* [PATCH v3 1/5] crypto: rsa-pkcs1pad: export rsa1_asn_lookup()
2024-05-21 15:26 [PATCH v3 0/5] KEYS: asymmetric: tpm2_key_rsa Jarkko Sakkinen
@ 2024-05-21 15:26 ` Jarkko Sakkinen
2024-05-21 15:26 ` [PATCH v3 2/5] lib: Expand asn1_encode_integer() to variable size integers Jarkko Sakkinen
` (3 subsequent siblings)
4 siblings, 0 replies; 6+ messages in thread
From: Jarkko Sakkinen @ 2024-05-21 15:26 UTC (permalink / raw)
To: Herbert Xu
Cc: linux-integrity, keyrings, Andreas.Fuchs, James Prestwood,
David Woodhouse, Eric Biggers, James Bottomley, Jarkko Sakkinen,
David S. Miller, open list:CRYPTO API, open list
ASN.1 template is required for TPM2 asymmetric keys, as it needs to be
piggy-packed with the input data before applying TPM2_RSA_Decrypt. This
patch prepares crypto subsystem for the addition of those keys.
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
---
crypto/rsa-pkcs1pad.c | 16 ++++++++++------
include/crypto/rsa-pkcs1pad.h | 20 ++++++++++++++++++++
2 files changed, 30 insertions(+), 6 deletions(-)
create mode 100644 include/crypto/rsa-pkcs1pad.h
diff --git a/crypto/rsa-pkcs1pad.c b/crypto/rsa-pkcs1pad.c
index cd501195f34a..00b6c14f861c 100644
--- a/crypto/rsa-pkcs1pad.c
+++ b/crypto/rsa-pkcs1pad.c
@@ -7,6 +7,7 @@
#include <crypto/algapi.h>
#include <crypto/akcipher.h>
+#include <crypto/rsa-pkcs1pad.h>
#include <crypto/internal/akcipher.h>
#include <crypto/internal/rsa.h>
#include <linux/err.h>
@@ -79,11 +80,7 @@ static const u8 rsa_digest_info_sha3_512[] = {
0x05, 0x00, 0x04, 0x40
};
-static const struct rsa_asn1_template {
- const char *name;
- const u8 *data;
- size_t size;
-} rsa_asn1_templates[] = {
+static const struct rsa_asn1_template rsa_asn1_templates[] = {
#define _(X) { #X, rsa_digest_info_##X, sizeof(rsa_digest_info_##X) }
_(md5),
_(sha1),
@@ -101,7 +98,13 @@ static const struct rsa_asn1_template {
{ NULL }
};
-static const struct rsa_asn1_template *rsa_lookup_asn1(const char *name)
+/**
+ * rsa_lookup_asn1() - Lookup the ASN.1 digest info given the hash
+ * name: hash algorithm name
+ *
+ * Returns the ASN.1 digest info on success, and NULL on failure.
+ */
+const struct rsa_asn1_template *rsa_lookup_asn1(const char *name)
{
const struct rsa_asn1_template *p;
@@ -110,6 +113,7 @@ static const struct rsa_asn1_template *rsa_lookup_asn1(const char *name)
return p;
return NULL;
}
+EXPORT_SYMBOL_GPL(rsa_lookup_asn1);
struct pkcs1pad_ctx {
struct crypto_akcipher *child;
diff --git a/include/crypto/rsa-pkcs1pad.h b/include/crypto/rsa-pkcs1pad.h
new file mode 100644
index 000000000000..32c7453ff644
--- /dev/null
+++ b/include/crypto/rsa-pkcs1pad.h
@@ -0,0 +1,20 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * RSA padding templates.
+ */
+
+#ifndef _CRYPTO_RSA_PKCS1PAD_H
+#define _CRYPTO_RSA_PKCS1PAD_H
+
+/*
+ * Hash algorithm name to ASN.1 template mapping.
+ */
+struct rsa_asn1_template {
+ const char *name;
+ const u8 *data;
+ size_t size;
+};
+
+const struct rsa_asn1_template *rsa_lookup_asn1(const char *name);
+
+#endif /* _CRYPTO_RSA_PKCS1PAD_H */
--
2.45.1
^ permalink raw reply related [flat|nested] 6+ messages in thread* [PATCH v3 2/5] lib: Expand asn1_encode_integer() to variable size integers
2024-05-21 15:26 [PATCH v3 0/5] KEYS: asymmetric: tpm2_key_rsa Jarkko Sakkinen
2024-05-21 15:26 ` [PATCH v3 1/5] crypto: rsa-pkcs1pad: export rsa1_asn_lookup() Jarkko Sakkinen
@ 2024-05-21 15:26 ` Jarkko Sakkinen
2024-05-21 15:26 ` [PATCH v3 3/5] KEYS: trusted: Move tpm2_key_decode() to the TPM driver Jarkko Sakkinen
` (2 subsequent siblings)
4 siblings, 0 replies; 6+ messages in thread
From: Jarkko Sakkinen @ 2024-05-21 15:26 UTC (permalink / raw)
To: Herbert Xu
Cc: linux-integrity, keyrings, Andreas.Fuchs, James Prestwood,
David Woodhouse, Eric Biggers, James Bottomley, Jarkko Sakkinen,
David S. Miller, open list:CRYPTO API, open list, Andrew Morton,
James Bottomley, Mimi Zohar, David Howells, Paul Moore,
James Morris, Serge E. Hallyn, open list:SECURITY SUBSYSTEM
Expand asn1_encode_integer() to variable size integers, meaning that it
will get a blob in big-endian format as integer and length of the blob as
parameters. This is required in order to encode RSA public key modulus.
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
---
v3:
* Fix off-by-one in indices when returning zero:
https://lore.kernel.org/linux-integrity/SN7PR18MB5314CFBD18B011F292809EBFE3EA2@SN7PR18MB5314.namprd18.prod.outlook.com/
---
include/linux/asn1_encoder.h | 3 +-
lib/asn1_encoder.c | 185 ++++++++++++----------
security/keys/trusted-keys/trusted_tpm2.c | 4 +-
3 files changed, 103 insertions(+), 89 deletions(-)
diff --git a/include/linux/asn1_encoder.h b/include/linux/asn1_encoder.h
index 08cd0c2ad34f..ad5fb18db9e2 100644
--- a/include/linux/asn1_encoder.h
+++ b/include/linux/asn1_encoder.h
@@ -9,9 +9,10 @@
#include <linux/bug.h>
#define asn1_oid_len(oid) (sizeof(oid)/sizeof(u32))
+
unsigned char *
asn1_encode_integer(unsigned char *data, const unsigned char *end_data,
- s64 integer);
+ const u8 *integer, int integer_len);
unsigned char *
asn1_encode_oid(unsigned char *data, const unsigned char *end_data,
u32 oid[], int oid_len);
diff --git a/lib/asn1_encoder.c b/lib/asn1_encoder.c
index 0fd3c454a468..266e8042742e 100644
--- a/lib/asn1_encoder.c
+++ b/lib/asn1_encoder.c
@@ -9,12 +9,78 @@
#include <linux/bug.h>
#include <linux/string.h>
#include <linux/module.h>
+#include <linux/slab.h>
+
+/**
+ * asn1_encode_length() - encode a length to follow an ASN.1 tag
+ * @data: pointer to encode at
+ * @data_len: pointer to remaining length (adjusted by routine)
+ * @len: length to encode
+ *
+ * This routine can encode lengths up to 65535 using the ASN.1 rules.
+ * It will accept a negative length and place a zero length tag
+ * instead (to keep the ASN.1 valid). This convention allows other
+ * encoder primitives to accept negative lengths as singalling the
+ * sequence will be re-encoded when the length is known.
