From: David H. <dho...@re...> - 2018-08-21 15:58:20
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Create a tpm_even_nonce struct and a tpm_odd_nonce struct to represent nonces in internal routines rather than directly using char arrays. Having two separate structures helps keep track of which nonce is used where. Signed-off-by: David Howells <dho...@re...> --- drivers/char/tpm/tpm-library.c | 151 +++++++++++++++++++++------------------- drivers/char/tpm/tpm-library.h | 10 ++- 2 files changed, 90 insertions(+), 71 deletions(-) diff --git a/drivers/char/tpm/tpm-library.c b/drivers/char/tpm/tpm-library.c index 7d1f55413f02..1c64282d1d0d 100644 --- a/drivers/char/tpm/tpm-library.c +++ b/drivers/char/tpm/tpm-library.c @@ -35,6 +35,19 @@ static atomic_t tpm_library_usage; static struct crypto_shash *tpm_hashalg; static struct crypto_shash *tpm_hmacalg; +static int tpm_gen_odd_nonce(struct tpm_chip *chip, + struct tpm_odd_nonce *ononce) +{ + int ret; + + ret = tpm_get_random(chip, ononce->data, TPM_NONCE_SIZE); + if (ret == TPM_NONCE_SIZE) + ret = 0; + else + pr_info("tpm_get_random failed (%d)\n", ret); + return ret; +} + static struct tpm_sdesc *tpm_init_sdesc(struct crypto_shash *alg) { struct tpm_sdesc *sdesc; @@ -124,23 +137,25 @@ out: * @digest: Result buffer - must be SHA1_DIGEST_SIZE in size * @key: The key to use in the HMAC generation * @keylen: The size of @key - * @h1: Even nonce - * @h2: Odd nonce - * @h3: Continuation flag + * @enonce: Even nonce + * @ononce: Odd nonce + * @cont: Continuation flag * @...: Pairs of size and pointer of data elements to load into hash * @0,0: Terminator * * calculate authorization info fields to send to TPM */ -static int TSS_authhmac(unsigned char *digest, const unsigned char *key, - unsigned int keylen, unsigned char *h1, - unsigned char *h2, unsigned char h3, ...) +static int TSS_authhmac(unsigned char *digest, + const unsigned char *key, unsigned keylen, + const struct tpm_even_nonce *enonce, + const struct tpm_odd_nonce *ononce, + unsigned char cont, + ...) { unsigned char paramdigest[SHA1_DIGEST_SIZE]; struct tpm_sdesc *sdesc; unsigned int dlen; unsigned char *data; - unsigned char c; int ret; va_list argp; @@ -150,11 +165,10 @@ static int TSS_authhmac(unsigned char *digest, const unsigned char *key, return PTR_ERR(sdesc); } - c = h3; ret = crypto_shash_init(&sdesc->shash); if (ret < 0) goto out; - va_start(argp, h3); + va_start(argp, cont); for (;;) { dlen = va_arg(argp, unsigned int); if (dlen == 0) @@ -174,9 +188,9 @@ static int TSS_authhmac(unsigned char *digest, const unsigned char *key, if (!ret) ret = TSS_rawhmac(digest, key, keylen, SHA1_DIGEST_SIZE, paramdigest, - TPM_NONCE_SIZE, h1, - TPM_NONCE_SIZE, h2, - 1, &c, + TPM_NONCE_SIZE, enonce->data, + TPM_NONCE_SIZE, ononce->data, + 1, &cont, 0, 0); out: kfree(sdesc); @@ -188,15 +202,15 @@ out: */ static int TSS_checkhmac1(unsigned char *buffer, const uint32_t command, - const unsigned char *ononce, - const unsigned char *key, - unsigned int keylen, ...) + const struct tpm_odd_nonce *ononce, + const unsigned char *key, unsigned keylen, + ...) { uint32_t bufsize; uint16_t tag; uint32_t ordinal; uint32_t result; - unsigned char *enonce; + struct tpm_even_nonce *enonce; unsigned char *continueflag; unsigned char *authdata; unsigned char testhmac[SHA1_DIGEST_SIZE]; @@ -217,7 +231,7 @@ static int