- (djm) Bug #564: Perform PAM account checks for all authentications…

… when

   UsePAM=yes; ok dtucker

ChangeLog

@@ -8,6 +8,8 @@
    be our 'mysignal' by default.  OK djm@
  - (dtucker) [acconfig.h auth.c configure.ac sshd.8] Bug #422 again: deny
    any access to locked accounts.  ok djm@
+ - (djm) Bug #564: Perform PAM account checks for all authentications when
+   UsePAM=yes; ok dtucker
 
 20030822
  - (djm) s/get_progname/ssh_get_progname/g to avoid conflict with Heimdal 
@@ -862,4 +864,4 @@
  - Fix sshd BindAddress and -b options for systems using fake-getaddrinfo.
    Report from [email protected], diagnosis from [email protected]
 
-$Id: ChangeLog,v 1.2902 2003/08/25 01:51:19 dtucker Exp $
+$Id: ChangeLog,v 1.2903 2003/08/25 03:08:49 djm Exp $

auth-pam.c

@@ -31,7 +31,7 @@
 
 /* Based on $FreeBSD: src/crypto/openssh/auth2-pam-freebsd.c,v 1.11 2003/03/31 13:48:18 des Exp $ */
 #include "includes.h"
-RCSID("$Id: auth-pam.c,v 1.66 2003/08/08 03:43:37 dtucker Exp $");
+RCSID("$Id: auth-pam.c,v 1.67 2003/08/25 03:08:49 djm Exp $");
 
 #ifdef USE_PAM
 #include <security/pam_appl.h>
@@ -49,6 +49,7 @@ RCSID("$Id: auth-pam.c,v 1.66 2003/08/08 03:43:37 dtucker Exp $");
 #include "servconf.h"
 #include "ssh2.h"
 #include "xmalloc.h"
+#include "auth-options.h"
 
 extern ServerOptions options;
 
@@ -130,10 +131,8 @@ static void sshpam_free_ctx(void *);
  * Conversation function for authentication thread.
  */
 static int
-sshpam_thread_conv(int n,
-	 const struct pam_message **msg,
-	 struct pam_response **resp,
-	 void *data)
+sshpam_thread_conv(int n, const struct pam_message **msg,
+    struct pam_response **resp, void *data)
 {
 	Buffer buffer;
 	struct pam_ctxt *ctxt;
@@ -216,9 +215,6 @@ sshpam_thread(void *ctxtp)
 	sshpam_err = pam_authenticate(sshpam_handle, 0);
 	if (sshpam_err != PAM_SUCCESS)
 		goto auth_fail;
-	sshpam_err = pam_acct_mgmt(sshpam_handle, 0);
-	if (sshpam_err != PAM_SUCCESS && sshpam_err != PAM_NEW_AUTHTOK_REQD)
-		goto auth_fail;
 	buffer_put_cstring(&buffer, "OK");
 	ssh_msg_send(ctxt->pam_csock, sshpam_err, &buffer);
 	buffer_free(&buffer);
@@ -246,12 +242,9 @@ sshpam_thread_cleanup(void *ctxtp)
 }
 
 static int
-sshpam_null_conv(int n,
-	 const struct pam_message **msg,
-	 struct pam_response **resp,
-	 void *data)
+sshpam_null_conv(int n, const struct pam_message **msg,
+    struct pam_response **resp, void *data)
 {
-
 	return (PAM_CONV_ERR);
 }
 
@@ -303,7 +296,7 @@ sshpam_init(const char *user)
 	debug("PAM: setting PAM_RHOST to \"%s\"", pam_rhost);
 	sshpam_err = pam_set_item(sshpam_handle, PAM_RHOST, pam_rhost);
 	if (sshpam_err != PAM_SUCCESS) {
-	pam_end(sshpam_handle, sshpam_err);
+		pam_end(sshpam_handle, sshpam_err);
 		sshpam_handle = NULL;
 		return (-1);
 	}
@@ -403,9 +396,6 @@ sshpam_query(void *ctx, char **name, char **info,
 			plen += snprintf(**prompts + plen, len, "%s", msg);
 			xfree(msg);
 			break;
-		case PAM_NEW_AUTHTOK_REQD:
-			sshpam_new_authtok_reqd = 1;
-			/* FALLTHROUGH */
 		case PAM_SUCCESS:
 		case PAM_AUTH_ERR:
 			if (**prompts != NULL) {
@@ -519,10 +509,24 @@ finish_pam(void)
 	sshpam_cleanup(NULL);
 }
 
