Based on an original PAM patch by Andrew Bartlett, re-written by me to

remove global static PAM variables, and to tidy up the PAM internals code.
Now looks like the rest of Samba.
Still needs testing.
Jeremy.

7 files changed, 886 insertions, 278 deletions

diff --git a/source/auth/pampass.c b/source/auth/pampass.c
index 9f4a8f57b91..83640bf5c86 100644
--- a/source/auth/pampass.c
+++ b/source/auth/pampass.c
@@ -44,31 +44,58 @@ extern int DEBUGLEVEL;
 #include <security/pam_appl.h>
 
 /*
- * Static variables used to communicate between the conversation function
- * and the server_login function
+ * Structure used to communicate between the conversation function
+ * and the server_login/change password functions.
  */
 
-static char *PAM_username;
-static char *PAM_password;
+struct smb_pam_userdata {
+	char *PAM_username;
+	char *PAM_password;
+	char *PAM_newpassword;
+};
+
+typedef int (*smb_pam_conv_fn)(int, const struct pam_message **, struct pam_response **, void *appdata_ptr);
 
 /*
  *  Macros to help make life easy
  */
 #define COPY_STRING(s) (s) ? strdup(s) : NULL
 
-/*
- * PAM error handler.
- */
+/*******************************************************************
+ PAM error handler.
+ *********************************************************************/
+
 static BOOL smb_pam_error_handler(pam_handle_t *pamh, int pam_error, char *msg, int dbglvl)
 {
 
 	if( pam_error != PAM_SUCCESS) {
-		DEBUG(dbglvl, ("PAM: %s : %s\n", msg, pam_strerror(pamh, pam_error)));
+		DEBUG(dbglvl, ("smb_pam_error_handler: PAM: %s : %s\n",
+				msg, pam_strerror(pamh, pam_error)));
 		return False;
 	}
 	return True;
 }
 
+/*******************************************************************
+ This function is a sanity check, to make sure that we NEVER report
+ failure as sucess.
+*********************************************************************/
+
+static BOOL smb_pam_nt_status_error_handler(pam_handle_t *pamh, int pam_error,
+							char *msg, int dbglvl, uint32 *nt_status)
+{
+	if (smb_pam_error_handler(pamh, pam_error, msg, dbglvl))
+		return True;
+
+	if (*nt_status == NT_STATUS_NOPROBLEMO) {
+		/* Complain LOUDLY */
+		DEBUG(0, ("smb_pam_nt_status_error_handler: PAM: BUG: PAM and NT_STATUS \
+error MISMATCH, forcing to NT_STATUS_LOGON_FAILURE"));
+		*nt_status = NT_STATUS_LOGON_FAILURE;
+	}
+	return False;
+}
+
 /*
  * PAM conversation function
  * Here we assume (for now, at least) that echo on means login name, and
@@ -82,6 +109,9 @@ static int smb_pam_conv(int num_msg,
 {
 	int replies = 0;
 	struct pam_response *reply = NULL;
+	struct smb_pam_userdata *udp = (struct smb_pam_userdata *)appdata_ptr;
+
+	*resp = NULL;
 
 	reply = malloc(sizeof(struct pam_response) * num_msg);
 	if (!reply)
@@ -91,15 +121,13 @@ static int smb_pam_conv(int num_msg,
 		switch (msg[replies]->msg_style) {
 			case PAM_PROMPT_ECHO_ON:
 				reply[replies].resp_retcode = PAM_SUCCESS;
-			reply[replies].resp =
-					COPY_STRING(PAM_username);
+				reply[replies].resp = COPY_STRING(udp->PAM_username);
 				/* PAM frees resp */
 				break;
 
 			case PAM_PROMPT_ECHO_OFF:
 				reply[replies].resp_retcode = PAM_SUCCESS;
-				reply[replies].resp =
-					COPY_STRING(PAM_password);
+				reply[replies].resp = COPY_STRING(udp->PAM_password);
 				/* PAM frees resp */
 				break;
 
@@ -123,41 +151,158 @@ static int smb_pam_conv(int num_msg,
 	return PAM_SUCCESS;
 }
 
-static struct pam_conv smb_pam_conversation = {
-	&smb_pam_conv,
-	NULL
-};
+/*
+ * PAM password change conversation function
+ * Here we assume (for now, at least) that echo on means login name, and
+ * echo off means password.
+ */
+
+static int smb_pam_passchange_conv(int num_msg,
+				const struct pam_message **msg,
+				struct pam_response **resp,
+				void *appdata_ptr)
+{
+	int replies = 0;
+	struct pam_response *reply = NULL;
+	fstring currentpw_prompt;
+	fstring newpw_prompt;
+	fstring repeatpw_prompt;
+	char *p = lp_passwd_chat();
+	struct smb_pam_userdata *udp = (struct smb_pam_userdata *)appdata_ptr;
+
+	/* Get the prompts... */
+
+	if (!next_token(&p, currentpw_prompt, NULL, sizeof(fstring)))
+		return PAM_CONV_ERR;
+	if (!next_token(&p, newpw_prompt, NULL, sizeof(fstring)))
+		return PAM_CONV_ERR;
+	if (!next_token(&p, repeatpw_prompt, NULL, sizeof(fstring)))
+		return PAM_CONV_ERR;
+
+	*resp = NULL;
+
+	reply = malloc(sizeof(struct pam_response) * num_msg);
+	if (!reply)
+		return PAM_CONV_ERR;
+
+	for (replies = 0; replies < num_msg; replies++) {
+		switch (msg[replies]->msg_style) {
+		case PAM_PROMPT_ECHO_ON:
+			reply[replies].resp_retcode = PAM_SUCCESS;
+			reply[replies].resp = COPY_STRING(udp->PAM_username);
+			/* PAM frees resp */
+			break;
+
+		case PAM_PROMPT_ECHO_OFF:
+			reply[replies].resp_retcode = PAM_SUCCESS;
+			DEBUG(10,("smb_pam_passchange_conv: PAM Replied: %s\n", msg[replies]->msg));
+			if (strncmp(currentpw_prompt, msg[replies]->msg, strlen(currentpw_prompt)) == 0) {
+				reply[replies].resp = COPY_STRING(udp->PAM_password);
+			} else if (strncmp(newpw_prompt, msg[replies]->msg, strlen(newpw_prompt)) == 0) {
+				reply[replies].resp = COPY_STRING(udp->PAM_newpassword);
+			} else if (strncmp(repeatpw_prompt, msg[replies]->msg, strlen(repeatpw_prompt)) == 0) {
+				reply[replies].resp = COPY_STRING(udp->PAM_newpassword);
+			} else {
+				DEBUG(3,("smb_pam_passchange_conv: Could not find reply for PAM prompt: %s\n",msg[replies]->msg));
+				DEBUG(5,("smb_pam_passchange_conv: Prompts available:\n CurrentPW: \"%s\"\n NewPW: \"%s\"\n \
+RepeatPW: \"%s\"\n",currentpw_prompt,newpw_prompt,repeatpw_prompt));
+			}
+			/* PAM frees resp */
+			break;
+
+		case PAM_TEXT_INFO:
+			/* fall through */
+
+		case PAM_ERROR_MSG:
+			/* ignore it... */
+			reply[replies].resp_retcode = PAM_SUCCESS;
+			reply[replies].resp = NULL;
+			break;
+
+		default:
+			/* Must be an error of some sort... */
+			free(reply);
+			reply = NULL;
+			return PAM_CONV_ERR;
+		}
+	}
+
+	if (reply)
+		*resp = reply;
+	return PAM_SUCCESS;
+}
+
+/***************************************************************************
+ Free up a malloced pam_conv struct.
+****************************************************************************/
+
+static void smb_free_pam_conv(struct pam_conv *pconv)
+{
+	if (pconv)
+		safe_free(pconv->appdata_ptr);
+
+	safe_free(pconv);
+}
+
+/***************************************************************************
+ Allocate a pam_conv struct.
+****************************************************************************/
+
+static struct pam_conv *smb_setup_pam_conv(smb_pam_conv_fn smb_pam_conv_fnptr, char *user,
+					char *passwd, char *newpass)
+{
+	struct pam_conv *pconv = (struct pam_conv *)malloc(sizeof(struct pam_conv));
+	struct smb_pam_userdata *udp = (struct smb_pam_userdata *)malloc(sizeof(struct smb_pam_userdata));
+
+	if (pconv == NULL || udp == NULL) {
+		safe_free(pconv);
+		safe_free(udp);
+		return NULL;
+	}
+
+	udp->PAM_username = user;
+	udp->PAM_password = passwd;
+	udp->PAM_newpassword = newpass;
+
+	pconv->conv = smb_pam_conv_fnptr;
+	pconv->appdata_ptr = (void *)udp;
+	return pconv;
+}
 
 /* 
  * PAM Closing out cleanup handler
  */
-static BOOL smb_pam_end(pam_handle_t *pamh)
+
+static BOOL smb_pam_end(pam_handle_t *pamh, struct pam_conv *smb_pam_conv_ptr)
 {
 	int pam_error;
+
+	smb_free_pam_conv(smb_pam_conv_ptr);
        
 	if( pamh != NULL ) {
 		pam_error = pam_end(pamh, 0);
 		if(smb_pam_error_handler(pamh, pam_error, "End Cleanup Failed", 2) == True) {
-			DEBUG(4, ("PAM: PAM_END OK.\n"));
+			DEBUG(4, ("smb_pam_end: PAM: PAM_END OK.\n"));
 			return True;
 		}
 	}
-	DEBUG(2,("PAM: not initialised"));
+	DEBUG(2,("smb_pam_end: PAM: not initialised"));
 	return False;
 }
 
