Experimental pam_chroot module (not connected to the build)

3 files changed, 193 insertions, 0 deletions

diff --git a/lib/libpam/modules/pam_chroot/Makefile b/lib/libpam/modules/pam_chroot/Makefile
new file mode 100644
index 0000000..6d0fc0e
--- /dev/null
+++ b/lib/libpam/modules/pam_chroot/Makefile
@@ -0,0 +1,7 @@
+# $FreeBSD$
+
+LIB=		pam_chroot
+SRCS=		pam_chroot.c
+MAN=		pam_chroot.8
+
+.include <bsd.lib.mk>
diff --git a/lib/libpam/modules/pam_chroot/pam_chroot.8 b/lib/libpam/modules/pam_chroot/pam_chroot.8
new file mode 100644
index 0000000..6ba8622
--- /dev/null
+++ b/lib/libpam/modules/pam_chroot/pam_chroot.8
@@ -0,0 +1,85 @@
+.\" Copyright (c) 2003 Networks Associates Technology, 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 February 10, 2003
+.Dt PAM_CHROOT 8
+.Os
+.Sh NAME
+.Nm pam_chroot
+.Nd Chroot PAM module
+.Sh SYNOPSIS
+.Op Ar service-name
+.Ar module-type
+.Ar control-flag
+.Pa pam_chroot
+.Op Ar arguments
+.Sh DESCRIPTION
+The chroot service module for PAM chroots users into either a
+predetermined directory or one derived from their home directory.
+If a user's home directory as specified in the
+.Dv passwd
+structure returned by
+.Xr getpwnam 3
+contains the string
+.Dq /./ ,
+the portion of the directory name to the left of that string is used
+as the chroot directory.
+Otherwise, the directory specified by the
+.Cm dir
+option (see below) is used.
+.Bl -tag -width ".Cm also_root"
+.It Cm also_root
+Do not hold user id 0 exempt from the chroot requirement.
+.It Cm always
+Report a failure if a chroot directory could not be derived from the
+user's home directory, and the
+.Cm dir
+option was not specified.
+.It Cm dir Ns = Ns Ar directory
+Specify the chroot directory to use if one could not be derived from
+the user's home directory.
+.El
+.Sh SEE ALSO
+.Xr pam.conf 5 ,
+.Xr pam 8
+.Sh AUTHORS
+The
+.Nm
+module and this manual page were developed for the
+.Fx
+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_chroot/pam_chroot.c b/lib/libpam/modules/pam_chroot/pam_chroot.c
new file mode 100644
index 0000000..07539b1
--- /dev/null
+++ b/lib/libpam/modules/pam_chroot/pam_chroot.c
@@ -0,0 +1,101 @@
+/*-
+ * Copyright (c) 2003 Networks Associates Technology, Inc.
+ * All rights reserved.
+ *
+ * This software was 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("$FreeBSD$");
+
+#include <sys/param.h>
+
+#include <pwd.h>
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+
+#define PAM_SM_SESSION
+
+#include <security/pam_appl.h>
+#include <security/pam_modules.h>
+#include <security/openpam.h>
+
+PAM_EXTERN int
+pam_sm_open_session(pam_handle_t *pamh, int flags __unused,
+    int argc __unused, const char *argv[] __unused)
+{
+	const char *dir, *end, *user;
+	struct passwd *pwd;
+	char buf[PATH_MAX];
+
+	if (pam_get_user(pamh, &user, NULL) != PAM_SUCCESS ||
+	    user == NULL || (pwd = getpwnam(user)) == NULL)
+		return (PAM_SESSION_ERR);
+	if (pwd->pw_uid == 0 && !openpam_get_option(pamh, "also_root"))
+		return (PAM_SUCCESS);
+	if (pwd->pw_dir == NULL)
+		return (PAM_SESSION_ERR);
+	if ((end = strstr(pwd->pw_dir, "/./")) != NULL) {
+		if (snprintf(buf, sizeof(buf), "%.*s",
+		    (int)(end - pwd->pw_dir), pwd->pw_dir) > (int)sizeof(buf)) {
+			openpam_log(PAM_LOG_ERROR,
+			    "%s's home directory is too long", user);
+			return (PAM_SESSION_ERR);
+		}
+		dir = buf;
+	} else if ((dir = openpam_get_option(pamh, "dir")) == NULL) {
+		if (openpam_get_option(pamh, "always")) {
+			openpam_log(PAM_LOG_ERROR,
+			    "%s has no chroot directory", user);
+			return (PAM_SESSION_ERR);
+		}
+		return (PAM_SUCCESS);
+	}
+
+	openpam_log(PAM_LOG_DEBUG, "chrooting %s to %s", dir, user);
+
+	if (chroot(dir) == -1) {
+		openpam_log(PAM_LOG_ERROR, "chroot(): %m");
+		return (PAM_SESSION_ERR);
+	}
+	chdir("/");
+	return (PAM_SUCCESS);
+}
+
+PAM_EXTERN int
+pam_sm_close_session(pam_handle_t *pamh __unused, int flags __unused,
+    int argc __unused, const char *argv[] __unused)
+{
+
+	return (PAM_SUCCESS);
+}
+
+PAM_MODULE_ENTRY("pam_chroot");