+++ /dev/null
-/*
- 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"
-#include "auth.h"
-#include "system/passwd.h"
-#include "smbd/smbd.h"
-#include "libsmb/libsmb.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 = NULL;
- NTSTATUS status;
- /* security = server just can't function with spnego */
- int flags = CLI_FULL_CONNECTION_DONT_SPNEGO;
- uint16_t sec_mode = 0;
-
- pserver = talloc_strdup(mem_ctx, lp_passwordserver());
- p = pserver;
-
- while(next_token_talloc(mem_ctx, &p, &desthost, LIST_SEP)) {
-
- desthost = talloc_sub_basic(mem_ctx,
- current_user_info.smb_name,
- current_user_info.domain,
- desthost);
- if (!desthost) {
- return NULL;
- }
- strupper_m(desthost);
-
- if (strequal(desthost, myhostname())) {
- DEBUG(1,("Password server loop - disabling "
- "password server %s\n", desthost));
- continue;
- }
-
- if(!resolve_name( desthost, &dest_ss, 0x20, false)) {
- DEBUG(1,("server_cryptkey: Can't resolve address for %s\n",desthost));
- continue;
- }
-
- if (ismyaddr((struct sockaddr *)(void *)&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) {
- return NULL;
- }
-
- status = cli_connect_nb(desthost, &dest_ss, 0, 0x20,
- lp_netbios_name(), SMB_SIGNING_DEFAULT,
- flags, &cli);
- 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"));
- return NULL;
- }
-
- DEBUG(3,("got session\n"));
-
- status = cli_negprot(cli, PROTOCOL_NT1);
-
- if (!NT_STATUS_IS_OK(status)) {
- TALLOC_FREE(mutex);
- DEBUG(1, ("%s rejected the negprot: %s\n",
- desthost, nt_errstr(status)));
- cli_shutdown(cli);
- return NULL;
- }
-
- sec_mode = cli_state_security_mode(cli);
- if (cli_state_protocol(cli) < PROTOCOL_LANMAN2 ||
- !(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...
- */
-
- status = cli_session_setup(cli, "", "", 0, "", 0, "");
- if (!NT_STATUS_IS_OK(status)) {
- TALLOC_FREE(mutex);
- DEBUG(0,("%s rejected the initial session setup (%s)\n",
- desthost, nt_errstr(status)));
- 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);
- NTSTATUS status;
- unsigned char garbage[16];
-
- if (!cli_state_is_connected(state->cli)) {
- return false;
- }
-
- /* Ping the server to keep the connection alive using SMBecho. */
- memset(garbage, 0xf0, sizeof(garbage));
- status = cli_echo(state->cli, 1, data_blob_const(garbage, sizeof(garbage)));
- if (NT_STATUS_IS_OK(status)) {
- return true;
- }
-
- DEBUG(2,("send_server_keepalive: password server SMBecho failed: %s\n",
- nt_errstr(status)));
- 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(server_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) {
- uint16_t sec_mode = cli_state_security_mode(cli);
- const uint8_t *server_challenge = cli_state_server_challenge(cli);
-
- DEBUG(3,("using password server validation\n"));
-
- if ((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;
- }
-
- 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(discard_const_p(TALLOC_CTX, auth_context), server_challenge ,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 struct auth_usersupplied_info *user_info,
- struct auth_serversupplied_info **server_info)
-{
- struct server_security_state *state = NULL;
- struct cli_state *cli = NULL;
- static bool tested_password_server = False;
- static bool bad_password_server = False;
- NTSTATUS nt_status = NT_STATUS_NOT_IMPLEMENTED;
- bool locally_made_cli = False;
- uint16_t sec_mode = 0;
-
- DEBUG(10, ("check_smbserver_security: Check auth for: [%s]\n",
- user_info->mapped.account_name));
-
- if (my_private_data == NULL) {
- DEBUG(10,("check_smbserver_security: "
- "password server is not connected\n"));
- return NT_STATUS_LOGON_FAILURE;
- }
-
- state = talloc_get_type_abort(my_private_data, struct server_security_state);
- cli = state->cli;
-
- if (cli) {
- } else {
- cli = server_cryptkey(mem_ctx);
- locally_made_cli = True;
- }
-
- if (!cli_state_is_connected(cli)) {
- DEBUG(1,("password server is not connected (cli not initialised)\n"));
- return NT_STATUS_LOGON_FAILURE;
- }
-
- sec_mode = cli_state_security_mode(cli);
- if ((sec_mode & NEGOTIATE_SECURITY_CHALLENGE_RESPONSE) == 0) {
- if (user_info->password_state != AUTH_PASSWORD_PLAIN) {
- DEBUG(1,("password server %s is plaintext, but we are encrypted. This just can't work :-(\n", cli_state_remote_name(cli)));
- return NT_STATUS_LOGON_FAILURE;
- }
- } else {
- const uint8_t *server_challenge = cli_state_server_challenge(cli);
-
- if (memcmp(server_challenge, 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_state_remote_name(cli)));
- 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->password.response.nt.length == sizeof(badpass)) &&
- !memcmp(badpass, user_info->password.response.nt.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,
- lp_netbios_name());
- 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->mapped.domain_name))) {
-
- /*
- * We connected to the password server so we
- * can say we've tested it.
