[openssl.org #2555] [PATCH] DTLS sequence number bug

[Robin Seggelmann via RT]

This patch fixes that the server increases the expected handshake sequence 
number while listening for new connections, although its supposed to not change 
its state. The server also reflects the record sequence numbers of ClientHellos 
in its HelloVerifyRequest and ServerHello messages now to remain stateless, as 
described in http://tools.ietf.org/html/draft-ietf-tls-rfc4347-bis-06.

Thanks to Yogesh Chopra for providing hints!

Best regards
Robin




--- ssl/d1_srvr.c       25 May 2011 14:29:55 -0000      1.20.2.18
+++ ssl/d1_srvr.c       6 Jul 2011 10:06:25 -0000
@@ -167,6 +167,8 @@
        s->in_handshake++;
        if (!SSL_in_init(s) || SSL_in_before(s)) SSL_clear(s);
 
+       s->d1->listen = listen;
+
        if (s->cert == NULL)
                {
                SSLerr(SSL_F_DTLS1_ACCEPT,SSL_R_NO_CERTIFICATE_SET);
@@ -276,6 +278,12 @@
 
                        s->init_num=0;
 
+                       /* Reflect ClientHello sequence to remain stateless 
while listening */
+                       if (listen)
+                               {
+                               memcpy(s->s3->write_sequence, 
s->s3->read_sequence, sizeof(s->s3->write_sequence));
+                               }
+
                        /* If we're just listening, stop here */
                        if (listen && s->state == SSL3_ST_SW_SRVR_HELLO_A)
                                {

dtls-seqnr-bug-0.9.8.patch
Description: Binary data

dtls-seqnr-bug-1.0.0.patch
Description: Binary data

dtls-seqnr-bug-1.0.1.patch
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