DSA wants to do its own hashing and will add other stuff into
     the hash.  We could use hashML-DSA or an external mu instead, but they
     aren't standardised for CMS yet.

 (3) Add support to the PKCS#7 and X.509 parsers for ML-DSA.

 (4) Modify sign-file to handle OpenSSL not permitting CMS_NOATTR with
     ML-DSA and add ML-DSA to the choice of algorithm with which to sign
     modules.  Note that this might need some more 'select' lines in the
     Kconfig to select the lib stuff as well.

This is based on Eric's libcrypto-next branch which has the core
implementation of ML-DSA.

The second half of the set adds RSASSA-PSS signing:

 (5) Add an info string parameter to the internal signature verification
     routines where that does not already exist.  This is necessary to pass
     extra parameters and is already supported in the KEYCTL_PKEY_VERIFY
     keyctl.

     Both X.509 and PKCS#7 provide for these parameters to be supplied, but
     it is tricky to pass the parameters in a blob with the signature or
     key data as there are checks on these sizes that are then violated;
     further, the way the parameters are laid out in the ASN.1 doesn't lend
     itself easily to simply extracting out a larger blob.

 (6) Add RSASSA-PSS support to the RSA driver in crypto/.  This parses the
     info string to get the verification parameters.

 (7) Add support to the PKCS#7 and X.509 parsers for RSASSA-PSS.

 (8) Modify sign-file to pass the extra parameters necessary to be able
     generate RSASSA-PSS.  For the moment, only select MGF1 with the same
     hash algorithm as for the data for the mask function.  Add RSASSA-PSS
     to the choice of algorithm with which to sign modules.

Note that I do still need to add some FIPS tests for both ML-DSA and
RSASSA-PSS in the form of X.509 certs, data and detached PKCS#7 signatures.
I'm not sure if I can use FIPS-standard tests for that.

The patches can also be found here:

	https://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs.git/log/?h=keys-pqc

David

Changes
=======
ver #11)
 - Rebased on Eric's libcrypto-next branch.
 - Added RSASSA-PSS support patches.

ver #10)
 - Replaced the Leancrypto ML-DSA implementation with Eric's.
 - Fixed Eric's implementation to have MODULE_* info.
 - Added a patch to drive Eric's ML-DSA implementation from crypto_sig.
 - Removed SHAKE256 from the list of available module hash algorithms.
 - Changed a some more ML_DSA to MLDSA in config symbols.

ver #9)
 - ML-DSA changes:
   - Separate output into four modules (1 common, 3 strength-specific).
     - Solves Kconfig issue with needing to select at least one strength.
   - Separate the strength-specific crypto-lib APIs.
     - This is now generated by preprocessor-templating.
   - Remove the multiplexor code.
   - Multiplex the crypto-lib APIs by C type.
 - Fix the PKCS#7/X.509 code to have the correct algo names.

ver #8)
 - Moved the ML-DSA code to lib/crypto/mldsa/.
 - Renamed some bits from ml-dsa to mldsa.
 - Created a simplified API and placed that in include/crypto/mldsa.h.
 - Made the testing code use the simplified API.
 - Fixed a warning about implicitly casting between uint16_t and __le16.

ver #7)
 - Rebased on Eric's tree as that now contains all the necessary SHA-3
   infrastructure and drop the SHA-3 patches from here.
 - Added a minimal patch to provide shake256 support for crypto_sig.
 - Got rid of the memory allocation wrappers.
 - Removed the ML-DSA keypair generation code and the signing code, leaving
   only the signature verification code.
 - Removed the secret key handling code.
 - Removed the secret keys from the kunit tests and the signing testing.
 - Removed some unused bits from the ML-DSA code.
 - Downgraded the kdoc comments to ordinary comments, but keep the markup
   for easier comparison to Leancrypto.

ver #6)
 - Added a patch to make the jitterentropy RNG use lib/sha3.
 - Added back the crypto/sha3_generic changes.
 - Added ML-DSA implementation (still needs more cleanup).
 - Added kunit test for ML-DSA.
 - Modified PKCS#7 to accommodate ML-DSA.
 - Modified PKCS#7 and X.509 to allow ML-DSA to be specified and used.
 - Modified sign-file to not use CMS_NOATTR with ML-DSA.
 - Allowed SHA3 and SHAKE* algorithms for module signing default.
 - Allowed ML-DSA-{44,65,87} to be selected as the module signing default.