-int
-do_pam_account(const char *user, const char *ruser)
+u_int
+do_pam_account(void)
 {
-	/* XXX */
+	sshpam_err = pam_acct_mgmt(sshpam_handle, 0);
+	debug3("%s: pam_acct_mgmt = %d", __func__, sshpam_err);
+
+	if (sshpam_err != PAM_SUCCESS && sshpam_err != PAM_NEW_AUTHTOK_REQD)
+		return (0);
+
+	if (sshpam_err == PAM_NEW_AUTHTOK_REQD) {
+		sshpam_new_authtok_reqd = 1;
+
+		/* Prevent forwardings until password changed */
+		no_port_forwarding_flag |= 2;
+		no_agent_forwarding_flag |= 2;
+		no_x11_forwarding_flag |= 2;
+	}
+
 	return (1);
 }
 
@@ -582,10 +586,8 @@ is_pam_password_change_required(void)
 }
 
 static int
-pam_chauthtok_conv(int n,
-	 const struct pam_message **msg,
-	 struct pam_response **resp,
-	 void *data)
+pam_chauthtok_conv(int n, const struct pam_message **msg,
+    struct pam_response **resp, void *data)
 {
 	char input[PAM_MAX_MSG_SIZE];
 	int i;
@@ -635,7 +637,7 @@ do_pam_chauthtok(void)
 	struct pam_conv pam_conv = { pam_chauthtok_conv, NULL };
 
 	if (use_privsep)
-		fatal("PAM: chauthtok not supprted with privsep");
+		fatal("Password expired (unable to change with privsep)");
 	sshpam_err = pam_set_item(sshpam_handle, PAM_CONV,
 	    (const void *)&pam_conv);
 	if (sshpam_err != PAM_SUCCESS)

auth-pam.h

@@ -1,4 +1,4 @@
-/* $Id: auth-pam.h,v 1.18 2003/05/19 01:28:44 djm Exp $ */
+/* $Id: auth-pam.h,v 1.19 2003/08/25 03:08:49 djm Exp $ */
 
 /*
  * Copyright (c) 2000 Damien Miller.  All rights reserved.
@@ -33,7 +33,7 @@
 
 void start_pam(const char *);
 void finish_pam(void);
-int do_pam_account(const char *, const char *);
+u_int do_pam_account(void);
 void do_pam_session(const char *, const char *);
 void do_pam_setcred(int );
 int is_pam_password_change_required(void);

auth1.c

@@ -290,6 +290,12 @@ do_authloop(Authctxt *authctxt)
 			authenticated = 0;
 #endif
 
+#ifdef USE_PAM
+		if (options.use_pam && authenticated && 
+		    !PRIVSEP(do_pam_account()))
+			authenticated = 0;
+#endif
+
 		/* Log before sending the reply */
 		auth_log(authctxt, authenticated, get_authname(type), info);
 

auth2.c

@@ -213,6 +213,11 @@ userauth_finish(Authctxt *authctxt, int authenticated, char *method)
 	    !auth_root_allowed(method))
 		authenticated = 0;
 
+#ifdef USE_PAM
+	if (options.use_pam && authenticated && !PRIVSEP(do_pam_account()))
+		authenticated = 0;
+#endif
+
 #ifdef _UNICOS
 	if (authenticated && cray_access_denied(authctxt->user)) {
 		authenticated = 0;

monitor.c

@@ -118,6 +118,7 @@ int mm_answer_sessid(int, Buffer *);
 