 /*
  * Start PAM authentication for specified account
  */
-static BOOL smb_pam_start(pam_handle_t **pamh, char *user, char *rhost)
+
+static BOOL smb_pam_start(pam_handle_t **pamh, char *user, char *rhost, struct pam_conv *pconv)
 {
 	int pam_error;
 
 	*pamh = (pam_handle_t *)NULL;
 
-	DEBUG(4,("PAM: Init user: %s\n", user));
+	DEBUG(4,("smb_pam_start: PAM: Init user: %s\n", user));
 
-	pam_error = pam_start("samba", user, &smb_pam_conversation, pamh);
+	pam_error = pam_start("samba", user, pconv, pamh);
 	if( !smb_pam_error_handler(*pamh, pam_error, "Init Failed", 0)) {
 		*pamh = (pam_handle_t *)NULL;
 		return False;
@@ -170,117 +315,134 @@ static BOOL smb_pam_start(pam_handle_t **pamh, char *user, char *rhost)
 	}
 
 #ifdef PAM_RHOST
-	DEBUG(4,("PAM: setting rhost to: %s\n", rhost));
+	DEBUG(4,("smb_pam_start: PAM: setting rhost to: %s\n", rhost));
 	pam_error = pam_set_item(*pamh, PAM_RHOST, rhost);
 	if(!smb_pam_error_handler(*pamh, pam_error, "set rhost failed", 0)) {
-		smb_pam_end(*pamh);
+		smb_pam_end(*pamh, pconv);
 		*pamh = (pam_handle_t *)NULL;
 		return False;
 	}
 #endif
 #ifdef PAM_TTY
-	DEBUG(4,("PAM: setting tty\n"));
+	DEBUG(4,("smb_pam_start: PAM: setting tty\n"));
 	pam_error = pam_set_item(*pamh, PAM_TTY, "samba");
 	if (!smb_pam_error_handler(*pamh, pam_error, "set tty failed", 0)) {
-		smb_pam_end(*pamh);
+		smb_pam_end(*pamh, pconv);
 		*pamh = (pam_handle_t *)NULL;
 		return False;
 	}
 #endif
-	DEBUG(4,("PAM: Init passed for user: %s\n", user));
+	DEBUG(4,("smb_pam_start: PAM: Init passed for user: %s\n", user));
 	return True;
 }
 
 /*
  * PAM Authentication Handler
  */
-static BOOL smb_pam_auth(pam_handle_t *pamh, char *user, char *password)
+static uint32 smb_pam_auth(pam_handle_t *pamh, char *user)
 {
 	int pam_error;
+	uint32 nt_status = NT_STATUS_LOGON_FAILURE;
 
 	/*
 	 * To enable debugging set in /etc/pam.d/samba:
 	 *	auth required /lib/security/pam_pwdb.so nullok shadow audit
 	 */
 	
-	DEBUG(4,("PAM: Authenticate User: %s\n", user));
-	pam_error = pam_authenticate(pamh, PAM_SILENT); /* Can we authenticate user? */
+	DEBUG(4,("smb_pam_auth: PAM: Authenticate User: %s\n", user));
+	pam_error = pam_authenticate(pamh, PAM_SILENT | lp_null_passwords() ? 0 : PAM_DISALLOW_NULL_AUTHTOK);
 	switch( pam_error ){
 		case PAM_AUTH_ERR:
-			DEBUG(2, ("PAM: Athentication Error\n"));
+			DEBUG(2, ("smb_pam_auth: PAM: Athentication Error for user %s\n", user));
+			nt_status = NT_STATUS_WRONG_PASSWORD;
 			break;
 		case PAM_CRED_INSUFFICIENT:
-			DEBUG(2, ("PAM: Insufficient Credentials\n"));
+			DEBUG(2, ("smb_pam_auth: PAM: Insufficient Credentials for user %s\n", user));
+			nt_status = NT_STATUS_INSUFFICIENT_LOGON_INFO;
 			break;
 		case PAM_AUTHINFO_UNAVAIL:
-			DEBUG(2, ("PAM: Authentication Information Unavailable\n"));
+			DEBUG(2, ("smb_pam_auth: PAM: Authentication Information Unavailable for user %s\n", user));
+			nt_status = NT_STATUS_LOGON_FAILURE;
 			break;
 		case PAM_USER_UNKNOWN:
-			DEBUG(2, ("PAM: Username NOT known to Authentication system\n"));
+			DEBUG(2, ("smb_pam_auth: PAM: Username %s NOT known to Authentication system\n", user));
+			nt_status = NT_STATUS_NO_SUCH_USER;
 			break;
 		case PAM_MAXTRIES:
-			DEBUG(2, ("PAM: One or more authentication modules reports user limit exceeeded\n"));
+			DEBUG(2, ("smb_pam_auth: PAM: One or more authentication modules reports user limit for user %s exceeeded\n", user));
+			nt_status = NT_STATUS_REMOTE_SESSION_LIMIT;
 			break;
 		case PAM_ABORT:
-			DEBUG(0, ("PAM: One or more PAM modules failed to load\n"));
+			DEBUG(0, ("smb_pam_auth: PAM: One or more PAM modules failed to load for user %s\n", user));
+			nt_status = NT_STATUS_LOGON_FAILURE;
+			break;
+		case PAM_SUCCESS:
+			DEBUG(4, ("smb_pam_auth: PAM: User %s Authenticated OK\n", user));
+			nt_status = NT_STATUS_NOPROBLEMO;
 			break;
-	        case PAM_SUCCESS:
-			DEBUG(4, ("PAM: User %s Authenticated OK\n", user));
-		        break;
 		default:
-			DEBUG(0, ("PAM: UNKNOWN ERROR while authenticating user %s\n", user));
-	}
-	if(!smb_pam_error_handler(pamh, pam_error, "Authentication Failure", 2)) {
-		smb_pam_end(pamh);
-		return False;
+			DEBUG(0, ("smb_pam_auth: PAM: UNKNOWN ERROR while authenticating user %s\n", user));
+			nt_status = NT_STATUS_LOGON_FAILURE;
+			break;
 	}
-	/* If this point is reached, the user has been authenticated. */
-	return (True);
+
+	smb_pam_nt_status_error_handler(pamh, pam_error, "Authentication Failure", 2, &nt_status);
+	return nt_status;
 }
 
 /* 
  * PAM Account Handler
  */
-static BOOL smb_pam_account(pam_handle_t *pamh, char * user, char * password, BOOL pam_auth)
+static uint32 smb_pam_account(pam_handle_t *pamh, char * user)
 {
 	int pam_error;
+	uint32 nt_status = NT_STATUS_ACCOUNT_DISABLED;
 
-	DEBUG(4,("PAM: Account Management for User: %s\n", user));
+	DEBUG(4,("smb_pam_account: PAM: Account Management for User: %s\n", user));
 	pam_error = pam_acct_mgmt(pamh, PAM_SILENT); /* Is user account enabled? */
 	switch( pam_error ) {
 		case PAM_AUTHTOK_EXPIRED:
-			DEBUG(2, ("PAM: User is valid but password is expired\n"));
+			DEBUG(2, ("smb_pam_account: PAM: User %s is valid but password is expired\n", user));
+			nt_status = NT_STATUS_PASSWORD_EXPIRED;
 			break;
 		case PAM_ACCT_EXPIRED:
-			DEBUG(2, ("PAM: User no longer permitted to access system\n"));
+			DEBUG(2, ("smb_pam_account: PAM: User %s no longer permitted to access system\n", user));
+			nt_status = NT_STATUS_ACCOUNT_EXPIRED;
 			break;
 		case PAM_AUTH_ERR:
-			DEBUG(2, ("PAM: There was an authentication error\n"));
+			DEBUG(2, ("smb_pam_account: PAM: There was an authentication error for user %s\n", user));
+			nt_status = NT_STATUS_LOGON_FAILURE;
 			break;
 		case PAM_PERM_DENIED:
-			DEBUG(0, ("PAM: User is NOT permitted to access system at this time\n"));
+			DEBUG(0, ("smb_pam_account: PAM: User %s is NOT permitted to access system at this time\n", user));
+			nt_status = NT_STATUS_ACCOUNT_RESTRICTION;
 			break;
 		case PAM_USER_UNKNOWN:
-			DEBUG(0, ("PAM: User \"%s\" is NOT known to account management\n", user));
+			DEBUG(0, ("smb_pam_account: PAM: User \"%s\" is NOT known to account management\n", user));
+			nt_status = NT_STATUS_NO_SUCH_USER;
+			break;
+		case PAM_SUCCESS:
+			DEBUG(4, ("smb_pam_account: PAM: Account OK for User: %s\n", user));
+			nt_status = NT_STATUS_NOPROBLEMO;
 			break;
-	        case PAM_SUCCESS:
-			DEBUG(4, ("PAM: Account OK for User: %s\n", user));
-		        break;
 		default:
-			DEBUG(0, ("PAM: UNKNOWN ERROR for User: %s\n", user));
-	}
-	if(!smb_pam_error_handler(pamh, pam_error, "Account Check Failed", 2)) {
-		smb_pam_end(pamh);
-		return False;
+			nt_status = NT_STATUS_ACCOUNT_DISABLED;
+			DEBUG(0, ("smb_pam_account: PAM: UNKNOWN PAM ERROR (%d) during Account Management for User: %s\n", pam_error, user));
+			break;
 	}
 
