tpm: Move tpm_get_random api into the TPM device driver
Move the tpm_get_random api from the trusted keys code into the TPM
device driver itself so that other callers can make use of it. Also,
change the api slightly so that the number of bytes read is returned in
the call, since the TPM command can potentially return fewer bytes than
requested.
Acked-by: David Safford <safford@linux.vnet.ibm.com>
Reviewed-by: H. Peter Anvin <hpa@linux.intel.com>
Signed-off-by: Kent Yoder <key@linux.vnet.ibm.com>
diff --git a/security/keys/trusted.c b/security/keys/trusted.c
index 2d5d041..3f163d0 100644
--- a/security/keys/trusted.c
+++ b/security/keys/trusted.c
@@ -369,38 +369,6 @@
}
/*
- * get a random value from TPM
- */
-static int tpm_get_random(struct tpm_buf *tb, unsigned char *buf, uint32_t len)
-{
- int ret;
-
- INIT_BUF(tb);
- store16(tb, TPM_TAG_RQU_COMMAND);
- store32(tb, TPM_GETRANDOM_SIZE);
- store32(tb, TPM_ORD_GETRANDOM);
- store32(tb, len);
- ret = trusted_tpm_send(TPM_ANY_NUM, tb->data, sizeof tb->data);
- if (!ret)
- memcpy(buf, tb->data + TPM_GETRANDOM_SIZE, len);
- return ret;
-}
-
-static int my_get_random(unsigned char *buf, int len)
-{
- struct tpm_buf *tb;
- int ret;
-
- tb = kmalloc(sizeof *tb, GFP_KERNEL);
- if (!tb)
- return -ENOMEM;
- ret = tpm_get_random(tb, buf, len);
-
- kfree(tb);
- return ret;
-}
-
-/*
* Lock a trusted key, by extending a selected PCR.
*
* Prevents a trusted key that is sealed to PCRs from being accessed.
@@ -413,8 +381,8 @@
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
- ret = my_get_random(hash, SHA1_DIGEST_SIZE);
- if (ret < 0)
+ ret = tpm_get_random(TPM_ANY_NUM, hash, SHA1_DIGEST_SIZE);
+ if (ret != SHA1_DIGEST_SIZE)
return ret;
return tpm_pcr_extend(TPM_ANY_NUM, pcrnum, hash) ? -EINVAL : 0;
}
@@ -429,8 +397,8 @@
unsigned char ononce[TPM_NONCE_SIZE];
int ret;
- ret = tpm_get_random(tb, ononce, TPM_NONCE_SIZE);
- if (ret < 0)
+ ret = tpm_get_random(TPM_ANY_NUM, ononce, TPM_NONCE_SIZE);
+ if (ret != TPM_NONCE_SIZE)
return ret;
INIT_BUF(tb);
@@ -524,8 +492,8 @@
if (ret < 0)
goto out;
- ret = tpm_get_random(tb, td->nonceodd, TPM_NONCE_SIZE);
- if (ret < 0)
+ ret = tpm_get_random(TPM_ANY_NUM, td->nonceodd, TPM_NONCE_SIZE);
+ if (ret != TPM_NONCE_SIZE)
goto out;
ordinal = htonl(TPM_ORD_SEAL);
datsize = htonl(datalen);
@@ -634,8 +602,8 @@
ordinal = htonl(TPM_ORD_UNSEAL);
keyhndl = htonl(SRKHANDLE);
- ret = tpm_get_random(tb, nonceodd, TPM_NONCE_SIZE);
- if (ret < 0) {
+ ret = tpm_get_random(TPM_ANY_NUM, nonceodd, TPM_NONCE_SIZE);
+ if (ret != TPM_NONCE_SIZE) {
pr_info("trusted_key: tpm_get_random failed (%d)\n", ret);
return ret;
}
@@ -935,6 +903,7 @@
char *datablob;
int ret = 0;
int key_cmd;
+ size_t key_len;
if (datalen <= 0 || datalen > 32767 || !data)
return -EINVAL;
@@ -974,8 +943,9 @@
pr_info("trusted_key: key_unseal failed (%d)\n", ret);
break;
case Opt_new:
- ret = my_get_random(payload->key, payload->key_len);
- if (ret < 0) {
+ key_len = payload->key_len;
+ ret = tpm_get_random(TPM_ANY_NUM, payload->key, key_len);
+ if (ret != key_len) {
pr_info("trusted_key: key_create failed (%d)\n", ret);
goto out;
}