ospfd: review ospf_check_md5_digest()

Rewrite some pointer arithmetics without the additional variables and
move byte order conversion inside the function.
This commit is contained in:
Denis Ovsienko 2012-01-30 20:32:39 +04:00 committed by David Lamparter
parent e52591481e
commit 2d8223c547

View File

@ -304,24 +304,14 @@ ospf_packet_max (struct ospf_interface *oi)
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 @@ ospf_check_md5_digest (struct ospf_interface *oi, struct stream *s,
/* 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 @@ ospf_verify_header (struct stream *ibuf, struct ospf_interface *oi,
{
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));