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-rw-r--r--ssl/s3_cbc.c178
1 files changed, 126 insertions, 52 deletions
diff --git a/ssl/s3_cbc.c b/ssl/s3_cbc.c
index e9b112c..3c2c165 100644
--- a/ssl/s3_cbc.c
+++ b/ssl/s3_cbc.c
@@ -53,8 +53,6 @@
*
*/
-#include <stdint.h>
-
#include "ssl_locl.h"
#include <openssl/md5.h>
@@ -118,7 +116,9 @@ int ssl3_cbc_remove_padding(const SSL* s,
good = constant_time_ge(rec->length, padding_length+overhead);
/* SSLv3 requires that the padding is minimal. */
good &= constant_time_ge(block_size, padding_length+1);
- rec->length -= good & (padding_length+1);
+ padding_length = good & (padding_length+1);
+ rec->length -= padding_length;
+ rec->type |= padding_length<<8; /* kludge: pass padding length */
return (int)((good & 1) | (~good & -1));
}
@@ -150,6 +150,21 @@ int tls1_cbc_remove_padding(const SSL* s,
if (overhead > rec->length)
return 0;
+ /* We can always safely skip the explicit IV. We check at the beginning
+ * of this function that the record has at least enough space for the
+ * IV, MAC and padding length byte. (These can be checked in
+ * non-constant time because it's all public information.) So, if the
+ * padding was invalid, then we didn't change |rec->length| and this is
+ * safe. If the padding was valid then we know that we have at least
+ * overhead+padding_length bytes of space and so this is still safe
+ * because overhead accounts for the explicit IV. */
+ if (has_explicit_iv)
+ {
+ rec->data += block_size;
+ rec->input += block_size;
+ rec->length -= block_size;
+ }
+
padding_length = rec->data[rec->length-1];
/* NB: if compression is in operation the first packet may not be of
@@ -172,6 +187,13 @@ int tls1_cbc_remove_padding(const SSL* s,
}
}
+ if (EVP_CIPHER_flags(s->enc_read_ctx->cipher)&EVP_CIPH_FLAG_AEAD_CIPHER)
+ {
+ /* padding is already verified */
+ rec->length -= padding_length;
+ return 1;
+ }
+
good = constant_time_ge(rec->length, overhead+padding_length);
/* The padding consists of a length byte at the end of the record and
* then that many bytes of padding, all with the same value as the
@@ -205,23 +227,9 @@ int tls1_cbc_remove_padding(const SSL* s,
good <<= sizeof(good)*8-1;
good = DUPLICATE_MSB_TO_ALL(good);
- rec->length -= good & (padding_length+1);
-
- /* We can always safely skip the explicit IV. We check at the beginning
- * of this function that the record has at least enough space for the
- * IV, MAC and padding length byte. (These can be checked in
- * non-constant time because it's all public information.) So, if the
- * padding was invalid, then we didn't change |rec->length| and this is
- * safe. If the padding was valid then we know that we have at least
- * overhead+padding_length bytes of space and so this is still safe
- * because overhead accounts for the explicit IV. */
- if (has_explicit_iv)
- {
- rec->data += block_size;
- rec->input += block_size;
- rec->length -= block_size;
- rec->orig_len -= block_size;
- }
+ padding_length = good & (padding_length+1);
+ rec->length -= padding_length;
+ rec->type |= padding_length<<8; /* kludge: pass padding length */
return (int)((good & 1) | (~good & -1));
}
@@ -248,7 +256,7 @@ int tls1_cbc_remove_padding(const SSL* s,
*/
void ssl3_cbc_copy_mac(unsigned char* out,
const SSL3_RECORD *rec,
- unsigned md_size)
+ unsigned md_size,unsigned orig_len)
{
#if defined(CBC_MAC_ROTATE_IN_PLACE)
unsigned char rotated_mac_buf[EVP_MAX_MD_SIZE*2];
@@ -267,7 +275,7 @@ void ssl3_cbc_copy_mac(unsigned char* out,
unsigned div_spoiler;
unsigned rotate_offset;
- OPENSSL_assert(rec->orig_len >= md_size);
+ OPENSSL_assert(orig_len >= md_size);
OPENSSL_assert(md_size <= EVP_MAX_MD_SIZE);
#if defined(CBC_MAC_ROTATE_IN_PLACE)
@@ -275,8 +283,8 @@ void ssl3_cbc_copy_mac(unsigned char* out,
#endif
/* This information is public so it's safe to branch based on it. */
- if (rec->orig_len > md_size + 255 + 1)
- scan_start = rec->orig_len - (md_size + 255 + 1);
+ if (orig_len > md_size + 255 + 1)
+ scan_start = orig_len - (md_size + 255 + 1);
/* div_spoiler contains a multiple of md_size that is used to cause the
* modulo operation to be constant time. Without this, the time varies
* based on the amount of padding when running on Intel chips at least.
