- /* !clear => s->read_hash != NULL => mac_size != -1 */
- int t;
- t=EVP_MD_CTX_size(s->read_hash);
- OPENSSL_assert(t >= 0);
- mac_size=t;
-
- if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH+mac_size)
- {
-#if 0 /* OK only for stream ciphers (then rr->length is visible from ciphertext anyway) */
- al=SSL_AD_RECORD_OVERFLOW;
- SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_PRE_MAC_LENGTH_TOO_LONG);
- goto f_err;
-#else
- goto err;
-#endif
- }
- /* check the MAC for rr->input (it's in mac_size bytes at the tail) */
- if (rr->length < mac_size)
+ /* s->read_hash != NULL => mac_size != -1 */
+ unsigned char *mac = NULL;
+ unsigned char mac_tmp[EVP_MAX_MD_SIZE];
+ mac_size=EVP_MD_CTX_size(s->read_hash);
+ OPENSSL_assert(mac_size <= EVP_MAX_MD_SIZE);
+
+ /* orig_len is the length of the record before any padding was
+ * removed. This is public information, as is the MAC in use,
+ * therefore we can safely process the record in a different
+ * amount of time if it's too short to possibly contain a MAC.
+ */
+ if (rr->orig_len < mac_size ||
+ /* CBC records must have a padding length byte too. */
+ (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE &&
+ rr->orig_len < mac_size+1))