-	/* Skip the pam_setcred() call if we didn't use pam_authenticate()
-	   for authentication -- it's an error to call pam_setcred without
-	   calling pam_authenticate first */
-	if (!pam_auth) {
-		DEBUG(4, ("PAM: Skipping setcred for user: %s (using encrypted passwords)\n", user));
-		return True;
-	}
+	smb_pam_nt_status_error_handler(pamh, pam_error, "Account Check Failed", 2, &nt_status);
+	return nt_status;
+}
+
+/*
+ * PAM Credential Setting
+ */
+
+static uint32 smb_pam_setcred(pam_handle_t *pamh, char * user)
+{
+	int pam_error;
+	uint32 nt_status = NT_STATUS_NO_TOKEN;
 
 	/*
 	 * This will allow samba to aquire a kerberos token. And, when
@@ -291,32 +453,34 @@ static BOOL smb_pam_account(pam_handle_t *pamh, char * user, char * password, BO
 	pam_error = pam_setcred(pamh, (PAM_ESTABLISH_CRED|PAM_SILENT)); 
 	switch( pam_error ) {
 		case PAM_CRED_UNAVAIL:
-			DEBUG(0, ("PAM: Credentials not found for user:%s", user ));
+			DEBUG(0, ("smb_pam_setcred: PAM: Credentials not found for user:%s\n", user ));
+			 nt_status = NT_STATUS_NO_TOKEN;
 			break;
 		case PAM_CRED_EXPIRED:
-			DEBUG(0, ("PAM: Credentials for user: \"%s\" EXPIRED!", user ));
+			DEBUG(0, ("smb_pam_setcred: PAM: Credentials for user: \"%s\" EXPIRED!\n", user ));
+			nt_status = NT_STATUS_PASSWORD_EXPIRED;
 			break;
 		case PAM_USER_UNKNOWN:
-			DEBUG(0, ("PAM: User: \"%s\" is NOT known so can not set credentials!", user ));
+			DEBUG(0, ("smb_pam_setcred: PAM: User: \"%s\" is NOT known so can not set credentials!\n", user ));
+			nt_status = NT_STATUS_NO_SUCH_USER;
 			break;
 		case PAM_CRED_ERR:
-			DEBUG(0, ("PAM: Unknown setcredentials error - unable to set credentials for %s", user ));
+			DEBUG(0, ("smb_pam_setcred: PAM: Unknown setcredentials error - unable to set credentials for %s\n", user ));
+			nt_status = NT_STATUS_LOGON_FAILURE;
+			break;
+		case PAM_SUCCESS:
+			DEBUG(4, ("smb_pam_setcred: PAM: SetCredentials OK for User: %s\n", user));
+			nt_status = NT_STATUS_NOPROBLEMO;
 			break;
-	        case PAM_SUCCESS:
-			DEBUG(4, ("PAM: SetCredentials OK for User: %s\n", user));
-		        break;
 		default:
-			DEBUG(0, ("PAM: Error Condition Unknown in pam_setcred function call!"));
-	}
-	if(!smb_pam_error_handler(pamh, pam_error, "Set Credential Failure", 2)) {
-		smb_pam_end(pamh);
-		return False;
+			DEBUG(0, ("smb_pam_setcred: PAM: UNKNOWN PAM ERROR (%d) during SetCredentials for User: %s\n", pam_error, user));
+			nt_status = NT_STATUS_NO_TOKEN;
+			break;
 	}
-	
-	/* If this point is reached, the user has been authenticated. */
-	return (True);
-}
 
+	smb_pam_nt_status_error_handler(pamh, pam_error, "Set Credential Failure", 2, &nt_status);
+	return nt_status;
+}
 
 /*
  * PAM Internal Session Handler
@@ -325,11 +489,8 @@ static BOOL smb_internal_pam_session(pam_handle_t *pamh, char *user, char *tty,
 {
 	int pam_error;
 
-	PAM_password = NULL;
-	PAM_username = user;
-
 #ifdef PAM_TTY
-	DEBUG(4,("PAM: tty set to: %s\n", tty));
+	DEBUG(4,("smb_internal_pam_session: PAM: tty set to: %s\n", tty));
 	pam_error = pam_set_item(pamh, PAM_TTY, tty);
 	if (!smb_pam_error_handler(pamh, pam_error, "set tty failed", 0))
 		return False;
@@ -340,7 +501,8 @@ static BOOL smb_internal_pam_session(pam_handle_t *pamh, char *user, char *tty,
 		if (!smb_pam_error_handler(pamh, pam_error, "session setup failed", 0))
 			return False;
 	} else {
-		pam_error = pam_close_session(pamh, PAM_SILENT);
+		pam_setcred(pamh, (PAM_DELETE_CRED|PAM_SILENT)); /* We don't care if this fails */
+		pam_error = pam_close_session(pamh, PAM_SILENT); /* This will probably pick up the error anyway */
 		if (!smb_pam_error_handler(pamh, pam_error, "session close failed", 0))
 			return False;
 	}
@@ -348,69 +510,147 @@ static BOOL smb_internal_pam_session(pam_handle_t *pamh, char *user, char *tty,
 }
 
 /*
+ * Internal PAM Password Changer.
+ */
+
+static BOOL smb_pam_chauthtok(pam_handle_t *pamh, char * user)
+{
+	int pam_error;
+
+	DEBUG(4,("smb_pam_chauthtok: PAM: Password Change for User: %s\n", user));
+
+	pam_error = pam_chauthtok(pamh, PAM_SILENT); /* Change Password */
+
+	switch( pam_error ) {
+	case PAM_AUTHTOK_ERR:
+		DEBUG(2, ("PAM: unable to obtain the new authentication token - is password to weak?\n"));
+		break;
+	case PAM_AUTHTOK_RECOVER_ERR:
+		DEBUG(2, ("PAM: unable to obtain the old authentication token - was the old password wrong?.\n"));
+		break;
+	case PAM_AUTHTOK_LOCK_BUSY:
+		DEBUG(2, ("PAM: unable to change the authentication token since it is currently locked.\n"));
+		break;
+	case PAM_AUTHTOK_DISABLE_AGING:
+		DEBUG(2, ("PAM: Authentication token aging has been disabled.\n"));
+		break;
+	case PAM_PERM_DENIED:
+		DEBUG(0, ("PAM: Permission denied.\n"));
+		break;
+	case PAM_TRY_AGAIN:
+		DEBUG(0, ("PAM: Could not update all authentication token(s). No authentication tokens were updated.\n"));
+		break;
+	case PAM_USER_UNKNOWN:
+		DEBUG(0, ("PAM: User not known to PAM\n"));
+		break;
+	case PAM_SUCCESS:
+		DEBUG(4, ("PAM: Account OK for User: %s\n", user));
+		break;
+	default:
+		DEBUG(0, ("PAM: UNKNOWN PAM ERROR (%d) for User: %s\n", pam_error, user));
+	}
+ 
+	if(!smb_pam_error_handler(pamh, pam_error, "Password Change Failed", 2)) {
+		return False;
+	}
+
+	/* If this point is reached, the password has changed. */
+	return True;
+}
+
+/*
  * PAM Externally accessible Session handler
  */
 
-BOOL smb_pam_session(BOOL flag, const char *in_user, char *tty, char *rhost)
+BOOL smb_pam_claim_session(char *user, char *tty, char *rhost)
 {
 	pam_handle_t *pamh = NULL;
-	char * user;
+	struct pam_conv *pconv = NULL;
 
 	/* Ignore PAM if told to. */
 
 	if (!lp_obey_pam_restrictions())
 		return True;
 
-	user = strdup(in_user);
-	if ( user == NULL ) {
-		DEBUG(0, ("PAM: PAM_session Malloc Failed!\n"));
+	if ((pconv = smb_setup_pam_conv(smb_pam_conv, user, NULL, NULL)) == NULL)
 		return False;
-	}
 
-	if (!smb_pam_start(&pamh, user, rhost)) {
+	if (!smb_pam_start(&pamh, user, rhost, pconv))
 		return False;
-	}
 
-	if (!smb_internal_pam_session(pamh, user, tty, flag)) {
-		smb_pam_end(pamh);
+	if (!smb_internal_pam_session(pamh, user, tty, True)) {
+		smb_pam_end(pamh, pconv);
 		return False;
 	}
-	return smb_pam_end(pamh);
+
+	return smb_pam_end(pamh, pconv);
 }
 
 /*
- * PAM Externally accessible Account handler
+ * PAM Externally accessible Session handler
  */
-BOOL smb_pam_accountcheck(char * user)
+
+BOOL smb_pam_close_session(char *user, char *tty, char *rhost)
 {
 	pam_handle_t *pamh = NULL;
-
-	PAM_username = user;
-	PAM_password = NULL;
+	struct pam_conv *pconv = NULL;
 
 	/* Ignore PAM if told to. */
 
 	if (!lp_obey_pam_restrictions())
 		return True;
 
