Remove unused SSLv3 from ssl3_cbc_record_digest_supported().

From Markus Uhlin <markus.uhlin at bredband dot net>

ok beck@ bcooK@

3 files changed, 33 insertions, 77 deletions

diff --git a/src/lib/libssl/s3_cbc.c b/src/lib/libssl/s3_cbc.c
index 414d493150..42aa4b8d4d 100644
--- a/src/lib/libssl/s3_cbc.c
+++ b/src/lib/libssl/s3_cbc.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: s3_cbc.c,v 1.12 2016/03/20 16:50:29 krw Exp $ */
+/* $OpenBSD: s3_cbc.c,v 1.13 2016/11/06 17:21:04 jsing Exp $ */
 /* ====================================================================
  * Copyright (c) 2012 The OpenSSL Project.  All rights reserved.
  *
@@ -349,7 +349,7 @@ ssl3_cbc_record_digest_supported(const EVP_MD_CTX *ctx)
         }
 }
 
-/* ssl3_cbc_digest_record computes the MAC of a decrypted, padded SSLv3/TLS
+/* ssl3_cbc_digest_record computes the MAC of a decrypted, padded TLS
  * record.
  *
  *   ctx: the EVP_MD_CTX from which we take the hash function.
@@ -362,7 +362,6 @@ ssl3_cbc_record_digest_supported(const EVP_MD_CTX *ctx)
  *     once the padding has been removed.
  *   data_plus_mac_plus_padding_size: the public length of the whole
  *     record, including padding.
- *   is_sslv3: non-zero if we are to use SSLv3. Otherwise, TLS.
  *
  * On entry: by virtue of having been through one of the remove_padding
  * functions, above, we know that data_plus_mac_size is large enough to contain
@@ -373,7 +372,7 @@ ssl3_cbc_digest_record(const EVP_MD_CTX *ctx, unsigned char* md_out,
     size_t* md_out_size, const unsigned char header[13],
     const unsigned char *data, size_t data_plus_mac_size,
     size_t data_plus_mac_plus_padding_size, const unsigned char *mac_secret,
-    unsigned mac_secret_length, char is_sslv3)
+    unsigned mac_secret_length)
 {
         union { double align;
                 unsigned char c[sizeof(LARGEST_DIGEST_CTX)];
@@ -381,7 +380,7 @@ ssl3_cbc_digest_record(const EVP_MD_CTX *ctx, unsigned char* md_out,
         void (*md_final_raw)(void *ctx, unsigned char *md_out);
         void (*md_transform)(void *ctx, const unsigned char *block);
         unsigned md_size, md_block_size = 64;
-        unsigned sslv3_pad_length = 40, header_length, variance_blocks,
+        unsigned header_length, variance_blocks,
         len, max_mac_bytes, num_blocks,
         num_starting_blocks, k, mac_end_offset, c, index_a, index_b;
         unsigned int bits;      /* at most 18 bits */
@@ -407,7 +406,6 @@ ssl3_cbc_digest_record(const EVP_MD_CTX *ctx, unsigned char* md_out,
                 md_final_raw = tls1_md5_final_raw;
                 md_transform = (void(*)(void *ctx, const unsigned char *block)) MD5_Transform;
                 md_size = 16;
-                sslv3_pad_length = 48;
                 length_is_big_endian = 0;
                 break;
         case NID_sha1:
@@ -459,33 +457,20 @@ ssl3_cbc_digest_record(const EVP_MD_CTX *ctx, unsigned char* md_out,
         OPENSSL_assert(md_size <= EVP_MAX_MD_SIZE);
 
         header_length = 13;
-        if (is_sslv3) {
-                header_length = mac_secret_length + sslv3_pad_length +
-                    8 /* sequence number */ +
-                    1 /* record type */ +
-                    2 /* record length */;
-        }
 
