openssl/openssl-1.0.0d-CVE-2011-4108.diff
alexander barakin aka sash-kan 9e319be35e add patches from upstream
2012-04-10 15:27:51 +04:00

68 lines
1.7 KiB
Diff

http://cvs.openssl.org/chngview?cn=21931
--- ssl/d1_pkt.c 2011-01-04 19:33:22.000000000 +0000
+++ ssl/d1_pkt.c.oden 2012-01-09 15:18:39.000000000 +0000
@@ -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)
{
- if (enc_err == 0)
- /* SSLerr() and ssl3_send_alert() have been called */
- goto err;
-
- /* otherwise enc_err == -1 */
- al=SSL_AD_BAD_RECORD_MAC;
- goto f_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)
{