Allocate the temporary buffer in tls1_PRF internally.

It's not worth saving the extra mallocs. This is preparation for moving SSLv3
to stateful AEADs; it'll share code TLS's SSL3_ENC_METHOD, but
tls1_generate_key_block is different, so that'll be pulled out into its own
hook.

Change-Id: I3f2136600758465c66ce23736041bb47f74efa6d
Reviewed-on: https://boringssl-review.googlesource.com/2690
Reviewed-by: Adam Langley <agl@google.com>
This commit is contained in:
David Benjamin 2014-12-22 10:42:51 -05:00 committed by Adam Langley
parent 2bca0988a4
commit af032d68b3

View File

@ -229,12 +229,24 @@ static int tls1_PRF(long digest_mask,
const void *seed2, int seed2_len, const void *seed2, int seed2_len,
const void *seed3, int seed3_len, const void *seed3, int seed3_len,
const uint8_t *sec, int slen, const uint8_t *sec, int slen,
uint8_t *out1, uint8_t *out2, int olen) { uint8_t *out, int olen) {
int len, i, idx, count; int len, i, idx, count;
const uint8_t *S1; const uint8_t *S1;
long m; long m;
const EVP_MD *md; const EVP_MD *md;
int ret = 0; int ret = 0;
uint8_t *tmp;
if (olen <= 0) {
return 1;
}
/* Allocate a temporary buffer. */
tmp = OPENSSL_malloc(olen);
if (tmp == NULL) {
OPENSSL_PUT_ERROR(SSL, tls1_PRF, ERR_R_MALLOC_FAILURE);
return 0;
}
/* Count number of digests and partition sec evenly */ /* Count number of digests and partition sec evenly */
count = 0; count = 0;
@ -248,7 +260,7 @@ static int tls1_PRF(long digest_mask,
slen = 0; slen = 0;
} }
S1 = sec; S1 = sec;
memset(out1, 0, olen); memset(out, 0, olen);
for (idx = 0; ssl_get_handshake_digest(idx, &m, &md); idx++) { for (idx = 0; ssl_get_handshake_digest(idx, &m, &md); idx++) {
if ((m << TLS1_PRF_DGST_SHIFT) & digest_mask) { if ((m << TLS1_PRF_DGST_SHIFT) & digest_mask) {
if (!md) { if (!md) {
@ -256,27 +268,29 @@ static int tls1_PRF(long digest_mask,
goto err; goto err;
} }
if (!tls1_P_hash(md, S1, len + (slen & 1), seed1, seed1_len, seed2, if (!tls1_P_hash(md, S1, len + (slen & 1), seed1, seed1_len, seed2,
seed2_len, seed3, seed3_len, out2, olen)) { seed2_len, seed3, seed3_len, tmp, olen)) {
goto err; goto err;
} }
S1 += len; S1 += len;
for (i = 0; i < olen; i++) { for (i = 0; i < olen; i++) {
out1[i] ^= out2[i]; out[i] ^= tmp[i];
} }
} }
} }
ret = 1; ret = 1;
err: err:
OPENSSL_cleanse(tmp, olen);
OPENSSL_free(tmp);
return ret; return ret;
} }
static int tls1_generate_key_block(SSL *s, uint8_t *km, uint8_t *tmp, int num) { static int tls1_generate_key_block(SSL *s, uint8_t *km, int num) {
return tls1_PRF(ssl_get_algorithm2(s), TLS_MD_KEY_EXPANSION_CONST, return tls1_PRF(ssl_get_algorithm2(s), TLS_MD_KEY_EXPANSION_CONST,
TLS_MD_KEY_EXPANSION_CONST_SIZE, s->s3->server_random, TLS_MD_KEY_EXPANSION_CONST_SIZE, s->s3->server_random,