@@ -289,9 +297,9 @@ void ssl3_cbc_copy_mac(unsigned char* out,
rotate_offset = (div_spoiler + mac_start - scan_start) % md_size;
memset(rotated_mac, 0, md_size);
- for (i = scan_start; i < rec->orig_len;)
+ for (i = scan_start; i < orig_len;)
{
- for (j = 0; j < md_size && i < rec->orig_len; i++, j++)
+ for (j = 0; j < md_size && i < orig_len; i++, j++)
{
unsigned char mac_started = constant_time_ge(i, mac_start);
unsigned char mac_ended = constant_time_ge(i, mac_end);
@@ -341,7 +349,9 @@ static void tls1_sha1_final_raw(void* ctx, unsigned char *md_out)
l2n(sha1->h3, md_out);
l2n(sha1->h4, md_out);
}
+#define LARGEST_DIGEST_CTX SHA_CTX
+#ifndef OPENSSL_NO_SHA256
static void tls1_sha256_final_raw(void* ctx, unsigned char *md_out)
{
SHA256_CTX *sha256 = ctx;
@@ -352,7 +362,11 @@ static void tls1_sha256_final_raw(void* ctx, unsigned char *md_out)
l2n(sha256->h[i], md_out);
}
}
+#undef LARGEST_DIGEST_CTX
+#define LARGEST_DIGEST_CTX SHA256_CTX
+#endif
+#ifndef OPENSSL_NO_SHA512
static void tls1_sha512_final_raw(void* ctx, unsigned char *md_out)
{
SHA512_CTX *sha512 = ctx;
@@ -363,19 +377,30 @@ static void tls1_sha512_final_raw(void* ctx, unsigned char *md_out)
l2n8(sha512->h[i], md_out);
}
}
+#undef LARGEST_DIGEST_CTX
+#define LARGEST_DIGEST_CTX SHA512_CTX
+#endif
/* ssl3_cbc_record_digest_supported returns 1 iff |ctx| uses a hash function
* which ssl3_cbc_digest_record supports. */
char ssl3_cbc_record_digest_supported(const EVP_MD_CTX *ctx)
{
- switch (ctx->digest->type)
+#ifdef OPENSSL_FIPS
+ if (FIPS_mode())
+ return 0;
+#endif
+ switch (EVP_MD_CTX_type(ctx))
{
case NID_md5:
case NID_sha1:
+#ifndef OPENSSL_NO_SHA256
case NID_sha224:
case NID_sha256:
+#endif
+#ifndef OPENSSL_NO_SHA512
case NID_sha384:
case NID_sha512:
+#endif
return 1;
default:
return 0;
@@ -413,14 +438,15 @@ void ssl3_cbc_digest_record(
unsigned mac_secret_length,
char is_sslv3)
{
- unsigned char md_state[sizeof(SHA512_CTX)];
+ union { double align;
+ unsigned char c[sizeof(LARGEST_DIGEST_CTX)]; } md_state;
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,
len, max_mac_bytes, num_blocks,
num_starting_blocks, k, mac_end_offset, c, index_a, index_b;
- uint64_t bits;
+ unsigned int bits; /* at most 18 bits */
unsigned char length_bytes[MAX_HASH_BIT_COUNT_BYTES];
/* hmac_pad is the masked HMAC key. */
unsigned char hmac_pad[MAX_HASH_BLOCK_SIZE];
@@ -436,35 +462,38 @@ void ssl3_cbc_digest_record(
* many possible overflows later in this function. */
OPENSSL_assert(data_plus_mac_plus_padding_size < 1024*1024);
- switch (ctx->digest->type)
+ switch (EVP_MD_CTX_type(ctx))
{
case NID_md5:
- MD5_Init((MD5_CTX*)md_state);
+ MD5_Init((MD5_CTX*)md_state.c);
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;
break;
case NID_sha1:
- SHA1_Init((SHA_CTX*)md_state);
+ SHA1_Init((SHA_CTX*)md_state.c);
md_final_raw = tls1_sha1_final_raw;
md_transform = (void(*)(void *ctx, const unsigned char *block)) SHA1_Transform;
md_size = 20;
break;
+#ifndef OPENSSL_NO_SHA256
case NID_sha224:
- SHA224_Init((SHA256_CTX*)md_state);
+ SHA224_Init((SHA256_CTX*)md_state.c);
md_final_raw = tls1_sha256_final_raw;
md_transform = (void(*)(void *ctx, const unsigned char *block)) SHA256_Transform;