ver #5)
 - Fix gen-hash-testvecs.py to correctly handle algo names that contain a
   dash.
 - Fix gen-hash-testvecs.py to not generate HMAC for SHA3-* or SHAKE* as
   these don't currently have HMAC variants implemented.
 - Fix algo names to be correct.
 - Fix kunit module description as it now tests all SHA3 variants.

ver #4)
 - Fix a couple of arm64 build problems.
 - Doc fixes:
   - Fix the description of the algorithm to be closer to the NIST spec's
     terminology.
   - Don't talk of finialising the context for XOFs.
   - Don't say "Return: None".
   - Declare the "Context" to be "Any context" and make no mention of the
     fact that it might use the FPU.
   - Change "initialise" to "initialize".
   - Don't warn that the context is relatively large for stack use.
 - Use size_t for size parameters/variables.
 - Make the module_exit unconditional.
 - Dropped the crypto/ dir-affecting patches for the moment.

ver #3)
 - Renamed conflicting arm64 functions.
 - Made a separate wrapper API for each algorithm in the family.
 - Removed sha3_init(), sha3_reinit() and sha3_final().
 - Removed sha3_ctx::digest_size.
 - Renamed sha3_ctx::partial to sha3_ctx::absorb_offset.
 - Refer to the output of SHAKE* as "output" not "digest".
 - Moved the Iota transform into the one-round function.
 - Made sha3_update() warn if called after sha3_squeeze().
 - Simplified the module-load test to not do update after squeeze.
 - Added Return: and Context: kdoc statements and expanded the kdoc
   headers.
 - Added an API description document.
 - Overhauled the kunit tests.
   - Only have one kunit test.
   - Only call the general hash tester on one algo.
   - Add separate simple cursory checks for the other algos.
   - Add resqueezing tests.
   - Add some NIST example tests.
 - Changed crypto/sha3_generic to use this
 - Added SHAKE128/256 to crypto/sha3_generic and crypto/testmgr
 - Folded struct sha3_state into struct sha3_ctx.

ver #2)
  - Simplify the endianness handling.
  - Rename sha3_final() to sha3_squeeze() and don't clear the context at the
    end as it's permitted to continue calling sha3_final() to extract
    continuations of the digest (needed by ML-DSA).
  - Don't reapply the end marker to the hash state in continuation
    sha3_squeeze() unless sha3_update() gets called again (needed by
    ML-DSA).
  - Give sha3_squeeze() the amount of digest to produce as a parameter
    rather than using ctx->digest_size and don't return the amount digested.
  - Reimplement sha3_final() as a wrapper around sha3_squeeze() that
    extracts ctx->digest_size amount of digest and then zeroes out the
    context.  The latter is necessary to avoid upsetting
    hash-test-template.h.
  - Provide a sha3_reinit() function to clear the state, but to leave the
    parameters that indicate the hash properties unaffected, allowing for
    reuse.
  - Provide a sha3_set_digestsize() function to change the size of the
    digest to be extracted by sha3_final().  sha3_squeeze() takes a
    parameter for this instead.
  - Don't pass the digest size as a parameter to shake128/256_init() but
    rather default to 128/256 bits as per the function name.
  - Provide a sha3_clear() function to zero out the context.

David Howells (8):
  crypto: Add ML-DSA crypto_sig support
  pkcs7: Allow the signing algo to calculate the digest itself
  pkcs7, x509: Add ML-DSA support
  modsign: Enable ML-DSA module signing
  crypto: Add supplementary info param to asymmetric key signature
    verification
  crypto: Add RSASSA-PSS support
  pkcs7, x509: Add RSASSA-PSS support
  modsign: Enable RSASSA-PSS module signing

