X-Git-Url: https://git.openssl.org/gitweb/?p=openssl.git;a=blobdiff_plain;f=ssl%2Fs3_cbc.c;h=8e11864b07f028776261e9c23879ee6b3a70b662;hp=29243f35a0b6b4838139d6cee49dfcb905002281;hb=cb8164b05e3bad5586c2a109bbdbab1ad65a1a6f;hpb=348240c676a1b2beaebb865e8be0b62f88c10b7d diff --git a/ssl/s3_cbc.c b/ssl/s3_cbc.c index 29243f35a0..8e11864b07 100644 --- a/ssl/s3_cbc.c +++ b/ssl/s3_cbc.c @@ -9,6 +9,7 @@ #include "internal/constant_time_locl.h" #include "ssl_locl.h" +#include "internal/cryptlib.h" #include #include @@ -89,8 +90,6 @@ static void tls1_sha512_final_raw(void *ctx, unsigned char *md_out) */ char ssl3_cbc_record_digest_supported(const EVP_MD_CTX *ctx) { - if (FIPS_mode()) - return 0; switch (EVP_MD_CTX_type(ctx)) { case NID_md5: case NID_sha1: @@ -167,7 +166,8 @@ int ssl3_cbc_digest_record(const EVP_MD_CTX *ctx, * This is a, hopefully redundant, check that allows us to forget about * many possible overflows later in this function. */ - OPENSSL_assert(data_plus_mac_plus_padding_size < 1024 * 1024); + if (!ossl_assert(data_plus_mac_plus_padding_size < 1024 * 1024)) + return 0; switch (EVP_MD_CTX_type(ctx)) { case NID_md5: @@ -229,15 +229,15 @@ int ssl3_cbc_digest_record(const EVP_MD_CTX *ctx, * ssl3_cbc_record_digest_supported should have been called first to * check that the hash function is supported. */ - OPENSSL_assert(0); - if (md_out_size) + if (md_out_size != NULL) *md_out_size = 0; - return 0; + return ossl_assert(0); } - OPENSSL_assert(md_length_size <= MAX_HASH_BIT_COUNT_BYTES); - OPENSSL_assert(md_block_size <= MAX_HASH_BLOCK_SIZE); - OPENSSL_assert(md_size <= EVP_MAX_MD_SIZE); + if (!ossl_assert(md_length_size <= MAX_HASH_BIT_COUNT_BYTES) + || !ossl_assert(md_block_size <= MAX_HASH_BLOCK_SIZE) + || !ossl_assert(md_size <= EVP_MAX_MD_SIZE)) + return 0; header_length = 13; if (is_sslv3) { @@ -256,12 +256,13 @@ int ssl3_cbc_digest_record(const EVP_MD_CTX *ctx, * of hash termination (0x80 + 64-bit length) don't fit in the final * block, we say that the final two blocks can vary based on the padding. * TLSv1 has MACs up to 48 bytes long (SHA-384) and the padding is not - * required to be minimal. Therefore we say that the final six blocks can + * required to be minimal. Therefore we say that the final |variance_blocks| + * blocks can * vary based on the padding. Later in the function, if the message is * short and there obviously cannot be this many blocks then * variance_blocks can be reduced. */ - variance_blocks = is_sslv3 ? 2 : 6; + variance_blocks = is_sslv3 ? 2 : ( ((255 + 1 + md_size + md_block_size - 1) / md_block_size) + 1); /* * From now on we're dealing with the MAC, which conceptually has 13 * bytes of `header' before the start of the data (TLS) or 71/75 bytes @@ -333,7 +334,8 @@ int ssl3_cbc_digest_record(const EVP_MD_CTX *ctx, */ bits += 8 * md_block_size; memset(hmac_pad, 0, md_block_size); - OPENSSL_assert(mac_secret_length <= sizeof(hmac_pad)); + if (!ossl_assert(mac_secret_length <= sizeof(hmac_pad))) + return 0; memcpy(hmac_pad, mac_secret, mac_secret_length); for (i = 0; i < md_block_size; i++) hmac_pad[i] ^= 0x36; @@ -400,8 +402,8 @@ int ssl3_cbc_digest_record(const EVP_MD_CTX *ctx, for (i = num_starting_blocks; i <= num_starting_blocks + variance_blocks; i++) { unsigned char block[MAX_HASH_BLOCK_SIZE]; - unsigned char is_block_a = constant_time_eq_8(i, index_a); - unsigned char is_block_b = constant_time_eq_8(i, index_b); + unsigned char is_block_a = constant_time_eq_8_s(i, index_a); + unsigned char is_block_b = constant_time_eq_8_s(i, index_b); for (j = 0; j < md_block_size; j++) { unsigned char b = 0, is_past_c, is_past_cp1; if (k < header_length) @@ -410,8 +412,8 @@ int ssl3_cbc_digest_record(const EVP_MD_CTX *ctx, b = data[k - header_length]; k++; - is_past_c = is_block_a & constant_time_ge_8(j, c); - is_past_cp1 = is_block_a & constant_time_ge_8(j, c + 1); + is_past_c = is_block_a & constant_time_ge_8_s(j, c); + is_past_cp1 = is_block_a & constant_time_ge_8_s(j, c + 1); /* * If this is the block containing the end of the application * data, and we are at the offset for the 0x80 value, then @@ -419,8 +421,8 @@ int ssl3_cbc_digest_record(const EVP_MD_CTX *ctx, */ b = constant_time_select_8(is_past_c, 0x80, b); /* - * If this the the block containing the end of the application - * data and we're past the 0x80 value then just write zero. + * If this block contains the end of the application data + * and we're past the 0x80 value then just write zero. */ b = b & ~is_past_cp1; /* @@ -483,49 +485,3 @@ int ssl3_cbc_digest_record(const EVP_MD_CTX *ctx, EVP_MD_CTX_free(md_ctx); return 0; } - -/* - * Due to the need to use EVP in FIPS mode we can't reimplement digests but - * we can ensure the number of blocks processed is equal for all cases by - * digesting additional data. - */ - -int tls_fips_digest_extra(const EVP_CIPHER_CTX *cipher_ctx, - EVP_MD_CTX *mac_ctx, const unsigned char *data, - size_t data_len, size_t orig_len) -{ - size_t block_size, digest_pad, blocks_data, blocks_orig; - if (EVP_CIPHER_CTX_mode(cipher_ctx) != EVP_CIPH_CBC_MODE) - return 1; - block_size = EVP_MD_CTX_block_size(mac_ctx); - /*- - * We are in FIPS mode if we get this far so we know we have only SHA* - * digests and TLS to deal with. - * Minimum digest padding length is 17 for SHA384/SHA512 and 9 - * otherwise. - * Additional header is 13 bytes. To get the number of digest blocks - * processed round up the amount of data plus padding to the nearest - * block length. Block length is 128 for SHA384/SHA512 and 64 otherwise. - * So we have: - * blocks = (payload_len + digest_pad + 13 + block_size - 1)/block_size - * equivalently: - * blocks = (payload_len + digest_pad + 12)/block_size + 1 - * HMAC adds a constant overhead. - * We're ultimately only interested in differences so this becomes - * blocks = (payload_len + 29)/128 - * for SHA384/SHA512 and - * blocks = (payload_len + 21)/64 - * otherwise. - */ - digest_pad = block_size == 64 ? 21 : 29; - blocks_orig = (orig_len + digest_pad) / block_size; - blocks_data = (data_len + digest_pad) / block_size; - /* - * MAC enough blocks to make up the difference between the original and - * actual lengths plus one extra block to ensure this is never a no op. - * The "data" pointer should always have enough space to perform this - * operation as it is large enough for a maximum length TLS buffer. - */ - return EVP_DigestSignUpdate(mac_ctx, data, - (blocks_orig - blocks_data + 1) * block_size); -}