1
0
mirror of https://github.com/samba-team/samba.git synced 2025-01-26 10:04:02 +03:00
Stefan Metzmacher 8cd1a2a118 CVE-2016-2110: auth/ntlmssp: implement gensec_ntlmssp_may_reset_crypto()
[MS-SPNG] requires the NTLMSSP RC4 states to be reset after
the SPNEGO exchange with mechListMic verification (new_spnego).

The 'reset_full' parameter is needed to support the broken
behavior that windows only resets the RC4 states but not the
sequence numbers. Which means this functionality is completely
useless... But we want to work against all windows versions...

BUG: https://bugzilla.samba.org/show_bug.cgi?id=11644

Signed-off-by: Stefan Metzmacher <metze@samba.org>
Reviewed-by: Günther Deschner <gd@samba.org>
2016-04-12 19:25:23 +02:00

311 lines
9.2 KiB
C

/*
Unix SMB/Netbios implementation.
Version 3.0
handle NLTMSSP, client server side parsing
Copyright (C) Andrew Tridgell 2001
Copyright (C) Andrew Bartlett <abartlet@samba.org> 2001-2005
Copyright (C) Stefan Metzmacher 2005
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 3 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, see <http://www.gnu.org/licenses/>.
*/
struct auth_session_info;
#include "includes.h"
#include "auth/ntlmssp/ntlmssp.h"
#include "auth/ntlmssp/ntlmssp_private.h"
#include "../libcli/auth/libcli_auth.h"
#include "librpc/gen_ndr/ndr_dcerpc.h"
#include "auth/gensec/gensec.h"
#include "auth/gensec/gensec_internal.h"
/**
* Callbacks for NTLMSSP - for both client and server operating modes
*
*/
static const struct ntlmssp_callbacks {
enum ntlmssp_role role;
enum ntlmssp_message_type command;
NTSTATUS (*sync_fn)(struct gensec_security *gensec_security,
TALLOC_CTX *out_mem_ctx,
DATA_BLOB in, DATA_BLOB *out);
} ntlmssp_callbacks[] = {
{
.role = NTLMSSP_CLIENT,
.command = NTLMSSP_INITIAL,
.sync_fn = ntlmssp_client_initial,
},{
.role = NTLMSSP_CLIENT,
.command = NTLMSSP_NEGOTIATE,
.sync_fn = gensec_ntlmssp_resume_ccache,
},{
.role = NTLMSSP_SERVER,
.command = NTLMSSP_NEGOTIATE,
.sync_fn = gensec_ntlmssp_server_negotiate,
},{
.role = NTLMSSP_CLIENT,
.command = NTLMSSP_CHALLENGE,
.sync_fn = ntlmssp_client_challenge,
},{
.role = NTLMSSP_SERVER,
.command = NTLMSSP_AUTH,
.sync_fn = gensec_ntlmssp_server_auth,
}
};
static NTSTATUS gensec_ntlmssp_update_find(struct gensec_security *gensec_security,
struct gensec_ntlmssp_context *gensec_ntlmssp,
const DATA_BLOB input, uint32_t *idx)
{
uint32_t ntlmssp_command;
uint32_t i;
if (gensec_ntlmssp->ntlmssp_state->expected_state == NTLMSSP_DONE) {
/* We are strict here because other modules, which we
* don't fully control (such as GSSAPI) are also
* strict, but are tested less often */
DEBUG(1, ("Called NTLMSSP after state machine was 'done'\n"));
return NT_STATUS_INVALID_PARAMETER;
}
if (!input.length) {
switch (gensec_ntlmssp->ntlmssp_state->role) {
case NTLMSSP_CLIENT:
if (gensec_ntlmssp->ntlmssp_state->resume_ccache) {
/*
* make sure gensec_ntlmssp_resume_ccache()
* will be called
*/
ntlmssp_command = NTLMSSP_NEGOTIATE;
break;
}
ntlmssp_command = NTLMSSP_INITIAL;
