Fix write failure handling in DTLS1.2

The DTLS code is supposed to drop packets if we try to write them out but
the underlying BIO write buffers are full. ssl3_write_pending() contains
an incorrect test for DTLS that controls this. The test only checks for
DTLS1 so DTLS1.2 does not correctly clear the internal OpenSSL buffer which
can later cause an assert to be hit. This commit changes the test to cover
all DTLS versions.

RT#3967

Reviewed-by: Tim Hudson <tjh@openssl.org>
(cherry picked from commit 5e8b24dbfb98ed7c5b355cb6a959906a418e264b)

diff --git a/ssl/s3_pkt.c b/ssl/s3_pkt.c
index 603c285ac4994088f03f6c8a6082ebfc47bfdaa4..379890237e8663b72a68f38a6e472a1d019e4312 100644 (file)
--- a/ssl/s3_pkt.c
+++ b/ssl/s3_pkt.c
@@ -1115,7 +1115,7 @@ int ssl3_write_pending(SSL *s, int type, const unsigned char *buf,
             s->rwstate = SSL_NOTHING;
             return (s->s3->wpend_ret);
         } else if (i <= 0) {
-            if (s->version == DTLS1_VERSION || s->version == DTLS1_BAD_VER) {
+            if (SSL_IS_DTLS(s)) {
                 /*
                  * For DTLS, just drop it. That's kind of the whole point in
                  * using a datagram service