-	if( smb_pam_start(&pamh, user, NULL)) {
-		if ( smb_pam_account(pamh, user, NULL, False)) {
-			return( smb_pam_end(pamh));
-		}
+	if ((pconv = smb_setup_pam_conv(smb_pam_conv, user, NULL, NULL)) == NULL)
+		return False;
+
+	if (!smb_pam_start(&pamh, user, rhost, pconv))
+		return False;
+
+	if (!smb_internal_pam_session(pamh, user, tty, False)) {
+		smb_pam_end(pamh, pconv);
+		return False;
 	}
-	DEBUG(0, ("PAM: Account Validation Failed - Rejecting User!\n"));
-	return( False );
+
+	return smb_pam_end(pamh, pconv);
 }
 
 /*
- * PAM Password Validation Suite
+ * PAM Externally accessible Account handler
  */
-BOOL smb_pam_passcheck(char * user, char * password)
+
+uint32 smb_pam_accountcheck(char * user)
 {
+	uint32 nt_status = NT_STATUS_ACCOUNT_DISABLED;
 	pam_handle_t *pamh = NULL;
+	struct pam_conv *pconv = NULL;
 
-	PAM_username = user;
-	PAM_password = password;
+	/* Ignore PAM if told to. */
+
+	if (!lp_obey_pam_restrictions())
+		return NT_STATUS_NOPROBLEMO;
+
+	if ((pconv = smb_setup_pam_conv(smb_pam_conv, user, NULL, NULL)) == NULL)
+		return False;
+
+	if (!smb_pam_start(&pamh, user, NULL, pconv))
+		return NT_STATUS_ACCOUNT_DISABLED;
+
+	if ((nt_status = smb_pam_account(pamh, user)) != NT_STATUS_NOPROBLEMO)
+		DEBUG(0, ("smb_pam_accountcheck: PAM: Account Validation Failed - Rejecting User %s!\n", user));
+
+	smb_pam_end(pamh, pconv);
+	return nt_status;
+}
+
+/*
+ * PAM Password Validation Suite
+ */
+
+uint32 smb_pam_passcheck(char * user, char * password)
+{
+	pam_handle_t *pamh = NULL;
+	uint32 nt_status = NT_STATUS_LOGON_FAILURE;
+	struct pam_conv *pconv = NULL;
 
 	/*
 	 * Note we can't ignore PAM here as this is the only
@@ -418,23 +658,76 @@ BOOL smb_pam_passcheck(char * user, char * password)
 	 * compiled --with-pam.
 	 */
 
-	if( smb_pam_start(&pamh, user, NULL)) {
-		if ( smb_pam_auth(pamh, user, password)) {
-			if ( smb_pam_account(pamh, user, password, True)) {
-				return( smb_pam_end(pamh));
-			}
-		}
+	if ((pconv = smb_setup_pam_conv(smb_pam_conv, user, password, NULL)) == NULL)
+		return False;
+
+	if (!smb_pam_start(&pamh, user, NULL, NULL))
+		return NT_STATUS_LOGON_FAILURE;
+
+	if ((nt_status = smb_pam_auth(pamh, user)) != NT_STATUS_NOPROBLEMO) {
+		DEBUG(0, ("smb_pam_passcheck: PAM: smb_pam_auth failed - Rejecting User %s !\n", user));
+		smb_pam_end(pamh, pconv);
+		return nt_status;
+	}
+
+	if ((nt_status = smb_pam_account(pamh, user)) != NT_STATUS_NOPROBLEMO) {
+		DEBUG(0, ("smb_pam_passcheck: PAM: smb_pam_account failed - Rejecting User %s !\n", user));
+		smb_pam_end(pamh, pconv);
+		return nt_status;
+	}
+
+	if ((nt_status = smb_pam_setcred(pamh, user)) != NT_STATUS_NOPROBLEMO) {
+		DEBUG(0, ("smb_pam_passcheck: PAM: smb_pam_setcred failed - Rejecting User %s !\n", user));
+		smb_pam_end(pamh, pconv);
+		return nt_status;
 	}
-	DEBUG(0, ("PAM: System Validation Failed - Rejecting User!\n"));
-	return( False );
+
+	smb_pam_end(pamh, pconv);
+	return nt_status;
+}
+
+/*
+ * PAM Password Change Suite
+ */
+
+BOOL smb_pam_passchange(char * user, char * oldpassword, char * newpassword)
+{
+	/* Appropriate quantities of root should be obtained BEFORE calling this function */
+	struct pam_conv *pconv = NULL;
+	pam_handle_t *pamh = NULL;
+
+	if ((pconv = smb_setup_pam_conv(smb_pam_passchange_conv, user, oldpassword, newpassword)) == NULL)
+		return False;
+
+	if(!smb_pam_start(&pamh, user, NULL, pconv))
+		return False;
+
+	if (!smb_pam_chauthtok(pamh, user)) {
+		DEBUG(0, ("smb_pam_passchange: PAM: Password Change Failed for user %s!\n", user));
+		smb_pam_end(pamh, pconv);
+		return False;
+	}
+
+	return smb_pam_end(pamh, pconv);
 }
 
 #else
 
 /* If PAM not used, no PAM restrictions on accounts. */
- BOOL smb_pam_accountcheck(char * user)
+ uint32 smb_pam_accountcheck(char * user)
+{
+	return NT_STATUS_NOPROBLEMO;
+}
+
+/* If PAM not used, also no PAM restrictions on sessions. */
+ BOOL smb_pam_claim_session(const char *user, char *tty, char *rhost)
 {
 	return True;
 }
 
+/* If PAM not used, also no PAM restrictions on sessions. */
+ BOOL smb_pam_close_session(const char *in_user, char *tty, char *rhost)
+{
+	return True;
+}
 #endif /* WITH_PAM */
diff --git a/source/include/proto.h b/source/include/proto.h
index 0989c2dd34b..6bb7c24ce5c 100644
--- a/source/include/proto.h
+++ b/source/include/proto.h
@@ -1984,9 +1984,11 @@ struct passdb_ops *nisplus_initialize_password_db(void);
 
 /*The following definitions come from  passdb/pampass.c  */
 
-BOOL smb_pam_session(BOOL flag, const char *in_user, char *tty, char *rhost);
-BOOL smb_pam_accountcheck(char * user);
-BOOL smb_pam_passcheck(char * user, char * password);
+BOOL smb_pam_claim_session(char *user, char *tty, char *rhost);
+BOOL smb_pam_close_session(char *user, char *tty, char *rhost);
+uint32 smb_pam_accountcheck(char * user);
+uint32 smb_pam_passcheck(char * user, char * password);
+BOOL smb_pam_passchange(char * user, char * oldpassword, char * newpassword);
 
 /*The following definitions come from  passdb/pass_check.c  */
 
@@ -3860,6 +3862,7 @@ void process_blocking_lock_queue(time_t t);
 
 BOOL chgpasswd(char *name, char *oldpass, char *newpass, BOOL as_root);
 BOOL chgpasswd(char *name, char *oldpass, char *newpass, BOOL as_root);
+BOOL chgpasswd(char *name, char *oldpass, char *newpass, BOOL as_root);
 BOOL check_lanman_password(char *user, uchar * pass1,
 			   uchar * pass2, struct smb_passwd **psmbpw);
 BOOL change_lanman_password(struct smb_passwd *smbpw, uchar * pass1,
diff --git a/source/passdb/pampass.c b/source/passdb/pampass.c
index 9f4a8f57b91..83640bf5c86 100644
--- a/source/passdb/pampass.c
+++ b/source/passdb/pampass.c
@@ -44,31 +44,58 @@ extern int DEBUGLEVEL;
 #include <security/pam_appl.h>
 
 /*
- * Static variables used to communicate between the conversation function
- * and the server_login function
+ * Structure used to communicate between the conversation function
+ * and the server_login/change password functions.
  */
 
-static char *PAM_username;
-static char *PAM_password;
+struct smb_pam_userdata {
+	char *PAM_username;
+	char *PAM_password;
+	char *PAM_newpassword;
+};
+
+typedef int (*smb_pam_conv_fn)(int, const struct pam_message **, struct pam_response **, void *appdata_ptr);
 
 /*
  *  Macros to help make life easy
  */
 #define COPY_STRING(s) (s) ? strdup(s) : NULL
 
-/*
- * PAM error handler.
- */
+/*******************************************************************
+ PAM error handler.
+ *********************************************************************/
+
 static BOOL smb_pam_error_handler(pam_handle_t *pamh, int pam_error, char *msg, int dbglvl)
 {
 
 	if( pam_error != PAM_SUCCESS) {
-		DEBUG(dbglvl, ("PAM: %s : %s\n", msg, pam_strerror(pamh, pam_error)));
+		DEBUG(dbglvl, ("smb_pam_error_handler: PAM: %s : %s\n",
+				msg, pam_strerror(pamh, pam_error)));
 		return False;
 	}
 	return True;
 }
 
