Add pam_ftpusers(8), which enforces /etc/ftpusers.

Sponsored by:	DARPA, NAI Labs

lib/libpam/modules/modules.inc

@@ -3,6 +3,7 @@
 MODULES		 =
 MODULES		+= pam_deny
 MODULES		+= pam_ftp
+MODULES		+= pam_ftpusers
 .if defined(MAKE_KERBEROS4) && !defined(NOCRYPT) && !defined(NO_OPENSSL)
 MODULES		+= pam_kerberosIV
 .endif

lib/libpam/modules/pam_ftpusers/Makefile

@@ -0,0 +1,7 @@
+# $FreeBSD$
+
+LIB=		pam_ftpusers
+SRCS=		pam_ftpusers.c
+MAN=		pam_ftpusers.8
+
+.include <bsd.lib.mk>

lib/libpam/modules/pam_ftpusers/pam_ftpusers.8

@@ -0,0 +1,99 @@
+.\" Copyright (c) 2001 Mark R V Murray
+.\" All rights reserved.
+.\" Copyright (c) 2002 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 April 17, 2002
+.Dt PAM_FTPUSERS 8
+.Os
+.Sh NAME
+.Nm pam_ftpusers
+.Nd ftpusers PAM module
+.Sh SYNOPSIS
+.Op Ar service-name
+.Ar module-type
+.Ar control-flag
+.Pa pam_ftpusers
+.Op Ar options
+.Sh DESCRIPTION
+The
+.Pa ftpusers
+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 Ftpusers Account Management Module
+The
+.Pa ftpusers
+account management component
+.Pq Fn pam_sm_acct_mgmt ,
+succeeds if and only if the user is listed in
+.Pa /etc/ftpusers .
+.Pp
+The following options may be passed to the authentication module:
+.Bl -tag -width ".Cm disallow"
+.It Cm debug
+.Xr syslog 3
+debugging information at
+.Dv LOG_DEBUG
+level.
+.It Cm no_warn
+suppress warning messages to the user.
+These messages include reasons why the user's authentication attempt
+was declined.
+.It Cm disallow
+reverse the semantics;
+.Nm
+will succeed if and only if the user is not listed in
+.Pa /etc/ftpusers .
+.El
+.Sh SEE ALSO
+.Xr ftpusers 5 ,
+.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.

lib/libpam/modules/pam_ftpusers/pam_ftpusers.c

@@ -0,0 +1,115 @@
+/*-
+ * Copyright (c) 2001 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 <ctype.h>
+#include <grp.h>
+#include <paths.h>
+#include <pwd.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#define PAM_SM_ACCOUNT
+
+#include <security/pam_appl.h>
+#include <security/pam_modules.h>
+#include <security/pam_mod_misc.h>
+#include <security/openpam.h>
+
+PAM_EXTERN int
+pam_sm_acct_mgmt(pam_handle_t *pamh, int flags __unused,
+    int argc __unused, const char *argv[] __unused)
+{
+	struct passwd *pwd;
+	struct group *grp;
+	const char *user;
+	int pam_err, found, allow;
+	char *line, *name, **mem;
+	size_t len, ulen;
+	FILE *f;
+
+	pam_err = pam_get_user(pamh, &user, NULL);
+	if (pam_err != PAM_SUCCESS)
+		return (pam_err);
+	if (user == NULL || (pwd = getpwnam(user)) == NULL)
+		return (PAM_SERVICE_ERR);
+
+	found = 0;
+	ulen = strlen(user);
+	if ((f = fopen(_PATH_FTPUSERS, "r")) == NULL) {
+		PAM_LOG("%s: %m", _PATH_FTPUSERS);
+		goto done;
+	}
+	while (!found && (line = fgetln(f, &len)) != NULL) {
+		if (*line == '#')
+			continue;
+		while (len > 0 && isspace(line[len - 1]))
+			--len;
+		if (len == 0)
+			continue;
+		/* simple case first */
+		if (*line != '@') {
+			if (len == ulen && strncmp(user, line, len) == 0)
+				found = 1;
+			continue;
+		}
+		/* member of specified group? */
+		asprintf(&name, "%.*s", (int)len - 1, line + 1);
+		if (name == NULL) {
+			fclose(f);
+			return (PAM_BUF_ERR);
+		}
+		grp = getgrnam(name);
+		free(name);
+		if (grp == NULL)
+			continue;
+		for (mem = grp->gr_mem; mem && *mem && !found; ++mem)
+			if (strcmp(user, *mem) == 0)
+				found = 1;
+	}
+ done:
+	allow = (openpam_get_option(pamh, "disallow") == NULL);
+	if (found)
+		pam_err = allow ? PAM_SUCCESS : PAM_AUTH_ERR;
+	else
+		pam_err = allow ? PAM_AUTH_ERR : PAM_SUCCESS;
+	if (f != NULL)
+		fclose(f);
+	return (pam_err);
+}
+
+PAM_MODULE_ENTRY("pam_ftpusers");