From 5ca4c20cfd37bac6486de040e9951b3b34755238 Mon Sep 17 00:00:00 2001
From: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Date: Thu, 5 Nov 2015 21:43:06 +0200
Subject: keys, trusted: select hash algorithm for TPM2 chips

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@linux.intel.com>
Tested-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: James Morris <james.l.morris@oracle.com>
Reviewed-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Acked-by: Peter Huewe <peterhuewe@gmx.de>
---
 security/keys/Kconfig   |  1 +
 security/keys/trusted.c | 27 ++++++++++++++++++++++++++-
 2 files changed, 27 insertions(+), 1 deletion(-)

(limited to 'security')

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;
 		}
-- 
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