PR: 1981

[openssl.git] / ssl / d1_pkt.c

diff --git a/ssl/d1_pkt.c b/ssl/d1_pkt.c
index 2e9d5452f7beb23679ea58275b534c52ff779804..a9404492ddc8f3f2588b0518560f3508a0fe3c8d 100644 (file)
--- a/ssl/d1_pkt.c
+++ b/ssl/d1_pkt.c
@@ -207,6 +207,10 @@ dtls1_buffer_record(SSL *s, record_pqueue *queue, unsigned char *priority)
        DTLS1_RECORD_DATA *rdata;
        pitem *item;
 
+       /* Limit the size of the queue to prevent DOS attacks */
+       if (pqueue_size(queue->q) >= 100)
+               return 0;
+               
        rdata = OPENSSL_malloc(sizeof(DTLS1_RECORD_DATA));
        item = pitem_new(priority, rdata);
        if (rdata == NULL || item == NULL)
@@ -582,26 +586,27 @@ again:
                        {
                        if (version != s->version)
                                {
-                               SSLerr(SSL_F_DTLS1_GET_RECORD,SSL_R_WRONG_VERSION_NUMBER);
-                               /* Send back error using their
-                                * version number :-) */
-                               s->version=version;
-                               al=SSL_AD_PROTOCOL_VERSION;
-                               goto f_err;
+                               /* unexpected version, silently discard */
+                               rr->length = 0;
+                               s->packet_length = 0;
+                               goto again;
                                }
                        }
 
-               if ((version & 0xff00) != (DTLS1_VERSION & 0xff00))
+               if ((version & 0xff00) != (s->version & 0xff00))
                        {
-                       SSLerr(SSL_F_DTLS1_GET_RECORD,SSL_R_WRONG_VERSION_NUMBER);
-                       goto err;
+                       /* wrong version, silently discard record */
+                       rr->length = 0;
+                       s->packet_length = 0;
+                       goto again;
                        }
 
                if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH)
                        {
-                       al=SSL_AD_RECORD_OVERFLOW;
-                       SSLerr(SSL_F_DTLS1_GET_RECORD,SSL_R_PACKET_LENGTH_TOO_LONG);
-                       goto f_err;
+                       /* record too long, silently discard it */
+                       rr->length = 0;
+                       s->packet_length = 0;
+                       goto again;
                        }
 
                /* now s->rstate == SSL_ST_READ_BODY */
@@ -619,6 +624,7 @@ again:
                /* this packet contained a partial record, dump it */
                if ( n != i)
                        {
+                       rr->length = 0;
                        s->packet_length = 0;
                        goto again;
                        }
@@ -632,6 +638,7 @@ again:
        bitmap = dtls1_get_bitmap(s, rr, &is_next_epoch);
        if ( bitmap == NULL)
                {
+               rr->length = 0;
                s->packet_length = 0;  /* dump this record */
                goto again;   /* get another record */
                }
@@ -656,6 +663,7 @@ again:
                {
                dtls1_record_bitmap_update(s, bitmap);
                dtls1_buffer_record(s, &(s->d1->unprocessed_rcds), rr->seq_num);
+               rr->length = 0;
                s->packet_length = 0;
                goto again;
                }
@@ -762,7 +770,14 @@ start:
                        pitem_free(item);
                        }
                }
-               
+
+       /* Check for timeout */
+       if (dtls1_is_timer_expired(s))
+               {
+               if (dtls1_read_failed(s, -1) > 0);
+                       goto start;
+               }
+
        /* get new packet if necessary */
        if ((rr->length == 0) || (s->rstate == SSL_ST_READ_BODY))
                {
@@ -1067,13 +1082,17 @@ start:
        if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC)
                {
                struct ccs_header_st ccs_hdr;
+               unsigned int ccs_hdr_len = DTLS1_CCS_HEADER_LENGTH;
 
                dtls1_get_ccs_header(rr->data, &ccs_hdr);
 
+               if (s->version == DTLS1_BAD_VER)
+                       ccs_hdr_len = 3;
+
                /* 'Change Cipher Spec' is just a single byte, so we know
                 * exactly what the record payload has to look like */
                /* XDTLS: check that epoch is consistent */
-               if (    (rr->length != DTLS1_CCS_HEADER_LENGTH) || 
+               if (    (rr->length != ccs_hdr_len) || 
                        (rr->off != 0) || (rr->data[0] != SSL3_MT_CCS))
                        {
                        i=SSL_AD_ILLEGAL_PARAMETER;
@@ -1087,6 +1106,16 @@ start:
                        s->msg_callback(0, s->version, SSL3_RT_CHANGE_CIPHER_SPEC, 
                                rr->data, 1, s, s->msg_callback_arg);
 
+               /* We can't process a CCS now, because previous handshake
+                * messages are still missing, so just drop it.
+                */
+               if (!s->d1->change_cipher_spec_ok)
+                       {
+                       goto start;
+                       }
+
+               s->d1->change_cipher_spec_ok = 0;
+
                s->s3->change_cipher_spec=1;
                if (!ssl3_do_change_cipher_spec(s))
                        goto err;
@@ -1094,6 +1123,9 @@ start:
                /* do this whenever CCS is processed */
                dtls1_reset_seq_numbers(s, SSL3_CC_READ);
 
+               if (s->version == DTLS1_BAD_VER)
+                       s->d1->handshake_read_seq++;
+
                goto start;
                }
 
@@ -1401,7 +1433,7 @@ int do_dtls1_write(SSL *s, int type, const unsigned char *buf, unsigned int len,
 #if 0
        /* 'create_empty_fragment' is true only when this function calls itself */
        if (!clear && !create_empty_fragment && !s->s3->empty_fragment_done
-               && SSL_version(s) != DTLS1_VERSION)
+           && SSL_version(s) != DTLS1_VERSION && SSL_version(s) != DTLS1_BAD_VER)
                {
                /* countermeasure against known-IV weakness in CBC ciphersuites
                 * (see http://www.openssl.org/~bodo/tls-cbc.txt) 
@@ -1428,7 +1460,6 @@ int do_dtls1_write(SSL *s, int type, const unsigned char *buf, unsigned int len,
                s->s3->empty_fragment_done = 1;
                }
 #endif
-
        p = wb->buf + prefix_len;
 
        /* write the header */