[PATCH v2 2/3] keys, trusted: select hash algorithm for TPM2 chips
From: Jarkko Sakkinen
Date: Sun Dec 13 2015 - 10:43:00 EST
Added 'hash=' option for selecting the hash algorithm for add_key()
syscall and documentation for it.
Added entry for sm3-256 to the following tables in order to support
TPM_ALG_SM3_256:
* hash_algo_name
* hash_digest_size
Includes support for the following hash algorithms:
* sha1
* sha256
* sha384
* sha512
* sm3-256
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@xxxxxxxxxxxxxxx>
Tested-by: Colin Ian King <colin.king@xxxxxxxxxxxxx>
Reviewed-by: James Morris <james.l.morris@xxxxxxxxxx>
---
Documentation/security/keys-trusted-encrypted.txt | 3 ++
crypto/hash_info.c | 2 ++
drivers/char/tpm/tpm.h | 10 +++++--
drivers/char/tpm/tpm2-cmd.c | 36 +++++++++++++++++++++--
include/crypto/hash_info.h | 3 ++
include/keys/trusted-type.h | 1 +
include/uapi/linux/hash_info.h | 1 +
security/keys/Kconfig | 1 +
security/keys/trusted.c | 27 ++++++++++++++++-
9 files changed, 77 insertions(+), 7 deletions(-)
diff --git a/Documentation/security/keys-trusted-encrypted.txt b/Documentation/security/keys-trusted-encrypted.txt
index e105ae9..fd2565b 100644
--- a/Documentation/security/keys-trusted-encrypted.txt
+++ b/Documentation/security/keys-trusted-encrypted.txt
@@ -38,6 +38,9 @@ Usage:
pcrlock= pcr number to be extended to "lock" blob
migratable= 0|1 indicating permission to reseal to new PCR values,
default 1 (resealing allowed)
+ hash= hash algorithm name as a string. For TPM 1.x the only
+ allowed value is sha1. For TPM 2.x the allowed values
+ are sha1, sha256, sha384, sha512 and sm3-256.
"keyctl print" returns an ascii hex copy of the sealed key, which is in standard
TPM_STORED_DATA format. The key length for new keys are always in bytes.
diff --git a/crypto/hash_info.c b/crypto/hash_info.c
index 3e7ff46..7b1e0b1 100644
--- a/crypto/hash_info.c
+++ b/crypto/hash_info.c
@@ -31,6 +31,7 @@ const char *const hash_algo_name[HASH_ALGO__LAST] = {
[HASH_ALGO_TGR_128] = "tgr128",
[HASH_ALGO_TGR_160] = "tgr160",
[HASH_ALGO_TGR_192] = "tgr192",
+ [HASH_ALGO_SM3_256] = "sm3-256",
};
EXPORT_SYMBOL_GPL(hash_algo_name);
@@ -52,5 +53,6 @@ const int hash_digest_size[HASH_ALGO__LAST] = {
[HASH_ALGO_TGR_128] = TGR128_DIGEST_SIZE,
[HASH_ALGO_TGR_160] = TGR160_DIGEST_SIZE,
[HASH_ALGO_TGR_192] = TGR192_DIGEST_SIZE,
+ [HASH_ALGO_SM3_256] = SM3256_DIGEST_SIZE,
};
EXPORT_SYMBOL_GPL(hash_digest_size);
diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h
index 347fc61..542a80c 100644
--- a/drivers/char/tpm/tpm.h
+++ b/drivers/char/tpm/tpm.h
@@ -83,16 +83,20 @@ enum tpm2_structures {
};
enum tpm2_return_codes {
- TPM2_RC_INITIALIZE = 0x0100,
- TPM2_RC_TESTING = 0x090A,
+ TPM2_RC_HASH = 0x0083, /* RC_FMT1 */