+ */
+static int asn1_encode_length(unsigned char **data, int *data_len, int len)
+{
+ if (*data_len < 1)
+ return -EINVAL;
+
+ if (len < 0) {
+ *((*data)++) = 0;
+ (*data_len)--;
+ return 0;
+ }
+
+ if (len <= 0x7f) {
+ *((*data)++) = len;
+ (*data_len)--;
+ return 0;
+ }
+
+ if (*data_len < 2)
+ return -EINVAL;
+
+ if (len <= 0xff) {
+ *((*data)++) = 0x81;
+ *((*data)++) = len & 0xff;
+ *data_len -= 2;
+ return 0;
+ }
+
+ if (*data_len < 3)
+ return -EINVAL;
+
+ if (len <= 0xffff) {
+ *((*data)++) = 0x82;
+ *((*data)++) = (len >> 8) & 0xff;
+ *((*data)++) = len & 0xff;
+ *data_len -= 3;
+ return 0;
+ }
+
+ if (WARN(len > 0xffffff, "ASN.1 length can't be > 0xffffff"))
+ return -EINVAL;
+
+ if (*data_len < 4)
+ return -EINVAL;
+ *((*data)++) = 0x83;
+ *((*data)++) = (len >> 16) & 0xff;
+ *((*data)++) = (len >> 8) & 0xff;
+ *((*data)++) = len & 0xff;
+ *data_len -= 4;
+
+ return 0;
+}
/**
* asn1_encode_integer() - encode positive integer to ASN.1
- * @data: pointer to the pointer to the data
- * @end_data: end of data pointer, points one beyond last usable byte in @data
- * @integer: integer to be encoded
+ * @data: pointer to the pointer to the data
+ * @end_data: end of data pointer, points one beyond last usable byte in @data
+ * @integer: integer to be encoded
+ * @integer_len: length in bytes of the integer blob
*
* This is a simplified encoder: it only currently does
* positive integers, but it should be simple enough to add the
@@ -22,15 +88,17 @@
*/
unsigned char *
asn1_encode_integer(unsigned char *data, const unsigned char *end_data,
- s64 integer)
+ const u8 *integer, int integer_len)
{
int data_len = end_data - data;
- unsigned char *d = &data[2];
bool found = false;
+ unsigned char *d;
+ int encoded_len;
+ u8 *encoded;
+ int ret;
int i;
- if (WARN(integer < 0,
- "BUG: integer encode only supports positive integers"))
+ if (WARN(!integer, "BUG: integer is null"))
return ERR_PTR(-EINVAL);
if (IS_ERR(data))
@@ -40,17 +108,22 @@ asn1_encode_integer(unsigned char *data, const unsigned char *end_data,
if (data_len < 3)
return ERR_PTR(-EINVAL);
- /* remaining length where at d (the start of the integer encoding) */
- data_len -= 2;
+ (*data++) = _tag(UNIV, PRIM, INT);
+ data_len--;
- data[0] = _tag(UNIV, PRIM, INT);
- if (integer == 0) {
- *d++ = 0;
- goto out;
+ if (!memchr_inv(integer, 0, integer_len)) {
+ data[0] = 1;
+ data[1] = 0;
+ return &data[2];
}
- for (i = sizeof(integer); i > 0 ; i--) {
- int byte = integer >> (8 * (i - 1));
+ encoded = kzalloc(integer_len, GFP_KERNEL);
+ if (!encoded)
+ return ERR_PTR(-ENOMEM);
+ d = encoded;
+
+ for (i = 0; i < integer_len; i++) {
+ int byte = integer[i];
if (!found && byte == 0)
continue;
@@ -67,21 +140,23 @@ asn1_encode_integer(unsigned char *data, const unsigned char *end_data,
* have len >= 1
*/
*d++ = 0;
- data_len--;
}
found = true;
- if (data_len == 0)
- return ERR_PTR(-EINVAL);
-
*d++ = byte;
- data_len--;
}
- out:
- data[1] = d - data - 2;
+ encoded_len = d - encoded;
- return d;
+ ret = asn1_encode_length(&data, &data_len, encoded_len);
+ if (ret) {
+ kfree(encoded);
+ return ERR_PTR(ret);
+ }
+
+ memcpy(data, encoded, encoded_len);
+ kfree(encoded);
+ return data + encoded_len;
}
EXPORT_SYMBOL_GPL(asn1_encode_integer);
@@ -176,70 +251,6 @@ asn1_encode_oid(unsigned char *data, const unsigned char *end_data,
}
EXPORT_SYMBOL_GPL(asn1_encode_oid);
-/**
- * asn1_encode_length() - encode a length to follow an ASN.1 tag
- * @data: pointer to encode at
- * @data_len: pointer to remaining length (adjusted by routine)
- * @len: length to encode
- *
- * This routine can encode lengths up to 65535 using the ASN.1 rules.
- * It will accept a negative length and place a zero length tag
- * instead (to keep the ASN.1 valid). This convention allows other
- * encoder primitives to accept negative lengths as singalling the
- * sequence will be re-encoded when the length is known.
- */
-static int asn1_encode_length(unsigned char **data, int *data_len, int len)
-{
- if (*data_len < 1)
- return -EINVAL;
-
- if (len < 0) {
- *((*data)++) = 0;
- (*data_len)--;
- return 0;
- }
-
- if (len <= 0x7f) {
- *((*data)++) = len;
- (*data_len)--;
- return 0;
- }
-
- if (*data_len < 2)
- return -EINVAL;
-
- if (len <= 0xff) {
- *((*data)++) = 0x81;
- *((*data)++) = len & 0xff;
- *data_len -= 2;
- return 0;
- }
-
- if (*data_len < 3)
- return -EINVAL;
-
- if (len <= 0xffff) {
- *((*data)++) = 0x82;
- *((*data)++) = (len >> 8) & 0xff;
- *((*data)++) = len & 0xff;
- *data_len -= 3;
- return 0;
- }
-
- if (WARN(len > 0xffffff, "ASN.1 length can't be > 0xffffff"))
- return -EINVAL;
-
- if (*data_len < 4)
- return -EINVAL;
- *((*data)++) = 0x83;
- *((*data)++) = (len >> 16) & 0xff;
- *((*data)++) = (len >> 8) & 0xff;
- *((*data)++) = len & 0xff;
- *data_len -= 4;
-
- return 0;
-}
-
/**
* asn1_encode_tag() - add a tag for optional or explicit value
* @data: pointer to place tag at
diff --git a/security/keys/trusted-keys/trusted_tpm2.c b/security/keys/trusted-keys/trusted_tpm2.c
index 8b7dd73d94c1..ec59f9389a2d 100644
--- a/security/keys/trusted-keys/trusted_tpm2.c
+++ b/security/keys/trusted-keys/trusted_tpm2.c
@@ -38,6 +38,7 @@ static int tpm2_key_encode(struct trusted_key_payload *payload,
u8 *end_work = scratch + SCRATCH_SIZE;
u8 *priv, *pub;
u16 priv_len, pub_len;
+ u32 key_handle;
int ret;
priv_len = get_unaligned_be16(src) + 2;
@@ -77,7 +78,8 @@ static int tpm2_key_encode(struct trusted_key_payload *payload,
goto err;
}
- work = asn1_encode_integer(work, end_work, options->keyhandle);
+ key_handle = cpu_to_be32(options->keyhandle);
+ work = asn1_encode_integer(work, end_work, (u8 *)&key_handle, 4);
work = asn1_encode_octet_string(work, end_work, pub, pub_len);
work = asn1_encode_octet_string(work, end_work, priv, priv_len);
--
2.45.1
^ permalink raw reply related [flat|nested] 6+ messages in thread* [PATCH v3 3/5] KEYS: trusted: Move tpm2_key_decode() to the TPM driver
2024-05-21 15:26 [PATCH v3 0/5] KEYS: asymmetric: tpm2_key_rsa Jarkko Sakkinen
2024-05-21 15:26 ` [PATCH v3 1/5] crypto: rsa-pkcs1pad: export rsa1_asn_lookup() Jarkko Sakkinen
2024-05-21 15:26 ` [PATCH v3 2/5] lib: Expand asn1_encode_integer() to variable size integers Jarkko Sakkinen
@ 2024-05-21 15:26 ` Jarkko Sakkinen
2024-05-21 15:26 ` [PATCH v3 4/5] tpm: tpm2_key: Extend parser to TPM_LoadableKey Jarkko Sakkinen
2024-05-21 15:26 ` [PATCH v3 5/5] keys: asymmetric: ASYMMETRIC_TPM2_KEY_RSA_SUBTYPE Jarkko Sakkinen
4 siblings, 0 replies; 6+ messages in thread
From: Jarkko Sakkinen @ 2024-05-21 15:26 UTC (permalink / raw)
To: Herbert Xu
Cc: linux-integrity, keyrings, Andreas.Fuchs, James Prestwood,
David Woodhouse, Eric Biggers, James Bottomley, Jarkko Sakkinen,
David S. Miller, open list:CRYPTO API, open list, Peter Huewe,
Jason Gunthorpe, James Bottomley, Mimi Zohar, David Howells,
Paul Moore, James Morris, Serge E. Hallyn,
open list:SECURITY SUBSYSTEM
Move tpm2_key_decode() to the TPM driver and export the symbols to make
them callable from trusted keys. It can re-used for asymmetric keys.