- */
- tested_password_server = True;
-
- if (!cli->is_guestlogin) {
- DEBUG(0,("server_validate: password server %s allows users as non-guest \
-with a bad password.\n", cli_state_remote_name(cli)));
- 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_state_remote_name(cli)));
- 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.
- */
- switch (user_info->password_state) {
- case AUTH_PASSWORD_PLAIN:
- /* Plaintext available */
- nt_status = cli_session_setup(
- cli, user_info->client.account_name,
- user_info->password.plaintext,
- strlen(user_info->password.plaintext),
- NULL, 0, user_info->mapped.domain_name);
- break;
-
- /* currently the hash values include a challenge-response as well */
- case AUTH_PASSWORD_HASH:
- case AUTH_PASSWORD_RESPONSE:
- nt_status = cli_session_setup(
- cli, user_info->client.account_name,
- (char *)user_info->password.response.lanman.data,
- user_info->password.response.lanman.length,
- (char *)user_info->password.response.nt.data,
- user_info->password.response.nt.length,
- user_info->mapped.domain_name);
- break;
- default:
- DEBUG(0,("user_info constructed for user '%s' was invalid - password_state=%u invalid.\n",user_info->mapped.account_name, user_info->password_state));
- nt_status = NT_STATUS_INTERNAL_ERROR;
- }
-
- if (!NT_STATUS_IS_OK(nt_status)) {
- DEBUG(1,("password server %s rejected the password: %s\n",
- cli_state_remote_name(cli), nt_errstr(nt_status)));
- }
-
- /* if logged in as guest then reject */
- if (cli->is_guestlogin) {
- DEBUG(1,("password server %s gave us guest only\n",
- cli_state_remote_name(cli)));
- nt_status = NT_STATUS_LOGON_FAILURE;
- }
-
- cli_ulogoff(cli);
-
- if (NT_STATUS_IS_OK(nt_status)) {
- char *real_username = NULL;
- struct passwd *pass = NULL;
-
- if ( (pass = smb_getpwnam(talloc_tos(), user_info->mapped.account_name,
- &real_username, True )) != NULL )
- {
- nt_status = make_server_info_pw(server_info, pass->pw_name, pass);
- TALLOC_FREE(pass);
- TALLOC_FREE(real_username);
- }
- 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)
-{
- struct auth_methods *result;
-
- result = talloc_zero(auth_context, struct auth_methods);
- if (result == NULL) {
- return NT_STATUS_NO_MEMORY;
- }
- result->name = "smbserver";
- result->auth = check_smbserver_security;
- result->get_chal = auth_get_challenge_server;
-
- *auth_method = result;
- return NT_STATUS_OK;
-}
-
-NTSTATUS auth_server_init(void)
-{
- return smb_register_auth(AUTH_INTERFACE_VERSION, "smbserver", auth_init_smbserver);
-}
git.samba.org / kai / samba-autobuild / .git / commitdiff