Replace pam_wheel(8) with pam_group(8) which has a cleaner interface. The

pam_wheel(8) module was written to work in spite of a broken libpam, and
has grown organically since its inception, which is reflected in both its
functionality and implementation.  Rather than clean up pam_wheel(8) and
break backward compatibility, I've chosen to reimplement it under a new,
more generic name.

Sponsored by:	DARPA, NAI Labs

lib/libpam/modules/modules.inc

@@ -6,6 +6,7 @@ MODULES		+= pam_echo
 MODULES		+= pam_exec
 MODULES		+= pam_ftp
 MODULES		+= pam_ftpusers
+MODULES		+= pam_group
 .if defined(MAKE_KERBEROS4) && !defined(NOCRYPT) && !defined(NO_OPENSSL)
 MODULES		+= pam_kerberosIV
 .endif
@@ -31,4 +32,3 @@ MODULES		+= pam_ssh
 .endif
 MODULES		+= pam_tacplus
 MODULES		+= pam_unix
-MODULES		+= pam_wheel

lib/libpam/modules/pam_group/pam_group.c

@@ -0,0 +1,118 @@
+/*-
+ * 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.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/types.h>
+
+#include <grp.h>
+#include <pwd.h>
+#include <stdarg.h>
+#include <stdio.h>
+#include <string.h>
+#include <syslog.h>
+#include <unistd.h>
+
+#define PAM_SM_AUTH
+
+#include <security/pam_appl.h>
+#include <security/pam_modules.h>
+#include <security/openpam.h>
+
+
+PAM_EXTERN int
+pam_sm_authenticate(pam_handle_t *pamh, int flags __unused,
+    int argc __unused, const char *argv[] __unused)
+{
+	const char *group, *user, *ruser;
+	char *const *list;
+	struct passwd *pwd;
+	struct group *grp;
+
+	/* get target account */
+	if (pam_get_item(pamh, PAM_USER, (const void **)&user) != PAM_SUCCESS
+	    || user == NULL || (pwd = getpwnam(user)) == NULL)
+		return (PAM_AUTH_ERR);
+	if (pwd->pw_uid != 0 && openpam_get_option(pamh, "root_only"))
+		return (PAM_IGNORE);
+
+	/* get applicant */
+	if (pam_get_item(pamh, PAM_RUSER, (const void **)&ruser) != PAM_SUCCESS
+	    || ruser == NULL || (pwd = getpwnam(ruser)) == NULL)
+		return (PAM_AUTH_ERR);
+
+	/* get regulating group */
+	if ((group = openpam_get_option(pamh, "group")) == NULL)
+		group = "wheel";
+	if ((grp = getgrnam(group)) == NULL || grp->gr_mem == NULL)
+		goto failed;
+
+	/* check if the group is empty */
+	if (*grp->gr_mem == NULL)
+		goto failed;
+
+	/* check membership */
+	if (pwd->pw_gid == grp->gr_gid)
+		goto found;
+	for (list = grp->gr_mem; *list != NULL; ++list)
+		if (strcmp(*list, pwd->pw_name) == 0)
+			goto found;
+
+ not_found:
+	fprintf(stderr, "couldn't find %s in %s\n", ruser, group);
+	if (openpam_get_option(pamh, "deny"))
+		return (PAM_SUCCESS);
+	return (PAM_AUTH_ERR);
+ found:
+	fprintf(stderr, "found %s in %s\n", ruser, group);
+	if (openpam_get_option(pamh, "deny"))
+		return (PAM_AUTH_ERR);
+	return (PAM_SUCCESS);
+ failed:
+	if (openpam_get_option(pamh, "fail_safe"))
+		goto found;
+	else
+		goto not_found;
+}
+
+PAM_EXTERN int
+pam_sm_setcred(pam_handle_t * pamh __unused, int flags __unused,
+    int argc __unused, const char *argv[] __unused)
+{
+
+	return (PAM_SUCCESS);
+}
+
+PAM_MODULE_ENTRY("pam_group");