first public release of samba4 code

(This used to be commit b0510b5428b3461aeb9bbe3cc95f62fc73e2b97f)

1 files changed, 402 insertions, 0 deletions

diff --git a/source4/auth/auth_server.c b/source4/auth/auth_server.c
new file mode 100644
index 00000000000..620d9a33c84
--- /dev/null
+++ b/source4/auth/auth_server.c
@@ -0,0 +1,402 @@
+/* 
+   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"
+
+#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;
+	fstring desthost;
+	struct in_addr dest_ip;
+	const char *p;
+	char *pserver;
+	BOOL connected_ok = False;
+
+	if (!(cli = cli_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))) {
+		standard_sub_basic(current_user_info.smb_name, desthost, 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 (cli_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"));
+		cli_shutdown(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"));
+		cli_shutdown(cli);
+		return NULL;
+	}
+	
+	if (strequal(desthost,myhostname(mem_ctx))) {
+		exit_server("Password server loop!");
+	}
+	
+	DEBUG(3,("got session\n"));
+
+	if (!cli_negprot(cli)) {
+		DEBUG(1,("%s rejected the negprot\n",desthost));
+		release_server_mutex();
+		cli_shutdown(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();
+		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 (!cli_session_setup(cli, "", "", 0, "", 0,
+			       "")) {
+		DEBUG(0,("%s rejected the initial session setup (%s)\n",
+			 desthost, cli_errstr(cli)));
+		release_server_mutex();
+		cli_shutdown(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 cli_state **cli = (struct cli_state **)private_data_pointer;
+	if (*cli && (*cli)->initialised) {
+		cli_shutdown(*cli);
+	}
+}
+
+/****************************************************************************
+ Send a 'keepalive' packet down the cli pipe.
+****************************************************************************/
+
+static void send_server_keepalive(void **private_data_pointer) 
+{
+	struct cli_state **cli = (struct cli_state **)private_data_pointer;
+	
+	/* also send a keepalive to the password server if its still
+	   connected */
+	if (cli && *cli && (*cli)->initialised) {
+		if (!send_nbt_keepalive((*cli)->fd)) {
+			DEBUG( 2, ( "password server keepalive failed.\n"));
+			cli_shutdown(*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 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 *)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"));
+			cli_shutdown(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 cli_state *cli;
+	static unsigned char 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 (cli_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"));
+				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 */
+		if (!cli_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 cli_nt_error() when the conversion is in */
+			nt_status = cli_nt_error(cli);
+		} else {
+			nt_status = NT_STATUS_OK;
+		}
+	} else {
+		if (!cli_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 cli_nt_error() when the conversion is in */
+			nt_status = cli_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;
+	}
+
+	cli_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(server_info, pass);
+		} else {
+			nt_status = NT_STATUS_NO_SUCH_USER;
+		}
+	}
+
+	if (locally_made_cli) {
+		cli_shutdown(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;
+}