md_size = 224/8;
break;
case NID_sha256:
- SHA256_Init((SHA256_CTX*)md_state);
+ SHA256_Init((SHA256_CTX*)md_state.c);
md_final_raw = tls1_sha256_final_raw;
md_transform = (void(*)(void *ctx, const unsigned char *block)) SHA256_Transform;
md_size = 32;
break;
+#endif
+#ifndef OPENSSL_NO_SHA512
case NID_sha384:
- SHA384_Init((SHA512_CTX*)md_state);
+ SHA384_Init((SHA512_CTX*)md_state.c);
md_final_raw = tls1_sha512_final_raw;
md_transform = (void(*)(void *ctx, const unsigned char *block)) SHA512_Transform;
md_size = 384/8;
@@ -472,13 +501,14 @@ void ssl3_cbc_digest_record(
md_length_size = 16;
break;
case NID_sha512:
- SHA512_Init((SHA512_CTX*)md_state);
+ SHA512_Init((SHA512_CTX*)md_state.c);
md_final_raw = tls1_sha512_final_raw;
md_transform = (void(*)(void *ctx, const unsigned char *block)) SHA512_Transform;
md_size = 64;
md_block_size = 128;
md_length_size = 16;
break;
+#endif
default:
/* ssl3_cbc_record_digest_supported should have been
* called first to check that the hash function is
@@ -577,17 +607,14 @@ void ssl3_cbc_digest_record(
for (i = 0; i < md_block_size; i++)
hmac_pad[i] ^= 0x36;
- md_transform(md_state, hmac_pad);
+ md_transform(md_state.c, hmac_pad);
}
- j = 0;
- if (md_length_size == 16)
- {
- memset(length_bytes, 0, 8);
- j = 8;
- }
- for (i = 0; i < 8; i++)
- length_bytes[i+j] = bits >> (8*(7-i));
+ memset(length_bytes,0,md_length_size-4);
+ length_bytes[md_length_size-4] = (unsigned char)(bits>>24);
+ length_bytes[md_length_size-3] = (unsigned char)(bits>>16);
+ length_bytes[md_length_size-2] = (unsigned char)(bits>>8);
+ length_bytes[md_length_size-1] = (unsigned char)bits;
if (k > 0)
{
@@ -598,21 +625,21 @@ void ssl3_cbc_digest_record(
* block that the header consumes: either 7 bytes
* (SHA1) or 11 bytes (MD5). */
unsigned overhang = header_length-md_block_size;
- md_transform(md_state, header);
+ 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, first_block);
+ md_transform(md_state.c, first_block);
for (i = 1; i < k/md_block_size - 1; i++)
- md_transform(md_state, data + md_block_size*i - overhang);
+ 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, first_block);
+ md_transform(md_state.c, first_block);
for (i = 1; i < k/md_block_size; i++)
- md_transform(md_state, data + md_block_size*i - 13);
+ md_transform(md_state.c, data + md_block_size*i - 13);
}
}
@@ -662,8 +689,8 @@ void ssl3_cbc_digest_record(
block[j] = b;
}
- md_transform(md_state, block);
- md_final_raw(md_state, block);
+ md_transform(md_state.c, block);
+ md_final_raw(md_state.c, block);
/* If this is index_b, copy the hash value to |mac_out|. */
for (j = 0; j < md_size; j++)
mac_out[j] |= block[j]&is_block_b;
@@ -694,3 +721,50 @@ void ssl3_cbc_digest_record(
*md_out_size = md_out_size_u;
EVP_MD_CTX_cleanup(&md_ctx);
}
+
+#ifdef OPENSSL_FIPS
+
+/* 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.
+ */
+
+void 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;
+ 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.
+ */
+ EVP_DigestSignUpdate(mac_ctx, data,
+ (blocks_orig - blocks_data + 1) * block_size);
+ }
+#endif
generated by cgit v1.1 at 2024-09-25 07:22:56 +0000