[RFC/RFT v4 2/5] KEYS: trusted: use common tpm_buf for TPM1.x code

From: Sumit Garg
Date: Tue Aug 13 2019 - 03:54:15 EST

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Utilize common heap based tpm_buf code for TPM1.x trusted keys rather
than using stack based tpm1_buf code. Also, remove tpm1_buf code.

Suggested-by: Jarkko Sakkinen <jarkko.sakkinen@xxxxxxxxxxxxxxx>
Signed-off-by: Sumit Garg <sumit.garg@xxxxxxxxxx>
---
include/keys/trusted.h | 37 +------------------
security/keys/trusted.c | 98 ++++++++++++++++++++++---------------------------
2 files changed, 44 insertions(+), 91 deletions(-)

diff --git a/include/keys/trusted.h b/include/keys/trusted.h
index 841ae11..29e3e9b 100644
--- a/include/keys/trusted.h
+++ b/include/keys/trusted.h
@@ -5,10 +5,6 @@
/* implementation specific TPM constants */
#define MAX_BUF_SIZE 1024
#define TPM_GETRANDOM_SIZE 14
-#define TPM_OSAP_SIZE 36
-#define TPM_OIAP_SIZE 10
-#define TPM_SEAL_SIZE 87
-#define TPM_UNSEAL_SIZE 104
#define TPM_SIZE_OFFSET 2
#define TPM_RETURN_OFFSET 6
#define TPM_DATA_OFFSET 10
@@ -17,13 +13,6 @@
#define LOAD32N(buffer, offset) (*(uint32_t *)&buffer[offset])
#define LOAD16(buffer, offset) (ntohs(*(uint16_t *)&buffer[offset]))

-struct tpm1_buf {
- int len;
- unsigned char data[MAX_BUF_SIZE];
-};
-
-#define INIT_BUF(tb) (tb->len = 0)
-
struct osapsess {
uint32_t handle;
unsigned char secret[SHA1_DIGEST_SIZE];
@@ -46,7 +35,7 @@ int TSS_checkhmac1(unsigned char *buffer,
unsigned int keylen, ...);

int trusted_tpm_send(unsigned char *cmd, size_t buflen);
-int oiap(struct tpm1_buf *tb, uint32_t *handle, unsigned char *nonce);
+int oiap(struct tpm_buf *tb, uint32_t *handle, unsigned char *nonce);

#define TPM_DEBUG 0

@@ -109,28 +98,4 @@ static inline void dump_tpm_buf(unsigned char *buf)
{
}
#endif
-
-static inline void store8(struct tpm1_buf *buf, const unsigned char value)
-{
- buf->data[buf->len++] = value;
-}
-
-static inline void store16(struct tpm1_buf *buf, const uint16_t value)
-{
- *(uint16_t *) & buf->data[buf->len] = htons(value);
- buf->len += sizeof value;
-}
-
-static inline void store32(struct tpm1_buf *buf, const uint32_t value)
-{
- *(uint32_t *) & buf->data[buf->len] = htonl(value);
- buf->len += sizeof value;
-}
-
-static inline void storebytes(struct tpm1_buf *buf, const unsigned char *in,
- const int len)
-{
- memcpy(buf->data + buf->len, in, len);
- buf->len += len;
-}
#endif
diff --git a/security/keys/trusted.c b/security/keys/trusted.c
index 0736671..f7134d6 100644
--- a/security/keys/trusted.c
+++ b/security/keys/trusted.c
@@ -395,7 +395,7 @@ static int pcrlock(const int pcrnum)
/*
* Create an object specific authorisation protocol (OSAP) session
*/
-static int osap(struct tpm1_buf *tb, struct osapsess *s,
+static int osap(struct tpm_buf *tb, struct osapsess *s,
const unsigned char *key, uint16_t type, uint32_t handle)
{
unsigned char enonce[TPM_NONCE_SIZE];
@@ -406,13 +406,10 @@ static int osap(struct tpm1_buf *tb, struct osapsess *s,
if (ret != TPM_NONCE_SIZE)
return ret;