break;
case NTLMSSP_SERVER:
if (gensec_security->want_features & GENSEC_FEATURE_DATAGRAM_MODE) {
/* 'datagram' mode - no neg packet */
ntlmssp_command = NTLMSSP_NEGOTIATE;
} else {
/* This is normal in SPNEGO mech negotiation fallback */
DEBUG(2, ("Failed to parse NTLMSSP packet: zero length\n"));
return NT_STATUS_INVALID_PARAMETER;
}
break;
}
} else {
if (!msrpc_parse(gensec_ntlmssp->ntlmssp_state,
&input, "Cd",
"NTLMSSP",
&ntlmssp_command)) {
DEBUG(1, ("Failed to parse NTLMSSP packet, could not extract NTLMSSP command\n"));
dump_data(2, input.data, input.length);
return NT_STATUS_INVALID_PARAMETER;
}
}
if (ntlmssp_command != gensec_ntlmssp->ntlmssp_state->expected_state) {
DEBUG(2, ("got NTLMSSP command %u, expected %u\n", ntlmssp_command,
gensec_ntlmssp->ntlmssp_state->expected_state));
return NT_STATUS_INVALID_PARAMETER;
}
for (i=0; i < ARRAY_SIZE(ntlmssp_callbacks); i++) {
if (ntlmssp_callbacks[i].role == gensec_ntlmssp->ntlmssp_state->role &&
ntlmssp_callbacks[i].command == ntlmssp_command) {
*idx = i;
return NT_STATUS_OK;
}
}
DEBUG(1, ("failed to find NTLMSSP callback for NTLMSSP mode %u, command %u\n",
gensec_ntlmssp->ntlmssp_state->role, ntlmssp_command));
return NT_STATUS_INVALID_PARAMETER;
}
/**
* Next state function for the wrapped NTLMSSP state machine
*
* @param gensec_security GENSEC state, initialised to NTLMSSP
* @param out_mem_ctx The TALLOC_CTX for *out to be allocated on
* @param in The request, as a DATA_BLOB
* @param out The reply, as an talloc()ed DATA_BLOB, on *out_mem_ctx
* @return Error, MORE_PROCESSING_REQUIRED if a reply is sent,
* or NT_STATUS_OK if the user is authenticated.
*/
NTSTATUS gensec_ntlmssp_update(struct gensec_security *gensec_security,
TALLOC_CTX *out_mem_ctx,
struct tevent_context *ev,
const DATA_BLOB input, DATA_BLOB *out)
{
struct gensec_ntlmssp_context *gensec_ntlmssp =
talloc_get_type_abort(gensec_security->private_data,
struct gensec_ntlmssp_context);
struct ntlmssp_state *ntlmssp_state = gensec_ntlmssp->ntlmssp_state;
NTSTATUS status;
uint32_t i;
*out = data_blob(NULL, 0);
if (!out_mem_ctx) {
/* if the caller doesn't want to manage/own the memory,
we can put it on our context */
out_mem_ctx = ntlmssp_state;
}
status = gensec_ntlmssp_update_find(gensec_security, gensec_ntlmssp, input, &i);
NT_STATUS_NOT_OK_RETURN(status);
status = ntlmssp_callbacks[i].sync_fn(gensec_security, out_mem_ctx, input, out);
NT_STATUS_NOT_OK_RETURN(status);
return NT_STATUS_OK;
}
static NTSTATUS gensec_ntlmssp_may_reset_crypto(struct gensec_security *gensec_security,
bool full_reset)
{
struct gensec_ntlmssp_context *gensec_ntlmssp =
talloc_get_type_abort(gensec_security->private_data,
struct gensec_ntlmssp_context);
struct ntlmssp_state *ntlmssp_state = gensec_ntlmssp->ntlmssp_state;
NTSTATUS status;
bool reset_seqnums = full_reset;
if (!gensec_ntlmssp_have_feature(gensec_security, GENSEC_FEATURE_SIGN)) {
return NT_STATUS_OK;
}
status = ntlmssp_sign_reset(ntlmssp_state, reset_seqnums);
if (!NT_STATUS_IS_OK(status)) {