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
---
v2:
Do not allocate blob twice. Use the one inside struct tpm2_key.
---
drivers/char/tpm/Kconfig | 1 +
drivers/char/tpm/Makefile | 5 +
drivers/char/tpm/tpm2_key.c | 111 +++++++++++++++
.../char/tpm}/tpm2key.asn1 | 0
include/crypto/tpm2_key.h | 33 +++++
security/keys/trusted-keys/Makefile | 2 -
security/keys/trusted-keys/trusted_tpm2.c | 127 +++---------------
7 files changed, 167 insertions(+), 112 deletions(-)
create mode 100644 drivers/char/tpm/tpm2_key.c
rename {security/keys/trusted-keys => drivers/char/tpm}/tpm2key.asn1 (100%)
create mode 100644 include/crypto/tpm2_key.h
diff --git a/drivers/char/tpm/Kconfig b/drivers/char/tpm/Kconfig
index e63a6a17793c..de2f4093c939 100644
--- a/drivers/char/tpm/Kconfig
+++ b/drivers/char/tpm/Kconfig
@@ -7,6 +7,7 @@ menuconfig TCG_TPM
tristate "TPM Hardware Support"
depends on HAS_IOMEM
imply SECURITYFS
+ select ASN1
select CRYPTO
select CRYPTO_HASH_INFO
help
diff --git a/drivers/char/tpm/Makefile b/drivers/char/tpm/Makefile
index 4c695b0388f3..071437058ef6 100644
--- a/drivers/char/tpm/Makefile
+++ b/drivers/char/tpm/Makefile
@@ -17,6 +17,11 @@ tpm-y += eventlog/tpm1.o
tpm-y += eventlog/tpm2.o
tpm-y += tpm-buf.o
+# TPM2 Asymmetric Key
+$(obj)/trusted_tpm2.o: $(obj)/tpm2key.asn1.h
+tpm-y += tpm2key.asn1.o
+tpm-y += tpm2_key.o
+
tpm-$(CONFIG_TCG_TPM2_HMAC) += tpm2-sessions.o
tpm-$(CONFIG_ACPI) += tpm_ppi.o eventlog/acpi.o
tpm-$(CONFIG_EFI) += eventlog/efi.o
diff --git a/drivers/char/tpm/tpm2_key.c b/drivers/char/tpm/tpm2_key.c
new file mode 100644
index 000000000000..0112362e432e
--- /dev/null
+++ b/drivers/char/tpm/tpm2_key.c
@@ -0,0 +1,111 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include <linux/oid_registry.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+#include <crypto/tpm2_key.h>
+#include <asm/unaligned.h>
+#include "tpm2key.asn1.h"
+
+#undef pr_fmt
+#define pr_fmt(fmt) "tpm2_key: "fmt
+
+int tpm2_key_parent(void *context, size_t hdrlen,
+ unsigned char tag,
+ const void *value, size_t vlen)
+{
+ struct tpm2_key *ctx = context;
+ const u8 *v = value;
+ int i;
+
+ ctx->parent = 0;
+ for (i = 0; i < vlen; i++) {
+ ctx->parent <<= 8;
+ ctx->parent |= v[i];
+ }
+
+ return 0;
+}
+
+int tpm2_key_type(void *context, size_t hdrlen,
+ unsigned char tag,
+ const void *value, size_t vlen)
+{
+ enum OID oid = look_up_OID(value, vlen);
+
+ if (oid != OID_TPMSealedData) {
+ char buffer[50];
+
+ sprint_oid(value, vlen, buffer, sizeof(buffer));
+ pr_debug("OID is \"%s\" which is not TPMSealedData\n",
+ buffer);
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+int tpm2_key_pub(void *context, size_t hdrlen,
+ unsigned char tag,
+ const void *value, size_t vlen)
+{
+ struct tpm2_key *ctx = context;
+
+ ctx->pub = value;
+ ctx->pub_len = vlen;
+
+ return 0;
+}
+
+int tpm2_key_priv(void *context, size_t hdrlen,
+ unsigned char tag,
+ const void *value, size_t vlen)
+{
+ struct tpm2_key *ctx = context;
+
+ ctx->priv = value;
+ ctx->priv_len = vlen;
+
+ return 0;
+}
+
+/**
+ * tpm_key_decode() - Decode TPM2 ASN.1 key.
+ * @src: ASN.1 source.
+ * @src_len: ASN.1 source length.
+ * @key: TPM2 asymmetric key.
+ * @max_key_len: Maximum length of the TPM2 asymmetric key.
+ *
+ * Decodes TPM2 ASN.1 key on success. Returns POSIX error code on failure.
+ */
+int tpm2_key_decode(const u8 *src, u32 src_len, struct tpm2_key *key,
+ u32 max_key_len)
+{
+ struct tpm2_key ctx;
+ u32 blob_len;
+ int ret;
+
+ memset(&ctx, 0, sizeof(ctx));
+
+ ret = asn1_ber_decoder(&tpm2key_decoder, &ctx, src, src_len);
+ if (ret < 0)
+ return ret;
+
+ blob_len = ctx.priv_len + ctx.pub_len;
+ if (blob_len > max_key_len)
+ return -E2BIG;
+
+ ctx.blob_len = blob_len;
+ ctx.blob = kmalloc(blob_len, GFP_KERNEL);
+ if (!ctx.blob)
+ return -ENOMEM;
+
+ memcpy((void *)ctx.blob, ctx.priv, ctx.priv_len);
+ memcpy((void *)ctx.blob + ctx.priv_len, ctx.pub, ctx.pub_len);
+ ctx.priv = ctx.blob;
+ ctx.pub = ctx.blob + ctx.priv_len;
+
+ memcpy(key, &ctx, sizeof(ctx));
+ return 0;
+}
+EXPORT_SYMBOL_GPL(tpm2_key_decode);
diff --git a/security/keys/trusted-keys/tpm2key.asn1 b/drivers/char/tpm/tpm2key.asn1
similarity index 100%
rename from security/keys/trusted-keys/tpm2key.asn1
rename to drivers/char/tpm/tpm2key.asn1
diff --git a/include/crypto/tpm2_key.h b/include/crypto/tpm2_key.h
new file mode 100644
index 000000000000..acf41b2e0c92
--- /dev/null
+++ b/include/crypto/tpm2_key.h
@@ -0,0 +1,33 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+#ifndef __LINUX_TPM2_KEY_H__
+#define __LINUX_TPM2_KEY_H__
+
+#include <linux/slab.h>
+
+/*
+ * TPM2 ASN.1 key
+ */
+struct tpm2_key {
+ u32 parent;
+ const u8 *blob;
+ u32 blob_len;
+ const u8 *pub;
+ u32 pub_len;
+ const u8 *priv;
+ u32 priv_len;
+};
+
+int tpm2_key_decode(const u8 *src, u32 src_len, struct tpm2_key *key,
+ u32 max_key_len);
+
+/**
+ * tpm2_key_free() - Release TPM2 asymmetric key resources and reset values
+ * @key: TPM2 asymmetric key.
