mirror of
https://github.com/samba-team/samba.git
synced 2024-12-24 21:34:56 +03:00
1ebfc66b2c
Another preparation to convert secrets.c to dbwrap: The dbwrap API does not
provide a sane tdb_lock_with_timeout abstraction. In the clustered case the DC
mutex is needed per-node anyway, so it is perfectly fine to use a local mutex
only.
(This used to be commit f94a63cd8f
)
465 lines
13 KiB
C
465 lines
13 KiB
C
/*
|
|
Unix SMB/CIFS implementation.
|
|
Authenticate to a remote server
|
|
Copyright (C) Andrew Tridgell 1992-1998
|
|
Copyright (C) Andrew Bartlett 2001
|
|
|
|
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/>.
|
|
*/
|
|
|
|
#include "includes.h"
|
|
|
|
#undef DBGC_CLASS
|
|
#define DBGC_CLASS DBGC_AUTH
|
|
|
|
extern userdom_struct current_user_info;
|
|
|
|
/****************************************************************************
|
|
Support for server level security.
|
|
****************************************************************************/
|
|
|
|
static struct cli_state *server_cryptkey(TALLOC_CTX *mem_ctx)
|
|
{
|
|
struct cli_state *cli = NULL;
|
|
char *desthost = NULL;
|
|
struct sockaddr_storage dest_ss;
|
|
const char *p;
|
|
char *pserver = NULL;
|
|
bool connected_ok = False;
|
|
struct named_mutex *mutex;
|
|
|
|
if (!(cli = cli_initialise()))
|
|
return NULL;
|
|
|
|
/* security = server just can't function with spnego */
|
|
cli->use_spnego = False;
|
|
|
|
pserver = talloc_strdup(mem_ctx, lp_passwordserver());
|
|
p = pserver;
|
|
|
|
while(next_token_talloc(mem_ctx, &p, &desthost, LIST_SEP)) {
|
|
NTSTATUS status;
|
|
|
|
desthost = talloc_sub_basic(mem_ctx,
|
|
current_user_info.smb_name,
|
|
current_user_info.domain,
|
|
desthost);
|
|
if (!desthost) {
|
|
return NULL;
|
|
}
|
|
strupper_m(desthost);
|
|
|
|
if(!resolve_name( desthost, &dest_ss, 0x20)) {
|
|
DEBUG(1,("server_cryptkey: Can't resolve address for %s\n",desthost));
|
|
continue;
|
|
}
|
|
|
|
if (ismyaddr(&dest_ss)) {
|
|
DEBUG(1,("Password server loop - disabling password server %s\n",desthost));
|
|
continue;
|
|
}
|
|
|
|
/* we use a mutex to prevent two connections at once - when a
|
|
Win2k PDC get two connections where one hasn't completed a
|
|
session setup yet it will send a TCP reset to the first
|
|
connection (tridge) */
|
|
|
|
mutex = grab_named_mutex(talloc_tos(), desthost, 10);
|
|
if (mutex == NULL) {
|
|
cli_shutdown(cli);
|
|
return NULL;
|
|
}
|
|
|
|
status = cli_connect(cli, desthost, &dest_ss);
|
|
if (NT_STATUS_IS_OK(status)) {
|
|
DEBUG(3,("connected to password server %s\n",desthost));
|
|
connected_ok = True;
|
|
break;
|
|
}
|
|
DEBUG(10,("server_cryptkey: failed to connect to server %s. Error %s\n",
|
|
desthost, nt_errstr(status) ));
|
|
TALLOC_FREE(mutex);
|
|
}
|
|
|
|
if (!connected_ok) {
|
|
DEBUG(0,("password server not available\n"));
|
|
cli_shutdown(cli);
|
|
return NULL;
|
|
}
|
|
|
|
if (!attempt_netbios_session_request(&cli, global_myname(),
|
|
desthost, &dest_ss)) {
|
|
TALLOC_FREE(mutex);
|
|
DEBUG(1,("password server fails session request\n"));
|
|
cli_shutdown(cli);
|
|
return NULL;
|
|
}
|
|
|
|
if (strequal(desthost,myhostname())) {
|
|
exit_server_cleanly("Password server loop!");
|
|
}
|
|
|
|
DEBUG(3,("got session\n"));
|
|
|
|
if (!cli_negprot(cli)) {
|
|
TALLOC_FREE(mutex);
|
|
DEBUG(1,("%s rejected the negprot\n",desthost));
|
|
cli_shutdown(cli);
|
|
return NULL;
|
|
}
|
|
|
|
if (cli->protocol < PROTOCOL_LANMAN2 ||
|
|
!(cli->sec_mode & NEGOTIATE_SECURITY_USER_LEVEL)) {
|
|
TALLOC_FREE(mutex);
|
|
DEBUG(1,("%s isn't in user level security mode\n",desthost));
|
|
cli_shutdown(cli);
|
|
return NULL;
|
|
}
|
|
|
|
/* Get the first session setup done quickly, to avoid silly
|
|
Win2k bugs. (The next connection to the server will kill
|
|
this one...
