Add a PAM module that provides an account management component for checking

either PAM_RHOST or PAM_TTY against /etc/login.access.o

This uncovers a problem with PAM_RHOST, in that if we always set it, there
is no way to distinguish between a user logging in locally and a user
logging in using 'ssh localhost'.  This will be fixed by first making sure
that all PAM modules can handle PAM_RHOST being unset (which is currently
not the case), and then modifying su(1) and login(1) to not set it for
local logins.

Sponsored by:	DARPA, NAI Labs

3 files changed, 285 insertions, 0 deletions

diff --git a/lib/libpam/modules/pam_login_access/Makefile b/lib/libpam/modules/pam_login_access/Makefile
new file mode 100644
index 0000000..280db96
--- /dev/null
+++ b/lib/libpam/modules/pam_login_access/Makefile
@@ -0,0 +1,35 @@
+# Copyright 2001 Mark R V Murray
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions
+# are met:
+# 1. Redistributions of source code must retain the above copyright
+#    notice, this list of conditions and the following disclaimer.
+# 2. Redistributions in binary form must reproduce the above copyright
+#    notice, this list of conditions and the following disclaimer in the
+#    documentation and/or other materials provided with the distribution.
+#
+# THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+# ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+# SUCH DAMAGE.
+#
+# $FreeBSD$
+
+LIB=		pam_login_access
+SHLIB_NAME=	pam_login_access.so
+SRCS=		pam_login_access.c login_access.c
+CFLAGS+=	-DLOGIN_ACCESS
+MAN=		pam_login_access.8
+
+.include <bsd.lib.mk>
+
+.PATH:		${.CURDIR}/../../../../usr.bin/login
diff --git a/lib/libpam/modules/pam_login_access/pam_login_access.8 b/lib/libpam/modules/pam_login_access/pam_login_access.8
new file mode 100644
index 0000000..2f96fc7
--- /dev/null
+++ b/lib/libpam/modules/pam_login_access/pam_login_access.8
@@ -0,0 +1,87 @@
+.\" Copyright (c) 2001 Mark R V Murray
+.\" All rights reserved.
+.\" Copyright (c) 2001 Networks Associates Technologies, Inc.
+.\" All rights reserved.
+.\"
+.\" Portions of this software were developed for the FreeBSD Project by
+.\" ThinkSec AS and NAI Labs, the Security Research Division of Network
+.\" Associates, Inc.  under DARPA/SPAWAR contract N66001-01-C-8035
+.\" ("CBOSS"), as part of the DARPA CHATS research program.
+.\"
+.\" Redistribution and use in source and binary forms, with or without
+.\" modification, are permitted provided that the following conditions
+.\" are met:
+.\" 1. Redistributions of source code must retain the above copyright
+.\"    notice, this list of conditions and the following disclaimer.
+.\" 2. Redistributions in binary form must reproduce the above copyright
+.\"    notice, this list of conditions and the following disclaimer in the
+.\"    documentation and/or other materials provided with the distribution.
+.\" 3. The name of the author may not be used to endorse or promote
+.\"    products derived from this software without specific prior written
+.\"    permission.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+.\" SUCH DAMAGE.
+.\"
+.\" $FreeBSD$
+.\"
+.Dd December 5, 2001
+.Dt PAM_LOGIN_ACCESS 8
+.Os
+.Sh NAME
+.Nm pam_login_access
+.Nd Self PAM module
+.Sh SYNOPSIS
+.Op Ar service-name
+.Ar module-type
+.Ar control-flag
+.Pa pam_login_access
+.Op Ar options
+.Sh DESCRIPTION
+The
+.Pa login.access
+authentication service module for PAM,
+.Nm
+provides functionality for only one PAM category:
+account management.
+In terms of the
+.Ar module-type
+parameter, this is the
+.Dq Li account
+feature.
+.Ss Login.access Account Management Module
+The
+.Pa login.access
+account management component
+.Pq Fn pam_sm_acct_mgmt ,
+returns success if and only the user is allowed to login in on the
+specified tty (in the case of a local login) or from the specified
+remote host (in the case of a remote login), according to the
+restrictions listed in
+.Pa /etc/login.access .
+.Sh SEE ALSO
+.Xr login.access 5 ,