+ */
+static inline void tpm2_key_destroy(struct tpm2_key *key)
+{
+ kfree(key->blob);
+ memset(key, 0, sizeof(*key));
+}
+
+#endif /* __LINUX_TPM2_KEY_H__ */
diff --git a/security/keys/trusted-keys/Makefile b/security/keys/trusted-keys/Makefile
index f0f3b27f688b..2674d5c10fc9 100644
--- a/security/keys/trusted-keys/Makefile
+++ b/security/keys/trusted-keys/Makefile
@@ -7,9 +7,7 @@ obj-$(CONFIG_TRUSTED_KEYS) += trusted.o
trusted-y += trusted_core.o
trusted-$(CONFIG_TRUSTED_KEYS_TPM) += trusted_tpm1.o
-$(obj)/trusted_tpm2.o: $(obj)/tpm2key.asn1.h
trusted-$(CONFIG_TRUSTED_KEYS_TPM) += trusted_tpm2.o
-trusted-$(CONFIG_TRUSTED_KEYS_TPM) += tpm2key.asn1.o
trusted-$(CONFIG_TRUSTED_KEYS_TEE) += trusted_tee.o
diff --git a/security/keys/trusted-keys/trusted_tpm2.c b/security/keys/trusted-keys/trusted_tpm2.c
index ec59f9389a2d..f255388d32b8 100644
--- a/security/keys/trusted-keys/trusted_tpm2.c
+++ b/security/keys/trusted-keys/trusted_tpm2.c
@@ -13,11 +13,10 @@
#include <keys/trusted-type.h>
#include <keys/trusted_tpm.h>
+#include <crypto/tpm2_key.h>
#include <asm/unaligned.h>
-#include "tpm2key.asn1.h"
-
static struct tpm2_hash tpm2_hash_map[] = {
{HASH_ALGO_SHA1, TPM_ALG_SHA1},
{HASH_ALGO_SHA256, TPM_ALG_SHA256},
@@ -28,9 +27,9 @@ static struct tpm2_hash tpm2_hash_map[] = {
static u32 tpm2key_oid[] = { 2, 23, 133, 10, 1, 5 };
-static int tpm2_key_encode(struct trusted_key_payload *payload,
- struct trusted_key_options *options,
- u8 *src, u32 len)
+static int tpm2_trusted_key_encode(struct trusted_key_payload *payload,
+ struct trusted_key_options *options,
+ u8 *src, u32 len)
{
const int SCRATCH_SIZE = PAGE_SIZE;
u8 *scratch = kmalloc(SCRATCH_SIZE, GFP_KERNEL);
@@ -100,106 +99,6 @@ static int tpm2_key_encode(struct trusted_key_payload *payload,
return ret;
}
-struct tpm2_key_context {
- u32 parent;
- const u8 *pub;
- u32 pub_len;
- const u8 *priv;
- u32 priv_len;
-};
-
-static int tpm2_key_decode(struct trusted_key_payload *payload,
- struct trusted_key_options *options,
- u8 **buf)
-{
- int ret;
- struct tpm2_key_context ctx;
- u8 *blob;
-
- memset(&ctx, 0, sizeof(ctx));
-
- ret = asn1_ber_decoder(&tpm2key_decoder, &ctx, payload->blob,
- payload->blob_len);
- if (ret < 0)
- return ret;
-
- if (ctx.priv_len + ctx.pub_len > MAX_BLOB_SIZE)
- return -EINVAL;
-
- blob = kmalloc(ctx.priv_len + ctx.pub_len + 4, GFP_KERNEL);
- if (!blob)
- return -ENOMEM;
-
- *buf = blob;
- options->keyhandle = ctx.parent;
-
- memcpy(blob, ctx.priv, ctx.priv_len);
- blob += ctx.priv_len;
-
- memcpy(blob, ctx.pub, ctx.pub_len);
-
- return 0;
-}
-
-int tpm2_key_parent(void *context, size_t hdrlen,
- unsigned char tag,
- const void *value, size_t vlen)
-{
- struct tpm2_key_context *ctx = context;
- const u8 *v = value;
- int i;
-
- ctx->parent = 0;
- for (i = 0; i < vlen; i++) {
- ctx->parent <<= 8;
- ctx->parent |= v[i];
- }
-
- return 0;
-}
-
-int tpm2_key_type(void *context, size_t hdrlen,
- unsigned char tag,
- const void *value, size_t vlen)
-{
- enum OID oid = look_up_OID(value, vlen);
-
- if (oid != OID_TPMSealedData) {
- char buffer[50];
-
- sprint_oid(value, vlen, buffer, sizeof(buffer));
- pr_debug("OID is \"%s\" which is not TPMSealedData\n",
- buffer);
- return -EINVAL;
- }
-
- return 0;
-}
-
-int tpm2_key_pub(void *context, size_t hdrlen,
- unsigned char tag,
- const void *value, size_t vlen)
-{
- struct tpm2_key_context *ctx = context;
-
- ctx->pub = value;
- ctx->pub_len = vlen;
-
- return 0;
-}
-
-int tpm2_key_priv(void *context, size_t hdrlen,
- unsigned char tag,
- const void *value, size_t vlen)
-{
- struct tpm2_key_context *ctx = context;
-
- ctx->priv = value;
- ctx->priv_len = vlen;
-
- return 0;
-}
-
/**
* tpm2_buf_append_auth() - append TPMS_AUTH_COMMAND to the buffer.
*
@@ -349,7 +248,8 @@ int tpm2_seal_trusted(struct tpm_chip *chip,
goto out;
}
- blob_len = tpm2_key_encode(payload, options, &buf.data[offset], blob_len);
+ blob_len = tpm2_trusted_key_encode(payload, options, &buf.data[offset],
+ blob_len);
out:
tpm_buf_destroy(&sized);
@@ -389,21 +289,27 @@ static int tpm2_load_cmd(struct tpm_chip *chip,
struct trusted_key_options *options,
u32 *blob_handle)
{
- struct tpm_buf buf;
unsigned int private_len;
unsigned int public_len;
unsigned int blob_len;
- u8 *blob, *pub;
+ struct tpm2_key key;
+ struct tpm_buf buf;
+ const u8 *blob, *pub;
int rc;
u32 attrs;
- rc = tpm2_key_decode(payload, options, &blob);
+ rc = tpm2_key_decode(payload->blob, payload->blob_len, &key, PAGE_SIZE);
if (rc) {
/* old form */
blob = payload->blob;
payload->old_format = 1;
+ } else {
+ blob = key.blob;
}
+ if (!blob)
+ return -ENOMEM;
+
/* new format carries keyhandle but old format doesn't */
if (!options->keyhandle)
return -EINVAL;
@@ -467,7 +373,8 @@ static int tpm2_load_cmd(struct tpm_chip *chip,
out:
if (blob != payload->blob)
- kfree(blob);
+ tpm2_key_destroy(&key);
+
tpm_buf_destroy(&buf);
if (rc > 0)
--
2.45.1
^ permalink raw reply related [flat|nested] 6+ messages in thread* [PATCH v3 4/5] tpm: tpm2_key: Extend parser to TPM_LoadableKey
2024-05-21 15:26 [PATCH v3 0/5] KEYS: asymmetric: tpm2_key_rsa Jarkko Sakkinen
` (2 preceding siblings ...)
2024-05-21 15:26 ` [PATCH v3 3/5] KEYS: trusted: Move tpm2_key_decode() to the TPM driver Jarkko Sakkinen
@ 2024-05-21 15:26 ` Jarkko Sakkinen
2024-05-21 15:26 ` [PATCH v3 5/5] keys: asymmetric: ASYMMETRIC_TPM2_KEY_RSA_SUBTYPE Jarkko Sakkinen
4 siblings, 0 replies; 6+ messages in thread
From: Jarkko Sakkinen @ 2024-05-21 15:26 UTC (permalink / raw)
To: Herbert Xu
Cc: linux-integrity, keyrings, Andreas.Fuchs, James Prestwood,
David Woodhouse, Eric Biggers, James Bottomley, Jarkko Sakkinen,
David S. Miller, open list:CRYPTO API, open list, Peter Huewe,
Jason Gunthorpe, James Bottomley, Mimi Zohar, David Howells,
Paul Moore, James Morris, Serge E. Hallyn,
open list:SECURITY SUBSYSTEM
Extend parser to TPM_LoadableKey. Add field for oid to struct tpm2_key
so that callers can differentiate different key types.