|
|
*/
|
|
|
|
if (!NT_STATUS_IS_OK(cli_session_setup(cli, "", "", 0, "", 0,
|
|
""))) {
|
|
TALLOC_FREE(mutex);
|
|
DEBUG(0,("%s rejected the initial session setup (%s)\n",
|
|
desthost, cli_errstr(cli)));
|
|
cli_shutdown(cli);
|
|
return NULL;
|
|
}
|
|
|
|
TALLOC_FREE(mutex);
|
|
|
|
DEBUG(3,("password server OK\n"));
|
|
|
|
return cli;
|
|
}
|
|
|
|
struct server_security_state {
|
|
struct cli_state *cli;
|
|
};
|
|
|
|
/****************************************************************************
|
|
Send a 'keepalive' packet down the cli pipe.
|
|
****************************************************************************/
|
|
|
|
static bool send_server_keepalive(const struct timeval *now,
|
|
void *private_data)
|
|
{
|
|
struct server_security_state *state = talloc_get_type_abort(
|
|
private_data, struct server_security_state);
|
|
|
|
if (!state->cli || !state->cli->initialised) {
|
|
return False;
|
|
}
|
|
|
|
if (send_keepalive(state->cli->fd)) {
|
|
return True;
|
|
}
|
|
|
|
DEBUG( 2, ( "send_server_keepalive: password server keepalive "
|
|
"failed.\n"));
|
|
cli_shutdown(state->cli);
|
|
state->cli = NULL;
|
|
return False;
|
|
}
|
|
|
|
static int destroy_server_security(struct server_security_state *state)
|
|
{
|
|
if (state->cli) {
|
|
cli_shutdown(state->cli);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static struct server_security_state *make_server_security_state(struct cli_state *cli)
|
|
{
|
|
struct server_security_state *result;
|
|
|
|
if (!(result = talloc(NULL, struct server_security_state))) {
|
|
DEBUG(0, ("talloc failed\n"));
|
|
cli_shutdown(cli);
|
|
return NULL;
|
|
}
|
|
|
|
result->cli = cli;
|
|
talloc_set_destructor(result, destroy_server_security);
|
|
|
|
if (lp_keepalive() != 0) {
|
|
struct timeval interval;
|
|
interval.tv_sec = lp_keepalive();
|
|
interval.tv_usec = 0;
|
|
|
|
if (event_add_idle(smbd_event_context(), result, interval,
|
|
"server_security_keepalive",
|
|
send_server_keepalive,
|
|
result) == NULL) {
|
|
DEBUG(0, ("event_add_idle failed\n"));
|
|
TALLOC_FREE(result);
|
|
return NULL;
|
|
}
|
|
}
|
|
|
|
return result;
|
|
}
|
|
|
|
/****************************************************************************
|
|
Get the challenge out of a password server.
|
|
****************************************************************************/
|
|
|
|
static DATA_BLOB auth_get_challenge_server(const struct auth_context *auth_context,
|
|
void **my_private_data,
|
|
TALLOC_CTX *mem_ctx)
|
|
{
|
|
struct cli_state *cli = server_cryptkey(mem_ctx);
|
|
|
|
if (cli) {
|
|
DEBUG(3,("using password server validation\n"));
|
|
|
|
if ((cli->sec_mode & NEGOTIATE_SECURITY_CHALLENGE_RESPONSE) == 0) {
|
|
/* We can't work with unencrypted password servers
|
|
unless 'encrypt passwords = no' */
|
|
DEBUG(5,("make_auth_info_server: Server is unencrypted, no challenge available..\n"));
|
|
|
|
/* However, it is still a perfectly fine connection
|
|
to pass that unencrypted password over */
|
|
*my_private_data =
|
|
(void *)make_server_security_state(cli);
|
|
return data_blob_null;
|
|
} else if (cli->secblob.length < 8) {
|
|
/* We can't do much if we don't get a full challenge */
|
|
DEBUG(2,("make_auth_info_server: Didn't receive a full challenge from server\n"));
|
|
cli_shutdown(cli);
|
|
return data_blob_null;
|
|
}
|
|
|
|
if (!(*my_private_data = (void *)make_server_security_state(cli))) {
|
|
return data_blob(NULL,0);
|
|
}
|
|
|
|
/* The return must be allocated on the caller's mem_ctx, as our own will be
|
|
destoyed just after the call. */
|
|
return data_blob_talloc(auth_context->mem_ctx, cli->secblob.data,8);
|
|
} else {
|
|
return data_blob_null;
|
|
}
|
|
}
|
|
|
|
|
|
/****************************************************************************
|
|
Check for a valid username and password in security=server mode.
