From 2d8223c5472129eba89d630dc4f2688ebeae1dd8 Mon Sep 17 00:00:00 2001 From: Denis Ovsienko Date: Mon, 30 Jan 2012 20:32:39 +0400 Subject: ospfd: review ospf_check_md5_digest() Rewrite some pointer arithmetics without the additional variables and move byte order conversion inside the function. --- ospfd/ospf_packet.c | 20 +++++--------------- 1 file changed, 5 insertions(+), 15 deletions(-) (limited to 'ospfd/ospf_packet.c') diff --git a/ospfd/ospf_packet.c b/ospfd/ospf_packet.c index b18117b5..15ec3733 100644 --- a/ospfd/ospf_packet.c +++ b/ospfd/ospf_packet.c @@ -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)); -- cgit v1.2.1