forked from osmocom/wireshark
6ea1842885
create a new dissector table where MAC algorithms for dns/tsig can be registered. register gssapi for the algorithm "gss.microsoft.com" since this is what w2k uses when performing dns updates. svn path=/trunk/; revision=16895
453 lines
12 KiB
C
453 lines
12 KiB
C
/* packet-gssapi.c
|
|
* Dissector for GSS-API tokens as described in rfc2078, section 3.1
|
|
* Copyright 2002, Tim Potter <tpot@samba.org>
|
|
* Copyright 2002, Richard Sharpe <rsharpe@samba.org> Added a few
|
|
* bits and pieces ...
|
|
*
|
|
* $Id$
|
|
*
|
|
* Ethereal - Network traffic analyzer
|
|
* By Gerald Combs <gerald@ethereal.com>
|
|
* Copyright 1998 Gerald Combs
|
|
*
|
|
* This program is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU General Public License
|
|
* as published by the Free Software Foundation; either version 2
|
|
* of the License, or (at your option) any later version.
|
|
*
|
|
* This program is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with this program; if not, write to the Free Software
|
|
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
|
|
*/
|
|
|
|
#ifdef HAVE_CONFIG_H
|
|
# include "config.h"
|
|
#endif
|
|
|
|
#ifdef HAVE_SYS_TYPES_H
|
|
# include <sys/types.h>
|
|
#endif
|
|
|
|
#include <string.h>
|
|
|
|
#include <glib.h>
|
|
#include <epan/packet.h>
|
|
|
|
#include <epan/dissectors/packet-dcerpc.h>
|
|
#include <epan/dissectors/packet-gssapi.h>
|
|
#include <epan/dissectors/packet-frame.h>
|
|
#include "epan/conversation.h"
|
|
#include "packet-ber.h"
|
|
#include "to_str.h"
|
|
|
|
static int proto_gssapi = -1;
|
|
|
|
static int hf_gssapi_oid = -1;
|
|
|
|
static gint ett_gssapi = -1;
|
|
|
|
/*
|
|
* Subdissectors
|
|
*/
|
|
|
|
static dissector_handle_t ntlmssp_handle = NULL;
|
|
|
|
static GHashTable *gssapi_oids;
|
|
|
|
static gint gssapi_oid_equal(gconstpointer k1, gconstpointer k2)
|
|
{
|
|
const char *key1 = (const char *)k1;
|
|
const char *key2 = (const char *)k2;
|
|
|
|
return strcmp(key1, key2) == 0;
|
|
}
|
|
|
|
static guint
|
|
gssapi_oid_hash(gconstpointer k)
|
|
{
|
|
const char *key = (const char *)k;
|
|
guint hash = 0, i;
|
|
|
|
for (i = 0; i < strlen(key); i++)
|
|
hash += key[i];
|
|
|
|
return hash;
|
|
}
|
|
|
|
void
|
|
gssapi_init_oid(const char *oid, int proto, int ett, dissector_handle_t handle,
|
|
dissector_handle_t wrap_handle, const gchar *comment)
|
|
{
|
|
char *key = g_strdup(oid);
|
|
gssapi_oid_value *value = g_malloc(sizeof(*value));
|
|
|
|
value->proto = find_protocol_by_id(proto);
|
|
value->ett = ett;
|
|
value->handle = handle;
|
|
value->wrap_handle = wrap_handle;
|
|
value->comment = comment;
|
|
|
|
g_hash_table_insert(gssapi_oids, key, value);
|
|
register_ber_oid_dissector_handle(key, handle, proto, comment);
|
|
}
|
|
|
|
/*
|
|
* This takes an OID in text string form as
|
|
* an argument.
|
|
*/
|
|
gssapi_oid_value *
|
|
gssapi_lookup_oid_str(const char *oid_key)
|
|
{
|
|
gssapi_oid_value *value;
|
|
value = g_hash_table_lookup(gssapi_oids, oid_key);
|
|
return value;
|
|
}
|
|
|
|
static int
|
|
dissect_gssapi_work(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
|
|
gboolean is_verifier)
|
|
{
|
|
proto_item *item;
|
|
proto_tree *subtree;
|
|
volatile int return_offset = 0;
|
|
gssapi_oid_value *value;
|
|
volatile dissector_handle_t handle;
|
|
conversation_t *volatile conversation;
|
|
tvbuff_t *oid_tvb;
|
|
int len, offset, start_offset, oid_start_offset;
|
|
gint8 class;
|
|
gboolean pc, ind_field;
|
|
gint32 tag;
|
|
guint32 len1;
|
|
const char *oid;
|
|
|
|
start_offset=0;
|
|
offset=start_offset;
|
|
|
|
/*
|
|
* We don't know whether the data is encrypted, so say it's
|
|
* not, for now. The subdissector must set gssapi_data_encrypted
|
|
* if it is.