|
|
- Validate a password with the password server.
|
|
****************************************************************************/
|
|
|
|
static NTSTATUS check_smbserver_security(const struct auth_context *auth_context,
|
|
void *my_private_data,
|
|
TALLOC_CTX *mem_ctx,
|
|
const auth_usersupplied_info *user_info,
|
|
auth_serversupplied_info **server_info)
|
|
{
|
|
struct cli_state *cli;
|
|
static bool tested_password_server = False;
|
|
static bool bad_password_server = False;
|
|
NTSTATUS nt_status = NT_STATUS_NOT_IMPLEMENTED;
|
|
bool locally_made_cli = False;
|
|
|
|
cli = (struct cli_state *)my_private_data;
|
|
|
|
if (cli) {
|
|
} else {
|
|
cli = server_cryptkey(mem_ctx);
|
|
locally_made_cli = True;
|
|
}
|
|
|
|
if (!cli || !cli->initialised) {
|
|
DEBUG(1,("password server is not connected (cli not initilised)\n"));
|
|
return NT_STATUS_LOGON_FAILURE;
|
|
}
|
|
|
|
if ((cli->sec_mode & NEGOTIATE_SECURITY_CHALLENGE_RESPONSE) == 0) {
|
|
if (user_info->encrypted) {
|
|
DEBUG(1,("password server %s is plaintext, but we are encrypted. This just can't work :-(\n", cli->desthost));
|
|
return NT_STATUS_LOGON_FAILURE;
|
|
}
|
|
} else {
|
|
if (memcmp(cli->secblob.data, auth_context->challenge.data, 8) != 0) {
|
|
DEBUG(1,("the challenge that the password server (%s) supplied us is not the one we gave our client. This just can't work :-(\n", cli->desthost));
|
|
return NT_STATUS_LOGON_FAILURE;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Attempt a session setup with a totally incorrect password.
|
|
* If this succeeds with the guest bit *NOT* set then the password
|
|
* server is broken and is not correctly setting the guest bit. We
|
|
* need to detect this as some versions of NT4.x are broken. JRA.
|
|
*/
|
|
|
|
/* I sure as hell hope that there aren't servers out there that take
|
|
* NTLMv2 and have this bug, as we don't test for that...
|
|
* - abartlet@samba.org
|
|
*/
|
|
|
|
if ((!tested_password_server) && (lp_paranoid_server_security())) {
|
|
unsigned char badpass[24];
|
|
char *baduser = NULL;
|
|
|
|
memset(badpass, 0x1f, sizeof(badpass));
|
|
|
|
if((user_info->nt_resp.length == sizeof(badpass)) &&
|
|
!memcmp(badpass, user_info->nt_resp.data, sizeof(badpass))) {
|
|
/*
|
|
* Very unlikely, our random bad password is the same as the users
|
|
* password.
|
|
*/
|
|
memset(badpass, badpass[0]+1, sizeof(badpass));
|
|
}
|
|
|
|
baduser = talloc_asprintf(mem_ctx,
|
|
"%s%s",
|
|
INVALID_USER_PREFIX,
|
|
global_myname());
|
|
if (!baduser) {
|
|
return NT_STATUS_NO_MEMORY;
|
|
}
|
|
|
|
if (NT_STATUS_IS_OK(cli_session_setup(cli, baduser,
|
|
(char *)badpass,
|
|
sizeof(badpass),
|
|
(char *)badpass,
|
|
sizeof(badpass),
|
|
user_info->domain))) {
|
|
|
|
/*
|
|
* We connected to the password server so we
|
|
* can say we've tested it.
