ospfd: review ospf_check_md5_digest()
Rewrite some pointer arithmetics without the additional variables and
move byte order conversion inside the function.
diff --git a/ospfd/ospf_packet.c b/ospfd/ospf_packet.c
index b18117b..15ec373 100644
--- a/ospfd/ospf_packet.c
+++ b/ospfd/ospf_packet.c
@@ -304,24 +304,14 @@
static int
-ospf_check_md5_digest (struct ospf_interface *oi, struct stream *s,
- u_int16_t length)
+ospf_check_md5_digest (struct ospf_interface *oi, struct ospf_header *ospfh)
{
- unsigned char *ibuf;
MD5_CTX ctx;
unsigned char digest[OSPF_AUTH_MD5_SIZE];
- unsigned char *pdigest;
struct crypt_key *ck;
- struct ospf_header *ospfh;
struct ospf_neighbor *nbr;
+ u_int16_t length = ntohs (ospfh->length);
-
- ibuf = STREAM_PNT (s);
- ospfh = (struct ospf_header *) ibuf;
-
- /* Get pointer to the end of the packet. */
- pdigest = ibuf + length;
-
/* Get secret key. */
ck = ospf_crypt_key_lookup (OSPF_IF_PARAM (oi, auth_crypt),
ospfh->u.crypt.key_id);
@@ -347,12 +337,12 @@
/* Generate a digest for the ospf packet - their digest + our digest. */
memset(&ctx, 0, sizeof(ctx));
MD5Init(&ctx);
- MD5Update(&ctx, ibuf, length);
+ MD5Update(&ctx, ospfh, length);
MD5Update(&ctx, ck->auth_key, OSPF_AUTH_MD5_SIZE);
MD5Final(digest, &ctx);
/* compare the two */
- if (memcmp (pdigest, digest, OSPF_AUTH_MD5_SIZE))
+ if (memcmp ((caddr_t)ospfh + length, digest, OSPF_AUTH_MD5_SIZE))
{
zlog_warn ("interface %s: ospf_check_md5 checksum mismatch",
IF_NAME (oi));
@@ -2431,7 +2421,7 @@
{
if (ospfh->checksum != 0)
return -1;
- if (ospf_check_md5_digest (oi, ibuf, ntohs (ospfh->length)) == 0)
+ if (ospf_check_md5_digest (oi, ospfh) == 0)
{
zlog_warn ("interface %s: ospf_read md5 authentication failed.",
IF_NAME (oi));