+/*******************************************************************
+ This function is a sanity check, to make sure that we NEVER report
+ failure as sucess.
+*********************************************************************/
+
+static BOOL smb_pam_nt_status_error_handler(pam_handle_t *pamh, int pam_error,
+							char *msg, int dbglvl, uint32 *nt_status)
+{
+	if (smb_pam_error_handler(pamh, pam_error, msg, dbglvl))
+		return True;
+
+	if (*nt_status == NT_STATUS_NOPROBLEMO) {
+		/* Complain LOUDLY */
+		DEBUG(0, ("smb_pam_nt_status_error_handler: PAM: BUG: PAM and NT_STATUS \
+error MISMATCH, forcing to NT_STATUS_LOGON_FAILURE"));
+		*nt_status = NT_STATUS_LOGON_FAILURE;
+	}
+	return False;
+}
+
 /*
  * PAM conversation function
  * Here we assume (for now, at least) that echo on means login name, and
@@ -82,6 +109,9 @@ static int smb_pam_conv(int num_msg,
 {
 	int replies = 0;
 	struct pam_response *reply = NULL;
+	struct smb_pam_userdata *udp = (struct smb_pam_userdata *)appdata_ptr;
+
+	*resp = NULL;
 
 	reply = malloc(sizeof(struct pam_response) * num_msg);
 	if (!reply)
@@ -91,15 +121,13 @@ static int smb_pam_conv(int num_msg,
 		switch (msg[replies]->msg_style) {
 			case PAM_PROMPT_ECHO_ON:
 				reply[replies].resp_retcode = PAM_SUCCESS;
-			reply[replies].resp =
-					COPY_STRING(PAM_username);
+				reply[replies].resp = COPY_STRING(udp->PAM_username);
 				/* PAM frees resp */
 				break;
 
 			case PAM_PROMPT_ECHO_OFF:
 				reply[replies].resp_retcode = PAM_SUCCESS;
-				reply[replies].resp =
-					COPY_STRING(PAM_password);
+				reply[replies].resp = COPY_STRING(udp->PAM_password);
 				/* PAM frees resp */
 				break;
 
@@ -123,41 +151,158 @@ static int smb_pam_conv(int num_msg,
 	return PAM_SUCCESS;
 }
 
-static struct pam_conv smb_pam_conversation = {
-	&smb_pam_conv,
-	NULL
-};
+/*
+ * PAM password change conversation function
+ * Here we assume (for now, at least) that echo on means login name, and
+ * echo off means password.
+ */
+
+static int smb_pam_passchange_conv(int num_msg,
+				const struct pam_message **msg,
+				struct pam_response **resp,
+				void *appdata_ptr)
+{
+	int replies = 0;
+	struct pam_response *reply = NULL;
+	fstring currentpw_prompt;
+	fstring newpw_prompt;
+	fstring repeatpw_prompt;
+	char *p = lp_passwd_chat();
+	struct smb_pam_userdata *udp = (struct smb_pam_userdata *)appdata_ptr;
+
+	/* Get the prompts... */
+
+	if (!next_token(&p, currentpw_prompt, NULL, sizeof(fstring)))
+		return PAM_CONV_ERR;
+	if (!next_token(&p, newpw_prompt, NULL, sizeof(fstring)))
+		return PAM_CONV_ERR;
+	if (!next_token(&p, repeatpw_prompt, NULL, sizeof(fstring)))
+		return PAM_CONV_ERR;
+
+	*resp = NULL;
+
+	reply = malloc(sizeof(struct pam_response) * num_msg);
+	if (!reply)
+		return PAM_CONV_ERR;
+
+	for (replies = 0; replies < num_msg; replies++) {
+		switch (msg[replies]->msg_style) {
+		case PAM_PROMPT_ECHO_ON:
+			reply[replies].resp_retcode = PAM_SUCCESS;
+			reply[replies].resp = COPY_STRING(udp->PAM_username);
+			/* PAM frees resp */
+			break;
+
+		case PAM_PROMPT_ECHO_OFF:
+			reply[replies].resp_retcode = PAM_SUCCESS;
+			DEBUG(10,("smb_pam_passchange_conv: PAM Replied: %s\n", msg[replies]->msg));
+			if (strncmp(currentpw_prompt, msg[replies]->msg, strlen(currentpw_prompt)) == 0) {
+				reply[replies].resp = COPY_STRING(udp->PAM_password);
+			} else if (strncmp(newpw_prompt, msg[replies]->msg, strlen(newpw_prompt)) == 0) {
+				reply[replies].resp = COPY_STRING(udp->PAM_newpassword);
+			} else if (strncmp(repeatpw_prompt, msg[replies]->msg, strlen(repeatpw_prompt)) == 0) {
+				reply[replies].resp = COPY_STRING(udp->PAM_newpassword);
+			} else {
+				DEBUG(3,("smb_pam_passchange_conv: Could not find reply for PAM prompt: %s\n",msg[replies]->msg));
+				DEBUG(5,("smb_pam_passchange_conv: Prompts available:\n CurrentPW: \"%s\"\n NewPW: \"%s\"\n \
+RepeatPW: \"%s\"\n",currentpw_prompt,newpw_prompt,repeatpw_prompt));
+			}
+			/* PAM frees resp */
+			break;
+
+		case PAM_TEXT_INFO:
+			/* fall through */
+
+		case PAM_ERROR_MSG:
+			/* ignore it... */
+			reply[replies].resp_retcode = PAM_SUCCESS;
+			reply[replies].resp = NULL;
+			break;
+
+		default:
+			/* Must be an error of some sort... */
+			free(reply);
+			reply = NULL;
+			return PAM_CONV_ERR;
+		}
+	}
+
+	if (reply)
+		*resp = reply;
+	return PAM_SUCCESS;
+}
+
+/***************************************************************************
+ Free up a malloced pam_conv struct.
+****************************************************************************/
+
+static void smb_free_pam_conv(struct pam_conv *pconv)
+{
+	if (pconv)
+		safe_free(pconv->appdata_ptr);
+
+	safe_free(pconv);
+}
+
+/***************************************************************************
+ Allocate a pam_conv struct.
+****************************************************************************/
+
+static struct pam_conv *smb_setup_pam_conv(smb_pam_conv_fn smb_pam_conv_fnptr, char *user,
+					char *passwd, char *newpass)
+{
+	struct pam_conv *pconv = (struct pam_conv *)malloc(sizeof(struct pam_conv));
+	struct smb_pam_userdata *udp = (struct smb_pam_userdata *)malloc(sizeof(struct smb_pam_userdata));
+
+	if (pconv == NULL || udp == NULL) {
+		safe_free(pconv);
+		safe_free(udp);
+		return NULL;
+	}
+
+	udp->PAM_username = user;
+	udp->PAM_password = passwd;
+	udp->PAM_newpassword = newpass;
+
+	pconv->conv = smb_pam_conv_fnptr;
+	pconv->appdata_ptr = (void *)udp;
+	return pconv;
+}
 
 /* 
  * PAM Closing out cleanup handler
  */
-static BOOL smb_pam_end(pam_handle_t *pamh)
+
+static BOOL smb_pam_end(pam_handle_t *pamh, struct pam_conv *smb_pam_conv_ptr)
 {
 	int pam_error;
+
+	smb_free_pam_conv(smb_pam_conv_ptr);
        
 	if( pamh != NULL ) {
 		pam_error = pam_end(pamh, 0);
 		if(smb_pam_error_handler(pamh, pam_error, "End Cleanup Failed", 2) == True) {
-			DEBUG(4, ("PAM: PAM_END OK.\n"));
+			DEBUG(4, ("smb_pam_end: PAM: PAM_END OK.\n"));
 			return True;
 		}
 	}
-	DEBUG(2,("PAM: not initialised"));
+	DEBUG(2,("smb_pam_end: PAM: not initialised"));
 	return False;
 }
 
 /*
  * Start PAM authentication for specified account
  */
-static BOOL smb_pam_start(pam_handle_t **pamh, char *user, char *rhost)
+
+static BOOL smb_pam_start(pam_handle_t **pamh, char *user, char *rhost, struct pam_conv *pconv)
 {
 	int pam_error;
 
 	*pamh = (pam_handle_t *)NULL;
 
-	DEBUG(4,("PAM: Init user: %s\n", user));
+	DEBUG(4,("smb_pam_start: PAM: Init user: %s\n", user));
 
-	pam_error = pam_start("samba", user, &smb_pam_conversation, pamh);
+	pam_error = pam_start("samba", user, pconv, pamh);
 	if( !smb_pam_error_handler(*pamh, pam_error, "Init Failed", 0)) {
 		*pamh = (pam_handle_t *)NULL;
 		return False;
@@ -170,117 +315,134 @@ static BOOL smb_pam_start(pam_handle_t **pamh, char *user, char *rhost)
 	}
 
 #ifdef PAM_RHOST
-	DEBUG(4,("PAM: setting rhost to: %s\n", rhost));
+	DEBUG(4,("smb_pam_start: PAM: setting rhost to: %s\n", rhost));
 	pam_error = pam_set_item(*pamh, PAM_RHOST, rhost);
 	if(!smb_pam_error_handler(*pamh, pam_error, "set rhost failed", 0)) {
-		smb_pam_end(*pamh);
+		smb_pam_end(*pamh, pconv);
 		*pamh = (pam_handle_t *)NULL;
 		return False;
 	}
 #endif
 #ifdef PAM_TTY
-	DEBUG(4,("PAM: setting tty\n"));
+	DEBUG(4,("smb_pam_start: PAM: setting tty\n"));
 	pam_error = pam_set_item(*pamh, PAM_TTY, "samba");
 	if (!smb_pam_error_handler(*pamh, pam_error, "set tty failed", 0)) {
-		smb_pam_end(*pamh);
+		smb_pam_end(*pamh, pconv);
 		*pamh = (pam_handle_t *)NULL;
 		return False;
 	}
 #endif
-	DEBUG(4,("PAM: Init passed for user: %s\n", user));
+	DEBUG(4,("smb_pam_start: PAM: Init passed for user: %s\n", user));
 	return True;
 }
 