 Documentation/admin-guide/module-signing.rst |  15 +-
 certs/Kconfig                                |  27 ++
 certs/Makefile                               |   4 +
 crypto/Kconfig                               |  10 +
 crypto/Makefile                              |   3 +
 crypto/asymmetric_keys/Makefile              |  12 +-
 crypto/asymmetric_keys/asymmetric_type.c     |   1 +
 crypto/asymmetric_keys/mgf1_params.asn1      |  12 +
 crypto/asymmetric_keys/pkcs7.asn1            |   2 +-
 crypto/asymmetric_keys/pkcs7_parser.c        | 114 +++---
 crypto/asymmetric_keys/pkcs7_verify.c        |  52 ++-
 crypto/asymmetric_keys/public_key.c          |  19 +-
 crypto/asymmetric_keys/rsassa_params.asn1    |  25 ++
 crypto/asymmetric_keys/rsassa_parser.c       | 233 +++++++++++
 crypto/asymmetric_keys/rsassa_parser.h       |  25 ++
 crypto/asymmetric_keys/signature.c           |   1 +
 crypto/asymmetric_keys/x509.asn1             |   2 +-
 crypto/asymmetric_keys/x509_cert_parser.c    | 120 ++++--
 crypto/asymmetric_keys/x509_parser.h         |  33 +-
 crypto/asymmetric_keys/x509_public_key.c     |  28 +-
 crypto/ecdsa-p1363.c                         |   5 +-
 crypto/ecdsa-x962.c                          |   5 +-
 crypto/ecdsa.c                               |   3 +-
 crypto/ecrdsa.c                              |   3 +-
 crypto/mldsa.c                               | 202 ++++++++++
 crypto/rsa.c                                 |   8 +
 crypto/rsassa-pkcs1.c                        |   3 +-
 crypto/rsassa-pss.c                          | 397 +++++++++++++++++++
 crypto/sig.c                                 |   3 +-
 include/crypto/internal/rsa.h                |   2 +
 include/crypto/public_key.h                  |   2 +
 include/crypto/sig.h                         |   9 +-
 include/linux/oid_registry.h                 |   7 +
 scripts/sign-file.c                          |  63 ++-
 34 files changed, 1307 insertions(+), 143 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
 create mode 100644 crypto/mldsa.c
 create mode 100644 crypto/rsassa-pss.c

[PATCH v11 1/8] crypto: Add ML-DSA crypto_sig support

[David Howells]

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");

[PATCH v11 2/8] pkcs7: Allow the signing algo to calculate the digest itself

[David Howells]

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;

[PATCH v11 3/8] pkcs7, x509: Add ML-DSA support

[David Howells]

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..30821a6a4f72 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 (Dilithium) */
+	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
 };
 

[PATCH v11 4/8] modsign: Enable ML-DSA module signing

[David Howells]

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 | 15 +++++------
 certs/Kconfig                                | 21 ++++++++++++++++
 certs/Makefile                               |  3 +++
 crypto/asymmetric_keys/pkcs7_verify.c        |  4 ---
 scripts/sign-file.c                          | 26 ++++++++++++++------
 5 files changed, 50 insertions(+), 19 deletions(-)

diff --git a/Documentation/admin-guide/module-signing.rst b/Documentation/admin-guide/module-signing.rst
index a8667a777490..1a055c0b3356 100644
--- a/Documentation/admin-guide/module-signing.rst
+++ b/Documentation/admin-guide/module-signing.rst
@@ -28,10 +28,11 @@ 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 (Dilithium) 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 uses SHAKE256.
 
 
 ==========================
@@ -146,9 +147,9 @@ 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..94b086684d07 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 (Dilithium) 44"
+	select CRYPTO_MLDSA
+	help
+	  Use an ML-DSA (Dilithium) 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 (Dilithium) 65"
+	select CRYPTO_MLDSA
+	help
+	  Use an ML-DSA (Dilithium) 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 (Dilithium) 87"
+	select CRYPTO_MLDSA
+	help
+	  Use an ML-DSA (Dilithium) 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 0f9f515b784d..f7ea1d41771d 100644
--- a/crypto/asymmetric_keys/pkcs7_verify.c
+++ b/crypto/asymmetric_keys/pkcs7_verify.c
@@ -424,10 +424,6 @@ 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..b726581075f9 100644
--- a/scripts/sign-file.c
+++ b/scripts/sign-file.c
@@ -315,18 +315,28 @@ 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"))
+			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

[PATCH v11 5/8] crypto: Add supplementary info param to asymmetric key signature verification

[David Howells]