 #ifdef USE_PAM
 int mm_answer_pam_start(int, Buffer *);
+int mm_answer_pam_account(int, Buffer *);
 int mm_answer_pam_init_ctx(int, Buffer *);
 int mm_answer_pam_query(int, Buffer *);
 int mm_answer_pam_respond(int, Buffer *);
@@ -165,6 +166,7 @@ struct mon_table mon_dispatch_proto20[] = {
     {MONITOR_REQ_AUTHPASSWORD, MON_AUTH, mm_answer_authpassword},
 #ifdef USE_PAM
     {MONITOR_REQ_PAM_START, MON_ONCE, mm_answer_pam_start},
+    {MONITOR_REQ_PAM_ACCOUNT, 0, mm_answer_pam_account},
     {MONITOR_REQ_PAM_INIT_CTX, MON_ISAUTH, mm_answer_pam_init_ctx},
     {MONITOR_REQ_PAM_QUERY, MON_ISAUTH, mm_answer_pam_query},
     {MONITOR_REQ_PAM_RESPOND, MON_ISAUTH, mm_answer_pam_respond},
@@ -214,6 +216,7 @@ struct mon_table mon_dispatch_proto15[] = {
 #endif
 #ifdef USE_PAM
     {MONITOR_REQ_PAM_START, MON_ONCE, mm_answer_pam_start},
+    {MONITOR_REQ_PAM_ACCOUNT, 0, mm_answer_pam_account},
     {MONITOR_REQ_PAM_INIT_CTX, MON_ISAUTH, mm_answer_pam_init_ctx},
     {MONITOR_REQ_PAM_QUERY, MON_ISAUTH, mm_answer_pam_query},
     {MONITOR_REQ_PAM_RESPOND, MON_ISAUTH, mm_answer_pam_respond},
@@ -295,6 +298,18 @@ monitor_child_preauth(struct monitor *pmonitor)
 			if (authctxt->pw->pw_uid == 0 &&
 			    !auth_root_allowed(auth_method))
 				authenticated = 0;
+#ifdef USE_PAM
+			/* PAM needs to perform account checks after auth */
+			if (options.use_pam) {
+				Buffer m;
+
+				buffer_init(&m);
+				mm_request_receive_expect(pmonitor->m_sendfd, 
+				    MONITOR_REQ_PAM_ACCOUNT, &m);
+				authenticated = mm_answer_pam_account(pmonitor->m_sendfd, &m);
+				buffer_free(&m);
+			}
+#endif
 		}
 
 		if (ent->flags & MON_AUTHDECIDE) {
@@ -771,9 +786,28 @@ mm_answer_pam_start(int socket, Buffer *m)
 
 	xfree(user);
 
+	monitor_permit(mon_dispatch, MONITOR_REQ_PAM_ACCOUNT, 1);
+
 	return (0);
 }
 
+int
+mm_answer_pam_account(int socket, Buffer *m)
+{
+	u_int ret;
+
+	if (!options.use_pam)
+		fatal("UsePAM not set, but ended up in %s anyway", __func__);
+
+	ret = do_pam_account();
+
+	buffer_put_int(m, ret);
+
+	mm_request_send(socket, MONITOR_ANS_PAM_ACCOUNT, m);
+
+	return (ret);
+}
+
 static void *sshpam_ctxt, *sshpam_authok;
 extern KbdintDevice sshpam_device;
 

monitor.h

@@ -51,6 +51,7 @@ enum monitor_reqtype {
 	MONITOR_REQ_RSARESPONSE, MONITOR_ANS_RSARESPONSE,
  	MONITOR_REQ_KRB5, MONITOR_ANS_KRB5,
 	MONITOR_REQ_PAM_START,
+	MONITOR_REQ_PAM_ACCOUNT, MONITOR_ANS_PAM_ACCOUNT,
 	MONITOR_REQ_PAM_INIT_CTX, MONITOR_ANS_PAM_INIT_CTX,
 	MONITOR_REQ_PAM_QUERY, MONITOR_ANS_PAM_QUERY,
 	MONITOR_REQ_PAM_RESPOND, MONITOR_ANS_PAM_RESPOND,

monitor_wrap.c

@@ -682,6 +682,30 @@ mm_start_pam(char *user)
 	buffer_free(&m);
 }
 
+u_int
+mm_do_pam_account(void)
+{
+	Buffer m;
+	u_int ret;
+
+	debug3("%s entering", __func__);
+	if (!options.use_pam)
+		fatal("UsePAM=no, but ended up in %s anyway", __func__);
+
+	buffer_init(&m);
+	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PAM_ACCOUNT, &m);
+
+	mm_request_receive_expect(pmonitor->m_recvfd, 
+	    MONITOR_ANS_PAM_ACCOUNT, &m);
+	ret = buffer_get_int(&m);
+
+	buffer_free(&m);
+
+	debug3("%s returning %d", __func__, ret);
+
+	return (ret);
+}
+
 void *
 mm_sshpam_init_ctx(Authctxt *authctxt)
 {

monitor_wrap.h

@@ -57,6 +57,7 @@ BIGNUM *mm_auth_rsa_generate_challenge(Key *);
 
 #ifdef USE_PAM
 void mm_start_pam(char *);
+u_int mm_do_pam_account(void);
 void *mm_sshpam_init_ctx(struct Authctxt *);
 int mm_sshpam_query(void *, char **, char **, u_int *, char ***, u_int **);
 int mm_sshpam_respond(void *, u_int, char **);

session.c

@@ -719,6 +719,7 @@ do_login(Session *s, const char *command)
 	if (options.use_pam && is_pam_password_change_required()) {
 		print_pam_messages();
 		do_pam_chauthtok();
+		/* XXX - signal [net] parent to enable forwardings */
 	}
 #endif