|
|
*/
|
|
pinfo->gssapi_data_encrypted = FALSE;
|
|
|
|
/*
|
|
* We need this later, so lets get it now ...
|
|
*/
|
|
|
|
conversation = find_conversation(pinfo->fd->num, &pinfo->src, &pinfo->dst,
|
|
pinfo->ptype, pinfo->srcport,
|
|
pinfo->destport, 0);
|
|
|
|
item = proto_tree_add_item(
|
|
tree, proto_gssapi, tvb, offset, -1, FALSE);
|
|
|
|
subtree = proto_item_add_subtree(item, ett_gssapi);
|
|
|
|
/*
|
|
* Catch the ReportedBoundsError exception; the stuff we've been
|
|
* handed doesn't necessarily run to the end of the packet, it's
|
|
* an item inside a packet, so if it happens to be malformed (or
|
|
* we, or a dissector we call, has a bug), so that an exception
|
|
* is thrown, we want to report the error, but return and let
|
|
* our caller dissect the rest of the packet.
|
|
*
|
|
* If it gets a BoundsError, we can stop, as there's nothing more
|
|
* in the packet after our blob to see, so we just re-throw the
|
|
* exception.
|
|
*/
|
|
TRY {
|
|
/* Read header */
|
|
offset = get_ber_identifier(tvb, offset, &class, &pc, &tag);
|
|
offset = get_ber_length(tree, tvb, offset, &len1, &ind_field);
|
|
|
|
if (!(class == BER_CLASS_APP && pc && tag == 0)) {
|
|
/*
|
|
* If we do not recognise an Application class,
|
|
* then we are probably dealing with an inner context
|
|
* token or a wrap token, and we should retrieve the
|
|
* gssapi_oid_value pointer from the per-frame data or,
|
|
* if there is no per-frame data (as would be the case
|
|
* the first time we dissect this frame), from the
|
|
* conversation that exists or that we created from
|
|
* pinfo (and then make it per-frame data).
|
|
* We need to make it per-frame data as there can be
|
|
* more than one GSS-API negotiation in a conversation.
|
|
*
|
|
* Note! We "cheat". Since we only need the pointer,
|
|
* we store that as the data. (That's not really
|
|
* "cheating" - the per-frame data and per-conversation
|
|
* data code doesn't care what you supply as a data
|
|
* pointer; it just treats it as an opaque pointer, it
|
|
* doesn't dereference it or free what it points to.)
|
|
*/
|
|
value = p_get_proto_data(pinfo->fd, proto_gssapi);
|
|
if (!value && !pinfo->fd->flags.visited)
|
|
{
|
|
/* No handle attached to this frame, but it's the first */
|
|
/* pass, so it'd be attached to the conversation. */
|
|
/* If we have a conversation, try to get the handle, */
|
|
/* and if we get one, attach it to the frame. */
|
|
if (conversation)
|
|
{
|
|
value = conversation_get_proto_data(conversation,
|
|
proto_gssapi);
|
|
if (value)
|
|
p_add_proto_data(pinfo->fd, proto_gssapi, value);
|
|
}
|
|
}
|
|
if (!value)
|
|
{
|
|
/* It could be NTLMSSP, with no OID. This can happen
|
|
for anything that microsoft calls 'Negotiate' or GSS-SPNEGO */
|
|
if (tvb_strneql(tvb, start_offset, "NTLMSSP", 7) == 0) {
|
|
call_dissector(ntlmssp_handle, tvb_new_subset(tvb, start_offset, -1, -1), pinfo, subtree);
|
|
} else {
|
|
proto_tree_add_text(subtree, tvb, start_offset, 0,
|
|
"Unknown header (class=%d, pc=%d, tag=%d)",
|
|
class, pc, tag);
|
|
}
|
|
return_offset = tvb_length(tvb);
|
|
goto done;
|
|
|
|
} else {
|
|
tvbuff_t *oid_tvb;
|
|
|
|
oid_tvb = tvb_new_subset(tvb, start_offset, -1, -1);
|
|
if (is_verifier)
|
|
handle = value->wrap_handle;
|
|
else
|
|
handle = value->handle;
|
|
len = call_dissector(handle, oid_tvb, pinfo, subtree);
|
|
if (len == 0)
|
|
return_offset = tvb_length(tvb);
|
|
else
|
|
return_offset = start_offset + len;
|
|
goto done; /* We are finished here */
|
|
}
|
|
}
|
|
|
|
/* Read oid */
|
|
oid_start_offset=offset;
|
|
offset=dissect_ber_object_identifier_str(FALSE, pinfo, subtree, tvb, offset, hf_gssapi_oid, &oid);
|
|
|
|
/*
|
|
* Hand off to subdissector.