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>
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/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 ++-
 include/crypto/public_key.h              | 1 +
 include/crypto/sig.h                     | 9 ++++++---
 12 files changed, 26 insertions(+), 13 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 041d04b5c953..26c0c0112ac4 100644
--- a/crypto/asymmetric_keys/signature.c
+++ b/crypto/asymmetric_keys/signature.c
@@ -29,6 +29,7 @@ void public_key_signature_free(struct public_key_signature *sig)
 			kfree(sig->auth_ids[i]);
 		kfree(sig->s);
 		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/include/crypto/public_key.h b/include/crypto/public_key.h
index e4ec8003a3a4..1e9a1e4e9916 100644
--- a/include/crypto/public_key.h
+++ b/include/crypto/public_key.h
@@ -47,6 +47,7 @@ struct public_key_signature {
 	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 */
+	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);
 }
 
 /**

[PATCH v11 6/8] crypto: Add RSASSA-PSS support

[David Howells]

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           | 397 ++++++++++++++++++++++++++++++++++
 include/crypto/internal/rsa.h |   2 +
 4 files changed, 408 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..7f27e8fa6fa7
--- /dev/null
+++ b/crypto/rsassa-pss.c
@@ -0,0 +1,397 @@
+// 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, *q;
+
+	ctx->pss_hash = NULL;
+	ctx->mgf1_hash = NULL;
+	ctx->salt_len = 0;
+
+	for (p = info; p && *p;) {
+		if (isspace(*p)) {
+			p++;
+			continue;
+		}
+		q = p++;
+		while (*p && !isspace(*p))
+			p++;
+
+		if (!*p)
+			p = NULL;
+		else
+			*p++ = 0;
+
+		switch (match_token(q, 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;
+}
+
+DEFINE_FREE(crypto_free_shash, struct crypto_shash*,
+	    if (!IS_ERR_OR_NULL(_T)) { crypto_free_shash(_T); });
+
+/*
+ * 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)
+{
+	struct crypto_shash *hash_tfm __free(crypto_free_shash) = NULL;
+	struct shash_desc *Hash __free(kfree) = NULL;
+	unsigned int counter, count_to, hLen, T_len;
+	__be32 *C;
+	int err;
+	u8 *T, *t, *to_hash;
+
+	hash_tfm = 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;
+
+	Hash = 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)
+{
+	struct crypto_shash *hash_tfm __free(crypto_free_shash);
+	struct shash_desc *Hash __free(kfree) = NULL;
+	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;
+
+	hash_tfm = 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;
+
+	Hash = 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 akcipher_request *rsa_req __free(kfree) = NULL;
+	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);
+	char *str __free(kfree) = NULL;
+	u8 *EM;
+	int err;
+
+	if (!info)
+		return -EINVAL;
+
+	str = 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 */
+	rsa_req = 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/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

[PATCH v11 7/8] pkcs7, x509: Add RSASSA-PSS support

[David Howells]

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     | 113 ++++++-----
 crypto/asymmetric_keys/public_key.c       |  10 +
 crypto/asymmetric_keys/rsassa_params.asn1 |  25 +++
 crypto/asymmetric_keys/rsassa_parser.c    | 233 ++++++++++++++++++++++
 crypto/asymmetric_keys/rsassa_parser.h    |  25 +++
 crypto/asymmetric_keys/x509.asn1          |   2 +-
 crypto/asymmetric_keys/x509_cert_parser.c |  96 +++++----
 crypto/asymmetric_keys/x509_parser.h      |  33 ++-
 crypto/asymmetric_keys/x509_public_key.c  |  28 ++-
 include/linux/oid_registry.h              |   2 +
 13 files changed, 490 insertions(+), 103 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..81996b60c1f1 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");
@@ -30,6 +31,8 @@ struct pkcs7_parse_context {
 	enum OID	last_oid;		/* Last OID encountered */
 	unsigned	x509_index;
 	unsigned	sinfo_index;
+	unsigned	algo_params_size;
+	const void	*algo_params;
 	const void	*raw_serial;
 	unsigned	raw_serial_size;
 	unsigned	raw_issuer_size;
@@ -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;
 }
 
@@ -275,12 +262,16 @@ 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:
+		goto rsassa_pss;
 	case OID_id_ecdsa_with_sha1:
 	case OID_id_ecdsa_with_sha224:
 	case OID_id_ecdsa_with_sha256:
@@ -289,34 +280,52 @@ 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;
 	}
+
+out:
+	ctx->algo_params = NULL;
+	ctx->algo_params_size = 0;
 	return 0;
+
+rsassa_pss:
+	if (!ctx->algo_params || !ctx->algo_params_size) {
+		pr_debug("RSASSA-PSS sig algo without parameters\n");
+		return -EBADMSG;
+	}
+
+	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";
+	goto out;
 }
 
