[PATCH v7 03/11] KEYS: trusted: remove redundant instance of tpm2_hash_map

[Jarkko Sakkinen <jarkko@kernel.org>]

Trusted keys duplicates tpm2_hash_map from TPM driver internals. Implement
and export `tpm2_find_hash_alg()` in order to address this glitch, and
replace redundant code block with a call this new function.

Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
---
v7:
- A new patch.
---
 drivers/char/tpm/tpm2-cmd.c               | 19 +++++++++++++++--
 include/linux/tpm.h                       |  7 ++-----
 security/keys/trusted-keys/trusted_tpm2.c | 25 +++++------------------
 3 files changed, 24 insertions(+), 27 deletions(-)

diff --git a/drivers/char/tpm/tpm2-cmd.c b/drivers/char/tpm/tpm2-cmd.c
index 97501c567c34..1393bfbeca64 100644
--- a/drivers/char/tpm/tpm2-cmd.c
+++ b/drivers/char/tpm/tpm2-cmd.c
@@ -18,7 +18,10 @@ static bool disable_pcr_integrity;
 module_param(disable_pcr_integrity, bool, 0444);
 MODULE_PARM_DESC(disable_pcr_integrity, "Disable integrity protection of TPM2_PCR_Extend");
 
-static struct tpm2_hash tpm2_hash_map[] = {
+static struct {
+	unsigned int crypto_id;
+	unsigned int alg_id;
+} tpm2_hash_map[] = {
 	{HASH_ALGO_SHA1, TPM_ALG_SHA1},
 	{HASH_ALGO_SHA256, TPM_ALG_SHA256},
 	{HASH_ALGO_SHA384, TPM_ALG_SHA384},
@@ -26,6 +29,18 @@ static struct tpm2_hash tpm2_hash_map[] = {
 	{HASH_ALGO_SM3_256, TPM_ALG_SM3_256},
 };
 
+int tpm2_find_hash_alg(unsigned int crypto_id)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(tpm2_hash_map); i++)
+		if (crypto_id == tpm2_hash_map[i].crypto_id)
+			return tpm2_hash_map[i].alg_id;
+
+	return -EINVAL;
+}
+EXPORT_SYMBOL_GPL(tpm2_find_hash_alg);
+
 int tpm2_get_timeouts(struct tpm_chip *chip)
 {
 	chip->timeout_a = msecs_to_jiffies(TPM2_TIMEOUT_A);
@@ -490,7 +505,7 @@ static int tpm2_init_bank_info(struct tpm_chip *chip, u32 bank_index)
 	for (i = 0; i < ARRAY_SIZE(tpm2_hash_map); i++) {
 		enum hash_algo crypto_algo = tpm2_hash_map[i].crypto_id;
 
-		if (bank->alg_id != tpm2_hash_map[i].tpm_id)
+		if (bank->alg_id != tpm2_hash_map[i].alg_id)
 			continue;
 
 		bank->digest_size = hash_digest_size[crypto_algo];
diff --git a/include/linux/tpm.h b/include/linux/tpm.h
index 0e9e043f728c..e5fc7b73de2d 100644
--- a/include/linux/tpm.h
+++ b/include/linux/tpm.h
@@ -410,11 +410,6 @@ enum tpm2_session_attributes {
 	TPM2_SA_AUDIT			= BIT(7),
 };
 
-struct tpm2_hash {
-	unsigned int crypto_id;
-	unsigned int tpm_id;
-};
-
 int tpm_buf_init(struct tpm_buf *buf, u16 tag, u32 ordinal);
 void tpm_buf_reset(struct tpm_buf *buf, u16 tag, u32 ordinal);
 int tpm_buf_init_sized(struct tpm_buf *buf);
@@ -465,6 +460,7 @@ static inline ssize_t tpm_ret_to_err(ssize_t ret)
 
 #if defined(CONFIG_TCG_TPM) || defined(CONFIG_TCG_TPM_MODULE)
 
+unsigned int tpm2_alg_to_crypto_id(unsigned int alg_id);
 extern int tpm_is_tpm2(struct tpm_chip *chip);
 extern __must_check int tpm_try_get_ops(struct tpm_chip *chip);
 extern void tpm_put_ops(struct tpm_chip *chip);
@@ -477,6 +473,7 @@ extern int tpm_pcr_extend(struct tpm_chip *chip, u32 pcr_idx,
 extern int tpm_get_random(struct tpm_chip *chip, u8 *data, size_t max);
 extern struct tpm_chip *tpm_default_chip(void);
 void tpm2_flush_context(struct tpm_chip *chip, u32 handle);
+int tpm2_find_hash_alg(unsigned int crypto_id);
 
 static inline void tpm_buf_append_empty_auth(struct tpm_buf *buf, u32 handle)
 {
diff --git a/security/keys/trusted-keys/trusted_tpm2.c b/security/keys/trusted-keys/trusted_tpm2.c
index 024be262702f..3205732fb4b7 100644
--- a/security/keys/trusted-keys/trusted_tpm2.c
+++ b/security/keys/trusted-keys/trusted_tpm2.c
@@ -18,14 +18,6 @@
 
 #include "tpm2key.asn1.h"
 
-static struct tpm2_hash tpm2_hash_map[] = {
-	{HASH_ALGO_SHA1, TPM_ALG_SHA1},
-	{HASH_ALGO_SHA256, TPM_ALG_SHA256},
-	{HASH_ALGO_SHA384, TPM_ALG_SHA384},
-	{HASH_ALGO_SHA512, TPM_ALG_SHA512},
-	{HASH_ALGO_SM3_256, TPM_ALG_SM3_256},
-};
-
 static u32 tpm2key_oid[] = { 2, 23, 133, 10, 1, 5 };
 
 static int tpm2_key_encode(struct trusted_key_payload *payload,
@@ -244,24 +236,17 @@ int tpm2_seal_trusted(struct tpm_chip *chip,
 	off_t offset = TPM_HEADER_SIZE;
 	struct tpm_buf buf, sized;
 	int blob_len = 0;
-	u32 hash;
+	int hash;
 	u32 flags;
-	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;
-
 	if (!options->keyhandle)
 		return -EINVAL;
 
+	hash = tpm2_find_hash_alg(options->hash);
+	if (hash)
+		return hash;
+
 	rc = tpm_try_get_ops(chip);
 	if (rc)
 		return rc;
-- 
2.52.0