SSL3_RANDOM_SIZE, s->s3->client_random, SSL3_RANDOM_SIZE, SSL3_RANDOM_SIZE, s->s3->client_random, SSL3_RANDOM_SIZE,
s->session->master_key, s->session->master_key_length, km, s->session->master_key, s->session->master_key_length, km,
tmp, num); num);
} }
/* tls1_aead_ctx_init allocates |*aead_ctx|, if needed and returns 1. It /* tls1_aead_ctx_init allocates |*aead_ctx|, if needed and returns 1. It
@ -582,7 +596,7 @@ int tls1_change_cipher_state(SSL *s, int which) {
} }
int tls1_setup_key_block(SSL *s) { int tls1_setup_key_block(SSL *s) {
uint8_t *p1, *p2 = NULL; uint8_t *p;
const EVP_CIPHER *c = NULL; const EVP_CIPHER *c = NULL;
const EVP_MD *hash = NULL; const EVP_MD *hash = NULL;
const EVP_AEAD *aead = NULL; const EVP_AEAD *aead = NULL;
@ -638,22 +652,16 @@ int tls1_setup_key_block(SSL *s) {
ssl3_cleanup_key_block(s); ssl3_cleanup_key_block(s);
p1 = (uint8_t *)OPENSSL_malloc(num); p = (uint8_t *)OPENSSL_malloc(num);
if (p1 == NULL) { if (p == NULL) {
OPENSSL_PUT_ERROR(SSL, tls1_setup_key_block, ERR_R_MALLOC_FAILURE); OPENSSL_PUT_ERROR(SSL, tls1_setup_key_block, ERR_R_MALLOC_FAILURE);
goto err; goto err;
} }
s->s3->tmp.key_block_length = num; s->s3->tmp.key_block_length = num;
s->s3->tmp.key_block = p1; s->s3->tmp.key_block = p;
p2 = (uint8_t *)OPENSSL_malloc(num); if (!tls1_generate_key_block(s, p, num)) {
if (p2 == NULL) {
OPENSSL_PUT_ERROR(SSL, tls1_setup_key_block, ERR_R_MALLOC_FAILURE);
goto err;
}
if (!tls1_generate_key_block(s, p1, p2, num)) {
goto err; goto err;
} }
@ -672,10 +680,6 @@ int tls1_setup_key_block(SSL *s) {
ret = 1; ret = 1;
err: err:
if (p2) {
OPENSSL_cleanse(p2, num);
OPENSSL_free(p2);
}
return ret; return ret;
cipher_unavailable_err: cipher_unavailable_err:
@ -983,7 +987,6 @@ int tls1_handshake_digest(SSL *s, uint8_t *out, size_t out_len) {
int tls1_final_finish_mac(SSL *s, const char *str, int slen, uint8_t *out) { int tls1_final_finish_mac(SSL *s, const char *str, int slen, uint8_t *out) {
uint8_t buf[2 * EVP_MAX_MD_SIZE]; uint8_t buf[2 * EVP_MAX_MD_SIZE];
uint8_t buf2[12];
int err = 0; int err = 0;
int digests_len; int digests_len;
@ -1000,14 +1003,14 @@ int tls1_final_finish_mac(SSL *s, const char *str, int slen, uint8_t *out) {
if (!tls1_PRF(ssl_get_algorithm2(s), str, slen, buf, digests_len, NULL, 0, if (!tls1_PRF(ssl_get_algorithm2(s), str, slen, buf, digests_len, NULL, 0,
s->session->master_key, s->session->master_key_length, out, s->session->master_key, s->session->master_key_length, out,
buf2, sizeof buf2)) { 12)) {
err = 1; err = 1;
} }
if (err) { if (err) {
return 0; return 0;
} else { } else {
return sizeof(buf2); return 12;
} }
} }
@ -1095,8 +1098,6 @@ int tls1_mac(SSL *ssl, uint8_t *md, int send) {
} }
int tls1_generate_master_secret(SSL *s, uint8_t *out, uint8_t *p, int len) { int tls1_generate_master_secret(SSL *s, uint8_t *out, uint8_t *p, int len) {