 /*
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..8c598517f785
--- /dev/null
+++ b/crypto/asymmetric_keys/rsassa_parser.c
@@ -0,0 +1,233 @@
+// 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) "RSAPSS: "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 = {};
+	struct rsassa_parameters *rsassa __free(kfree);
+	long ret;
+
+	rsassa = 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)
+{
+	struct rsassa_parameters *rsassa __free(rsassa_params_free) = NULL;
+	const char *mf, *mh;
+
+	rsassa = 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..6c431bf181f2 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
@@ -104,15 +83,15 @@ 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 +125,7 @@ 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 +158,7 @@ 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 +190,9 @@ 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 +251,24 @@ int x509_note_sig_algo(void *context, size_t hdrlen, unsigned char tag,
 		goto ml_dsa;
 	}
 
+rsassa_pss:
+	if (!ctx->algo_params || !ctx->algo_params_size) {
+		pr_debug("RSASSA-PSS sig algo without parameters\n");
+		return -EBADMSG;
+	}
+
+	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 +325,8 @@ 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 +480,16 @@ 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 +508,28 @@ 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) {
+			struct rsassa_parameters *params __free(rsassa_params_free) = NULL;
+			ctx->key_params = ctx->algo_params;
+			ctx->key_params_size = ctx->algo_params_size;
+			ctx->algo_params = NULL;
+			ctx->algo_params_size = 0;
+
+			params = 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 +567,8 @@ 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..be2e1f6cb9f5 100644
--- a/crypto/asymmetric_keys/x509_parser.h
+++ b/crypto/asymmetric_keys/x509_parser.h
@@ -23,8 +23,6 @@ struct x509_certificate {
 	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 */
 	const void	*raw_serial;		/* Raw serial number in ASN.1 */
 	unsigned	raw_serial_size;
 	unsigned	raw_issuer_size;
@@ -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	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;
+};
+
 /*
  * 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 12e3341e806b..b2f8542accc4 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;
 		}
diff --git a/include/linux/oid_registry.h b/include/linux/oid_registry.h
index 30821a6a4f72..d546ea7999b9 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 */

[PATCH v11 8/8] modsign: Enable RSASSA-PSS module signing

[David Howells]

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>
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
---
 certs/Kconfig       |  6 ++++++
 certs/Makefile      |  1 +
 scripts/sign-file.c | 39 +++++++++++++++++++++++++++++++++++++--
 3 files changed, 44 insertions(+), 2 deletions(-)

diff --git a/certs/Kconfig b/certs/Kconfig
index 94b086684d07..beb8991ad761 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 b726581075f9..ca605095194e 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;
@@ -329,13 +330,47 @@ int main(int argc, char **argv)
 		    !EVP_PKEY_is_a(private_key, "ML-DSA-65") &&
 		    !EVP_PKEY_is_a(private_key, "ML-DSA-87"))
 			flags |= use_signed_attrs;
+		if (EVP_PKEY_is_a(private_key, "RSASSA-PSS"))
+			flags |= CMS_KEY_PARAM;
+	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);
+		}
 
 		/* 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");
 

Re: [PATCH v11 2/8] pkcs7: Allow the signing algo to calculate the digest itself

[Ignat Korchagin]

Hi David,

On Mon, Jan 5, 2026 at 3:22 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);

Can we refactor this so we allocate the right size from the start.
Alternatively, should we just unconditionally use this approach
"overallocating" some times?

> +                       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 */

It seems this controls if we hash authenticated attributes, not the
data itself. Maybe reflect this in the name? Something like
do_authattrs_hash or authattrs_algo_passthrough?

>         const char *pkey_algo;
>         const char *hash_algo;
>         const char *encoding;
>

Ignat

Re: [PATCH v11 3/8] pkcs7, x509: Add ML-DSA support

[Eric Biggers]

On Mon, Jan 05, 2026 at 03:21:28PM +0000, David Howells wrote:
> 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(+)

This "PKCS#7" (really CMS -- the kernel misleadingly uses the old name)
stuff is really hard to understand.  I'm trying to understand what
message you're actually passing to mldsa_verify().  That's kind of the
whole point, after all.

