1
0
mirror of https://github.com/samba-team/samba.git synced 2024-12-23 17:34:34 +03:00
samba-mirror/source4/auth/auth_server.c
Tim Potter 878e139f09 r9357: Remove DBGC_CLASS cruft copied over from Samba 3. I would like to
replace this with something funkier.
(This used to be commit 8d376d56c7)
2007-10-10 13:33:27 -05:00

379 lines
11 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 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., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include "includes.h"
/****************************************************************************
Support for server level security.
****************************************************************************/
static struct smbcli_state *server_cryptkey(TALLOC_CTX *mem_ctx)
{
struct smbcli_state *cli = NULL;
fstring desthost;
struct ipv4_addr dest_ip;
const char *p;
char *pserver;
BOOL connected_ok = False;
if (!(cli = smbcli_initialise(cli)))
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( &p, desthost, LIST_SEP, sizeof(desthost))) {
strupper(desthost);
if(!resolve_name( desthost, &dest_ip, 0x20)) {
DEBUG(1,("server_cryptkey: Can't resolve address for %s\n",desthost));
continue;
}
if (ismyip(dest_ip)) {
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) */
if (!grab_server_mutex(desthost)) {
return NULL;
}
if (smbcli_connect(cli, desthost, &dest_ip)) {
DEBUG(3,("connected to password server %s\n",desthost));
connected_ok = True;
break;
}
}
if (!connected_ok) {
release_server_mutex();
DEBUG(0,("password server not available\n"));
talloc_free(cli);
return NULL;
}
if (!attempt_netbios_session_request(cli, lp_netbios_name(),
desthost, &dest_ip)) {
release_server_mutex();
DEBUG(1,("password server fails session request\n"));
talloc_free(cli);
return NULL;
}
if (strequal(desthost,myhostname(mem_ctx))) {
exit_server("Password server loop!");
}
DEBUG(3,("got session\n"));
if (!smbcli_negprot(cli)) {
DEBUG(1,("%s rejected the negprot\n",desthost));
release_server_mutex();
talloc_free(cli);
return NULL;
}
if (cli->protocol < PROTOCOL_LANMAN2 ||
!(cli->sec_mode & NEGOTIATE_SECURITY_USER_LEVEL)) {
DEBUG(1,("%s isn't in user level security mode\n",desthost));
release_server_mutex();
talloc_free(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 (!smbcli_session_setup(cli, "", "", 0, "", 0,
"")) {
DEBUG(0,("%s rejected the initial session setup (%s)\n",
desthost, smbcli_errstr(cli)));
release_server_mutex();
talloc_free(cli);
return NULL;
}
release_server_mutex();
DEBUG(3,("password server OK\n"));
return cli;
}
/****************************************************************************
Clean up our allocated cli.
****************************************************************************/
static void free_server_private_data(void **private_data_pointer)
{
struct smbcli_state **cli = (struct smbcli_state **)private_data_pointer;
if (*cli && (*cli)->initialised) {
talloc_free(*cli);
}
}
/****************************************************************************
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 smbcli_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 *)cli;
return data_blob(NULL, 0);
} 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"));
talloc_free(cli);
return data_blob(NULL, 0);
}
*my_private_data = (void *)cli;
/* 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, 0);
}
}
/****************************************************************************
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 smbcli_state *cli;
static uint8_t badpass[24];
static fstring baduser;
static BOOL tested_password_server = False;
static BOOL bad_password_server = False;
NTSTATUS nt_status = NT_STATUS_LOGON_FAILURE;
BOOL locally_made_cli = False;
/*
* Check that the requested domain is not our own machine name.
* If it is, we should never check the PDC here, we use our own local
* password file.
*/
if(is_myname(user_info->domain.str)) {
DEBUG(3,("check_smbserver_security: Requested domain was for this machine.\n"));
return NT_STATUS_LOGON_FAILURE;
}
cli = 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;
}
}
if(badpass[0] == 0)
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));
}
if(baduser[0] == 0) {
fstrcpy(baduser, INVALID_USER_PREFIX);
fstrcat(baduser, lp_netbios_name());
}
/*
* 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())) {
if (smbcli_session_setup(cli, baduser, (char *)badpass, sizeof(badpass),
(char *)badpass, sizeof(badpass), user_info->domain.str)) {
/*
* 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"));
smbcli_ulogoff(cli);
/*
* Password server has the bug.
*/
bad_password_server = True;
return NT_STATUS_LOGON_FAILURE;
}
smbcli_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 */
if (!smbcli_session_setup(cli, user_info->smb_name.str,
(char *)user_info->plaintext_password.data,
user_info->plaintext_password.length,
NULL, 0,
user_info->domain.str)) {
DEBUG(1,("password server %s rejected the password\n", cli->desthost));
/* Make this smbcli_nt_error() when the conversion is in */
nt_status = smbcli_nt_error(cli);
} else {
nt_status = NT_STATUS_OK;
}
} else {
if (!smbcli_session_setup(cli, user_info->smb_name.str,
(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.str)) {
DEBUG(1,("password server %s rejected the password\n", cli->desthost));
/* Make this smbcli_nt_error() when the conversion is in */
nt_status = smbcli_nt_error(cli);
} else {
nt_status = NT_STATUS_OK;
}
}
/* 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;
}
smbcli_ulogoff(cli);
if NT_STATUS_IS_OK(nt_status) {
struct passwd *pass = Get_Pwnam(user_info->internal_username.str);
if (pass) {
nt_status = make_server_info_pw(auth_context, server_info, pass);
} else {
nt_status = NT_STATUS_NO_SUCH_USER;
}
}
if (locally_made_cli) {
talloc_free(cli);
}
return(nt_status);
}
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;
(*auth_method)->send_keepalive = send_server_keepalive;
(*auth_method)->free_private_data = free_server_private_data;
return NT_STATUS_OK;
}