From b7d60e7662f903fc2e5a137bf1fce9a6b431776a Mon Sep 17 00:00:00 2001 From: "Dr. Stephen Henson" Date: Tue, 19 Jan 2016 13:58:51 +0000 Subject: [PATCH] use TLS PRF Modify libssl to use EVP_PKEY TLS PRF. Reviewed-by: Matt Caswell --- ssl/t1_enc.c | 188 ++++++++++++--------------------------------------- 1 file changed, 44 insertions(+), 144 deletions(-) diff --git a/ssl/t1_enc.c b/ssl/t1_enc.c index 9885f24fe8..23b3640634 100644 --- a/ssl/t1_enc.c +++ b/ssl/t1_enc.c @@ -141,103 +141,10 @@ # include #endif #include -#include -#include +#include #include -/* seed1 through seed5 are virtually concatenated */ -static int tls1_P_hash(const EVP_MD *md, const unsigned char *sec, - int sec_len, - const void *seed1, int seed1_len, - const void *seed2, int seed2_len, - const void *seed3, int seed3_len, - const void *seed4, int seed4_len, - const void *seed5, int seed5_len, - unsigned char *out, int olen) -{ - int chunk; - size_t j; - EVP_MD_CTX *ctx = NULL, *ctx_tmp = NULL, *ctx_init = NULL; - EVP_PKEY *mac_key = NULL; - unsigned char A1[EVP_MAX_MD_SIZE]; - size_t A1_len; - int ret = 0; - - chunk = EVP_MD_size(md); - OPENSSL_assert(chunk >= 0); - - ctx = EVP_MD_CTX_new(); - ctx_tmp = EVP_MD_CTX_new(); - ctx_init = EVP_MD_CTX_new(); - if (ctx == NULL || ctx_tmp == NULL || ctx_init == NULL) - goto err; - EVP_MD_CTX_set_flags(ctx_init, EVP_MD_CTX_FLAG_NON_FIPS_ALLOW); - mac_key = EVP_PKEY_new_mac_key(EVP_PKEY_HMAC, NULL, sec, sec_len); - if (!mac_key) - goto err; - if (!EVP_DigestSignInit(ctx_init, NULL, md, NULL, mac_key)) - goto err; - if (!EVP_MD_CTX_copy_ex(ctx, ctx_init)) - goto err; - if (seed1 && !EVP_DigestSignUpdate(ctx, seed1, seed1_len)) - goto err; - if (seed2 && !EVP_DigestSignUpdate(ctx, seed2, seed2_len)) - goto err; - if (seed3 && !EVP_DigestSignUpdate(ctx, seed3, seed3_len)) - goto err; - if (seed4 && !EVP_DigestSignUpdate(ctx, seed4, seed4_len)) - goto err; - if (seed5 && !EVP_DigestSignUpdate(ctx, seed5, seed5_len)) - goto err; - if (!EVP_DigestSignFinal(ctx, A1, &A1_len)) - goto err; - - for (;;) { - /* Reinit mac contexts */ - if (!EVP_MD_CTX_copy_ex(ctx, ctx_init)) - goto err; - if (!EVP_DigestSignUpdate(ctx, A1, A1_len)) - goto err; - if (olen > chunk && !EVP_MD_CTX_copy_ex(ctx_tmp, ctx)) - goto err; - if (seed1 && !EVP_DigestSignUpdate(ctx, seed1, seed1_len)) - goto err; - if (seed2 && !EVP_DigestSignUpdate(ctx, seed2, seed2_len)) - goto err; - if (seed3 && !EVP_DigestSignUpdate(ctx, seed3, seed3_len)) - goto err; - if (seed4 && !EVP_DigestSignUpdate(ctx, seed4, seed4_len)) - goto err; - if (seed5 && !EVP_DigestSignUpdate(ctx, seed5, seed5_len)) - goto err; - - if (olen > chunk) { - if (!EVP_DigestSignFinal(ctx, out, &j)) - goto err; - out += j; - olen -= j; - /* calc the next A1 value */ - if (!EVP_DigestSignFinal(ctx_tmp, A1, &A1_len)) - goto err; - } else { /* last one */ - - if (!EVP_DigestSignFinal(ctx, A1, &A1_len)) - goto