- INIT_BUF(tb);
- store16(tb, TPM_TAG_RQU_COMMAND);
- store32(tb, TPM_OSAP_SIZE);
- store32(tb, TPM_ORD_OSAP);
- store16(tb, type);
- store32(tb, handle);
- storebytes(tb, ononce, TPM_NONCE_SIZE);
+ tpm_buf_reset(tb, TPM_TAG_RQU_COMMAND, TPM_ORD_OSAP);
+ tpm_buf_append_u16(tb, type);
+ tpm_buf_append_u32(tb, handle);
+ tpm_buf_append(tb, ononce, TPM_NONCE_SIZE);

ret = trusted_tpm_send(tb->data, MAX_BUF_SIZE);
if (ret < 0)
@@ -430,17 +427,14 @@ static int osap(struct tpm1_buf *tb, struct osapsess *s,
/*
* Create an object independent authorisation protocol (oiap) session
*/
-int oiap(struct tpm1_buf *tb, uint32_t *handle, unsigned char *nonce)
+int oiap(struct tpm_buf *tb, uint32_t *handle, unsigned char *nonce)
{
int ret;

if (!chip)
return -ENODEV;

- INIT_BUF(tb);
- store16(tb, TPM_TAG_RQU_COMMAND);
- store32(tb, TPM_OIAP_SIZE);
- store32(tb, TPM_ORD_OIAP);
+ tpm_buf_reset(tb, TPM_TAG_RQU_COMMAND, TPM_ORD_OIAP);
ret = trusted_tpm_send(tb->data, MAX_BUF_SIZE);
if (ret < 0)
return ret;
@@ -464,7 +458,7 @@ struct tpm_digests {
* Have the TPM seal(encrypt) the trusted key, possibly based on
* Platform Configuration Registers (PCRs). AUTH1 for sealing key.
*/
-static int tpm_seal(struct tpm1_buf *tb, uint16_t keytype,
+static int tpm_seal(struct tpm_buf *tb, uint16_t keytype,
uint32_t keyhandle, const unsigned char *keyauth,
const unsigned char *data, uint32_t datalen,
unsigned char *blob, uint32_t *bloblen,
@@ -535,20 +529,17 @@ static int tpm_seal(struct tpm1_buf *tb, uint16_t keytype,
goto out;

/* build and send the TPM request packet */
- INIT_BUF(tb);
- store16(tb, TPM_TAG_RQU_AUTH1_COMMAND);
- store32(tb, TPM_SEAL_SIZE + pcrinfosize + datalen);
- store32(tb, TPM_ORD_SEAL);
- store32(tb, keyhandle);
- storebytes(tb, td->encauth, SHA1_DIGEST_SIZE);
- store32(tb, pcrinfosize);
- storebytes(tb, pcrinfo, pcrinfosize);
- store32(tb, datalen);
- storebytes(tb, data, datalen);
- store32(tb, sess.handle);
- storebytes(tb, td->nonceodd, TPM_NONCE_SIZE);
- store8(tb, cont);
- storebytes(tb, td->pubauth, SHA1_DIGEST_SIZE);
+ tpm_buf_reset(tb, TPM_TAG_RQU_AUTH1_COMMAND, TPM_ORD_SEAL);
+ tpm_buf_append_u32(tb, keyhandle);
+ tpm_buf_append(tb, td->encauth, SHA1_DIGEST_SIZE);
+ tpm_buf_append_u32(tb, pcrinfosize);
+ tpm_buf_append(tb, pcrinfo, pcrinfosize);
+ tpm_buf_append_u32(tb, datalen);
+ tpm_buf_append(tb, data, datalen);
+ tpm_buf_append_u32(tb, sess.handle);
+ tpm_buf_append(tb, td->nonceodd, TPM_NONCE_SIZE);
+ tpm_buf_append_u8(tb, cont);
+ tpm_buf_append(tb, td->pubauth, SHA1_DIGEST_SIZE);

ret = trusted_tpm_send(tb->data, MAX_BUF_SIZE);
if (ret < 0)
@@ -579,7 +570,7 @@ static int tpm_seal(struct tpm1_buf *tb, uint16_t keytype,
/*
* use the AUTH2_COMMAND form of unseal, to authorize both key and blob
*/
-static int tpm_unseal(struct tpm1_buf *tb,
+static int tpm_unseal(struct tpm_buf *tb,
uint32_t keyhandle, const unsigned char *keyauth,
const unsigned char *blob, int bloblen,
const unsigned char *blobauth,
@@ -628,20 +619,17 @@ static int tpm_unseal(struct tpm1_buf *tb,
return ret;

/* build and send TPM request packet */
- INIT_BUF(tb);
- store16(tb, TPM_TAG_RQU_AUTH2_COMMAND);
- store32(tb, TPM_UNSEAL_SIZE + bloblen);
- store32(tb, TPM_ORD_UNSEAL);
- store32(tb, keyhandle);
- storebytes(tb, blob, bloblen);
- store32(tb, authhandle1);
- storebytes(tb, nonceodd, TPM_NONCE_SIZE);
- store8(tb, cont);
- storebytes(tb, authdata1, SHA1_DIGEST_SIZE);
- store32(tb, authhandle2);
- storebytes(tb, nonceodd, TPM_NONCE_SIZE);
- store8(tb, cont);
- storebytes(tb, authdata2, SHA1_DIGEST_SIZE);
+ tpm_buf_reset(tb, TPM_TAG_RQU_AUTH2_COMMAND, TPM_ORD_UNSEAL);
+ tpm_buf_append_u32(tb, keyhandle);
+ tpm_buf_append(tb, blob, bloblen);
+ tpm_buf_append_u32(tb, authhandle1);
+ tpm_buf_append(tb, nonceodd, TPM_NONCE_SIZE);
+ tpm_buf_append_u8(tb, cont);
+ tpm_buf_append(tb, authdata1, SHA1_DIGEST_SIZE);
+ tpm_buf_append_u32(tb, authhandle2);
+ tpm_buf_append(tb, nonceodd, TPM_NONCE_SIZE);
+ tpm_buf_append_u8(tb, cont);
+ tpm_buf_append(tb, authdata2, SHA1_DIGEST_SIZE);

ret = trusted_tpm_send(tb->data, MAX_BUF_SIZE);
if (ret < 0) {
@@ -670,23 +658,23 @@ static int tpm_unseal(struct tpm1_buf *tb,
static int key_seal(struct trusted_key_payload *p,
struct trusted_key_options *o)
{
- struct tpm1_buf *tb;
+ struct tpm_buf tb;
int ret;

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

/* include migratable flag at end of sealed key */
p->key[p->key_len] = p->migratable;

- ret = tpm_seal(tb, o->keytype, o->keyhandle, o->keyauth,
+ ret = tpm_seal(&tb, o->keytype, o->keyhandle, o->keyauth,
p->key, p->key_len + 1, p->blob, &p->blob_len,
o->blobauth, o->pcrinfo, o->pcrinfo_len);
if (ret < 0)
pr_info("trusted_key: srkseal failed (%d)\n", ret);

- kzfree(tb);
+ tpm_buf_destroy(&tb);
return ret;
}

@@ -696,14 +684,14 @@ static int key_seal(struct trusted_key_payload *p,
static int key_unseal(struct trusted_key_payload *p,
struct trusted_key_options *o)
{
- struct tpm1_buf *tb;
+ struct tpm_buf tb;
int ret;

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

- ret = tpm_unseal(tb, o->keyhandle, o->keyauth, p->blob, p->blob_len,
+ ret = tpm_unseal(&tb, o->keyhandle, o->keyauth, p->blob, p->blob_len,
o->blobauth, p->key, &p->key_len);
if (ret < 0)
pr_info("trusted_key: srkunseal failed (%d)\n", ret);
@@ -711,7 +699,7 @@ static int key_unseal(struct trusted_key_payload *p,
/* pull migratable flag out of sealed key */
p->migratable = p->key[--p->key_len];

- kzfree(tb);
+ tpm_buf_destroy(&tb);
return ret;
}

--
2.7.4

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