|
|
*/
|
|
tested_password_server = True;
|
|
|
|
if ((SVAL(cli->inbuf,smb_vwv2) & 1) == 0) {
|
|
DEBUG(0,("server_validate: password server %s allows users as non-guest \
|
|
with a bad password.\n", cli->desthost));
|
|
DEBUG(0,("server_validate: This is broken (and insecure) behaviour. Please do not \
|
|
use this machine as the password server.\n"));
|
|
cli_ulogoff(cli);
|
|
|
|
/*
|
|
* Password server has the bug.
|
|
*/
|
|
bad_password_server = True;
|
|
return NT_STATUS_LOGON_FAILURE;
|
|
}
|
|
cli_ulogoff(cli);
|
|
}
|
|
} else {
|
|
|
|
/*
|
|
* We have already tested the password server.
|
|
* Fail immediately if it has the bug.
|
|
*/
|
|
|
|
if(bad_password_server) {
|
|
DEBUG(0,("server_validate: [1] password server %s allows users as non-guest \
|
|
with a bad password.\n", cli->desthost));
|
|
DEBUG(0,("server_validate: [1] This is broken (and insecure) behaviour. Please do not \
|
|
use this machine as the password server.\n"));
|
|
return NT_STATUS_LOGON_FAILURE;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Now we know the password server will correctly set the guest bit, or is
|
|
* not guest enabled, we can try with the real password.
|
|
*/
|
|
|
|
if (!user_info->encrypted) {
|
|
/* Plaintext available */
|
|
nt_status = cli_session_setup(
|
|
cli, user_info->smb_name,
|
|
(char *)user_info->plaintext_password.data,
|
|
user_info->plaintext_password.length,
|
|
NULL, 0, user_info->domain);
|
|
|
|
} else {
|
|
nt_status = cli_session_setup(
|
|
cli, user_info->smb_name,
|
|
(char *)user_info->lm_resp.data,
|
|
user_info->lm_resp.length,
|
|
(char *)user_info->nt_resp.data,
|
|
user_info->nt_resp.length,
|
|
user_info->domain);
|
|
}
|
|
|
|
if (!NT_STATUS_IS_OK(nt_status)) {
|
|
DEBUG(1,("password server %s rejected the password: %s\n",
|
|
cli->desthost, nt_errstr(nt_status)));
|
|
}
|
|
|
|
/* if logged in as guest then reject */
|
|
if ((SVAL(cli->inbuf,smb_vwv2) & 1) != 0) {
|
|
DEBUG(1,("password server %s gave us guest only\n", cli->desthost));
|
|
nt_status = NT_STATUS_LOGON_FAILURE;
|
|
}
|
|
|
|
cli_ulogoff(cli);
|
|
|
|
if (NT_STATUS_IS_OK(nt_status)) {
|
|
fstring real_username;
|
|
struct passwd *pass;
|
|
|
|
if ( (pass = smb_getpwnam( NULL, user_info->internal_username,
|
|
real_username, True )) != NULL )
|
|
{
|
|
/* if a real user check pam account restrictions */
|
|
/* only really perfomed if "obey pam restriction" is true */
|
|
nt_status = smb_pam_accountcheck(pass->pw_name);
|
|
if ( !NT_STATUS_IS_OK(nt_status)) {
|
|
DEBUG(1, ("PAM account restriction prevents user login\n"));
|
|
} else {
|
|
|
|
nt_status = make_server_info_pw(server_info, pass->pw_name, pass);
|
|
}
|
|
TALLOC_FREE(pass);
|
|
}
|
|
else
|
|
{
|
|
nt_status = NT_STATUS_NO_SUCH_USER;
|
|
}
|
|
}
|
|
|
|
if (locally_made_cli) {
|
|
cli_shutdown(cli);
|
|
}
|
|
|
|
return(nt_status);
|
|
}
|
|
|
|
static NTSTATUS auth_init_smbserver(struct auth_context *auth_context, const char* param, auth_methods **auth_method)
|
|
{
|
|
if (!make_auth_methods(auth_context, auth_method)) {
|
|
return NT_STATUS_NO_MEMORY;
|
|
}
|
|
(*auth_method)->name = "smbserver";
|
|
(*auth_method)->auth = check_smbserver_security;
|
|
(*auth_method)->get_chal = auth_get_challenge_server;
|
|
return NT_STATUS_OK;
|
|
}
|
|
|
|
NTSTATUS auth_server_init(void)
|
|
{
|
|
return smb_register_auth(AUTH_INTERFACE_VERSION, "smbserver", auth_init_smbserver);
|
|
}
|