err; - memcpy(out, A1, olen); - break; - } - } - ret = 1; - err: - EVP_PKEY_free(mac_key); - EVP_MD_CTX_free(ctx); - EVP_MD_CTX_free(ctx_tmp); - EVP_MD_CTX_free(ctx_init); - OPENSSL_cleanse(A1, sizeof(A1)); - return ret; -} - -/* seed1 through seed5 are virtually concatenated */ +/* seed1 through seed5 are concatenated */ static int tls1_PRF(SSL *s, const void *seed1, int seed1_len, const void *seed2, int seed2_len, @@ -245,43 +152,46 @@ static int tls1_PRF(SSL *s, const void *seed4, int seed4_len, const void *seed5, int seed5_len, const unsigned char *sec, int slen, - unsigned char *out1, unsigned char *out2, int olen) + unsigned char *out, int olen) { const EVP_MD *md = ssl_prf_md(s); + EVP_PKEY_CTX *pctx = NULL; + + int ret = 0; + size_t outlen = olen; if (md == NULL) { /* Should never happen */ SSLerr(SSL_F_TLS1_PRF, ERR_R_INTERNAL_ERROR); return 0; } - if (EVP_MD_type(md) == NID_md5_sha1) { - int i; - if (!tls1_P_hash(EVP_md5(), sec, slen/2 + (slen & 1), - seed1, seed1_len, seed2, seed2_len, seed3, - seed3_len, seed4, seed4_len, seed5, seed5_len, - out1, olen)) - return 0; - if (!tls1_P_hash(EVP_sha1(), sec + slen/2, slen/2 + (slen & 1), - seed1, seed1_len, seed2, seed2_len, seed3, - seed3_len, seed4, seed4_len, seed5, seed5_len, - out2, olen)) - return 0; - for (i = 0; i < olen; i++) - out1[i] ^= out2[i]; - return 1; - } - memset(out2, 0, olen); - if (!tls1_P_hash(md, sec, slen, - seed1, seed1_len, seed2, seed2_len, seed3, - seed3_len, seed4, seed4_len, seed5, seed5_len, - out1, olen)) - return 0; + pctx = EVP_PKEY_CTX_new_id(EVP_PKEY_TLS1_PRF, NULL); + if (pctx == NULL || EVP_PKEY_derive_init(pctx) <= 0 + || EVP_PKEY_CTX_set_tls1_prf_md(pctx, md) <= 0 + || EVP_PKEY_CTX_set1_tls1_prf_secret(pctx, sec, slen) <= 0) + goto err; - return 1; + if (EVP_PKEY_CTX_add1_tls1_prf_seed(pctx, seed1, seed1_len) <= 0) + goto err; + if (EVP_PKEY_CTX_add1_tls1_prf_seed(pctx, seed2, seed2_len) <= 0) + goto err; + if (EVP_PKEY_CTX_add1_tls1_prf_seed(pctx, seed3, seed3_len) <= 0) + goto err; + if (EVP_PKEY_CTX_add1_tls1_prf_seed(pctx, seed4, seed4_len) <= 0) + goto err; + if (EVP_PKEY_CTX_add1_tls1_prf_seed(pctx, seed5, seed5_len) <= 0) + goto err; + + if (EVP_PKEY_derive(pctx, out, &outlen) <= 0) + goto err; + ret = 1; + + err: + EVP_PKEY_CTX_free(pctx); + return ret; } -static int tls1_generate_key_block(SSL *s, unsigned char *km, - unsigned char *tmp, int num) +static int tls1_generate_key_block(SSL *s, unsigned char *km, int num) { int ret; ret = tls1_PRF(s, @@ -289,7 +199,7 @@ static int tls1_generate_key_block(SSL *s, unsigned char *km, TLS_MD_KEY_EXPANSION_CONST_SIZE, s->s3->server_random, SSL3_RANDOM_SIZE, s->s3->client_random, SSL3_RANDOM_SIZE, NULL, 0, NULL, 0, s->session->master_key, - s->session->master_key_length, km, tmp, num); + s->session->master_key_length, km, num); return ret; } @@ -550,7 +460,7 @@ int tls1_change_cipher_state(SSL *s, int which) int tls1_setup_key_block(SSL *s) { - unsigned char *p1, *p2 = NULL; + unsigned char *p; const EVP_CIPHER *c; const EVP_MD *hash; int num; @@ -578,19 +488,14 @@ int tls1_setup_key_block(SSL *s) ssl3_cleanup_key_block(s); - if ((p1 = OPENSSL_malloc(num)) == NULL) { + if ((p = OPENSSL_malloc(num)) == NULL) { SSLerr(SSL_F_TLS1_SETUP_KEY_BLOCK, ERR_R_MALLOC_FAILURE); goto err; } s->s3->tmp.key_block_length = num; - s->s3->tmp.key_block = p1; + s->s3->tmp.key_block = p; - if ((p2 = OPENSSL_malloc(num)) == NULL) { - SSLerr(SSL_F_TLS1_SETUP_KEY_BLOCK, ERR_R_MALLOC_FAILURE); - OPENSSL_free(p1); - goto err; - } #ifdef TLS_DEBUG printf("client random\n"); { @@ -614,7 +519,7 @@ int tls1_setup_key_block(SSL *s) ((z + 1) % 16) ? ' ' : '\n'); } #endif - if (!tls1_generate_key_block(s, p1, p2, num)) + if (!tls1_generate_key_block(s, p, num)) goto err; #ifdef TLS_DEBUG printf("\nkey block\n"); @@ -646,7 +551,6 @@ int tls1_setup_key_block(SSL *s) ret = 1; err: - OPENSSL_clear_free(p2, num); return (ret); } @@ -655,7 +559,6 @@ int tls1_final_finish_mac(SSL *s, const char *str, int slen, { int hashlen; unsigned char hash[EVP_MAX_MD_SIZE]; - unsigned char buf2[12]; if (!ssl3_digest_cached_records(s, 0)) return 0; @@ -665,21 +568,17 @@ int tls1_final_finish_mac(SSL *s, const char *str, int slen, if (hashlen == 0) return 0; - if (!tls1_PRF(s, - str, slen, hash, hashlen, NULL, 0, NULL, 0, NULL, 0, + if (!tls1_PRF(s, str, slen, hash, hashlen, NULL, 0, NULL, 0, NULL, 0, s->session->master_key, s->session->master_key_length, - out, buf2, sizeof buf2)) + out, TLS1_FINISH_MAC_LENGTH)) return 0; OPENSSL_cleanse(hash, hashlen); - OPENSSL_cleanse(buf2, sizeof(buf2)); - return sizeof(buf2); + return TLS1_FINISH_MAC_LENGTH; } int tls1_generate_master_secret(SSL *s, unsigned char *out, unsigned char *p, int len) { - unsigned char buff[SSL_MAX_MASTER_KEY_LENGTH]; - if (s->session->flags & SSL_SESS_FLAG_EXTMS) { unsigned char hash[EVP_MAX_MD_SIZE * 2]; int hashlen; @@ -701,7 +600,8 @@ int tls1_generate_master_secret(SSL *s, unsigned char *out, unsigned char *p, hash, hashlen, NULL, 0, NULL, 0, - NULL, 0, p, len, s->session->master_key, buff, sizeof buff); + NULL, 0, p, len, s->session->master_key, + SSL3_MASTER_SECRET_SIZE); OPENSSL_cleanse(hash, hashlen); } else { tls1_PRF(s, @@ -710,9 +610,9 @@ int tls1_generate_master_secret(SSL *s, unsigned char *out, unsigned char *p, s->s3->client_random, SSL3_RANDOM_SIZE, NULL, 0, s->s3->server_random, SSL3_RANDOM_SIZE, - NULL, 0, p, len, s->session->master_key, buff, sizeof buff); + NULL, 0, p, len, s->session->master_key, + SSL3_MASTER_SECRET_SIZE); } - OPENSSL_cleanse(buff, sizeof buff); #ifdef SSL_DEBUG fprintf(stderr, "Premaster Secret:\n"); BIO_dump_fp(stderr, (char *)p, len); @@ -817,7 +717,7 @@ int tls1_export_keying_material(SSL *s, unsigned char *out, size_t olen, NULL, 0, NULL, 0, s->session->master_key, s->session->master_key_length, - out, buff, olen); + out, olen); goto ret; err1: