[PATCH] KEYS: asym_tpm: Use common tpm_buf for asymmetric keys

From: Sumit Garg
Date: Wed Sep 11 2019 - 07:22:51 EST


Switch to utilize common heap based tpm_buf code for TPM based
asymmetric keys rather than using stack based tpm_buf code.

Reported-by: kbuild test robot <lkp@xxxxxxxxx>
Signed-off-by: Sumit Garg <sumit.garg@xxxxxxxxxx>
---
crypto/asymmetric_keys/asym_tpm.c | 99 ++++++++++++++++-----------------------
1 file changed, 41 insertions(+), 58 deletions(-)

diff --git a/crypto/asymmetric_keys/asym_tpm.c b/crypto/asymmetric_keys/asym_tpm.c
index ec3f309..d16d893 100644
--- a/crypto/asymmetric_keys/asym_tpm.c
+++ b/crypto/asymmetric_keys/asym_tpm.c
@@ -21,10 +21,6 @@
#define TPM_ORD_LOADKEY2 65
#define TPM_ORD_UNBIND 30
#define TPM_ORD_SIGN 60
-#define TPM_LOADKEY2_SIZE 59
-#define TPM_FLUSHSPECIFIC_SIZE 18
-#define TPM_UNBIND_SIZE 63
-#define TPM_SIGN_SIZE 63

#define TPM_RT_KEY 0x00000001

@@ -68,16 +64,13 @@ static int tpm_loadkey2(struct tpm_buf *tb,
return ret;

/* build the request buffer */
- INIT_BUF(tb);
- store16(tb, TPM_TAG_RQU_AUTH1_COMMAND);
- store32(tb, TPM_LOADKEY2_SIZE + keybloblen);
- store32(tb, TPM_ORD_LOADKEY2);
- store32(tb, keyhandle);
- storebytes(tb, keyblob, keybloblen);
- store32(tb, authhandle);
- storebytes(tb, nonceodd, TPM_NONCE_SIZE);
- store8(tb, cont);
- storebytes(tb, authdata, SHA1_DIGEST_SIZE);
+ tpm_buf_reset(tb, TPM_TAG_RQU_AUTH1_COMMAND, TPM_ORD_LOADKEY2);
+ tpm_buf_append_u32(tb, keyhandle);
+ tpm_buf_append(tb, keyblob, keybloblen);
+ tpm_buf_append_u32(tb, authhandle);
+ tpm_buf_append(tb, nonceodd, TPM_NONCE_SIZE);
+ tpm_buf_append_u8(tb, cont);
+ tpm_buf_append(tb, authdata, SHA1_DIGEST_SIZE);

ret = trusted_tpm_send(tb->data, MAX_BUF_SIZE);
if (ret < 0) {
@@ -101,12 +94,9 @@ static int tpm_loadkey2(struct tpm_buf *tb,
*/
static int tpm_flushspecific(struct tpm_buf *tb, uint32_t handle)
{
- INIT_BUF(tb);
- store16(tb, TPM_TAG_RQU_COMMAND);
- store32(tb, TPM_FLUSHSPECIFIC_SIZE);
- store32(tb, TPM_ORD_FLUSHSPECIFIC);
- store32(tb, handle);
- store32(tb, TPM_RT_KEY);
+ tpm_buf_reset(tb, TPM_TAG_RQU_COMMAND, TPM_ORD_FLUSHSPECIFIC);
+ tpm_buf_append_u32(tb, handle);
+ tpm_buf_append_u32(tb, TPM_RT_KEY);

return trusted_tpm_send(tb->data, MAX_BUF_SIZE);
}
@@ -155,17 +145,14 @@ static int tpm_unbind(struct tpm_buf *tb,
return ret;

/* build the request buffer */
- INIT_BUF(tb);
- store16(tb, TPM_TAG_RQU_AUTH1_COMMAND);
- store32(tb, TPM_UNBIND_SIZE + bloblen);
- store32(tb, TPM_ORD_UNBIND);
- store32(tb, keyhandle);
- store32(tb, bloblen);
- storebytes(tb, blob, bloblen);
- store32(tb, authhandle);
- storebytes(tb, nonceodd, TPM_NONCE_SIZE);
- store8(tb, cont);
- storebytes(tb, authdata, SHA1_DIGEST_SIZE);
+ tpm_buf_reset(tb, TPM_TAG_RQU_AUTH1_COMMAND, TPM_ORD_UNBIND);
+ tpm_buf_append_u32(tb, keyhandle);
+ tpm_buf_append_u32(tb, bloblen);
+ tpm_buf_append(tb, blob, bloblen);
+ tpm_buf_append_u32(tb, authhandle);
+ tpm_buf_append(tb, nonceodd, TPM_NONCE_SIZE);
+ tpm_buf_append_u8(tb, cont);
+ tpm_buf_append(tb, authdata, SHA1_DIGEST_SIZE);

ret = trusted_tpm_send(tb->data, MAX_BUF_SIZE);
if (ret < 0) {
@@ -241,17 +228,14 @@ static int tpm_sign(struct tpm_buf *tb,
return ret;