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
---
v3:
* Fixup klog messages:
https://lore.kernel.org/linux-integrity/SN7PR18MB53140F4341BC441C1C11586EE3EA2@SN7PR18MB5314.namprd18.prod.outlook.com/
---
drivers/char/tpm/tpm2_key.c | 17 ++++++++++++-----
include/crypto/tpm2_key.h | 2 ++
security/keys/trusted-keys/trusted_tpm2.c | 4 ++++
3 files changed, 18 insertions(+), 5 deletions(-)
diff --git a/drivers/char/tpm/tpm2_key.c b/drivers/char/tpm/tpm2_key.c
index 0112362e432e..06be1cc0156b 100644
--- a/drivers/char/tpm/tpm2_key.c
+++ b/drivers/char/tpm/tpm2_key.c
@@ -32,16 +32,23 @@ int tpm2_key_type(void *context, size_t hdrlen,
const void *value, size_t vlen)
{
enum OID oid = look_up_OID(value, vlen);
-
- if (oid != OID_TPMSealedData) {
+ struct tpm2_key *key = context;
+
+ switch (oid) {
+ case OID_TPMSealedData:
+ pr_debug("TPMSealedData\n");
+ break;
+ case OID_TPMLoadableKey:
+ pr_debug("TPMLodableKey\n");
+ break;
+ default:
char buffer[50];
-
sprint_oid(value, vlen, buffer, sizeof(buffer));
- pr_debug("OID is \"%s\" which is not TPMSealedData\n",
- buffer);
+ pr_debug("Unknown OID \"%s\"\n", buffer);
return -EINVAL;
}
+ key->oid = oid;
return 0;
}
diff --git a/include/crypto/tpm2_key.h b/include/crypto/tpm2_key.h
index acf41b2e0c92..2d2434233000 100644
--- a/include/crypto/tpm2_key.h
+++ b/include/crypto/tpm2_key.h
@@ -2,12 +2,14 @@
#ifndef __LINUX_TPM2_KEY_H__
#define __LINUX_TPM2_KEY_H__
+#include <linux/oid_registry.h>
#include <linux/slab.h>
/*
* TPM2 ASN.1 key
*/
struct tpm2_key {
+ enum OID oid;
u32 parent;
const u8 *blob;
u32 blob_len;
diff --git a/security/keys/trusted-keys/trusted_tpm2.c b/security/keys/trusted-keys/trusted_tpm2.c
index f255388d32b8..ce4c667c3ee3 100644
--- a/security/keys/trusted-keys/trusted_tpm2.c
+++ b/security/keys/trusted-keys/trusted_tpm2.c
@@ -305,6 +305,10 @@ static int tpm2_load_cmd(struct tpm_chip *chip,
payload->old_format = 1;
} else {
blob = key.blob;
+ if (key.oid != OID_TPMSealedData) {
+ tpm2_key_destroy(&key);
+ return -EINVAL;
+ }
}
if (!blob)
--
2.45.1
^ permalink raw reply related [flat|nested] 6+ messages in thread* [PATCH v3 5/5] keys: asymmetric: ASYMMETRIC_TPM2_KEY_RSA_SUBTYPE
2024-05-21 15:26 [PATCH v3 0/5] KEYS: asymmetric: tpm2_key_rsa Jarkko Sakkinen
` (3 preceding siblings ...)
2024-05-21 15:26 ` [PATCH v3 4/5] tpm: tpm2_key: Extend parser to TPM_LoadableKey Jarkko Sakkinen
@ 2024-05-21 15:26 ` Jarkko Sakkinen
4 siblings, 0 replies; 6+ messages in thread
From: Jarkko Sakkinen @ 2024-05-21 15:26 UTC (permalink / raw)
To: Herbert Xu
Cc: linux-integrity, keyrings, Andreas.Fuchs, James Prestwood,
David Woodhouse, Eric Biggers, James Bottomley, Jarkko Sakkinen,
David S. Miller, open list:CRYPTO API, open list, David Howells,
James Bottomley, Stefan Berger, Ard Biesheuvel, Mario Limonciello
From: James Prestwood <prestwoj@gmail.com>
Based on earlier work by James Prestwood.
Add ASN.1 compatible asymmetric TPM2 RSA key subtype:
1. Signing and decryption (with the private key) is handled by
TPM2_RSA_Decrypt.
2. Encryption (with the public key) is handled by the kernel RSA
implementation.
Link: https://lore.kernel.org/all/20200518172704.29608-1-prestwoj@gmail.com/
Signed-off-by: James Prestwood <prestwoj@gmail.com>
Co-developed-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
---
v3:
* Drop the special case for null handle i.e. do not define policy.
* Remove empty line:
https://lore.kernel.org/linux-integrity/SN7PR18MB531494159D3996799475209DE3EA2@SN7PR18MB5314.namprd18.prod.outlook.com/
v2:
* Remove two spurios pr_info() messsages that I forgot to remove.
* Clean up padding functions and add additional checks for length
also in tpm2_unpad_pcks1().
* Add the missing success check kzalloc() in tpm2_key_rsa_decrypt().
* Check that params->out_len for capacity before copying the result.
---
crypto/asymmetric_keys/Kconfig | 16 +
crypto/asymmetric_keys/Makefile | 1 +
crypto/asymmetric_keys/tpm2_key_rsa.c | 688 ++++++++++++++++++++++++++
include/linux/tpm.h | 2 +
4 files changed, 707 insertions(+)
create mode 100644 crypto/asymmetric_keys/tpm2_key_rsa.c
diff --git a/crypto/asymmetric_keys/Kconfig b/crypto/asymmetric_keys/Kconfig
index e1345b8f39f1..4d14bb0c346e 100644
--- a/crypto/asymmetric_keys/Kconfig
+++ b/crypto/asymmetric_keys/Kconfig
@@ -15,6 +15,7 @@ config ASYMMETRIC_PUBLIC_KEY_SUBTYPE
select MPILIB
select CRYPTO_HASH_INFO
select CRYPTO_AKCIPHER
+ select CRYPTO_RSA
select CRYPTO_SIG
select CRYPTO_HASH
help
@@ -23,6 +24,21 @@ config ASYMMETRIC_PUBLIC_KEY_SUBTYPE
appropriate hash algorithms (such as SHA-1) must be available.
ENOPKG will be reported if the requisite algorithm is unavailable.
+config ASYMMETRIC_TPM2_KEY_RSA_SUBTYPE
+ tristate "Asymmetric TPM2 RSA crypto algorithm subtype"
+ depends on TCG_TPM
+ select TCG_TPM2_HMAC
+ select CRYPTO_RSA
+ select CRYPTO_SHA256
+ select CRYPTO_HASH_INFO
+ select ASN1
+ select ASN1_ENCODER
+ help
+ This option provides support for asymmetric TPM2 key type handling.
+ If signature generation and/or verification are to be used,
+ appropriate hash algorithms (such as SHA-256) must be available.
+ ENOPKG will be reported if the requisite algorithm is unavailable.
+
config X509_CERTIFICATE_PARSER
tristate "X.509 certificate parser"
depends on ASYMMETRIC_PUBLIC_KEY_SUBTYPE
diff --git a/crypto/asymmetric_keys/Makefile b/crypto/asymmetric_keys/Makefile
index bc65d3b98dcb..c6da84607824 100644
--- a/crypto/asymmetric_keys/Makefile
+++ b/crypto/asymmetric_keys/Makefile
@@ -11,6 +11,7 @@ asymmetric_keys-y := \
signature.o
obj-$(CONFIG_ASYMMETRIC_PUBLIC_KEY_SUBTYPE) += public_key.o
+obj-$(CONFIG_ASYMMETRIC_TPM2_KEY_RSA_SUBTYPE) += tpm2_key_rsa.o
#
# X.509 Certificate handling
diff --git a/crypto/asymmetric_keys/tpm2_key_rsa.c b/crypto/asymmetric_keys/tpm2_key_rsa.c
new file mode 100644
index 000000000000..ecdfa169f406
--- /dev/null
+++ b/crypto/asymmetric_keys/tpm2_key_rsa.c
@@ -0,0 +1,688 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* TPM2 asymmetric public-key crypto subtype
+ *
+ * See Documentation/crypto/asymmetric-keys.rst
+ *
+ * Copyright (c) 2020 Intel Corporation
+ */
+
+#include <asm/unaligned.h>
+#include <crypto/akcipher.h>
+#include <crypto/public_key.h>
+#include <crypto/rsa-pkcs1pad.h>
+#include <crypto/tpm2_key.h>
+#include <keys/asymmetric-parser.h>
+#include <keys/asymmetric-subtype.h>
+#include <keys/trusted-type.h>
+#include <linux/asn1_encoder.h>
+#include <linux/keyctl.h>
+#include <linux/module.h>
+#include <linux/scatterlist.h>
+#include <linux/slab.h>
+#include <linux/tpm.h>
+
+#undef pr_fmt
+#define pr_fmt(fmt) "tpm2_key_rsa: "fmt
+
+#define PUB_KEY_BUF_SIZE 512
+
+struct tpm2_key_rsa {
+ struct tpm2_key key;
+ const u8 *pub;
+ int pub_len;
+};
+
+static const int PKCS1_PAD_MIN_SIZE = 11;
+
+/*
+ * Fill the data with PKCS#1 v1.5 padding.