         /* variance_blocks is the number of blocks of the hash that we have to
          * calculate in constant time because they could be altered by the
          * padding value.
          *
-         * In SSLv3, the padding must be minimal so the end of the plaintext
-         * varies by, at most, 15+20 = 35 bytes. (We conservatively assume that
-         * the MAC size varies from 0..20 bytes.) In case the 9 bytes 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 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 = 6;
         /* 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
-         * (SSLv3) */
+         * bytes of `header' before the start of the data (TLS) */
         len = data_plus_mac_plus_padding_size + header_length;
         /* max_mac_bytes contains the maximum bytes of bytes in the MAC, including
         * |header|, assuming that there's no padding. */
@@ -515,30 +500,23 @@ ssl3_cbc_digest_record(const EVP_MD_CTX *ctx, unsigned char* md_out,
          * length, in bits. */
         index_b = (mac_end_offset + md_length_size) / md_block_size;
         /* bits is the hash-length in bits. It includes the additional hash
-         * block for the masked HMAC key, or whole of |header| in the case of
-         * SSLv3. */
+         * block for the masked HMAC key. */
 
-        /* For SSLv3, if we're going to have any starting blocks then we need
-         * at least two because the header is larger than a single block. */
-        if (num_blocks > variance_blocks + (is_sslv3 ? 1 : 0)) {
+        if (num_blocks > variance_blocks) {
                 num_starting_blocks = num_blocks - variance_blocks;
                 k = md_block_size*num_starting_blocks;
         }
 
         bits = 8*mac_end_offset;
-        if (!is_sslv3) {
-                /* Compute the initial HMAC block. For SSLv3, the padding and
-                 * secret bytes are included in |header| because they take more
-                 * than a single block. */
-                bits += 8*md_block_size;
-                memset(hmac_pad, 0, md_block_size);
-                OPENSSL_assert(mac_secret_length <= sizeof(hmac_pad));
-                memcpy(hmac_pad, mac_secret, mac_secret_length);
-                for (i = 0; i < md_block_size; i++)
-                        hmac_pad[i] ^= 0x36;
-
-                md_transform(md_state.c, hmac_pad);
-        }
+        /* Compute the initial HMAC block. */
+        bits += 8*md_block_size;
+        memset(hmac_pad, 0, md_block_size);
+        OPENSSL_assert(mac_secret_length <= sizeof(hmac_pad));
+        memcpy(hmac_pad, mac_secret, mac_secret_length);
+        for (i = 0; i < md_block_size; i++)
+                hmac_pad[i] ^= 0x36;
+
+        md_transform(md_state.c, hmac_pad);
 
         if (length_is_big_endian) {
                 memset(length_bytes, 0, md_length_size - 4);
@@ -555,26 +533,12 @@ ssl3_cbc_digest_record(const EVP_MD_CTX *ctx, unsigned char* md_out,
         }
 
         if (k > 0) {
-                if (is_sslv3) {
-                        /* The SSLv3 header is larger than a single block.
-                         * overhang is the number of bytes beyond a single
-                         * block that the header consumes: either 7 bytes
-                         * (SHA1) or 11 bytes (MD5). */
-                        unsigned overhang = header_length - md_block_size;
-                        md_transform(md_state.c, header);
-                        memcpy(first_block, header + md_block_size, overhang);
-                        memcpy(first_block + overhang, data, md_block_size - overhang);
-                        md_transform(md_state.c, first_block);
-                        for (i = 1; i < k/md_block_size - 1; i++)
-                                md_transform(md_state.c, data + md_block_size*i - overhang);
-                } else {
-                        /* k is a multiple of md_block_size. */
-                        memcpy(first_block, header, 13);
-                        memcpy(first_block + 13, data, md_block_size - 13);
-                        md_transform(md_state.c, first_block);
-                        for (i = 1; i < k/md_block_size; i++)
-                                md_transform(md_state.c, data + md_block_size*i - 13);
-                }
+                /* k is a multiple of md_block_size. */
+                memcpy(first_block, header, 13);
+                memcpy(first_block + 13, data, md_block_size - 13);
+                md_transform(md_state.c, first_block);
+                for (i = 1; i < k/md_block_size; i++)
+                        md_transform(md_state.c, data + md_block_size*i - 13);
         }
 
