/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 * Copyright (c) 2016 by Delphix. All rights reserved.
 * Copyright 2023 OmniOS Community Edition (OmniOSce) Association.
 */

#include <syslog.h>
#include <pwd.h>
#include <unistd.h>
#include <strings.h>
#include <security/pam_appl.h>
#include <security/pam_modules.h>
#include <libintl.h>

static int parse_allow_name(const char *, char *);

/*
 * pam_sm_acct_mgmt     main account managment routine.
 *                      XXX: The routine just prints out a warning message.
 *                           It may need to force the user to change their
 *                           passwd.
 */

int
pam_sm_acct_mgmt(pam_handle_t *pamh, int flags, int argc, const char **argv)
{
        const char *user;
        const char *pg;
        int i;
        int debug __unused = 0;
        int nowarn __unused = 0;
        int error = 0;

        if (argc == 0)
                return (PAM_SUCCESS);

        if (pam_get_item(pamh, PAM_USER, (const void **)&user) != PAM_SUCCESS)
                return (PAM_SERVICE_ERR);

        if (pam_get_item(pamh, PAM_SERVICE, (const void **)&pg) != PAM_SUCCESS)
                return (PAM_SERVICE_ERR);

        /*
         * kludge alert. su needs to be handled specially for allow policy.
         * we want to use the policy of the current user not the "destination"
         * user. This will enable us to prevent su to root but not to rlogin,
         * telnet, rsh, ftp to root.
         *
         * description of problem: user name is the "destination" name. not
         * the current name. The allow policy needs to be applied to the
         * current name in the case of su. user is "root" in this case and
         * we will be getting the root policy instead of the user policy.
         */
        if (strcmp(pg, "su") == 0) {
                struct passwd *pw;
                uid_t uid;
                uid = getuid();
                pw = getpwuid(uid);
                if (pw == NULL)
                        return (PAM_SYSTEM_ERR);
                user = pw->pw_name;
        }

        if (user == 0 || *user == '\0' || (strcmp(user, "root") == 0))
                return (PAM_SUCCESS);

        for (i = 0; i < argc; i++) {
                if (strcasecmp(argv[i], "debug") == 0)
                        debug = 1;
                else if (strcasecmp(argv[i], "nowarn") == 0) {
                        nowarn = 1;
                        flags = flags | PAM_SILENT;
                } else if (strncmp(argv[i], "allow=", 6) == 0)
                        error |= parse_allow_name(user, (char *)(argv[i]+6));
                else
                        syslog(LOG_DEBUG, "illegal option %s", argv[i]);
        }
        return (error?PAM_SUCCESS:PAM_AUTH_ERR);
}

static char *getname();

static int
parse_allow_name(const char *who, char *cp)
{
        char name[256];

        /* catch "allow=" */
        if (*cp == '\0')
                return (0);
        while (cp) {
                cp = getname(cp, name);
                /* catch things such as =, and ,, */
                if (*name == '\0')
                        continue;
                if (strcmp(who, name) == 0)
                        return (1);
        }
        return (0);
}

static char *
getname(char *cp, char *name)
{
        /* force name to be initially null string */
        *name = '\0';

        /* end of string? */
        if (*cp == '\0')
                return ((char *)0);
        while (*cp) {
                /* end of name? */
                if (*cp == ',' || *cp == '\0')
                        break;
                *name++ = *cp++;
        }
        /* make name into string */
        *name++ = '\0';
        return ((*cp == '\0')? (char *)0 : ++cp);
}