uint8_t buff[SSL_MAX_MASTER_KEY_LENGTH];
if (s->s3->tmp.extended_master_secret) { if (s->s3->tmp.extended_master_secret) {
uint8_t digests[2 * EVP_MAX_MD_SIZE]; uint8_t digests[2 * EVP_MAX_MD_SIZE];
int digests_len; int digests_len;
@ -1119,14 +1120,19 @@ int tls1_generate_master_secret(SSL *s, uint8_t *out, uint8_t *p, int len) {
return 0; return 0;
} }
tls1_PRF(ssl_get_algorithm2(s), TLS_MD_EXTENDED_MASTER_SECRET_CONST, if (!tls1_PRF(ssl_get_algorithm2(s), TLS_MD_EXTENDED_MASTER_SECRET_CONST,
TLS_MD_EXTENDED_MASTER_SECRET_CONST_SIZE, digests, digests_len, TLS_MD_EXTENDED_MASTER_SECRET_CONST_SIZE, digests,
NULL, 0, p, len, s->session->master_key, buff, sizeof(buff)); digests_len, NULL, 0, p, len, s->session->master_key,
SSL_MAX_MASTER_KEY_LENGTH)) {
return 0;
}
} else { } else {
tls1_PRF(ssl_get_algorithm2(s), TLS_MD_MASTER_SECRET_CONST, if (!tls1_PRF(ssl_get_algorithm2(s), TLS_MD_MASTER_SECRET_CONST,
TLS_MD_MASTER_SECRET_CONST_SIZE, s->s3->client_random, TLS_MD_MASTER_SECRET_CONST_SIZE, s->s3->client_random,
SSL3_RANDOM_SIZE, s->s3->server_random, SSL3_RANDOM_SIZE, p, len, SSL3_RANDOM_SIZE, s->s3->server_random, SSL3_RANDOM_SIZE, p,
s->session->master_key, buff, sizeof buff); len, s->session->master_key, SSL_MAX_MASTER_KEY_LENGTH)) {
return 0;
}
} }
return SSL3_MASTER_SECRET_SIZE; return SSL3_MASTER_SECRET_SIZE;
@ -1136,16 +1142,10 @@ int tls1_export_keying_material(SSL *s, uint8_t *out, size_t olen,
const char *label, size_t llen, const char *label, size_t llen,
const uint8_t *context, size_t contextlen, const uint8_t *context, size_t contextlen,
int use_context) { int use_context) {
uint8_t *buff;
uint8_t *val = NULL; uint8_t *val = NULL;
size_t vallen, currentvalpos; size_t vallen, currentvalpos;
int ret; int ret;
buff = OPENSSL_malloc(olen);
if (buff == NULL) {
goto err2;
}
/* construct PRF arguments we construct the PRF argument ourself rather than /* construct PRF arguments we construct the PRF argument ourself rather than
* passing separate values into the TLS PRF to ensure that the concatenation * passing separate values into the TLS PRF to ensure that the concatenation
* of values does not create a prohibited label. */ * of values does not create a prohibited label. */
@ -1193,7 +1193,7 @@ int tls1_export_keying_material(SSL *s, uint8_t *out, size_t olen,
ret = tls1_PRF(ssl_get_algorithm2(s), val, vallen, NULL, 0, NULL, 0, ret = tls1_PRF(ssl_get_algorithm2(s), val, vallen, NULL, 0, NULL, 0,
s->session->master_key, s->session->master_key_length, out, s->session->master_key, s->session->master_key_length, out,
buff, olen); olen);
goto out; goto out;
@ -1208,9 +1208,6 @@ err2:
ret = 0; ret = 0;
out: out:
if (buff != NULL) {
OPENSSL_free(buff);
}
if (val != NULL) { if (val != NULL) {
OPENSSL_free(val); OPENSSL_free(val);
} }