+ */
+static int tpm2_pad_pkcs1(const u8 *in, int in_len, u8 *out, int out_len)
+{
+ unsigned int prefix_len = out_len - in_len - 3;
+
+ if (in_len > out_len - PKCS1_PAD_MIN_SIZE)
+ return -EBADMSG;
+
+ /* prefix */
+ out[0] = 0;
+ out[1] = 1;
+ memset(&out[2], 0xff, prefix_len);
+ out[2 + prefix_len] = 0;
+ /* payload */
+ memcpy(&out[2 + prefix_len + 1], in, in_len);
+
+ return 0;
+}
+
+/*
+ * RFC 3447 - Section 7.2.2
+ * Size of the input data should be checked against public key size by
+ * the caller.
+ */
+static const u8 *tpm2_unpad_pkcs1(const u8 *in, int in_len, int *out_len)
+{
+ int i;
+
+ if (in[0] != 0 || in[1] != 2)
+ return NULL;
+
+ i = 2;
+ while (in[i] != 0 && i < in_len)
+ i++;
+
+ if (i == in_len || i < (PKCS1_PAD_MIN_SIZE - 1))
+ return NULL;
+
+ *out_len = in_len - i - 1;
+ return in + i + 1;
+}
+
+/*
+ * Outputs the cipher algorithm name on success, and retuns -ENOPKG
+ * on failure.
+ */
+static int tpm2_key_get_akcipher(const char *encoding, const char *hash_algo,
+ char *cipher)
+{
+ ssize_t ret;
+
+ if (strcmp(encoding, "pkcs1") == 0) {
+ if (!hash_algo) {
+ strcpy(cipher, "pkcs1pad(rsa)");
+ return 0;
+ }
+
+ ret = snprintf(cipher, CRYPTO_MAX_ALG_NAME,
+ "pkcs1pad(rsa,%s)",
+ hash_algo);
+ if (ret >= CRYPTO_MAX_ALG_NAME)
+ return -ENOPKG;
+
+ return 0;
+ }
+
+ if (strcmp(encoding, "raw") == 0) {
+ strcpy(cipher, "rsa");
+ return 0;
+ }
+
+ return -ENOPKG;
+}
+
+static int tpm2_key_rsa_extract_pub(struct tpm2_key_rsa *key_rsa)
+{
+ struct tpm2_key *key = &key_rsa->key;
+ struct tpm_buf buf;
+ off_t offset = 2;
+ u16 policy_len;
+ u32 attr;
+ u16 bits;
+ u16 type;
+ u16 len;
+ u16 alg;
+ u32 exp;
+
+ buf.flags = TPM_BUF_TPM2B;
+ buf.length = key->pub_len;
+ buf.data = (void *)key->pub;
+
+ if (get_unaligned_be16(key->pub) != buf.length - 2)
+ return -EINVAL;
+
+ type = tpm_buf_read_u16(&buf, &offset);
+ pr_debug("pub type: 0x%04x\n", type);
+ if (type != TPM_ALG_RSA)
+ return -EINVAL;
+
+ alg = tpm_buf_read_u16(&buf, &offset);
+ pr_debug("pub name alg: 0x%04x\n", alg);
+ attr = tpm_buf_read_u32(&buf, &offset);
+ pr_debug("pub attributes: 0x%08x\n", attr);
+ policy_len = tpm_buf_read_u16(&buf, &offset);
+ pr_debug("pub policy length: %u bytes\n", policy_len);
+ offset += policy_len;
+
+ alg = tpm_buf_read_u16(&buf, &offset);
+ pr_debug("pub symmetric: 0x%04x\n", alg);
+ if (alg != TPM_ALG_NULL)
+ return -EINVAL;
+
+ alg = tpm_buf_read_u16(&buf, &offset);
+ pr_debug("pub symmetric scheme: 0x%04x\n", alg);
+ if (alg != TPM_ALG_NULL)
+ return -EINVAL;
+
+ bits = tpm_buf_read_u16(&buf, &offset);
+ pr_debug("pub bits: %u\n", bits);
+
+ exp = tpm_buf_read_u32(&buf, &offset);
+ pr_debug("pub exponent: 0x%08x\n", exp);
+ if (exp != 0x00000000 && exp != 0x00010001)
+ return -EINVAL;
+
+ len = tpm_buf_read_u16(&buf, &offset);
+ pr_debug("pub modulus: %u bytes\n", len);
+ key_rsa->pub = key->pub + offset;
+ key_rsa->pub_len = len;
+
+ return buf.flags & TPM_BUF_BOUNDARY_ERROR ? -EIO : 0;
+}
+
+static int tpm2_key_rsa_encode(const struct tpm2_key_rsa *key, u8 *buf)
+{
+ const int SCRATCH_SIZE = PAGE_SIZE;
+ const u8 exp[3] = {1, 0, 1};
+ u8 *scratch, *work, *work1, *end_work;
+ int pub_len = key->pub_len;
+ const u8 *pub = key->pub;
+ int ret;
+
+ scratch = kmalloc(SCRATCH_SIZE, GFP_KERNEL);
+ if (!scratch)
+ return -ENOMEM;
+
+ work = scratch;
+ end_work = &scratch[SCRATCH_SIZE];
+
+ work = asn1_encode_integer(work, end_work, pub, pub_len);
+ if (IS_ERR(work)) {
+ ret = PTR_ERR(work);
+ goto err;
+ }
+
+ work = asn1_encode_integer(work, end_work, exp, 3);
+ if (IS_ERR(work)) {
+ ret = PTR_ERR(work);
+ goto err;
+ }
+
+ work1 = buf;
+ work1 = asn1_encode_sequence(work1, &work1[PUB_KEY_BUF_SIZE],
+ scratch, work - scratch);
+ if (IS_ERR(work1)) {
+ ret = PTR_ERR(work1);
+ goto err;
+ }
+
+ memset(work1, 0, 8);
+
+ kfree(scratch);
+ return work1 - buf;
+
+err:
+ kfree(scratch);
+ return ret;
+}
+
+/*
+ * Encryption operation is performed with the public key. Hence it is done
+ * in software
+ */
+static int tpm2_key_rsa_encrypt(struct tpm2_key_rsa *key,
+ struct kernel_pkey_params *params,
+ const void *in, void *out)
+{
+ char cipher[CRYPTO_MAX_ALG_NAME];
+ struct scatterlist in_sg, out_sg;
+ u8 enc_pub_key[PUB_KEY_BUF_SIZE];
+ struct akcipher_request *req;
+ struct crypto_akcipher *tfm;
+ struct crypto_wait cwait;
+ int rc;
+
+ rc = tpm2_key_get_akcipher(params->encoding, params->hash_algo, cipher);
+ if (rc < 0)
+ return rc;
+
+ tfm = crypto_alloc_akcipher(cipher, 0, 0);
+ if (IS_ERR(tfm))
+ return PTR_ERR(tfm);
+
+ rc = tpm2_key_rsa_encode(key, enc_pub_key);
+ if (rc < 0)
+ goto err_tfm;
+
+ rc = crypto_akcipher_set_pub_key(tfm, enc_pub_key, rc);
+ if (rc < 0)
+ goto err_tfm;
+
+ req = akcipher_request_alloc(tfm, GFP_KERNEL);
+ if (!req) {
+ rc = -ENOMEM;
+ goto err_tfm;
+ }
+
+ sg_init_one(&in_sg, in, params->in_len);
+ sg_init_one(&out_sg, out, params->out_len);
+ akcipher_request_set_crypt(req, &in_sg, &out_sg, params->in_len,
+ params->out_len);
+
+ crypto_init_wait(&cwait);
+ akcipher_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG |
+ CRYPTO_TFM_REQ_MAY_SLEEP,
+ crypto_req_done, &cwait);
+
+ rc = crypto_akcipher_encrypt(req);
+ rc = crypto_wait_req(rc, &cwait);
+ if (!rc)
+ rc = req->dst_len;
+
+ akcipher_request_free(req);