         memset(mac_out, 0, sizeof(mac_out));
@@ -632,21 +596,14 @@ ssl3_cbc_digest_record(const EVP_MD_CTX *ctx, unsigned char* md_out,
                 EVP_MD_CTX_cleanup(&md_ctx);
                 return 0;
         }
-        if (is_sslv3) {
-                /* We repurpose |hmac_pad| to contain the SSLv3 pad2 block. */
-                memset(hmac_pad, 0x5c, sslv3_pad_length);
 
-                EVP_DigestUpdate(&md_ctx, mac_secret, mac_secret_length);
-                EVP_DigestUpdate(&md_ctx, hmac_pad, sslv3_pad_length);
-                EVP_DigestUpdate(&md_ctx, mac_out, md_size);
-        } else {
-                /* Complete the HMAC in the standard manner. */
-                for (i = 0; i < md_block_size; i++)
-                        hmac_pad[i] ^= 0x6a;
+        /* Complete the HMAC in the standard manner. */
+        for (i = 0; i < md_block_size; i++)
+                hmac_pad[i] ^= 0x6a;
+
+        EVP_DigestUpdate(&md_ctx, hmac_pad, md_block_size);
+        EVP_DigestUpdate(&md_ctx, mac_out, md_size);
 
-                EVP_DigestUpdate(&md_ctx, hmac_pad, md_block_size);
-                EVP_DigestUpdate(&md_ctx, mac_out, md_size);
-        }
         EVP_DigestFinal(&md_ctx, md_out, &md_out_size_u);
         if (md_out_size)
                 *md_out_size = md_out_size_u;
diff --git a/src/lib/libssl/ssl_locl.h b/src/lib/libssl/ssl_locl.h
index 4386f0f7e5..6c36795b1d 100644
--- a/src/lib/libssl/ssl_locl.h
+++ b/src/lib/libssl/ssl_locl.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: ssl_locl.h,v 1.135 2016/11/05 08:26:36 jsing Exp $ */
+/* $OpenBSD: ssl_locl.h,v 1.136 2016/11/06 17:21:04 jsing Exp $ */
 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  * All rights reserved.
  *
@@ -834,7 +834,7 @@ int ssl3_cbc_digest_record(const EVP_MD_CTX *ctx, unsigned char *md_out,
     size_t *md_out_size, const unsigned char header[13],
     const unsigned char *data, size_t data_plus_mac_size,
     size_t data_plus_mac_plus_padding_size, const unsigned char *mac_secret,
-    unsigned mac_secret_length, char is_sslv3);
+    unsigned mac_secret_length);
 
 __END_HIDDEN_DECLS
 
diff --git a/src/lib/libssl/t1_enc.c b/src/lib/libssl/t1_enc.c
index 6305a6ffb9..04219eb1b7 100644
--- a/src/lib/libssl/t1_enc.c
+++ b/src/lib/libssl/t1_enc.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: t1_enc.c,v 1.86 2016/11/03 08:15:22 jsing Exp $ */
+/* $OpenBSD: t1_enc.c,v 1.87 2016/11/06 17:21:04 jsing Exp $ */
 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  * All rights reserved.
  *
@@ -1242,8 +1242,7 @@ tls1_mac(SSL *ssl, unsigned char *md, int send)
                     md, &md_size, header, rec->input,
                     rec->length + md_size, orig_len,
                     ssl->s3->read_mac_secret,
-                    ssl->s3->read_mac_secret_size,
-                    0 /* not SSLv3 */))
+                    ssl->s3->read_mac_secret_size))
                         return -1;
         } else {
                 EVP_DigestSignUpdate(mac_ctx, header, sizeof(header));