This is another rather major change to the samba authenticaion

subystem.

The particular aim is to modularized the interface - so that we
can have arbitrary password back-ends.

This code adds one such back-end, a 'winbind' module to authenticate
against the winbind_auth_crap functionality.  While fully-functional
this code is mainly useful as a demonstration, because we don't get
back the info3 as we would for direct ntdomain authentication.

This commit introduced the new 'auth methods' parameter, in the
spirit of the 'auth order' discussed on the lists.  It is renamed
because not all the methods may be consulted, even if previous
methods fail - they may not have a suitable challenge for example.

Also, we have a 'local' authentication method, for old-style
'unix if plaintext, sam if encrypted' authentication and a
'guest' module to handle guest logins in a single place.

While this current design is not ideal, I feel that it does
provide a better infrastructure than the current design, and can
be built upon.

The following parameters have changed:
 - use rhosts =

  This has been replaced by the 'rhosts' authentication method,
 and can be specified like 'auth methods = guest rhosts'

 - hosts equiv =

  This needs both this parameter and an 'auth methods' entry
  to be effective.  (auth methods = guest hostsequiv ....)

 - plaintext to smbpasswd =

  This is replaced by specifying 'sam' rather than 'local'
  in the auth methods.

The security = parameter is unchanged, and now provides defaults
for the 'auth methods' parameter.

The available auth methods are:

guest
rhosts
hostsequiv
sam (passdb direct hash access)
unix (PAM, crypt() etc)
local (the combination of the above, based on encryption)
smbserver (old security=server)
ntdomain (old security=domain)
winbind (use winbind to cache DC connections)


Assistance in testing, or the production of new and interesting
authentication modules is always appreciated.

Andrew Bartlett
(This used to be commit 8d31eae52a9757739711dbb82035a4dfe6b40c99)

1 files changed, 142 insertions, 30 deletions

diff --git a/source3/auth/auth_server.c b/source3/auth/auth_server.c
index ddbc284d50..067b5b2997 100644
--- a/source3/auth/auth_server.c
+++ b/source3/auth/auth_server.c
@@ -25,30 +25,18 @@
 extern pstring global_myname;
 
 /****************************************************************************
- Return the client state structure.
-****************************************************************************/
-
-struct cli_state *server_client(void)
-{
-	static struct cli_state pw_cli;
-	return &pw_cli;
-}
-
-/****************************************************************************
  Support for server level security.
 ****************************************************************************/
 
-struct cli_state *server_cryptkey(void)
+static struct cli_state *server_cryptkey(void)
 {
-	struct cli_state *cli;
+	struct cli_state *cli = NULL;
 	fstring desthost;
 	struct in_addr dest_ip;
 	char *p, *pserver;
 	BOOL connected_ok = False;
 
-	cli = server_client();
-
-	if (!cli_initialise(cli))
+	if (!(cli = cli_initialise(cli)))
 		return NULL;
 
 	/* security = server just can't function with spnego */
@@ -88,7 +76,11 @@ struct cli_state *server_cryptkey(void)
 
 	if (!attempt_netbios_session_request(cli, global_myname, desthost, &dest_ip))
 		return NULL;
-
+	
+	if (strequal(desthost,myhostname())) {
+		exit_server("Password server loop!");
+	}
+	
 	DEBUG(3,("got session\n"));
 
 	if (!cli_negprot(cli)) {
@@ -109,13 +101,82 @@ struct cli_state *server_cryptkey(void)
 	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);
+		
+		SAFE_FREE(*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_keepalive((*cli)->fd)) {
+			DEBUG( 2, ( "password server keepalive failed.\n"));
+			cli_shutdown(*cli);
+			SAFE_FREE(*cli);
+		}
+	}
+}
+
+/****************************************************************************
+ Get the challange out of a password server.
+****************************************************************************/
+
+static DATA_BLOB auth_get_challange_server(void **my_private_data, const struct authsupplied_info *auth_info) 
+{
+	struct cli_state *cli = server_cryptkey();
+	
+	if (cli) {
+		DEBUG(3,("using password server validation\n"));
+		if ((cli->sec_mode & 2) == 0) {
+			/* We can't work with unencrypted password servers
+			   unless 'encrypt passwords = no' */
+			DEBUG(5,("make_auth_info_server: Server is unencrypted, no challange available..\n"));
+
+			*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 challange */
+			DEBUG(2,("make_auth_info_server: Didn't receive a full challange from server\n"));
+			cli_shutdown(cli);
+			return data_blob(NULL, 0);
+		}
+
+		*my_private_data = (void *)cli;
+		
+		return data_blob(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.
 ****************************************************************************/
 
-NTSTATUS check_server_security(const auth_usersupplied_info *user_info, auth_serversupplied_info **server_info)
+static NTSTATUS check_smbserver_security(void *my_private_data, 
+				  const auth_usersupplied_info *user_info, 
+				  const auth_authsupplied_info *auth_info,
+				  auth_serversupplied_info **server_info)
 {
 	struct cli_state *cli;
 	static unsigned char badpass[24];
@@ -123,13 +184,32 @@ NTSTATUS check_server_security(const auth_usersupplied_info *user_info, auth_ser
 	static BOOL tested_password_server = False;
 	static BOOL bad_password_server = False;
 	NTSTATUS nt_status = NT_STATUS_LOGON_FAILURE;
+	BOOL locally_made_cli = False;
 
-	cli = server_client();
+	cli = my_private_data;
+	
+	if (cli) {
+	} else {
+		cli = server_cryptkey();
+		locally_made_cli = True;
+	}
 
-	if (!cli->initialised) {
+	if (!cli || !cli->initialised) {
 		DEBUG(1,("password server %s is not connected\n", cli->desthost));
-		return(NT_STATUS_LOGON_FAILURE);
+		return NT_STATUS_LOGON_FAILURE;
 	}  
+	
+	if ((cli->sec_mode & 2) == 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_info->challange.data, 8) != 0) {
+			DEBUG(1,("the challange 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));
@@ -206,17 +286,32 @@ use this machine as the password server.\n"));
 	 * not guest enabled, we can try with the real password.
 	 */
 
-	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);
+	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 {
-		nt_status = NT_STATUS_OK;
+		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 */
@@ -238,5 +333,22 @@ use this machine as the password server.\n"));
 		}
 	}
 
+	if (locally_made_cli) {
+		cli_shutdown(cli);
+		SAFE_FREE(cli);
+	}
+
 	return(nt_status);
 }
+
+BOOL auth_init_smbserver(auth_methods **auth_method) 
+{
+	if (!make_auth_methods(auth_method)) {
+		return False;
+	}
+	(*auth_method)->auth = check_smbserver_security;
+	(*auth_method)->get_chal = auth_get_challange_server;
+	(*auth_method)->send_keepalive = send_server_keepalive;
+	(*auth_method)->free_private_data = free_server_private_data;
+	return True;
+}