/* build the request buffer */
- INIT_BUF(tb);
- store16(tb, TPM_TAG_RQU_AUTH1_COMMAND);
- store32(tb, TPM_SIGN_SIZE + bloblen);
- store32(tb, TPM_ORD_SIGN);
- store32(tb, keyhandle);
- store32(tb, bloblen);
- storebytes(tb, blob, bloblen);
- store32(tb, authhandle);
- storebytes(tb, nonceodd, TPM_NONCE_SIZE);
- store8(tb, cont);
- storebytes(tb, authdata, SHA1_DIGEST_SIZE);
+ tpm_buf_reset(tb, TPM_TAG_RQU_AUTH1_COMMAND, TPM_ORD_SIGN);
+ tpm_buf_append_u32(tb, keyhandle);
+ tpm_buf_append_u32(tb, bloblen);
+ tpm_buf_append(tb, blob, bloblen);
+ tpm_buf_append_u32(tb, authhandle);
+ tpm_buf_append(tb, nonceodd, TPM_NONCE_SIZE);
+ tpm_buf_append_u8(tb, cont);
+ tpm_buf_append(tb, authdata, SHA1_DIGEST_SIZE);

ret = trusted_tpm_send(tb->data, MAX_BUF_SIZE);
if (ret < 0) {
@@ -519,7 +503,7 @@ static int tpm_key_decrypt(struct tpm_key *tk,
struct kernel_pkey_params *params,
const void *in, void *out)
{
- struct tpm_buf *tb;
+ struct tpm_buf tb;
uint32_t keyhandle;
uint8_t srkauth[SHA1_DIGEST_SIZE];
uint8_t keyauth[SHA1_DIGEST_SIZE];
@@ -533,14 +517,14 @@ static int tpm_key_decrypt(struct tpm_key *tk,
if (strcmp(params->encoding, "pkcs1"))
return -ENOPKG;

- tb = kzalloc(sizeof(*tb), GFP_KERNEL);
- if (!tb)
- return -ENOMEM;
+ r = tpm_buf_init(&tb, 0, 0);
+ if (r)
+ return r;

/* TODO: Handle a non-all zero SRK authorization */
memset(srkauth, 0, sizeof(srkauth));

- r = tpm_loadkey2(tb, SRKHANDLE, srkauth,
+ r = tpm_loadkey2(&tb, SRKHANDLE, srkauth,
tk->blob, tk->blob_len, &keyhandle);
if (r < 0) {
pr_devel("loadkey2 failed (%d)\n", r);
@@ -550,16 +534,16 @@ static int tpm_key_decrypt(struct tpm_key *tk,
/* TODO: Handle a non-all zero key authorization */
memset(keyauth, 0, sizeof(keyauth));

- r = tpm_unbind(tb, keyhandle, keyauth,
+ r = tpm_unbind(&tb, keyhandle, keyauth,
in, params->in_len, out, params->out_len);
if (r < 0)
pr_devel("tpm_unbind failed (%d)\n", r);

- if (tpm_flushspecific(tb, keyhandle) < 0)
+ if (tpm_flushspecific(&tb, keyhandle) < 0)
pr_devel("flushspecific failed (%d)\n", r);

error:
- kzfree(tb);
+ tpm_buf_destroy(&tb);
pr_devel("<==%s() = %d\n", __func__, r);
return r;
}
@@ -643,7 +627,7 @@ static int tpm_key_sign(struct tpm_key *tk,
struct kernel_pkey_params *params,
const void *in, void *out)
{
- struct tpm_buf *tb;
+ struct tpm_buf tb;
uint32_t keyhandle;
uint8_t srkauth[SHA1_DIGEST_SIZE];
uint8_t keyauth[SHA1_DIGEST_SIZE];
@@ -681,15 +665,14 @@ static int tpm_key_sign(struct tpm_key *tk,
goto error_free_asn1_wrapped;
}

- r = -ENOMEM;
- tb = kzalloc(sizeof(*tb), GFP_KERNEL);
- if (!tb)
+ r = tpm_buf_init(&tb, 0, 0);
+ if (r)
goto error_free_asn1_wrapped;

/* TODO: Handle a non-all zero SRK authorization */
memset(srkauth, 0, sizeof(srkauth));

- r = tpm_loadkey2(tb, SRKHANDLE, srkauth,
+ r = tpm_loadkey2(&tb, SRKHANDLE, srkauth,
tk->blob, tk->blob_len, &keyhandle);
if (r < 0) {
pr_devel("loadkey2 failed (%d)\n", r);
@@ -699,15 +682,15 @@ static int tpm_key_sign(struct tpm_key *tk,
/* TODO: Handle a non-all zero key authorization */
memset(keyauth, 0, sizeof(keyauth));

- r = tpm_sign(tb, keyhandle, keyauth, in, in_len, out, params->out_len);
+ r = tpm_sign(&tb, keyhandle, keyauth, in, in_len, out, params->out_len);
if (r < 0)
pr_devel("tpm_sign failed (%d)\n", r);

- if (tpm_flushspecific(tb, keyhandle) < 0)
+ if (tpm_flushspecific(&tb, keyhandle) < 0)
pr_devel("flushspecific failed (%d)\n", r);

error_free_tb:
- kzfree(tb);
+ tpm_buf_destroy(&tb);
error_free_asn1_wrapped:
kfree(asn1_wrapped);
pr_devel("<==%s() = %d\n", __func__, r);
--
2.7.4