DEBUG(1, ("Could not reset NTLMSSP signing/sealing system (error was: %s)\n",
nt_errstr(status)));
return status;
}
return NT_STATUS_OK;
}
static const char *gensec_ntlmssp_oids[] = {
GENSEC_OID_NTLMSSP,
NULL
};
static const struct gensec_security_ops gensec_ntlmssp_security_ops = {
.name = "ntlmssp",
.sasl_name = GENSEC_SASL_NAME_NTLMSSP, /* "NTLM" */
.auth_type = DCERPC_AUTH_TYPE_NTLMSSP,
.oid = gensec_ntlmssp_oids,
.client_start = gensec_ntlmssp_client_start,
.server_start = gensec_ntlmssp_server_start,
.magic = gensec_ntlmssp_magic,
.update = gensec_ntlmssp_update,
.may_reset_crypto= gensec_ntlmssp_may_reset_crypto,
.sig_size = gensec_ntlmssp_sig_size,
.sign_packet = gensec_ntlmssp_sign_packet,
.check_packet = gensec_ntlmssp_check_packet,
.seal_packet = gensec_ntlmssp_seal_packet,
.unseal_packet = gensec_ntlmssp_unseal_packet,
.wrap = gensec_ntlmssp_wrap,
.unwrap = gensec_ntlmssp_unwrap,
.session_key = gensec_ntlmssp_session_key,
.session_info = gensec_ntlmssp_session_info,
.have_feature = gensec_ntlmssp_have_feature,
.enabled = true,
.priority = GENSEC_NTLMSSP
};
static const struct gensec_security_ops gensec_ntlmssp_resume_ccache_ops = {
.name = "ntlmssp_resume_ccache",
.client_start = gensec_ntlmssp_resume_ccache_start,
.update = gensec_ntlmssp_update,
.session_key = gensec_ntlmssp_session_key,
.have_feature = gensec_ntlmssp_have_feature,
.enabled = true,
.priority = GENSEC_NTLMSSP
};
_PUBLIC_ NTSTATUS gensec_ntlmssp_init(void)
{
NTSTATUS ret;
ret = gensec_register(&gensec_ntlmssp_security_ops);
if (!NT_STATUS_IS_OK(ret)) {
DEBUG(0,("Failed to register '%s' gensec backend!\n",
gensec_ntlmssp_security_ops.name));
return ret;
}
ret = gensec_register(&gensec_ntlmssp_resume_ccache_ops);
if (!NT_STATUS_IS_OK(ret)) {
DEBUG(0,("Failed to register '%s' gensec backend!\n",
gensec_ntlmssp_resume_ccache_ops.name));
return ret;
}
return ret;
}
static struct gensec_security *gensec_find_child_by_ops(struct gensec_security *gensec_security,
const struct gensec_security_ops *ops)
{
struct gensec_security *current = gensec_security;
while (current != NULL) {
if (current->ops == ops) {
return current;
}
current = current->child_security;
}
return NULL;
}
uint32_t gensec_ntlmssp_neg_flags(struct gensec_security *gensec_security)
{
struct gensec_ntlmssp_context *gensec_ntlmssp;
gensec_security = gensec_find_child_by_ops(gensec_security,
&gensec_ntlmssp_security_ops);
if (gensec_security == NULL) {
return 0;
}
gensec_ntlmssp = talloc_get_type_abort(gensec_security->private_data,
struct gensec_ntlmssp_context);
return gensec_ntlmssp->ntlmssp_state->neg_flags;
}
const char *gensec_ntlmssp_server_domain(struct gensec_security *gensec_security)
{
struct gensec_ntlmssp_context *gensec_ntlmssp;
gensec_security = gensec_find_child_by_ops(gensec_security,
&gensec_ntlmssp_security_ops);
if (gensec_security == NULL) {
return NULL;
}
gensec_ntlmssp = talloc_get_type_abort(gensec_security->private_data,
struct gensec_ntlmssp_context);
return gensec_ntlmssp->ntlmssp_state->server.netbios_domain;
}