Convert dtls1_get_message_header to CBS and change to int.

Changed return value from void to int.  It should never return an error
given that the input length is not checked yet.

ok miod@

1 files changed, 32 insertions, 12 deletions

diff --git a/src/lib/libssl/d1_both.c b/src/lib/libssl/d1_both.c
index 534db59ee8..5c93af8bd9 100644
--- a/src/lib/libssl/d1_both.c
+++ b/src/lib/libssl/d1_both.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: d1_both.c,v 1.32 2015/02/09 10:53:28 jsing Exp $ */
+/* $OpenBSD: d1_both.c,v 1.33 2015/07/18 23:00:23 doug Exp $ */
 /*
  * DTLS implementation written by Nagendra Modadugu
  * (nagendra@cs.stanford.edu) for the OpenSSL project 2005.
@@ -125,6 +125,7 @@
 #include <openssl/x509.h>
 
 #include "pqueue.h"
+#include "bytestring.h"
 
 #define RSMBLY_BITMASK_SIZE(msg_len) (((msg_len) + 7) / 8)
 
@@ -798,16 +799,15 @@ again:
                 return i;
         }
         /* Handshake fails if message header is incomplete */
-        if (i != DTLS1_HM_HEADER_LENGTH) {
+        if (i != DTLS1_HM_HEADER_LENGTH ||
+            /* parse the message fragment header */
+            dtls1_get_message_header(wire, &msg_hdr) == 0) {
                 al = SSL_AD_UNEXPECTED_MESSAGE;
                 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,
                     SSL_R_UNEXPECTED_MESSAGE);
                 goto f_err;
         }
 
-        /* parse the message fragment header */
-        dtls1_get_message_header(wire, &msg_hdr);
-
         /*
          * if this is a future (or stale) message it gets buffered
          * (or dropped)--no further processing at this time
@@ -1372,16 +1372,36 @@ dtls1_guess_mtu(unsigned int curr_mtu)
         return curr_mtu;
 }
 
-void
+int
 dtls1_get_message_header(unsigned char *data, struct hm_header_st *msg_hdr)
 {
-        memset(msg_hdr, 0x00, sizeof(struct hm_header_st));
-        msg_hdr->type = *(data++);
-        n2l3(data, msg_hdr->msg_len);
+        CBS header;
+        uint32_t msg_len, frag_off, frag_len;
+        uint16_t seq;
+        uint8_t type;
+
+        CBS_init(&header, data, sizeof(*msg_hdr));
+
+        memset(msg_hdr, 0, sizeof(*msg_hdr));
+
+        if (!CBS_get_u8(&header, &type))
+                return 0;
+        if (!CBS_get_u24(&header, &msg_len))
+                return 0;
+        if (!CBS_get_u16(&header, &seq))
+                return 0;
+        if (!CBS_get_u24(&header, &frag_off))
+                return 0;
+        if (!CBS_get_u24(&header, &frag_len))
+                return 0;
 
-        n2s(data, msg_hdr->seq);
-        n2l3(data, msg_hdr->frag_off);
-        n2l3(data, msg_hdr->frag_len);
+        msg_hdr->type = type;
+        msg_hdr->msg_len = msg_len;
+        msg_hdr->seq = seq;
+        msg_hdr->frag_off = frag_off;
+        msg_hdr->frag_len = frag_len;
+
+        return 1;
 }
 
 void