- (dtucker) [auth-pam.c auth-pam.h auth1.c auth2.c monitor.c monitor_wrap.c

monitor_wrap.h] Bug #808: Ensure force_pwchange is correctly initialized
   even if keyboard-interactive is not used by the client.  Prevents segfaults
   in some cases where the user's password is expired (note this is not
   considered a security exposure).  ok djm@

ChangeLog

@@ -1,6 +1,14 @@
 20040308
  - (dtucker) [sshd.c] Back out rev 1.270 as it caused problems on some
-   platforms (eg SCO, HP-UX) with logging in the wrong TZ.
+   platforms (eg SCO, HP-UX) with logging in the wrong TZ.  ok djm@
+ - (dtucker) [configure.ac sshd.c openbsd-compat/bsd-misc.h
+   openbsd-compat/setenv.c] Unset KRB5CCNAME on AIX to prevent it from being
+   inherited by the child.  ok djm@
+ - (dtucker) [auth-pam.c auth-pam.h auth1.c auth2.c monitor.c monitor_wrap.c
+   monitor_wrap.h] Bug #808: Ensure force_pwchange is correctly initialized
+   even if keyboard-interactive is not used by the client.  Prevents segfaults
+   in some cases where the user's password is expired (note this is not
+   considered a security exposure).  ok djm@
 
 20040307
  - (tim) [regress/login-timeout.sh] fix building outside of source tree.
@@ -861,4 +869,4 @@
    - (djm) Trim deprecated options from INSTALL. Mention UsePAM
    - (djm) Fix quote handling in sftp; Patch from admorten AT umich.edu
 
-$Id: ChangeLog,v 1.3278 2004/03/08 11:13:12 dtucker Exp $
+$Id: ChangeLog,v 1.3279 2004/03/08 12:04:06 dtucker 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 1.97 2004/03/04 09:03:54 dtucker Exp $");
+RCSID("$Id: auth-pam.c,v 1.98 2004/03/08 12:04:06 dtucker Exp $");
 
 #ifdef USE_PAM
 #if defined(HAVE_SECURITY_PAM_APPL_H)
@@ -160,7 +160,7 @@ static int sshpam_session_open = 0;
 static int sshpam_cred_established = 0;
 static int sshpam_account_status = -1;
 static char **sshpam_env = NULL;
-static int *force_pwchange;
+static Authctxt *the_authctxt = NULL;
 
 /* Some PAM implementations don't implement this */
 #ifndef HAVE_PAM_GETENVLIST
@@ -180,7 +180,9 @@ void
 pam_password_change_required(int reqd)
 {
 	debug3("%s %d", __func__, reqd);
-	*force_pwchange = reqd;
+	if (the_authctxt == NULL)
+		fatal("%s: PAM authctxt not initialized", __func__);
+	the_authctxt->force_pwchange = reqd;
 	if (reqd) {
 		no_port_forwarding_flag |= 2;
 		no_agent_forwarding_flag |= 2;
@@ -339,6 +341,9 @@ sshpam_thread(void *ctxtp)
 	sshpam_conv.conv = sshpam_thread_conv;
 	sshpam_conv.appdata_ptr = ctxt;
 
+	if (the_authctxt == NULL)
+		fatal("%s: PAM authctxt not initialized", __func__);
+
 	buffer_init(&buffer);
 	sshpam_err = pam_set_item(sshpam_handle, PAM_CONV,
 	    (const void *)&sshpam_conv);
@@ -351,7 +356,7 @@ sshpam_thread(void *ctxtp)
 	if (compat20) {
 		if (!do_pam_account())
 			goto auth_fail;
-		if (*force_pwchange) {
+		if (the_authctxt->force_pwchange) {
 			sshpam_err = pam_chauthtok(sshpam_handle,
 			    PAM_CHANGE_EXPIRED_AUTHTOK);
 			if (sshpam_err != PAM_SUCCESS)
@@ -365,7 +370,7 @@ sshpam_thread(void *ctxtp)
 #ifndef USE_POSIX_THREADS
 	/* Export variables set by do_pam_account */
 	buffer_put_int(&buffer, sshpam_account_status);
-	buffer_put_int(&buffer, *force_pwchange);
+	buffer_put_int(&buffer, the_authctxt->force_pwchange);
 
 	/* Export any environment strings set in child */
 	for(i = 0; environ[i] != NULL; i++)
@@ -446,11 +451,11 @@ sshpam_cleanup(void)
 }
 
 static int
-sshpam_init(const char *user)
+sshpam_init(Authctxt *authctxt)
 {
 	extern u_int utmp_len;
 	extern char *__progname;
-	const char *pam_rhost, *pam_user;
+	const char *pam_rhost, *pam_user, *user = authctxt->user;
 
 	if (sshpam_handle != NULL) {
 		/* We already have a PAM context; check if the user matches */
@@ -464,6 +469,8 @@ sshpam_init(const char *user)
 	debug("PAM: initializing for \"%s\"", user);
 	sshpam_err =
 	    pam_start(SSHD_PAM_SERVICE, user, &null_conv, &sshpam_handle);
+	the_authctxt = authctxt;
+
 	if (sshpam_err != PAM_SUCCESS) {
 		pam_end(sshpam_handle, sshpam_err);
 		sshpam_handle = NULL;
@@ -506,7 +513,7 @@ sshpam_init_ctx(Authctxt *authctxt)
 		return NULL;
 
