Don't crash when processing a zero-length, TLS >= 1.1 record.

The previous CBC patch was bugged in that there was a path through enc()
in s3_pkt.c/d1_pkt.c which didn't set orig_len. orig_len would be left
at the previous value which could suggest that the packet was a
sufficient length when it wasn't.

ssl/s3_enc.c

@@ -466,6 +466,15 @@ void ssl3_cleanup_key_block(SSL *s)
 	s->s3->tmp.key_block_length=0;
 	}
 
+/* ssl3_enc encrypts/decrypts the record in |s->wrec| / |s->rrec|, respectively.
+ *
+ * Returns:
+ *   0: (in non-constant time) if the record is publically invalid (i.e. too
+ *       short etc).
+ *   1: if the record's padding is valid / the encryption was successful.
+ *   -1: if the record's padding is invalid or, if sending, an internal error
+ *       occured.
+ */
 int ssl3_enc(SSL *s, int send)
 	{
 	SSL3_RECORD *rec;
@@ -532,8 +541,6 @@ int ssl3_enc(SSL *s, int send)
 		
 		EVP_Cipher(ds,rec->data,rec->input,l);
 
-		rec->orig_len = rec->length;
-
 		if (EVP_MD_CTX_md(s->read_hash) != NULL)
 			mac_size = EVP_MD_CTX_size(s->read_hash);
 		if ((bs != 1) && !send)