|
|
*/
|
|
|
|
if (((value = gssapi_lookup_oid_str(oid)) == NULL) ||
|
|
!proto_is_protocol_enabled(value->proto)) {
|
|
/* No dissector for this oid */
|
|
proto_tree_add_text(subtree, tvb, oid_start_offset, -1,
|
|
"Token object");
|
|
|
|
return_offset = tvb_length(tvb);
|
|
goto done;
|
|
}
|
|
|
|
/*
|
|
* This is not needed, as the sub-dissector adds a tree
|
|
sub_item = proto_tree_add_item(subtree, value->proto, tvb,
|
|
offset, -1, FALSE);
|
|
|
|
oid_subtree = proto_item_add_subtree(sub_item, value->ett);
|
|
*/
|
|
|
|
/*
|
|
* Here we should create a conversation if needed and
|
|
* save a pointer to the data for that OID for the
|
|
* GSSAPI protocol.
|
|
*/
|
|
|
|
if (!conversation) { /* Create one */
|
|
conversation = conversation_new(pinfo->fd->num, &pinfo->src,
|
|
&pinfo->dst,
|
|
pinfo->ptype,
|
|
pinfo->srcport,
|
|
pinfo->destport, 0);
|
|
}
|
|
|
|
/*
|
|
* Now add the proto data ...
|
|
* but only if it is not already there.
|
|
*/
|
|
|
|
if (!conversation_get_proto_data(conversation,
|
|
proto_gssapi)) {
|
|
conversation_add_proto_data(conversation,
|
|
proto_gssapi, value);
|
|
}
|
|
|
|
if (is_verifier) {
|
|
handle = value->wrap_handle;
|
|
if (handle != NULL) {
|
|
oid_tvb = tvb_new_subset(tvb, offset, -1, -1);
|
|
len = call_dissector(handle, oid_tvb, pinfo,
|
|
subtree);
|
|
if (len == 0)
|
|
return_offset = tvb_length(tvb);
|
|
else
|
|
return_offset = offset + len;
|
|
} else {
|
|
proto_tree_add_text(subtree, tvb, offset, -1,
|
|
"Authentication verifier");
|
|
return_offset = tvb_length(tvb);
|
|
}
|
|
} else {
|
|
handle = value->handle;
|
|
if (handle != NULL) {
|
|
oid_tvb = tvb_new_subset(tvb, offset, -1, -1);
|
|
len = call_dissector(handle, oid_tvb, pinfo,
|
|
subtree);
|
|
if (len == 0)
|
|
return_offset = tvb_length(tvb);
|
|
else
|
|
return_offset = offset + len;
|
|
} else {
|
|
proto_tree_add_text(subtree, tvb, offset, -1,
|
|
"Authentication credentials");
|
|
return_offset = tvb_length(tvb);
|
|
}
|
|
}
|
|
|
|
done:
|
|
;
|
|
} CATCH(BoundsError) {
|
|
RETHROW;
|
|
} CATCH(ReportedBoundsError) {
|
|
show_reported_bounds_error(tvb, pinfo, tree);
|
|
} ENDTRY;
|
|
|
|
proto_item_set_len(item, return_offset);
|
|
return return_offset;
|
|
}
|
|
|
|
static void
|
|
dissect_gssapi(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
|
|
{
|
|
dissect_gssapi_work(tvb, pinfo, tree, FALSE);
|
|
}
|
|
|
|
static int
|
|
dissect_gssapi_verf(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
|
|
{
|
|
return dissect_gssapi_work(tvb, pinfo, tree, TRUE);
|
|
}
|
|
|
|
void
|
|
proto_register_gssapi(void)
|
|
{
|
|
static hf_register_info hf[] = {
|
|
{ &hf_gssapi_oid, {
|
|
"OID", "gss-api.OID", FT_STRING, BASE_NONE,
|
|
NULL, 0, "This is a GSS-API Object Identifier", HFILL }},
|
|
};
|
|
|
|
static gint *ett[] = {
|
|
&ett_gssapi,
|
|
};
|
|
|
|
proto_gssapi = proto_register_protocol(
|
