diff options
| author | Guy Harris <guy@alum.mit.edu> | 2004-07-05 10:15:30 +0000 |
|---|---|---|
| committer | Guy Harris <guy@alum.mit.edu> | 2004-07-05 10:15:30 +0000 |
| commit | a3e07cdd793a35bce0ee2919132a7ce0fc0be68a (patch) | |
| tree | 8d570b4c420c5602ff8b78e2b09029975f83ccf9 | |
| parent | b373ded136367f49569569272830e32e0bdd49da (diff) | |
From Yaniv Kaul:
Don't try to dissect the MD5 authentication data as a route
entry (RTE). It's not. I made sure it's also the last entry in
the packet and it gets dissected only if MD5 authentication is
used.
Some implementation use the Auth. Data Length field value as
the WHOLE Authentication data length (0xFFFF (2 bytes) + 0x0001
(2 bytes) + 16 bytes of auth. data = 20) while others only as
the auth. data length ( = 16). Since MD5's auth data is 16
bytes anyway, I've hard coded it in the code (in #define), and
not relied on auth_data_len. I've tested it on implementations
using either way and it seems to work fine.
svn path=/trunk/; revision=11317
| -rw-r--r-- | packet-rip.c | 15 |
1 files changed, 10 insertions, 5 deletions
diff --git a/packet-rip.c b/packet-rip.c index 63dae42808..9b9358ad58 100644 --- a/packet-rip.c +++ b/packet-rip.c @@ -6,7 +6,7 @@ * RFC2082 ( Keyed Message Digest Algorithm ) * Emanuele Caratti <wiz@iol.it> * - * $Id: packet-rip.c,v 1.34 2003/10/18 18:46:37 guy Exp $ + * $Id: packet-rip.c,v 1.35 2004/07/05 10:15:30 guy Exp $ * * Ethereal - Network traffic analyzer * By Gerald Combs <gerald@ethereal.com> @@ -75,6 +75,7 @@ static const value_string rip_auth_type[] = { #define RIP_HEADER_LENGTH 4 #define RIP_ENTRY_LENGTH 20 +#define MD5_AUTH_DATA_LEN 16 static int proto_rip = -1; static int hf_rip_command = -1; @@ -110,6 +111,7 @@ dissect_rip(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree) guint8 version; guint16 family; gint trailer_len = 0; + gboolean is_md5_auth = FALSE; if (check_col(pinfo->cinfo, COL_PROTOCOL)) col_set_str(pinfo->cinfo, COL_PROTOCOL, "RIP"); @@ -156,8 +158,11 @@ dissect_rip(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree) case 0xFFFF: if( offset == RIP_HEADER_LENGTH ) { trailer_len=dissect_rip_authentication(tvb, offset, rip_tree); + is_md5_auth = TRUE; break; } + if(is_md5_auth && tvb_reported_length_remaining(tvb, offset) == 20) + break; /* Intentional fall through: auth Entry MUST be the first! */ default: proto_tree_add_text(rip_tree, tvb, offset, @@ -317,13 +322,13 @@ dissect_rip_authentication(tvbuff_t *tvb, int offset, proto_tree *tree) proto_tree_add_text( rip_authentication_tree, tvb, offset+12, 8, "Zero Padding" ); ti = proto_tree_add_text( rip_authentication_tree, tvb, offset-4+digest_off, - auth_data_len, "Authentication Data Trailer" ); + MD5_AUTH_DATA_LEN+4, "Authentication Data Trailer" ); rip_authentication_tree = proto_item_add_subtree(ti, ett_auth_vec ); proto_tree_add_text( rip_authentication_tree, tvb, offset-4+digest_off+4, - auth_data_len-4, "Authentication Data: %s", + MD5_AUTH_DATA_LEN, "Authentication Data: %s", rip_bytestring_to_str( - tvb_get_ptr( tvb, offset-4+digest_off+4,auth_data_len-4), - auth_data_len-4, ' ')); + tvb_get_ptr( tvb, offset-4+digest_off+4,MD5_AUTH_DATA_LEN), + MD5_AUTH_DATA_LEN, ' ')); break; } return auth_data_len; |