+ TPM2_RC_INITIALIZE = 0x0100, /* RC_VER1 */
TPM2_RC_DISABLED = 0x0120,
+ TPM2_RC_TESTING = 0x090A, /* RC_WARN */
};
enum tpm2_algorithms {
TPM2_ALG_SHA1 = 0x0004,
TPM2_ALG_KEYEDHASH = 0x0008,
TPM2_ALG_SHA256 = 0x000B,
- TPM2_ALG_NULL = 0x0010
+ TPM2_ALG_SHA384 = 0x000C,
+ TPM2_ALG_SHA512 = 0x000D,
+ TPM2_ALG_NULL = 0x0010,
+ TPM2_ALG_SM3_256 = 0x0012,
};
enum tpm2_command_codes {
diff --git a/drivers/char/tpm/tpm2-cmd.c b/drivers/char/tpm/tpm2-cmd.c
index c121304..d9d0822 100644
--- a/drivers/char/tpm/tpm2-cmd.c
+++ b/drivers/char/tpm/tpm2-cmd.c
@@ -16,6 +16,7 @@
*/
#include "tpm.h"
+#include <crypto/hash_info.h>
#include <keys/trusted-type.h>
enum tpm2_object_attributes {
@@ -104,6 +105,19 @@ struct tpm2_cmd {
union tpm2_cmd_params params;
} __packed;
+struct tpm2_hash {
+ unsigned int crypto_id;
+ unsigned int tpm_id;
+};
+
+static struct tpm2_hash tpm2_hash_map[] = {
+ {HASH_ALGO_SHA1, TPM2_ALG_SHA1},
+ {HASH_ALGO_SHA256, TPM2_ALG_SHA256},
+ {HASH_ALGO_SHA384, TPM2_ALG_SHA384},
+ {HASH_ALGO_SHA512, TPM2_ALG_SHA512},
+ {HASH_ALGO_SM3_256, TPM2_ALG_SM3_256},
+};
+
/*
* Array with one entry per ordinal defining the maximum amount
* of time the chip could take to return the result. The values
@@ -429,8 +443,20 @@ int tpm2_seal_trusted(struct tpm_chip *chip,
{
unsigned int blob_len;
struct tpm_buf buf;
+ u32 hash;
+ int i;
int rc;
+ for (i = 0; i < ARRAY_SIZE(tpm2_hash_map); i++) {
+ if (options->hash == tpm2_hash_map[i].crypto_id) {
+ hash = tpm2_hash_map[i].tpm_id;
+ break;
+ }
+ }
+
+ if (i == ARRAY_SIZE(tpm2_hash_map))
+ return -EINVAL;
+
rc = tpm_buf_init(&buf, TPM2_ST_SESSIONS, TPM2_CC_CREATE);
if (rc)
return rc;
@@ -455,7 +481,7 @@ int tpm2_seal_trusted(struct tpm_chip *chip,
tpm_buf_append_u16(&buf, 14);
tpm_buf_append_u16(&buf, TPM2_ALG_KEYEDHASH);
- tpm_buf_append_u16(&buf, TPM2_ALG_SHA256);
+ tpm_buf_append_u16(&buf, hash);
tpm_buf_append_u32(&buf, TPM2_ATTR_USER_WITH_AUTH);
tpm_buf_append_u16(&buf, 0); /* policy digest size */
tpm_buf_append_u16(&buf, TPM2_ALG_NULL);
@@ -488,8 +514,12 @@ int tpm2_seal_trusted(struct tpm_chip *chip,
out:
tpm_buf_destroy(&buf);
- if (rc > 0)
- rc = -EPERM;
+ if (rc > 0) {
+ if ((rc & TPM2_RC_HASH) == TPM2_RC_HASH)
+ rc = -EINVAL;
+ else
+ rc = -EPERM;
+ }
return rc;
}
diff --git a/include/crypto/hash_info.h b/include/crypto/hash_info.h
index e1e5a3e..56f217d 100644
--- a/include/crypto/hash_info.h
+++ b/include/crypto/hash_info.h
@@ -34,6 +34,9 @@
#define TGR160_DIGEST_SIZE 20
#define TGR192_DIGEST_SIZE 24
+/* not defined in include/crypto/ */
+#define SM3256_DIGEST_SIZE 32
+
extern const char *const hash_algo_name[HASH_ALGO__LAST];
extern const int hash_digest_size[HASH_ALGO__LAST];
diff --git a/include/keys/trusted-type.h b/include/keys/trusted-type.h
