Sanity check record length before skipping explicit IV in DTLS

to fix DoS attack.

Thanks to Codenomicon for discovering this issue using Fuzz-o-Matic

fuzzing as a service testing platform.

(CVE-2012-2333)

diff -up openssl-fips-0.9.8e/ssl/d1_enc.c.reclen openssl-fips-0.9.8e/ssl/d1_enc.c

--- openssl-fips-0.9.8e/ssl/d1_enc.c.reclen	2006-02-08 20:16:32.000000000 +0100

+++ openssl-fips-0.9.8e/ssl/d1_enc.c	2012-05-15 12:14:25.510013029 +0200

@@ -252,7 +252,7 @@ int dtls1_enc(SSL *s, int send)

 				}

 			/* TLS 1.0 does not bound the number of padding bytes by the block size.

 			 * All of them must have value 'padding_length'. */

-			if (i > (int)rec->length)

+			if (i + bs > (int)rec->length)

 				{

 				/* Incorrect padding. SSLerr() and ssl3_alert are done

 				 * by caller: we don't want to reveal whether this is