OpenSSL 1.0.0f: merge

1 files changed, 16 insertions, 10 deletions

diff --git a/src/lib/libssl/d1_pkt.c b/src/lib/libssl/d1_pkt.c
index 39aac73e10..e0c0f0cc9a 100644
--- a/src/lib/libssl/d1_pkt.c
+++ b/src/lib/libssl/d1_pkt.c
@@ -375,6 +375,7 @@ dtls1_process_record(SSL *s)
         SSL3_RECORD *rr;
         unsigned int mac_size;
         unsigned char md[EVP_MAX_MD_SIZE];
+        int decryption_failed_or_bad_record_mac = 0;
 
 
         rr= &(s->s3->rrec);
@@ -409,13 +410,10 @@ dtls1_process_record(SSL *s)
         enc_err = s->method->ssl3_enc->enc(s,0);
         if (enc_err <= 0)
                 {
-                /* decryption failed, silently discard message */
-                if (enc_err < 0)
-                        {
-                        rr->length = 0;
-                        s->packet_length = 0;
-                        }
-                goto err;
+                /* To minimize information leaked via timing, we will always
+                 * perform all computations before discarding the message.
+                 */
+                decryption_failed_or_bad_record_mac = 1;
                 }
 
 #ifdef TLS_DEBUG
@@ -445,7 +443,7 @@ printf("\n");
                         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_PRE_MAC_LENGTH_TOO_LONG);
                         goto f_err;
 #else
-                        goto err;
+                        decryption_failed_or_bad_record_mac = 1;
 #endif                  
                         }
                 /* check the MAC for rr->input (it's in mac_size bytes at the tail) */
@@ -456,17 +454,25 @@ printf("\n");
                         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_LENGTH_TOO_SHORT);
                         goto f_err;
 #else
-                        goto err;
+                        decryption_failed_or_bad_record_mac = 1;
 #endif
                         }
                 rr->length-=mac_size;
                 i=s->method->ssl3_enc->mac(s,md,0);
                 if (i < 0 || memcmp(md,&(rr->data[rr->length]),mac_size) != 0)
                         {
-                        goto err;
+                        decryption_failed_or_bad_record_mac = 1;
                         }
                 }
 
+        if (decryption_failed_or_bad_record_mac)
+                {
+                /* decryption failed, silently discard message */
+                rr->length = 0;
+                s->packet_length = 0;
+                goto err;
+                }
+
         /* r->length is now just compressed */
         if (s->expand != NULL)
                 {