From 07705c788e9bcd8d35dfbb59d2b12c61b8601c9a Mon Sep 17 00:00:00 2001
From: Darren Tucker <dtucker@zip.com.au>
Date: Thu, 18 Dec 2003 15:34:31 +1100
Subject: [PATCH]  - (dtucker) [auth-pam.c] Do PAM chauthtok during SSH2
 keyboard-interactive    authentication.  Partially fixes bug #423.  Feedback
 & ok djm@

Some background on why this is the way it is:
* Solaris 8's pam_chauthtok ignores the CHANGE_EXPIRED_AUTHTOK flag, so
  we must call do_pam_account() to figure out if the password is expired.
* AIX 5.2 does not like having pam_acct_mgmt() called twice, once from the
  authentication thread and once from the main shell child, so we cache the
  result, which must be passed from the authentication thread back to the
  monitor.
---
 ChangeLog  |  4 +++-
 auth-pam.c | 64 +++++++++++++++++++++++++++++++++++++++++++-----------
 2 files changed, 54 insertions(+), 14 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 40d0a21db..5727be82b 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,7 @@
 20031218
  - (dtucker) [configure.ac] Don't use setre[ug]id on DG-UX, from Tom Orban.
+ - (dtucker) [auth-pam.c] Do PAM chauthtok during SSH2 keyboard-interactive
+   authentication.  Partially fixes bug #423.  Feedback & ok djm@
 
 20031217
  - (djm) OpenBSD CVS Sync
@@ -1610,4 +1612,4 @@
  - Fix sshd BindAddress and -b options for systems using fake-getaddrinfo.
    Report from murple@murple.net, diagnosis from dtucker@zip.com.au
 
-$Id: ChangeLog,v 1.3150 2003/12/18 01:52:19 dtucker Exp $
+$Id: ChangeLog,v 1.3151 2003/12/18 04:34:31 dtucker Exp $
diff --git a/auth-pam.c b/auth-pam.c
index 621940ab9..2fe1e3382 100644
--- a/auth-pam.c
+++ b/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 1.84 2003/11/21 12:56:47 djm Exp $");
+RCSID("$Id: auth-pam.c,v 1.85 2003/12/18 04:34:32 dtucker Exp $");
 
 #ifdef USE_PAM
 #include <security/pam_appl.h>
@@ -53,6 +53,7 @@ RCSID("$Id: auth-pam.c,v 1.84 2003/11/21 12:56:47 djm Exp $");
 
 extern ServerOptions options;
 extern Buffer loginmsg;
+extern int compat20;
 
 #define __unused
 
@@ -118,6 +119,7 @@ static int sshpam_authenticated = 0;
 static int sshpam_new_authtok_reqd = 0;
 static int sshpam_session_open = 0;
 static int sshpam_cred_established = 0;
+static int sshpam_account_status = -1;
 static char **sshpam_env = NULL;
 
 struct pam_ctxt {
@@ -144,6 +146,21 @@ pam_getenvlist(pam_handle_t *pamh)
 }
 #endif
 
+void
+pam_password_change_required(int reqd)
+{
+	sshpam_new_authtok_reqd = reqd;
+	if (reqd) {
+		no_port_forwarding_flag |= 2;
+		no_agent_forwarding_flag |= 2;
+		no_x11_forwarding_flag |= 2;
+	} else {
+		no_port_forwarding_flag &= ~2;
+		no_agent_forwarding_flag &= ~2;
+		no_x11_forwarding_flag &= ~2;
+
+	}
+}
 /* Import regular and PAM environment from subprocess */
 static void
 import_environments(Buffer *b)
@@ -152,6 +169,10 @@ import_environments(Buffer *b)
 	u_int i, num_env;
 	int err;
 
+	/* Import variables set by do_pam_account */
+	sshpam_account_status = buffer_get_int(b);
+	pam_password_change_required(buffer_get_int(b));
+
 	/* Import environment from subprocess */
 	num_env = buffer_get_int(b);
 	sshpam_env = xmalloc((num_env + 1) * sizeof(*sshpam_env));
@@ -290,9 +311,26 @@ sshpam_thread(void *ctxtp)
 	sshpam_err = pam_authenticate(sshpam_handle, 0);
 	if (sshpam_err != PAM_SUCCESS)
 		goto auth_fail;
+
+	/* if (compat20) { */
+		if (!do_pam_account())
+			goto auth_fail;
+		if (sshpam_new_authtok_reqd) {
+			sshpam_err = pam_chauthtok(sshpam_handle,
+			    PAM_CHANGE_EXPIRED_AUTHTOK);
+			if (sshpam_err != PAM_SUCCESS)
+				goto auth_fail;
+			pam_password_change_required(0);
+		}
+	/* } */
+
 	buffer_put_cstring(&buffer, "OK");
 
 #ifndef USE_POSIX_THREADS
+	/* Export variables set by do_pam_account */
+	buffer_put_int(&buffer, sshpam_account_status);
+	buffer_put_int(&buffer, sshpam_new_authtok_reqd);
+
 	/* Export any environment strings set in child */
 	for(i = 0; environ[i] != NULL; i++)
 		; /* Count */
@@ -611,22 +649,22 @@ finish_pam(void)
 u_int
 do_pam_account(void)
 {
+	if (sshpam_account_status != -1)
+		return (sshpam_account_status);
+
 	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;
+	
+	if (sshpam_err != PAM_SUCCESS && sshpam_err != PAM_NEW_AUTHTOK_REQD) {
+		sshpam_account_status = 0;
+		return (sshpam_account_status);
 	}
 
-	return (1);
+	if (sshpam_err == PAM_NEW_AUTHTOK_REQD)
+		pam_password_change_required(1);
+
+	sshpam_account_status = 1;
+	return (sshpam_account_status);
 }
 
 void