 /*
  * PAM Authentication Handler
  */
-static BOOL smb_pam_auth(pam_handle_t *pamh, char *user, char *password)
+static uint32 smb_pam_auth(pam_handle_t *pamh, char *user)
 {
 	int pam_error;
+	uint32 nt_status = NT_STATUS_LOGON_FAILURE;
 
 	/*
 	 * To enable debugging set in /etc/pam.d/samba:
 	 *	auth required /lib/security/pam_pwdb.so nullok shadow audit
 	 */
 	
-	DEBUG(4,("PAM: Authenticate User: %s\n", user));
-	pam_error = pam_authenticate(pamh, PAM_SILENT); /* Can we authenticate user? */
+	DEBUG(4,("smb_pam_auth: PAM: Authenticate User: %s\n", user));
+	pam_error = pam_authenticate(pamh, PAM_SILENT | lp_null_passwords() ? 0 : PAM_DISALLOW_NULL_AUTHTOK);
 	switch( pam_error ){
 		case PAM_AUTH_ERR:
-			DEBUG(2, ("PAM: Athentication Error\n"));
+			DEBUG(2, ("smb_pam_auth: PAM: Athentication Error for user %s\n", user));
+			nt_status = NT_STATUS_WRONG_PASSWORD;
 			break;
 		case PAM_CRED_INSUFFICIENT:
-			DEBUG(2, ("PAM: Insufficient Credentials\n"));
+			DEBUG(2, ("smb_pam_auth: PAM: Insufficient Credentials for user %s\n", user));
+			nt_status = NT_STATUS_INSUFFICIENT_LOGON_INFO;
 			break;
 		case PAM_AUTHINFO_UNAVAIL:
-			DEBUG(2, ("PAM: Authentication Information Unavailable\n"));
+			DEBUG(2, ("smb_pam_auth: PAM: Authentication Information Unavailable for user %s\n", user));
+			nt_status = NT_STATUS_LOGON_FAILURE;
 			break;
 		case PAM_USER_UNKNOWN:
-			DEBUG(2, ("PAM: Username NOT known to Authentication system\n"));
+			DEBUG(2, ("smb_pam_auth: PAM: Username %s NOT known to Authentication system\n", user));
+			nt_status = NT_STATUS_NO_SUCH_USER;
 			break;
 		case PAM_MAXTRIES:
-			DEBUG(2, ("PAM: One or more authentication modules reports user limit exceeeded\n"));
+			DEBUG(2, ("smb_pam_auth: PAM: One or more authentication modules reports user limit for user %s exceeeded\n", user));
+			nt_status = NT_STATUS_REMOTE_SESSION_LIMIT;
 			break;
 		case PAM_ABORT:
-			DEBUG(0, ("PAM: One or more PAM modules failed to load\n"));
+			DEBUG(0, ("smb_pam_auth: PAM: One or more PAM modules failed to load for user %s\n", user));
+			nt_status = NT_STATUS_LOGON_FAILURE;
+			break;
+		case PAM_SUCCESS:
+			DEBUG(4, ("smb_pam_auth: PAM: User %s Authenticated OK\n", user));
+			nt_status = NT_STATUS_NOPROBLEMO;
 			break;
-	        case PAM_SUCCESS:
-			DEBUG(4, ("PAM: User %s Authenticated OK\n", user));
-		        break;
 		default:
-			DEBUG(0, ("PAM: UNKNOWN ERROR while authenticating user %s\n", user));
-	}
-	if(!smb_pam_error_handler(pamh, pam_error, "Authentication Failure", 2)) {
-		smb_pam_end(pamh);
-		return False;
+			DEBUG(0, ("smb_pam_auth: PAM: UNKNOWN ERROR while authenticating user %s\n", user));
+			nt_status = NT_STATUS_LOGON_FAILURE;
+			break;
 	}
-	/* If this point is reached, the user has been authenticated. */
-	return (True);
+
+	smb_pam_nt_status_error_handler(pamh, pam_error, "Authentication Failure", 2, &nt_status);
+	return nt_status;
 }
 
 /* 
  * PAM Account Handler
  */
-static BOOL smb_pam_account(pam_handle_t *pamh, char * user, char * password, BOOL pam_auth)
+static uint32 smb_pam_account(pam_handle_t *pamh, char * user)
 {
 	int pam_error;
+	uint32 nt_status = NT_STATUS_ACCOUNT_DISABLED;
 
-	DEBUG(4,("PAM: Account Management for User: %s\n", user));
+	DEBUG(4,("smb_pam_account: PAM: Account Management for User: %s\n", user));
 	pam_error = pam_acct_mgmt(pamh, PAM_SILENT); /* Is user account enabled? */
 	switch( pam_error ) {
 		case PAM_AUTHTOK_EXPIRED:
-			DEBUG(2, ("PAM: User is valid but password is expired\n"));
+			DEBUG(2, ("smb_pam_account: PAM: User %s is valid but password is expired\n", user));
+			nt_status = NT_STATUS_PASSWORD_EXPIRED;
 			break;
 		case PAM_ACCT_EXPIRED:
-			DEBUG(2, ("PAM: User no longer permitted to access system\n"));
+			DEBUG(2, ("smb_pam_account: PAM: User %s no longer permitted to access system\n", user));
+			nt_status = NT_STATUS_ACCOUNT_EXPIRED;
 			break;
 		case PAM_AUTH_ERR:
-			DEBUG(2, ("PAM: There was an authentication error\n"));
+			DEBUG(2, ("smb_pam_account: PAM: There was an authentication error for user %s\n", user));
+			nt_status = NT_STATUS_LOGON_FAILURE;
 			break;
 		case PAM_PERM_DENIED:
-			DEBUG(0, ("PAM: User is NOT permitted to access system at this time\n"));
+			DEBUG(0, ("smb_pam_account: PAM: User %s is NOT permitted to access system at this time\n", user));
+			nt_status = NT_STATUS_ACCOUNT_RESTRICTION;
 			break;
 		case PAM_USER_UNKNOWN:
-			DEBUG(0, ("PAM: User \"%s\" is NOT known to account management\n", user));
+			DEBUG(0, ("smb_pam_account: PAM: User \"%s\" is NOT known to account management\n", user));
+			nt_status = NT_STATUS_NO_SUCH_USER;
+			break;
+		case PAM_SUCCESS:
+			DEBUG(4, ("smb_pam_account: PAM: Account OK for User: %s\n", user));
+			nt_status = NT_STATUS_NOPROBLEMO;
 			break;
-	        case PAM_SUCCESS:
-			DEBUG(4, ("PAM: Account OK for User: %s\n", user));
-		        break;
 		default:
-			DEBUG(0, ("PAM: UNKNOWN ERROR for User: %s\n", user));
-	}
-	if(!smb_pam_error_handler(pamh, pam_error, "Account Check Failed", 2)) {
-		smb_pam_end(pamh);
-		return False;
+			nt_status = NT_STATUS_ACCOUNT_DISABLED;
+			DEBUG(0, ("smb_pam_account: PAM: UNKNOWN PAM ERROR (%d) during Account Management for User: %s\n", pam_error, user));
+			break;
 	}
 
-	/* Skip the pam_setcred() call if we didn't use pam_authenticate()
-	   for authentication -- it's an error to call pam_setcred without
-	   calling pam_authenticate first */
-	if (!pam_auth) {
-		DEBUG(4, ("PAM: Skipping setcred for user: %s (using encrypted passwords)\n", user));
-		return True;
-	}
+	smb_pam_nt_status_error_handler(pamh, pam_error, "Account Check Failed", 2, &nt_status);
+	return nt_status;
+}
+
+/*
+ * PAM Credential Setting
+ */
+
+static uint32 smb_pam_setcred(pam_handle_t *pamh, char * user)
+{
+	int pam_error;
+	uint32 nt_status = NT_STATUS_NO_TOKEN;
 
 	/*
 	 * This will allow samba to aquire a kerberos token. And, when
@@ -291,32 +453,34 @@ static BOOL smb_pam_account(pam_handle_t *pamh, char * user, char * password, BO
 	pam_error = pam_setcred(pamh, (PAM_ESTABLISH_CRED|PAM_SILENT)); 
 	switch( pam_error ) {
 		case PAM_CRED_UNAVAIL:
-			DEBUG(0, ("PAM: Credentials not found for user:%s", user ));
+			DEBUG(0, ("smb_pam_setcred: PAM: Credentials not found for user:%s\n", user ));
+			 nt_status = NT_STATUS_NO_TOKEN;
 			break;
 		case PAM_CRED_EXPIRED:
-			DEBUG(0, ("PAM: Credentials for user: \"%s\" EXPIRED!", user ));
+			DEBUG(0, ("smb_pam_setcred: PAM: Credentials for user: \"%s\" EXPIRED!\n", user ));
+			nt_status = NT_STATUS_PASSWORD_EXPIRED;
 			break;
 		case PAM_USER_UNKNOWN:
-			DEBUG(0, ("PAM: User: \"%s\" is NOT known so can not set credentials!", user ));
+			DEBUG(0, ("smb_pam_setcred: PAM: User: \"%s\" is NOT known so can not set credentials!\n", user ));
+			nt_status = NT_STATUS_NO_SUCH_USER;
 			break;
 		case PAM_CRED_ERR:
-			DEBUG(0, ("PAM: Unknown setcredentials error - unable to set credentials for %s", user ));
+			DEBUG(0, ("smb_pam_setcred: PAM: Unknown setcredentials error - unable to set credentials for %s\n", user ));
+			nt_status = NT_STATUS_LOGON_FAILURE;
+			break;
+		case PAM_SUCCESS:
+			DEBUG(4, ("smb_pam_setcred: PAM: SetCredentials OK for User: %s\n", user));
+			nt_status = NT_STATUS_NOPROBLEMO;
 			break;
-	        case PAM_SUCCESS:
-			DEBUG(4, ("PAM: SetCredentials OK for User: %s\n", user));
-		        break;
 		default:
-			DEBUG(0, ("PAM: Error Condition Unknown in pam_setcred function call!"));
-	}
-	if(!smb_pam_error_handler(pamh, pam_error, "Set Credential Failure", 2)) {
-		smb_pam_end(pamh);
-		return False;
+			DEBUG(0, ("smb_pam_setcred: PAM: UNKNOWN PAM ERROR (%d) during SetCredentials for User: %s\n", pam_error, user));
+			nt_status = NT_STATUS_NO_TOKEN;
+			break;
 	}
-	
-	/* If this point is reached, the user has been authenticated. */
-	return (True);
-}
 