The message comes from the byte array public_key_signature::digest
(which is misleadingly named, as it's not always a digest).  In turn,
that comes from the following:

1.) If the CMS object doesn't include signed attributes, then it's a
    digest of the real message the caller provided.

2.) If the CMS object includes signed attributes, then the message is
    the signed attributes as a byte array.  The signed attributes are
    required to include a message digest attribute whose value matches a
    digest of the real message the caller provided.

In either (1) or (2), the digest algorithm used comes from the CMS
object itself, from SignerInfo::digestAlgorithm.  The kernel allows
SHA-1, SHA-224, SHA-256, SHA-384, SHA-512, SM3, Streebog-256,
Streebog-512, SHA3-256, SHA3-384, and SHA3-512.

So, a couple issues.  First, case (1) isn't actually compatible with
RFC 9882 (https://datatracker.ietf.org/doc/rfc9882/) which is the
specification for ML-DSA support in CMS.  RFC 9882 is clear that if
there are no signed attributes, then the ML-DSA signature is computed
directly over the signed-data, not over a digest of it.

That needs to either be implemented correctly, or not at all.  (If only
(2) is actually needed, then "not at all" probably would be preferable.)

Second, because the digest algorithm comes from the untrusted signature
object and the kernel is allowing different many digest algorithms,
attackers are free to search for preimages across algorithms.  For
example, if an attacker can find a Streebog-512 digest that matches a
particular SHA-512 digest that was used in a valid signature, they could
forge signatures.  This would only require a weakness in Streebog-512.

While the root cause of this seems to be a flaw in CMS itself, it can be
mitigated by more strictly limiting the allowed digest algorithms.  The
kernel already does this for the existing signature algorithms.

For simplicity and to avoid this issue entirely, I suggest just allowing
SHA-512 only.  That's the only one that RFC 9882 says MUST be supported
with ML-DSA.

- Eric

Re: [PATCH v11 4/8] modsign: Enable ML-DSA module signing

[Eric Biggers]

On Mon, Jan 05, 2026 at 03:21:29PM +0000, David Howells wrote:
> 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)").

The ML-DSA specification specifies the XOFs used.  This has nothing to
do with the API.

> +config MODULE_SIG_KEY_TYPE_MLDSA_44
> +	bool "ML-DSA (Dilithium) 44"
> +	select CRYPTO_MLDSA
> +	help
> +	  Use an ML-DSA (Dilithium) 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 (Dilithium) 65"
> +	select CRYPTO_MLDSA
> +	help
> +	  Use an ML-DSA (Dilithium) 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 (Dilithium) 87"
> +	select CRYPTO_MLDSA
> +	help
> +	  Use an ML-DSA (Dilithium) 87 key (NIST FIPS 204) for module signing
> +	  with a SHAKE256 'hash' of the authenticatedAttributes.

Kind of weird naming here.  We don't have "AES (Rijndael) 256" and
"SHA-3 (Keccak) 512".  We have AES-256 and SHA3-256.

Similarly, these should be ML-DSA-44, etc.

Yes, NIST went with boring names instead of the original cool names.
That's just how it is.

Also unclear why the above help text mentions anything about SHAKE256 or
the authenticatedAttributes.  That's an implementation detail.  (And the
CMS specification calls them signed attributes anyway.)

- Eric

Re: [PATCH v11 3/8] pkcs7, x509: Add ML-DSA support

[Eric Biggers]

On Tue, Jan 06, 2026 at 12:02:51AM -0800, Eric Biggers wrote:
> For simplicity and to avoid this issue entirely, I suggest just allowing
> SHA-512 only.  That's the only one that RFC 9882 says MUST be supported
> with ML-DSA.

That being said, this is only applicable for the case where signed
attributes are used.  If you can get the other case working properly and
just support that case, where the real user message is what is passed to
ML-DSA, that would also avoid this issue and be much simpler.

- Eric

Re: [PATCH v11 3/8] pkcs7, x509: Add ML-DSA support

[David Howells]

Eric Biggers <ebiggers@kernel.org> wrote:

> This "PKCS#7" (really CMS -- the kernel misleadingly uses the old name)

I implemented PKCS#7 first and then added CMS on top of that.

> That needs to either be implemented correctly, or not at all.  (If only
> (2) is actually needed, then "not at all" probably would be preferable.)

At the time of writing, openssl didn't fully support CMS with ML-DSA, and that
limited things.

David