|
"GSS-API Generic Security Service Application Program Interface",
|
|
"GSS-API", "gss-api");
|
|
|
|
proto_register_field_array(proto_gssapi, hf, array_length(hf));
|
|
proto_register_subtree_array(ett, array_length(ett));
|
|
|
|
register_dissector("gssapi", dissect_gssapi, proto_gssapi);
|
|
new_register_dissector("gssapi_verf", dissect_gssapi_verf, proto_gssapi);
|
|
|
|
gssapi_oids = g_hash_table_new(gssapi_oid_hash, gssapi_oid_equal);
|
|
}
|
|
|
|
static int wrap_dissect_gssapi(tvbuff_t *tvb, int offset,
|
|
packet_info *pinfo,
|
|
proto_tree *tree, guint8 *drep _U_)
|
|
{
|
|
tvbuff_t *auth_tvb;
|
|
|
|
auth_tvb = tvb_new_subset(tvb, offset, -1, -1);
|
|
|
|
dissect_gssapi(auth_tvb, pinfo, tree);
|
|
|
|
return tvb_length_remaining(tvb, offset);
|
|
}
|
|
|
|
int wrap_dissect_gssapi_verf(tvbuff_t *tvb, int offset,
|
|
packet_info *pinfo,
|
|
proto_tree *tree, guint8 *drep _U_)
|
|
{
|
|
tvbuff_t *auth_tvb;
|
|
|
|
auth_tvb = tvb_new_subset(tvb, offset, -1, -1);
|
|
|
|
return dissect_gssapi_verf(auth_tvb, pinfo, tree);
|
|
}
|
|
|
|
tvbuff_t *
|
|
wrap_dissect_gssapi_payload(tvbuff_t *data_tvb,
|
|
tvbuff_t *auth_tvb,
|
|
int offset _U_,
|
|
packet_info *pinfo,
|
|
dcerpc_auth_info *auth_info _U_)
|
|
{
|
|
tvbuff_t *result;
|
|
|
|
/* we need a full auth and a full data tvb or else we cant
|
|
decrypt anything
|
|
*/
|
|
if((!auth_tvb)||(!data_tvb)){
|
|
return NULL;
|
|
}
|
|
|
|
pinfo->decrypt_gssapi_tvb=DECRYPT_GSSAPI_DCE;
|
|
pinfo->gssapi_wrap_tvb=NULL;
|
|
pinfo->gssapi_encrypted_tvb=data_tvb;
|
|
pinfo->gssapi_decrypted_tvb=NULL;
|
|
dissect_gssapi_verf(auth_tvb, pinfo, NULL);
|
|
result=pinfo->gssapi_decrypted_tvb;
|
|
|
|
pinfo->decrypt_gssapi_tvb=0;
|
|
pinfo->gssapi_wrap_tvb=NULL;
|
|
pinfo->gssapi_encrypted_tvb=NULL;
|
|
pinfo->gssapi_decrypted_tvb=NULL;
|
|
|
|
return result;
|
|
}
|
|
|
|
static dcerpc_auth_subdissector_fns gssapi_auth_fns = {
|
|
wrap_dissect_gssapi, /* Bind */
|
|
wrap_dissect_gssapi, /* Bind ACK */
|
|
wrap_dissect_gssapi, /* AUTH3 */
|
|
wrap_dissect_gssapi_verf, /* Request verifier */
|
|
wrap_dissect_gssapi_verf, /* Response verifier */
|
|
NULL, /* Request data */
|
|
NULL /* Response data */
|
|
};
|
|
|
|
void
|
|
proto_reg_handoff_gssapi(void)
|
|
{
|
|
dissector_handle_t gssapi_handle;
|
|
|
|
ntlmssp_handle = find_dissector("ntlmssp");
|
|
|
|
register_dcerpc_auth_subdissector(DCE_C_AUTHN_LEVEL_CONNECT,
|
|
DCE_C_RPC_AUTHN_PROTOCOL_SPNEGO,
|
|
&gssapi_auth_fns);
|
|
register_dcerpc_auth_subdissector(DCE_C_AUTHN_LEVEL_PKT_INTEGRITY,
|
|
DCE_C_RPC_AUTHN_PROTOCOL_SPNEGO,
|
|
&gssapi_auth_fns);
|
|
register_dcerpc_auth_subdissector(DCE_C_AUTHN_LEVEL_PKT_PRIVACY,
|
|
DCE_C_RPC_AUTHN_PROTOCOL_SPNEGO,
|
|
&gssapi_auth_fns);
|
|
|
|
gssapi_handle = create_dissector_handle(dissect_gssapi, proto_gssapi);
|
|
dissector_add_string("dns.tsig.mac", "gss.microsoft.com", gssapi_handle);
|
|
}
|