+.Xr pam.conf 5 ,
+.Xr pam 8
+.Sh AUTHORS
+The
+.Xr login.access 5
+access control scheme was designed and implemented by
+.An Wietse Venema .
+.Pp
+The
+.Nm
+module and this manual page were developed for the FreeBSD Project by
+ThinkSec AS and NAI Labs, the Security Research Division of Network
+Associates, Inc.  under DARPA/SPAWAR contract N66001-01-C-8035
+.Pq Dq CBOSS ,
+as part of the DARPA CHATS research program.
diff --git a/lib/libpam/modules/pam_login_access/pam_login_access.c b/lib/libpam/modules/pam_login_access/pam_login_access.c
new file mode 100644
index 0000000..557184f
--- /dev/null
+++ b/lib/libpam/modules/pam_login_access/pam_login_access.c
@@ -0,0 +1,163 @@
+/*-
+ * Copyright (c) 2001 Mark R V Murray
+ * All rights reserved.
+ * Copyright (c) 2001 Networks Associates Technologies, Inc.
+ * All rights reserved.
+ *
+ * Portions of this software were developed for the FreeBSD Project by
+ * ThinkSec AS and NAI Labs, the Security Research Division of Network
+ * Associates, Inc.  under DARPA/SPAWAR contract N66001-01-C-8035
+ * ("CBOSS"), as part of the DARPA CHATS research program.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote
+ *    products derived from this software without specific prior written
+ *    permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#define _BSD_SOURCE
+
+#include <sys/param.h>
+
+#include <unistd.h>
+#include <syslog.h>
+
+#define PAM_SM_AUTH
+#define PAM_SM_ACCOUNT
+#define PAM_SM_SESSION
+#define PAM_SM_PASSWORD
+
+#include <security/pam_modules.h>
+#include <pam_mod_misc.h>
+
+extern int login_access(const char *, const char *);
+
+PAM_EXTERN int
+pam_sm_authenticate(pam_handle_t *pamh, int flags, int argc, const char **argv)
+{
+	struct options options;
+
+	pam_std_option(&options, NULL, argc, argv);
+
+	PAM_LOG("Options processed");
+
+	PAM_RETURN(PAM_IGNORE);
+}
+
+PAM_EXTERN int
+pam_sm_setcred(pam_handle_t *pamh, int flags, int argc, const char **argv)
+{
+	struct options options;
+
+	pam_std_option(&options, NULL, argc, argv);
+
+	PAM_LOG("Options processed");
+
+	PAM_RETURN(PAM_IGNORE);
+}
+
+PAM_EXTERN int
+pam_sm_acct_mgmt(pam_handle_t *pamh, int flags, int argc ,const char **argv)
+{
+	struct options options;
+	const char *rhost, *tty, *user;
+	char hostname[MAXHOSTNAMELEN];
+	int pam_err;
+
+	pam_std_option(&options, NULL, argc, argv);
+
+	PAM_LOG("Options processed");
+
+	pam_err = pam_get_item(pamh, PAM_USER, (const void **)&user);
+	if (pam_err != PAM_SUCCESS)
+		PAM_RETURN(pam_err);
+
+	if (user == NULL)
+		PAM_RETURN(PAM_SERVICE_ERR);
+
+	PAM_LOG("Got user: %s", user);
+
+	pam_err = pam_get_item(pamh, PAM_RHOST, (const void **)&rhost);
+	if (pam_err != PAM_SUCCESS)
+		PAM_RETURN(pam_err);
+
+	pam_err = pam_get_item(pamh, PAM_TTY, (const void **)&tty);
+	if (pam_err != PAM_SUCCESS)
+		PAM_RETURN(pam_err);
+
+	gethostname(hostname, sizeof hostname);
+
+	if (strcmp(hostname, rhost) == 0) {
+		PAM_LOG("Checking login.access for user %s on tty %s",
+		    user, tty);
+		if (login_access(user, tty) != 0)
+			PAM_RETURN(PAM_SUCCESS);
+	} else {
+		PAM_LOG("Checking login.access for user %s from host %s",
+		    user, rhost);
+		if (login_access(user, rhost) != 0)
+			PAM_RETURN(PAM_SUCCESS);
+	}
+	
+	PAM_RETURN(PAM_AUTH_ERR);
+}
+
+PAM_EXTERN int
+pam_sm_chauthtok(pam_handle_t *pamh, int flags, int argc, const char **argv)
+{
+	struct options options;
+
+	pam_std_option(&options, NULL, argc, argv);
+
+	PAM_LOG("Options processed");
+
+	PAM_RETURN(PAM_IGNORE);
+}
+
+PAM_EXTERN int
+pam_sm_open_session(pam_handle_t *pamh, int flags, int argc, const char **argv)
+{
+	struct options options;
+
+	pam_std_option(&options, NULL, argc, argv);
+
+	PAM_LOG("Options processed");
+
+	PAM_RETURN(PAM_IGNORE);
+}
+
+PAM_EXTERN int
+pam_sm_close_session(pam_handle_t *pamh, int flags, int argc, const char **argv)
+{
+	struct options options;
+
+	pam_std_option(&options, NULL, argc, argv);
+
+	PAM_LOG("Options processed");
+
+	PAM_RETURN(PAM_IGNORE);
+}
+
+PAM_MODULE_ENTRY("pam_self");