+	smb_pam_nt_status_error_handler(pamh, pam_error, "Set Credential Failure", 2, &nt_status);
+	return nt_status;
+}
 
 /*
  * PAM Internal Session Handler
@@ -325,11 +489,8 @@ static BOOL smb_internal_pam_session(pam_handle_t *pamh, char *user, char *tty,
 {
 	int pam_error;
 
-	PAM_password = NULL;
-	PAM_username = user;
-
 #ifdef PAM_TTY
-	DEBUG(4,("PAM: tty set to: %s\n", tty));
+	DEBUG(4,("smb_internal_pam_session: PAM: tty set to: %s\n", tty));
 	pam_error = pam_set_item(pamh, PAM_TTY, tty);
 	if (!smb_pam_error_handler(pamh, pam_error, "set tty failed", 0))
 		return False;
@@ -340,7 +501,8 @@ static BOOL smb_internal_pam_session(pam_handle_t *pamh, char *user, char *tty,
 		if (!smb_pam_error_handler(pamh, pam_error, "session setup failed", 0))
 			return False;
 	} else {
-		pam_error = pam_close_session(pamh, PAM_SILENT);
+		pam_setcred(pamh, (PAM_DELETE_CRED|PAM_SILENT)); /* We don't care if this fails */
+		pam_error = pam_close_session(pamh, PAM_SILENT); /* This will probably pick up the error anyway */
 		if (!smb_pam_error_handler(pamh, pam_error, "session close failed", 0))
 			return False;
 	}
@@ -348,69 +510,147 @@ static BOOL smb_internal_pam_session(pam_handle_t *pamh, char *user, char *tty,
 }
 
 /*
+ * Internal PAM Password Changer.
+ */
+
+static BOOL smb_pam_chauthtok(pam_handle_t *pamh, char * user)
+{
+	int pam_error;
+
+	DEBUG(4,("smb_pam_chauthtok: PAM: Password Change for User: %s\n", user));
+
+	pam_error = pam_chauthtok(pamh, PAM_SILENT); /* Change Password */
+
+	switch( pam_error ) {
+	case PAM_AUTHTOK_ERR:
+		DEBUG(2, ("PAM: unable to obtain the new authentication token - is password to weak?\n"));
+		break;
+	case PAM_AUTHTOK_RECOVER_ERR:
+		DEBUG(2, ("PAM: unable to obtain the old authentication token - was the old password wrong?.\n"));
+		break;
+	case PAM_AUTHTOK_LOCK_BUSY:
+		DEBUG(2, ("PAM: unable to change the authentication token since it is currently locked.\n"));
+		break;
+	case PAM_AUTHTOK_DISABLE_AGING:
+		DEBUG(2, ("PAM: Authentication token aging has been disabled.\n"));
+		break;
+	case PAM_PERM_DENIED:
+		DEBUG(0, ("PAM: Permission denied.\n"));
+		break;
+	case PAM_TRY_AGAIN:
+		DEBUG(0, ("PAM: Could not update all authentication token(s). No authentication tokens were updated.\n"));
+		break;
+	case PAM_USER_UNKNOWN:
+		DEBUG(0, ("PAM: User not known to PAM\n"));
+		break;
+	case PAM_SUCCESS:
+		DEBUG(4, ("PAM: Account OK for User: %s\n", user));
+		break;
+	default:
+		DEBUG(0, ("PAM: UNKNOWN PAM ERROR (%d) for User: %s\n", pam_error, user));
+	}
+ 
+	if(!smb_pam_error_handler(pamh, pam_error, "Password Change Failed", 2)) {
+		return False;
+	}
+
+	/* If this point is reached, the password has changed. */
+	return True;
+}
+
+/*
  * PAM Externally accessible Session handler
  */
 
-BOOL smb_pam_session(BOOL flag, const char *in_user, char *tty, char *rhost)
+BOOL smb_pam_claim_session(char *user, char *tty, char *rhost)
 {
 	pam_handle_t *pamh = NULL;
-	char * user;
+	struct pam_conv *pconv = NULL;
 
 	/* Ignore PAM if told to. */
 
 	if (!lp_obey_pam_restrictions())
 		return True;
 
-	user = strdup(in_user);
-	if ( user == NULL ) {
-		DEBUG(0, ("PAM: PAM_session Malloc Failed!\n"));
+	if ((pconv = smb_setup_pam_conv(smb_pam_conv, user, NULL, NULL)) == NULL)
 		return False;
-	}
 
-	if (!smb_pam_start(&pamh, user, rhost)) {
+	if (!smb_pam_start(&pamh, user, rhost, pconv))
 		return False;
-	}
 
-	if (!smb_internal_pam_session(pamh, user, tty, flag)) {
-		smb_pam_end(pamh);
+	if (!smb_internal_pam_session(pamh, user, tty, True)) {
+		smb_pam_end(pamh, pconv);
 		return False;
 	}
-	return smb_pam_end(pamh);
+
+	return smb_pam_end(pamh, pconv);
 }
 
 /*
- * PAM Externally accessible Account handler
+ * PAM Externally accessible Session handler
  */
-BOOL smb_pam_accountcheck(char * user)
+
+BOOL smb_pam_close_session(char *user, char *tty, char *rhost)
 {
 	pam_handle_t *pamh = NULL;
-
-	PAM_username = user;
-	PAM_password = NULL;
+	struct pam_conv *pconv = NULL;
 
 	/* Ignore PAM if told to. */
 
 	if (!lp_obey_pam_restrictions())
 		return True;
 
-	if( smb_pam_start(&pamh, user, NULL)) {
-		if ( smb_pam_account(pamh, user, NULL, False)) {
-			return( smb_pam_end(pamh));
-		}
+	if ((pconv = smb_setup_pam_conv(smb_pam_conv, user, NULL, NULL)) == NULL)
+		return False;
+
+	if (!smb_pam_start(&pamh, user, rhost, pconv))
+		return False;
+
+	if (!smb_internal_pam_session(pamh, user, tty, False)) {
+		smb_pam_end(pamh, pconv);
+		return False;
 	}
-	DEBUG(0, ("PAM: Account Validation Failed - Rejecting User!\n"));
-	return( False );
+
+	return smb_pam_end(pamh, pconv);
 }
 
 /*
- * PAM Password Validation Suite
+ * PAM Externally accessible Account handler
  */
-BOOL smb_pam_passcheck(char * user, char * password)
+
+uint32 smb_pam_accountcheck(char * user)
 {
+	uint32 nt_status = NT_STATUS_ACCOUNT_DISABLED;
 	pam_handle_t *pamh = NULL;
+	struct pam_conv *pconv = NULL;
 
-	PAM_username = user;
-	PAM_password = password;
+	/* Ignore PAM if told to. */
+
+	if (!lp_obey_pam_restrictions())
+		return NT_STATUS_NOPROBLEMO;
+
+	if ((pconv = smb_setup_pam_conv(smb_pam_conv, user, NULL, NULL)) == NULL)
+		return False;
+
+	if (!smb_pam_start(&pamh, user, NULL, pconv))
+		return NT_STATUS_ACCOUNT_DISABLED;
+
+	if ((nt_status = smb_pam_account(pamh, user)) != NT_STATUS_NOPROBLEMO)
+		DEBUG(0, ("smb_pam_accountcheck: PAM: Account Validation Failed - Rejecting User %s!\n", user));
+
+	smb_pam_end(pamh, pconv);
+	return nt_status;
+}
+
+/*
+ * PAM Password Validation Suite
+ */
+
+uint32 smb_pam_passcheck(char * user, char * password)
+{
+	pam_handle_t *pamh = NULL;
+	uint32 nt_status = NT_STATUS_LOGON_FAILURE;
+	struct pam_conv *pconv = NULL;
 
 	/*
 	 * Note we can't ignore PAM here as this is the only
@@ -418,23 +658,76 @@ BOOL smb_pam_passcheck(char * user, char * password)
 	 * compiled --with-pam.
 	 */
 