+
+err_tfm:
+ crypto_free_akcipher(tfm);
+
+ return rc;
+}
+
+static int __tpm2_key_rsa_decrypt(struct tpm_chip *chip,
+ struct tpm2_key_rsa *key,
+ struct kernel_pkey_params *params,
+ const void *in, int in_len, void *out)
+{
+ unsigned int offset = 0;
+ u32 key_handle = 0;
+ struct tpm_buf buf;
+ u16 decrypted_len;
+ u32 parent;
+ u8 *pos;
+ int ret;
+
+ ret = tpm_try_get_ops(chip);
+ if (ret)
+ return ret;
+
+ ret = tpm2_start_auth_session(chip);
+ if (ret)
+ goto err_ops;
+
+ parent = key->key.parent;
+
+ ret = tpm_buf_init(&buf, TPM2_ST_SESSIONS, TPM2_CC_LOAD);
+ if (ret < 0)
+ goto err_parent;
+
+ tpm_buf_append_name(chip, &buf, parent, NULL);
+ tpm_buf_append_hmac_session(chip, &buf, TPM2_SA_CONTINUE_SESSION |
+ TPM2_SA_ENCRYPT, NULL, 0);
+ tpm_buf_append(&buf, key->key.blob, key->key.blob_len);
+ if (buf.flags & TPM_BUF_OVERFLOW) {
+ ret = -E2BIG;
+ goto err_buf;
+ }
+ tpm_buf_fill_hmac_session(chip, &buf);
+ ret = tpm_transmit_cmd(chip, &buf, 4, "RSA key loading");
+ ret = tpm_buf_check_hmac_response(chip, &buf, ret);
+ if (ret) {
+ ret = -EIO;
+ goto err_buf;
+ }
+ key_handle = be32_to_cpup((__be32 *)&buf.data[TPM_HEADER_SIZE]);
+
+ tpm_buf_reset(&buf, TPM2_ST_SESSIONS, TPM2_CC_RSA_DECRYPT);
+ tpm_buf_append_name(chip, &buf, key_handle, NULL);
+ tpm_buf_append_hmac_session(chip, &buf, TPM2_SA_DECRYPT, NULL, 0);
+ tpm_buf_append_u16(&buf, in_len);
+ tpm_buf_append(&buf, in, in_len);
+ tpm_buf_append_u16(&buf, TPM_ALG_NULL);
+ tpm_buf_append_u16(&buf, 0);
+ tpm_buf_fill_hmac_session(chip, &buf);
+ ret = tpm_transmit_cmd(chip, &buf, 4, "RSA key decrypting");
+ ret = tpm_buf_check_hmac_response(chip, &buf, ret);
+ if (ret) {
+ ret = -EIO;
+ goto err_blob;
+ }
+
+ pos = buf.data + TPM_HEADER_SIZE + 4;
+ decrypted_len = be16_to_cpup((__be16 *)pos);
+ pos += 2;
+
+ if (params->out_len < decrypted_len) {
+ ret = -EMSGSIZE;
+ goto err_blob;
+ }
+
+ memcpy(out, pos, decrypted_len);
+ ret = decrypted_len;
+
+err_blob:
+ tpm2_flush_context(chip, key_handle);
+
+err_buf:
+ tpm_buf_destroy(&buf);
+
+err_parent:
+ if (key->key.parent == TPM2_RH_NULL)
+ tpm2_flush_context(chip, parent);
+
+err_auth:
+ if (ret < 0)
+ tpm2_end_auth_session(chip);
+
+err_ops:
+ tpm_put_ops(chip);
+ return ret;
+}
+
+static int tpm2_key_rsa_decrypt(struct tpm_chip *chip, struct tpm2_key_rsa *key,
+ struct kernel_pkey_params *params,
+ const void *in, void *out)
+{
+ const u8 *ptr;
+ int out_len;
+ u8 *work;
+ int ret;
+
+ work = kzalloc(params->out_len, GFP_KERNEL);
+ if (!work)
+ return -ENOMEM;
+
+ ret = __tpm2_key_rsa_decrypt(chip, key, params, in, params->in_len,
+ work);
+ if (ret < 0)
+ goto err;
+
+ ptr = tpm2_unpad_pkcs1(work, ret, &out_len);
+ if (!ptr) {
+ ret = -EINVAL;
+ goto err;
+ }
+
+ if (out_len > params->out_len) {
+ ret = -EMSGSIZE;
+ goto err;
+ }
+
+ memcpy(out, ptr, out_len);
+ kfree(work);
+ return out_len;
+
+err:
+ kfree(work);
+ return ret;
+}
+
+/*
+ * Sign operation is an encryption using the TPM's private key. With RSA the
+ * only difference between encryption and decryption is where the padding goes.
+ * Since own padding can be used, TPM2_RSA_Decrypt can be repurposed to do
+ * encryption.
+ */
+static int tpm2_key_rsa_sign(struct tpm_chip *chip, struct tpm2_key_rsa *key,
+ struct kernel_pkey_params *params,
+ const void *in, void *out)
+{
+ const struct rsa_asn1_template *asn1;
+ u32 in_len = params->in_len;
+ void *asn1_wrapped = NULL;
+ int pub_len = key->pub_len;
+ u8 *padded;
+ int ret;
+
+ if (strcmp(params->encoding, "pkcs1") != 0) {
+ ret = -ENOPKG;
+ goto err;
+ }
+
+ if (params->hash_algo) {
+ asn1 = rsa_lookup_asn1(params->hash_algo);
+ if (!asn1) {
+ ret = -ENOPKG;
+ goto err;
+ }
+
+ /* Request enough space for the ASN.1 template + input hash */
+ asn1_wrapped = kzalloc(in_len + asn1->size, GFP_KERNEL);
+ if (!asn1_wrapped) {
+ ret = -ENOMEM;
+ goto err;
+ }
+
+ /* Copy ASN.1 template, then the input */
+ memcpy(asn1_wrapped, asn1->data, asn1->size);
+ memcpy(asn1_wrapped + asn1->size, in, in_len);
+
+ in = asn1_wrapped;
+ in_len += asn1->size;
+ }
+
+ /* with padding: */
+ padded = kmalloc(pub_len, GFP_KERNEL);
+ tpm2_pad_pkcs1(in, in_len, padded, pub_len);
+ ret = __tpm2_key_rsa_decrypt(chip, key, params, padded, pub_len, out);
+ kfree(padded);
+
+err:
+ kfree(asn1_wrapped);
+ return ret;
+}
+
+static void tpm2_key_rsa_describe(const struct key *asymmetric_key,
+ struct seq_file *m)
+{
+ struct tpm2_key_rsa *key = asymmetric_key->payload.data[asym_crypto];
+
+ if (!key) {
+ pr_err("key blob missing");
+ return;
+ }
+
+ seq_puts(m, "TPM2/RSA");
+}
+
+static void tpm2_key_rsa_destroy(void *payload0, void *payload3)
+{
+ struct tpm2_key *key = payload0;
+
+ if (!key)
+ return;
+
+ tpm2_key_destroy(key);
+ kfree(key);
+}
+
+static int tpm2_key_rsa_eds_op(struct kernel_pkey_params *params,
+ const void *in, void *out)
+{
+ struct tpm2_key_rsa *key = params->key->payload.data[asym_crypto];
+ struct tpm_chip *chip = tpm_default_chip();
+
+ if (!chip)
+ return -ENODEV;
+
+ switch (params->op) {
+ case kernel_pkey_encrypt:
+ return tpm2_key_rsa_encrypt(key, params, in, out);
+ case kernel_pkey_decrypt:
+ return tpm2_key_rsa_decrypt(chip, key, params, in, out);
+ case kernel_pkey_sign:
+ return tpm2_key_rsa_sign(chip, key, params, in, out);