index f91ecd9..a6a1008 100644
--- a/include/keys/trusted-type.h
+++ b/include/keys/trusted-type.h
@@ -36,6 +36,7 @@ struct trusted_key_options {
uint32_t pcrinfo_len;
unsigned char pcrinfo[MAX_PCRINFO_SIZE];
int pcrlock;
+ uint32_t hash;
};
extern struct key_type key_type_trusted;
diff --git a/include/uapi/linux/hash_info.h b/include/uapi/linux/hash_info.h
index ca18c45..ebf8fd8 100644
--- a/include/uapi/linux/hash_info.h
+++ b/include/uapi/linux/hash_info.h
@@ -31,6 +31,7 @@ enum hash_algo {
HASH_ALGO_TGR_128,
HASH_ALGO_TGR_160,
HASH_ALGO_TGR_192,
+ HASH_ALGO_SM3_256,
HASH_ALGO__LAST
};
diff --git a/security/keys/Kconfig b/security/keys/Kconfig
index 72483b8..fe4d74e 100644
--- a/security/keys/Kconfig
+++ b/security/keys/Kconfig
@@ -54,6 +54,7 @@ config TRUSTED_KEYS
select CRYPTO
select CRYPTO_HMAC
select CRYPTO_SHA1
+ select CRYPTO_HASH_INFO
help
This option provides support for creating, sealing, and unsealing
keys in the kernel. Trusted keys are random number symmetric keys,
diff --git a/security/keys/trusted.c b/security/keys/trusted.c
index 7c183c7..8f1300c 100644
--- a/security/keys/trusted.c
+++ b/security/keys/trusted.c
@@ -11,6 +11,7 @@
* See Documentation/security/keys-trusted-encrypted.txt
*/
+#include <crypto/hash_info.h>
#include <linux/uaccess.h>
#include <linux/module.h>
#include <linux/init.h>
@@ -710,7 +711,8 @@ enum {
Opt_err = -1,
Opt_new, Opt_load, Opt_update,
Opt_keyhandle, Opt_keyauth, Opt_blobauth,
- Opt_pcrinfo, Opt_pcrlock, Opt_migratable
+ Opt_pcrinfo, Opt_pcrlock, Opt_migratable,
+ Opt_hash,
};
static const match_table_t key_tokens = {
@@ -723,6 +725,7 @@ static const match_table_t key_tokens = {
{Opt_pcrinfo, "pcrinfo=%s"},
{Opt_pcrlock, "pcrlock=%s"},
{Opt_migratable, "migratable=%s"},
+ {Opt_hash, "hash=%s"},
{Opt_err, NULL}
};
@@ -737,6 +740,14 @@ static int getoptions(char *c, struct trusted_key_payload *pay,
unsigned long handle;
unsigned long lock;
unsigned long token_mask = 0;
+ int i;
+ int tpm2;
+
+ tpm2 = tpm_is_tpm2(TPM_ANY_NUM);
+ if (tpm2 < 0)
+ return tpm2;
+
+ opt->hash = tpm2 ? HASH_ALGO_SHA256 : HASH_ALGO_SHA1;
while ((p = strsep(&c, " \t"))) {
if (*p == '\0' || *p == ' ' || *p == '\t')
@@ -790,6 +801,20 @@ static int getoptions(char *c, struct trusted_key_payload *pay,
return -EINVAL;
opt->pcrlock = lock;
break;
+ case Opt_hash:
+ for (i = 0; i < HASH_ALGO__LAST; i++) {
+ if (!strcmp(args[0].from, hash_algo_name[i])) {
+ opt->hash = i;
+ break;
+ }
+ }
+ if (i == HASH_ALGO__LAST)
+ return -EINVAL;
+ if (!tpm2 && i != HASH_ALGO_SHA1) {
+ pr_info("trusted_key: TPM 1.x only supports SHA-1.\n");
+ return -EINVAL;
+ }
+ break;
default:
return -EINVAL;
}
--
2.5.0
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