 	/* Initialize PAM */
-	if (sshpam_init(authctxt->user) == -1) {
+	if (sshpam_init(authctxt) == -1) {
 		error("PAM: initialization failed");
 		return (NULL);
 	}
@@ -514,8 +521,6 @@ sshpam_init_ctx(Authctxt *authctxt)
 	ctxt = xmalloc(sizeof *ctxt);
 	memset(ctxt, 0, sizeof(*ctxt));
 
-	force_pwchange = &(authctxt->force_pwchange);
-
 	/* Start the authentication thread */
 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, socks) == -1) {
 		error("PAM: failed create sockets: %s", strerror(errno));
@@ -674,12 +679,12 @@ KbdintDevice mm_sshpam_device = {
  * This replaces auth-pam.c
  */
 void
-start_pam(const char *user)
+start_pam(Authctxt *authctxt)
 {
 	if (!options.use_pam)
 		fatal("PAM: initialisation requested when UsePAM=no");
 
-	if (sshpam_init(user) == -1)
+	if (sshpam_init(authctxt) == -1)
 		fatal("PAM: initialisation failed");
 }
 

auth-pam.h

@@ -1,4 +1,4 @@
-/* $Id: auth-pam.h,v 1.24 2004/02/10 02:23:29 dtucker Exp $ */
+/* $Id: auth-pam.h,v 1.25 2004/03/08 12:04:07 dtucker Exp $ */
 
 /*
  * Copyright (c) 2000 Damien Miller.  All rights reserved.
@@ -31,7 +31,7 @@
 # define SSHD_PAM_SERVICE		__progname
 #endif
 
-void start_pam(const char *);
+void start_pam(Authctxt *);
 void finish_pam(void);
 u_int do_pam_account(void);
 void do_pam_session(void);

auth1.c

@@ -307,7 +307,7 @@ do_authentication(Authctxt *authctxt)
 
 #ifdef USE_PAM
 	if (options.use_pam)
-		PRIVSEP(start_pam(user));
+		PRIVSEP(start_pam(authctxt));
 #endif
 
 	/*

auth2.c

@@ -150,24 +150,24 @@ input_userauth_request(int type, u_int32_t seq, void *ctxt)
 	if (authctxt->attempt++ == 0) {
 		/* setup auth context */
 		authctxt->pw = PRIVSEP(getpwnamallow(user));
+		authctxt->user = xstrdup(user);
 		if (authctxt->pw && strcmp(service, "ssh-connection")==0) {
 			authctxt->valid = 1;
 			debug2("input_userauth_request: setting up authctxt for %s", user);
 #ifdef USE_PAM
 			if (options.use_pam)
-				PRIVSEP(start_pam(authctxt->pw->pw_name));
+				PRIVSEP(start_pam(authctxt));
 #endif
 		} else {
 			logit("input_userauth_request: illegal user %s", user);
 			authctxt->pw = fakepw();
 #ifdef USE_PAM
 			if (options.use_pam)
-				PRIVSEP(start_pam(user));
+				PRIVSEP(start_pam(authctxt));
 #endif
 		}
 		setproctitle("%s%s", authctxt->pw ? user : "unknown",
 		    use_privsep ? " [net]" : "");
-		authctxt->user = xstrdup(user);
 		authctxt->service = xstrdup(service);
 		authctxt->style = style ? xstrdup(style) : NULL;
 		if (use_privsep)

monitor.c

@@ -782,16 +782,10 @@ mm_answer_skeyrespond(int socket, Buffer *m)
 int
 mm_answer_pam_start(int socket, Buffer *m)
 {
-	char *user;
-
 	if (!options.use_pam)
 		fatal("UsePAM not set, but ended up in %s anyway", __func__);
 
-	user = buffer_get_string(m, NULL);
+	start_pam(authctxt);
-
-	start_pam(user);
-
-	xfree(user);
 
 	monitor_permit(mon_dispatch, MONITOR_REQ_PAM_ACCOUNT, 1);
 

monitor_wrap.c

@@ -686,7 +686,7 @@ mm_session_pty_cleanup2(Session *s)
 
 #ifdef USE_PAM
 void
-mm_start_pam(char *user)
+mm_start_pam(Authctxt *authctxt)
 {
 	Buffer m;
 
@@ -695,8 +695,6 @@ mm_start_pam(char *user)
 		fatal("UsePAM=no, but ended up in %s anyway", __func__);
 
 	buffer_init(&m);
-	buffer_put_cstring(&m, user);
-
 	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PAM_START, &m);
 
 	buffer_free(&m);

monitor_wrap.h

@@ -66,7 +66,7 @@ OM_uint32 mm_ssh_gssapi_checkmic(Gssctxt *, gss_buffer_t, gss_buffer_t);
 #endif
 
 #ifdef USE_PAM
-void mm_start_pam(char *);
+void mm_start_pam(struct Authctxt *);
 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 **);