-	if( smb_pam_start(&pamh, user, NULL)) {
-		if ( smb_pam_auth(pamh, user, password)) {
-			if ( smb_pam_account(pamh, user, password, True)) {
-				return( smb_pam_end(pamh));
-			}
-		}
+	if ((pconv = smb_setup_pam_conv(smb_pam_conv, user, password, NULL)) == NULL)
+		return False;
+
+	if (!smb_pam_start(&pamh, user, NULL, NULL))
+		return NT_STATUS_LOGON_FAILURE;
+
+	if ((nt_status = smb_pam_auth(pamh, user)) != NT_STATUS_NOPROBLEMO) {
+		DEBUG(0, ("smb_pam_passcheck: PAM: smb_pam_auth failed - Rejecting User %s !\n", user));
+		smb_pam_end(pamh, pconv);
+		return nt_status;
+	}
+
+	if ((nt_status = smb_pam_account(pamh, user)) != NT_STATUS_NOPROBLEMO) {
+		DEBUG(0, ("smb_pam_passcheck: PAM: smb_pam_account failed - Rejecting User %s !\n", user));
+		smb_pam_end(pamh, pconv);
+		return nt_status;
+	}
+
+	if ((nt_status = smb_pam_setcred(pamh, user)) != NT_STATUS_NOPROBLEMO) {
+		DEBUG(0, ("smb_pam_passcheck: PAM: smb_pam_setcred failed - Rejecting User %s !\n", user));
+		smb_pam_end(pamh, pconv);
+		return nt_status;
 	}
-	DEBUG(0, ("PAM: System Validation Failed - Rejecting User!\n"));
-	return( False );
+
+	smb_pam_end(pamh, pconv);
+	return nt_status;
+}
+
+/*
+ * PAM Password Change Suite
+ */
+
+BOOL smb_pam_passchange(char * user, char * oldpassword, char * newpassword)
+{
+	/* Appropriate quantities of root should be obtained BEFORE calling this function */
+	struct pam_conv *pconv = NULL;
+	pam_handle_t *pamh = NULL;
+
+	if ((pconv = smb_setup_pam_conv(smb_pam_passchange_conv, user, oldpassword, newpassword)) == NULL)
+		return False;
+
+	if(!smb_pam_start(&pamh, user, NULL, pconv))
+		return False;
+
+	if (!smb_pam_chauthtok(pamh, user)) {
+		DEBUG(0, ("smb_pam_passchange: PAM: Password Change Failed for user %s!\n", user));
+		smb_pam_end(pamh, pconv);
+		return False;
+	}
+
+	return smb_pam_end(pamh, pconv);
 }
 
 #else
 
 /* If PAM not used, no PAM restrictions on accounts. */
- BOOL smb_pam_accountcheck(char * user)
+ uint32 smb_pam_accountcheck(char * user)
+{
+	return NT_STATUS_NOPROBLEMO;
+}
+
+/* If PAM not used, also no PAM restrictions on sessions. */
+ BOOL smb_pam_claim_session(const char *user, char *tty, char *rhost)
 {
 	return True;
 }
 
+/* If PAM not used, also no PAM restrictions on sessions. */
+ BOOL smb_pam_close_session(const char *in_user, char *tty, char *rhost)
+{
+	return True;
+}
 #endif /* WITH_PAM */
diff --git a/source/rpc_server/srv_netlog_nt.c b/source/rpc_server/srv_netlog_nt.c
index d41ae44ac60..fa6b9458152 100644
--- a/source/rpc_server/srv_netlog_nt.c
+++ b/source/rpc_server/srv_netlog_nt.c
@@ -594,9 +594,11 @@ uint32 _net_sam_logon(pipes_struct *p, NET_Q_SAM_LOGON *q_u, NET_R_SAM_LOGON *r_
 	} 
 
 #ifdef WITH_PAM
-	if (!smb_pam_accountcheck(nt_username)) {
-	  return NT_STATUS_ACCOUNT_DISABLED;
-	}
+	become_root();
+	status = smb_pam_accountcheck(nt_username);
+	unbecome_root();
+	if (status != NT_STATUS_NOPROBLEMO)
+		return status;
 #endif
 
 	if (!(smb_pass->acct_ctrl & ACB_PWNOTREQ)) {
diff --git a/source/smbd/chgpasswd.c b/source/smbd/chgpasswd.c
index 63f425f4cc3..1b879890813 100644
--- a/source/smbd/chgpasswd.c
+++ b/source/smbd/chgpasswd.c
@@ -53,6 +53,24 @@ extern int DEBUGLEVEL;
 
 #if ALLOW_CHANGE_PASSWORD
 
+#ifdef WITH_PAM
+BOOL chgpasswd(char *name, char *oldpass, char *newpass, BOOL as_root)
+{
+	BOOL ret;
+
+	if (as_root)
+		become_root();
+
+	ret = smb_pam_passchange(name, oldpass, newpass);
+
+	if (as_root)
+		unbecome_root();
+
+	return ret;
+}     
+
+#else /* WITH_PAM */
+
 static int findpty(char **slave)
 {
 	int master;
@@ -526,7 +544,10 @@ BOOL chgpasswd(char *name, char *oldpass, char *newpass, BOOL as_root)
 		(passwordprogram, name, chatsequence, as_root));
 }
 
+#endif /* WITH_PAM */
+
 #else /* ALLOW_CHANGE_PASSWORD */
+
 BOOL chgpasswd(char *name, char *oldpass, char *newpass, BOOL as_root)
 {
 	DEBUG(0, ("Password changing not compiled in (user=%s)\n", name));
diff --git a/source/smbd/password.c b/source/smbd/password.c
index ef457739c67..4beedbe2a5f 100644
--- a/source/smbd/password.c
+++ b/source/smbd/password.c
@@ -491,24 +491,24 @@ BOOL smb_password_ok(struct smb_passwd *smb_pass, uchar chal[8],
 	/* Try against the lanman password. smb_pass->smb_passwd == NULL means
 	   no password, allow access. */
 
-	DEBUG(4,("Checking LM MD4 password\n"));
-
 	if((smb_pass->smb_passwd == NULL) && 
 	   (smb_pass->acct_ctrl & ACB_PWNOTREQ)) {
-		DEBUG(4,("no password required for user %s\n",
+		DEBUG(4,("smb_password_ok: no password required for user %s\n",
 			 smb_pass->smb_name));
 		return True;
 	}
 
-	if((smb_pass->smb_passwd != NULL) && 
-	   smb_password_check((char *)lm_pass, 
+	if(lp_lanman_auth() && (smb_pass->smb_passwd != NULL)) {
+		DEBUG(4,("smb_password_ok: Checking LM password\n"));
+
+		if (smb_password_check((char *)lm_pass, 
 			      (uchar *)smb_pass->smb_passwd, challenge)) {
-		DEBUG(4,("LM MD4 password check succeeded\n"));
-		return(True);
+			DEBUG(4,("smb_password_ok: LM password check succeeded\n"));
+			return(True);
+		}
+		DEBUG(4,("LM password check failed\n"));
 	}
 
-	DEBUG(4,("LM MD4 password check failed\n"));
-
 	return False;
 }
 
@@ -621,14 +621,14 @@ BOOL password_ok(char *user, char *password, int pwlen, struct passwd *pwd)
 		 */
 
 		if (ret)
-		  return smb_pam_accountcheck(user);
+		  return (smb_pam_accountcheck(user) == NT_STATUS_NOPROBLEMO);
 
 		return ret;
 	} 
 
-	return pass_check(user, password, pwlen, pwd, 
+	return (pass_check(user, password, pwlen, pwd, 
 			  lp_update_encrypted() ? 
-			  update_smbpassword_file : NULL);
+			  update_smbpassword_file : NULL));
 }
 
 /****************************************************************************
diff --git a/source/smbd/session.c b/source/smbd/session.c
index 3131fb9f542..40654c0f43c 100644
--- a/source/smbd/session.c
+++ b/source/smbd/session.c
@@ -99,6 +99,13 @@ BOOL session_claim(uint16 vuid)
 	sessionid.id_num = i;
 	sessionid.pid = pid;
 
+	if (!smb_pam_claim_session(sessionid.username, sessionid.id_str, sessionid.hostname)) {
+		DEBUG(1,("pam_session rejected the session for %s [%s]\n",
+				sessionid.username, sessionid.id_str));
+		tdb_delete(tdb, key);
+		return False;
+	}
+
 	dlen = tdb_pack(dbuf, sizeof(dbuf), "fffdd",
 			sessionid.username, sessionid.hostname, sessionid.id_str,
 			sessionid.id_num, sessionid.pid);
@@ -110,15 +117,6 @@ BOOL session_claim(uint16 vuid)
 		return False;
 	}
 
-#if WITH_PAM
-	if (!smb_pam_session(True, sessionid.username, sessionid.id_str, sessionid.hostname)) {
-		DEBUG(1,("smb_pam_session rejected the session for %s [%s]\n",
-			 sessionid.username, sessionid.id_str));
-		tdb_delete(tdb, key);
-		return False;
-	}
-#endif
-
 #if WITH_UTMP	
 	if (lp_utmp()) {
 		sys_utmp_claim(sessionid.username, sessionid.hostname, 
@@ -169,9 +167,7 @@ void session_yield(uint16 vuid)
 	}
 #endif
 
-#if WITH_PAM
-	smb_pam_session(False, sessionid.username, sessionid.id_str, sessionid.hostname);
-#endif
+	smb_pam_close_session(sessionid.username, sessionid.id_str, sessionid.hostname);
 
 	tdb_delete(tdb, key);
 }