TSS_checkhmac1(unsigned char *buffer, return -EINVAL; authdata = buffer + bufsize - SHA1_DIGEST_SIZE; continueflag = authdata - 1; - enonce = continueflag - TPM_NONCE_SIZE; + enonce = (void *)continueflag - TPM_NONCE_SIZE; sdesc = tpm_init_sdesc(tpm_hashalg); if (IS_ERR(sdesc)) { @@ -253,8 +267,8 @@ static int TSS_checkhmac1(unsigned char *buffer, ret = TSS_rawhmac(testhmac, key, keylen, SHA1_DIGEST_SIZE, paramdigest, - TPM_NONCE_SIZE, enonce, - TPM_NONCE_SIZE, ononce, + TPM_NONCE_SIZE, enonce->data, + TPM_NONCE_SIZE, ononce->data, 1, continueflag, 0, 0); if (ret < 0) @@ -270,24 +284,23 @@ out: /* * verify the AUTH2_COMMAND (unseal) result from TPM */ -static int TSS_checkhmac2(unsigned char *buffer, +static int TSS_checkhmac2(const unsigned char *buffer, const uint32_t command, - const unsigned char *ononce, - const unsigned char *key1, - unsigned int keylen1, - const unsigned char *key2, - unsigned int keylen2, ...) + const struct tpm_odd_nonce *ononce, + const unsigned char *key1, unsigned keylen1, + const unsigned char *key2, unsigned keylen2, + ...) { uint32_t bufsize; uint16_t tag; uint32_t ordinal; uint32_t result; - unsigned char *enonce1; - unsigned char *continueflag1; - unsigned char *authdata1; - unsigned char *enonce2; - unsigned char *continueflag2; - unsigned char *authdata2; + const struct tpm_even_nonce *enonce1; + const unsigned char *continueflag1; + const unsigned char *authdata1; + const struct tpm_even_nonce *enonce2; + const unsigned char *continueflag2; + const unsigned char *authdata2; unsigned char testhmac1[SHA1_DIGEST_SIZE]; unsigned char testhmac2[SHA1_DIGEST_SIZE]; unsigned char paramdigest[SHA1_DIGEST_SIZE]; @@ -311,8 +324,8 @@ static int TSS_checkhmac2(unsigned char *buffer, authdata2 = buffer + bufsize - (SHA1_DIGEST_SIZE); continueflag1 = authdata1 - 1; continueflag2 = authdata2 - 1; - enonce1 = continueflag1 - TPM_NONCE_SIZE; - enonce2 = continueflag2 - TPM_NONCE_SIZE; + enonce1 = (const void *)continueflag1 - TPM_NONCE_SIZE; + enonce2 = (const void *)continueflag2 - TPM_NONCE_SIZE; sdesc = tpm_init_sdesc(tpm_hashalg); if (IS_ERR(sdesc)) { @@ -349,8 +362,8 @@ static int TSS_checkhmac2(unsigned char *buffer, ret = TSS_rawhmac(testhmac1, key1, keylen1, SHA1_DIGEST_SIZE, paramdigest, - TPM_NONCE_SIZE, enonce1, - TPM_NONCE_SIZE, ononce, + TPM_NONCE_SIZE, enonce1->data, + TPM_NONCE_SIZE, ononce->data, 1, continueflag1, 0, 0); if (ret < 0) @@ -361,8 +374,8 @@ static int TSS_checkhmac2(unsigned char *buffer, } ret = TSS_rawhmac(testhmac2, key2, keylen2, SHA1_DIGEST_SIZE, paramdigest, - TPM_NONCE_SIZE, enonce2, - TPM_NONCE_SIZE, ononce, + TPM_NONCE_SIZE, enonce2->data, + TPM_NONCE_SIZE, ononce->data, 1, continueflag2, 0, 0); if (ret < 0) @@ -400,12 +413,12 @@ static int tpm_create_osap(struct tpm_chip *chip, const unsigned char *keyauth, enum tpm_entity_type keytype, uint32_t keyhandle) { - unsigned char enonce[TPM_NONCE_SIZE]; - unsigned char ononce[TPM_NONCE_SIZE]; + struct tpm_even_nonce enonce; + struct tpm_odd_nonce ononce; int ret; - ret = tpm_get_random(chip, ononce, TPM_NONCE_SIZE); - if (ret != TPM_NONCE_SIZE) + ret = tpm_gen_odd_nonce(chip, &ononce); + if (ret < 0) return ret; INIT_BUF(tb); @@ -414,7 +427,7 @@ static int tpm_create_osap(struct tpm_chip *chip, store32(tb, TPM_ORD_OSAP); store16(tb, keytype); store32(tb, keyhandle); - storebytes(tb, ononce, TPM_NONCE_SIZE); + storebytes(tb, ononce.data, TPM_NONCE_SIZE); ret = tpm_send_dump(chip, tb->data, MAX_BUF_SIZE, "creating OSAP session"); @@ -422,13 +435,13 @@ static int tpm_create_osap(struct tpm_chip *chip, return ret; s->handle = LOAD32(tb->data, TPM_DATA_OFFSET); - memcpy(s->enonce, &(tb->data[TPM_DATA_OFFSET + sizeof(uint32_t)]), + memcpy(s->enonce.data, &(tb->data[TPM_DATA_OFFSET + sizeof(uint32_t)]), TPM_NONCE_SIZE); - memcpy(enonce, &(tb->data[TPM_DATA_OFFSET + sizeof(uint32_t) + + memcpy(enonce.data, &(tb->data[TPM_DATA_OFFSET + sizeof(uint32_t) + TPM_NONCE_SIZE]), TPM_NONCE_SIZE); return TSS_rawhmac(s->secret, keyauth, SHA1_DIGEST_SIZE, - TPM_NONCE_SIZE, enonce, - TPM_NONCE_SIZE, ononce, + TPM_NONCE_SIZE, enonce.data, + TPM_NONCE_SIZE, ononce.data, 0, 0); } @@ -436,7 +449,7 @@ static int tpm_create_osap(struct tpm_chip *chip, * Create an object independent authorisation protocol (oiap) session */ static int tpm_create_oiap(struct tpm_chip *chip, struct tpm_buf *tb, - uint32_t *handle, unsigned char *nonce) + uint32_t *handle, struct tpm_even_nonce *enonce) { int ret; @@ -450,7 +463,7 @@ static int tpm_create_oiap(struct tpm_chip *chip, struct tpm_buf *tb, return ret; *handle = LOAD32(tb->data, TPM_DATA_OFFSET); - memcpy(nonce, &tb->data[TPM_DATA_OFFSET + sizeof(uint32_t)], + memcpy(enonce->data, &tb->data[TPM_DATA_OFFSET + sizeof(uint32_t)], TPM_NONCE_SIZE); return 0; } @@ -460,7 +473,7 @@ struct tpm_digests { unsigned char pubauth[SHA1_DIGEST_SIZE]; unsigned char xorwork[SHA1_DIGEST_SIZE * 2]; unsigned char xorhash[SHA1_DIGEST_SIZE]; - unsigned char nonceodd[TPM_NONCE_SIZE]; + struct tpm_odd_nonce ononce; }; /** @@ -517,13 +530,13 @@ int tpm_seal(struct tpm_chip *chip, /* calculate encrypted authorization value */ memcpy(td->xorwork, sess.secret, SHA1_DIGEST_SIZE); - memcpy(td->xorwork + SHA1_DIGEST_SIZE, sess.enonce, SHA1_DIGEST_SIZE); + memcpy(td->xorwork + SHA1_DIGEST_SIZE, sess.enonce.data, SHA1_DIGEST_SIZE); ret = TSS_sha1(td->xorwork, SHA1_DIGEST_SIZE * 2, td->xorhash); if (ret < 0) goto out; - ret = tpm_get_random(chip, td->nonceodd, TPM_NONCE_SIZE); - if (ret != TPM_NONCE_SIZE) + ret = tpm_gen_odd_nonce(chip, &td->ononce); + if (ret < 0) goto out; ordinal = htonl(TPM_ORD_SEAL); datsize = htonl(rawlen); @@ -538,7 +551,7 @@ int tpm_seal(struct tpm_chip *chip, if (pcrinfosize == 0) { /* no pcr info specified */ ret = TSS_authhmac(td->pubauth, sess.secret, SHA1_DIGEST_SIZE, - sess.enonce, td->nonceodd, cont, + &sess.enonce, &td->ononce, cont, sizeof(uint32_t), &ordinal, SHA1_DIGEST_SIZE, td->encauth, sizeof(uint32_t), &pcrsize, @@ -548,7 +561,7 @@ int tpm_seal(struct tpm_chip *chip, } else { /* pcr info specified */ ret = TSS_authhmac(td->pubauth, sess.secret, SHA1_DIGEST_SIZE, - sess.enonce, td->nonceodd, cont, + &sess.enonce, &td->ononce, cont, sizeof(uint32_t), &ordinal, SHA1_DIGEST_SIZE, td->encauth, sizeof(uint32_t), &pcrsize, @@ -572,7 +585,7 @@ int tpm_seal(struct tpm_chip *chip, store32(tb, rawlen); storebytes(tb, rawdata, rawlen); store32(tb, sess.handle); - storebytes(tb, td->nonceodd, TPM_NONCE_SIZE); + storebytes(tb, td->ononce.data, TPM_NONCE_SIZE); store8(tb, cont); storebytes(tb, td->pubauth, SHA1_DIGEST_SIZE); @@ -589,7 +602,7 @@ int tpm_seal(struct tpm_chip *chip, sizeof(uint32_t) + encdatasize; /* check the HMAC in the response */ - ret = TSS_checkhmac1(tb->data, ordinal, td->nonceodd, + ret = TSS_checkhmac1(tb->data, ordinal, &td->ononce, sess.secret, SHA1_DIGEST_SIZE, storedsize, TPM_DATA_OFFSET, 0, 0); @@ -625,9 +638,9 @@ int tpm_unseal(struct tpm_chip *chip, struct tpm_buf *tb, const unsigned char *decauth, unsigned char *rawbuffer, unsigned int *_rawlen) { - unsigned char nonceodd[TPM_NONCE_SIZE]; - unsigned char enonce1[TPM_NONCE_SIZE]; - unsigned char enonce2[TPM_NONCE_SIZE]; + struct tpm_odd_nonce ononce; + struct tpm_even_nonce enonce1; + struct tpm_even_nonce enonce2; unsigned char authdata1[SHA1_DIGEST_SIZE]; unsigned char authdata2[SHA1_DIGEST_SIZE]; uint32_t authhandle1 = 0; @@ -638,12 +651,12 @@ int tpm_unseal(struct tpm_chip *chip, struct tpm_buf *tb, int ret; /* sessions for unsealing key and data */ - ret = tpm_create_oiap(chip, tb, &authhandle1, enonce1); + ret = tpm_create_oiap(chip, tb, &authhandle1, &enonce1); if (ret < 0) { pr_info("Failed to create OIAP 1 (%d)\n", ret); return ret; } - ret = tpm_create_oiap(chip, tb, &authhandle2, enonce2); + ret = tpm_create_oiap(chip, tb, &authhandle2, &enonce2); if (ret < 0) { pr_info("Failed to create OIAP 2 (%d)\n", ret); return ret; @@ -651,20 +664,18 @@ int tpm_unseal(struct tpm_chip *chip, struct tpm_buf *tb, ordinal = htonl(TPM_ORD_UNSEAL); keyhndl = htonl(SRKHANDLE); - ret = tpm_get_random(chip, nonceodd, TPM_NONCE_SIZE); - if (ret != TPM_NONCE_SIZE) { - pr_info("tpm_get_random failed (%d)\n", ret); + ret = tpm_gen_odd_nonce(chip, &ononce); + if (ret < 0) return ret; - } ret = TSS_authhmac(authdata1, keyauth, TPM_NONCE_SIZE, - enonce1, nonceodd, cont, + &enonce1, &ononce, cont, sizeof(uint32_t), &ordinal, enclen, encdata, 0, 0); if (ret < 0) return ret; ret = TSS_authhmac(authdata2, decauth, TPM_NONCE_SIZE, - enonce2, nonceodd, cont, + &enonce2, &ononce, cont, sizeof(uint32_t), &ordinal, enclen, encdata, 0, 0); @@ -679,11 +690,11 @@ int tpm_unseal(struct tpm_chip *chip, struct tpm_buf *tb, store32(tb, keyhandle); storebytes(tb, encdata, enclen); store32(tb, authhandle1); - storebytes(tb, nonceodd, TPM_NONCE_SIZE); + storebytes(tb, ononce.data, TPM_NONCE_SIZE); store8(tb, cont); storebytes(tb, authdata1, SHA1_DIGEST_SIZE); store32(tb, authhandle2); - storebytes(tb, nonceodd, TPM_NONCE_SIZE); + storebytes(tb, ononce.data, TPM_NONCE_SIZE); store8(tb, cont); storebytes(tb, authdata2, SHA1_DIGEST_SIZE); @@ -695,7 +706,7 @@ int tpm_unseal(struct tpm_chip *chip, struct tpm_buf *tb, } *_rawlen = LOAD32(tb->data, TPM_DATA_OFFSET); - ret = TSS_checkhmac2(tb->data, ordinal, nonceodd, + ret = TSS_checkhmac2(tb->data, ordinal, &ononce, keyauth, SHA1_DIGEST_SIZE, decauth, SHA1_DIGEST_SIZE, sizeof(uint32_t), TPM_DATA_OFFSET, diff --git a/drivers/char/tpm/tpm-library.h b/drivers/char/tpm/tpm-library.h index 6f7571cc6d6c..ceb0ea1cd2bb 100644 --- a/drivers/char/tpm/tpm-library.h +++ b/drivers/char/tpm/tpm-library.h @@ -15,10 +15,18 @@ #define LOAD32N(buffer, offset) (*(uint32_t *)&buffer[offset]) #define LOAD16(buffer, offset) (ntohs(*(uint16_t *)&buffer[offset])) +struct tpm_even_nonce { + unsigned char data[TPM_NONCE_SIZE]; +}; + +struct tpm_odd_nonce { + unsigned char data[TPM_NONCE_SIZE]; +}; + struct tpm_osapsess { uint32_t handle; unsigned char secret[SHA1_DIGEST_SIZE]; - unsigned char enonce[TPM_NONCE_SIZE]; + struct tpm_even_nonce enonce; }; static inline void store8(struct tpm_buf *buf, const unsigned char value) |