+ default:
+ return -EOPNOTSUPP;
+ }
+}
+
+static int tpm2_key_rsa_verify(const struct key *key,
+ const struct public_key_signature *sig)
+{
+ const struct tpm2_key_rsa *tpm2_key = key->payload.data[asym_crypto];
+ char alg_name[CRYPTO_MAX_ALG_NAME];
+ u8 enc_pub_key[PUB_KEY_BUF_SIZE];
+ struct akcipher_request *req;
+ struct scatterlist src_sg[2];
+ struct crypto_akcipher *tfm;
+ struct crypto_wait cwait;
+ int rc;
+
+ if (!sig->digest)
+ return -ENOPKG;
+
+ rc = tpm2_key_get_akcipher(sig->encoding, sig->hash_algo, alg_name);
+ if (rc < 0)
+ return rc;
+
+ tfm = crypto_alloc_akcipher(alg_name, 0, 0);
+ if (IS_ERR(tfm))
+ return PTR_ERR(tfm);
+
+ rc = tpm2_key_rsa_encode(tpm2_key, enc_pub_key);
+ if (rc < 0)
+ goto err_tfm;
+
+ rc = crypto_akcipher_set_pub_key(tfm, enc_pub_key, rc);
+ if (rc < 0)
+ goto err_tfm;
+
+ rc = -ENOMEM;
+ req = akcipher_request_alloc(tfm, GFP_KERNEL);
+ if (!req)
+ goto err_tfm;
+
+ sg_init_table(src_sg, 2);
+ sg_set_buf(&src_sg[0], sig->s, sig->s_size);
+ sg_set_buf(&src_sg[1], sig->digest, sig->digest_size);
+ akcipher_request_set_crypt(req, src_sg, NULL, sig->s_size,
+ sig->digest_size);
+ crypto_init_wait(&cwait);
+ akcipher_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG |
+ CRYPTO_TFM_REQ_MAY_SLEEP,
+ crypto_req_done, &cwait);
+ rc = crypto_wait_req(crypto_akcipher_verify(req), &cwait);
+
+ akcipher_request_free(req);
+
+err_tfm:
+ crypto_free_akcipher(tfm);
+ return rc;
+}
+
+static int tpm2_key_rsa_query(const struct kernel_pkey_params *params,
+ struct kernel_pkey_query *info)
+{
+ struct tpm2_key_rsa *tk = params->key->payload.data[asym_crypto];
+ char alg_name[CRYPTO_MAX_ALG_NAME];
+ u8 enc_pub_key[PUB_KEY_BUF_SIZE];
+ struct crypto_akcipher *tfm;
+ unsigned int len;
+ int ret;
+
+ ret = tpm2_key_get_akcipher(params->encoding, params->hash_algo, alg_name);
+ if (ret < 0)
+ return ret;
+
+ tfm = crypto_alloc_akcipher(alg_name, 0, 0);
+ if (IS_ERR(tfm))
+ return PTR_ERR(tfm);
+
+ ret = tpm2_key_rsa_encode(tk, enc_pub_key);
+ if (ret < 0)
+ goto err_tfm;
+
+ ret = crypto_akcipher_set_pub_key(tfm, enc_pub_key, ret);
+ if (ret < 0)
+ goto err_tfm;
+
+ len = crypto_akcipher_maxsize(tfm);
+
+ info->key_size = tk->pub_len * 8;
+ info->max_data_size = tk->pub_len;
+ info->max_sig_size = len;
+ info->max_enc_size = len;
+ info->max_dec_size = tk->pub_len;
+
+ info->supported_ops = KEYCTL_SUPPORTS_ENCRYPT |
+ KEYCTL_SUPPORTS_DECRYPT |
+ KEYCTL_SUPPORTS_VERIFY |
+ KEYCTL_SUPPORTS_SIGN;
+
+err_tfm:
+ crypto_free_akcipher(tfm);
+ return ret;
+}
+
+/*
+ * Asymmetric TPM2 RSA key. Signs and decrypts with TPM.
+ */
+struct asymmetric_key_subtype tpm2_key_rsa_subtype = {
+ .owner = THIS_MODULE,
+ .name = "tpm2_key_rsa",
+ .name_len = sizeof("tpm2_key_rsa") - 1,
+ .describe = tpm2_key_rsa_describe,
+ .destroy = tpm2_key_rsa_destroy,
+ .query = tpm2_key_rsa_query,
+ .eds_op = tpm2_key_rsa_eds_op,
+ .verify_signature = tpm2_key_rsa_verify,
+};
+EXPORT_SYMBOL_GPL(tpm2_key_rsa_subtype);
+
+/*
+ * Attempt to parse a data blob for a key as a TPM private key blob.
+ */
+static int tpm2_key_preparse(struct key_preparsed_payload *prep)
+{
+ struct tpm2_key_rsa *key;
+ int ret;
+
+ key = kzalloc(sizeof(*key), GFP_KERNEL);
+ if (!key)
+ return -ENOMEM;
+
+ /*
+ * TPM 2.0 RSA keys are recommended to be 2048 bits long. Assume the
+ * blob is no more than 4x that.
+ */
+ if (prep->datalen > 256 * 4) {
+ kfree(key);
+ return -EMSGSIZE;
+ }
+
+ ret = tpm2_key_decode(prep->data, prep->datalen, &key->key, PAGE_SIZE);
+ if (ret) {
+ kfree(key);
+ return ret;
+ }
+
+ if (key->key.oid != OID_TPMLoadableKey) {
+ tpm2_key_destroy(&key->key);
+ kfree(key);
+ return -EINVAL;
+ }
+
+ ret = tpm2_key_rsa_extract_pub(key);
+ if (ret < 0) {
+ tpm2_key_destroy(&key->key);
+ kfree(key);
+ return ret;
+ }
+
+ prep->payload.data[asym_subtype] = &tpm2_key_rsa_subtype;
+ prep->payload.data[asym_key_ids] = NULL;
+ prep->payload.data[asym_crypto] = key;
+ prep->payload.data[asym_auth] = NULL;
+ prep->quotalen = 100;
+ return 0;
+}
+
+static struct asymmetric_key_parser tpm2_key_rsa_parser = {
+ .owner = THIS_MODULE,
+ .name = "tpm2_key_rsa_parser",
+ .parse = tpm2_key_preparse,
+};
+
+static int __init tpm2_key_rsa_init(void)
+{
+ return register_asymmetric_key_parser(&tpm2_key_rsa_parser);
+}
+
+static void __exit tpm2_key_rsa_exit(void)
+{
+ unregister_asymmetric_key_parser(&tpm2_key_rsa_parser);
+}
+
+module_init(tpm2_key_rsa_init);
+module_exit(tpm2_key_rsa_exit);
+
+MODULE_DESCRIPTION("Asymmetric TPM2 RSA key");
+MODULE_LICENSE("GPL");
diff --git a/include/linux/tpm.h b/include/linux/tpm.h
index c17e4efbb2e5..040be2c75868 100644
--- a/include/linux/tpm.h
+++ b/include/linux/tpm.h
@@ -43,6 +43,7 @@ enum tpm2_session_types {
/* if you add a new hash to this, increment TPM_MAX_HASHES below */
enum tpm_algorithms {
TPM_ALG_ERROR = 0x0000,
+ TPM_ALG_RSA = 0x0001,
TPM_ALG_SHA1 = 0x0004,
TPM_ALG_AES = 0x0006,
TPM_ALG_KEYEDHASH = 0x0008,
@@ -271,6 +272,7 @@ enum tpm2_command_codes {
TPM2_CC_NV_READ = 0x014E,
TPM2_CC_CREATE = 0x0153,
TPM2_CC_LOAD = 0x0157,
+ TPM2_CC_RSA_DECRYPT = 0x0159,
TPM2_CC_SEQUENCE_UPDATE = 0x015C,
TPM2_CC_UNSEAL = 0x015E,
TPM2_CC_CONTEXT_LOAD = 0x0161,
--
2.45.1
^ permalink raw reply related [flat|nested] 6+ messages in thread