/*
 * 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 2008 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 *
 * Copyright 2023 OmniOS Community Edition (OmniOSce) Association.
 */

#include <sys/types.h>
#include <sys/varargs.h>
#include <string.h>
#include <syslog.h>
#include <stdlib.h>
#include <unistd.h>
#include <pwd.h>
#include <nss_dbdefs.h>

#include <security/pam_appl.h>
#include <security/pam_modules.h>
#include <security/pam_impl.h>

#include <libintl.h>
#include <passwdutil.h>

#include <errno.h>
#include <netsmb/smb_keychain.h>

/*ARGSUSED*/
int
pam_sm_authenticate(pam_handle_t *pamh, int flags, int argc, const char **argv)
{
        return (PAM_IGNORE);
}

int
pam_sm_setcred(pam_handle_t *pamh, int flags, int argc, const char **argv)
{
        boolean_t debug = B_FALSE;
        char dom[20];
        const char *user;
        const char *pw;
        const char *service;
        struct passwd pwbuf;
        char buf[NSS_BUFLEN_PASSWD];
        char *home;
        uid_t uid;
        int res = PAM_SUCCESS;
        int i, mask;

        for (i = 0; i < argc; i++) {
                if (strcmp(argv[i], "debug") == 0)
                        debug = B_TRUE;
        }

        /* Since our creds don't time out, ignore a refresh. */
        if ((flags & PAM_REFRESH_CRED) != 0)
                return (PAM_IGNORE);

        /* Check for unknown options */
        mask = PAM_ESTABLISH_CRED | PAM_REINITIALIZE_CRED | PAM_DELETE_CRED;
        if ((flags & ~mask) != 0)
                return (PAM_IGNORE);

        (void) pam_get_item(pamh, PAM_SERVICE, (const void **)&service);
        (void) pam_get_item(pamh, PAM_USER, (const void **)&user);

        if (user == NULL || *user == '\0') {
                __pam_log(LOG_AUTH | LOG_ERR,
                    "pam_smbfs_login: username is empty");
                return (PAM_IGNORE);
        }
        if (getpwnam_r(user, &pwbuf, buf, sizeof (buf)) == NULL) {
                __pam_log(LOG_AUTH | LOG_ERR,
                    "pam_smbfs_login: username %s can't be found", user);
                return (PAM_IGNORE);
        }
        uid = pwbuf.pw_uid;
        home = pwbuf.pw_dir;

        (void) pam_get_item(pamh, PAM_AUTHTOK, (const void **)&pw);
        if (pw == NULL) {
                /*
                 * A module on the stack has removed PAM_AUTHTOK.
                 */
                return (PAM_IGNORE);
        }

        res = smbfs_default_dom_usr(home, NULL, dom, sizeof (dom), NULL, 0);
        if (res != 0)
                (void) strcpy(dom, "WORKGROUP");

        if (debug)
                __pam_log(LOG_AUTH | LOG_DEBUG,
                    "pam_smbfs_login: service %s, dom %s, user %s",
                    service, dom, user);

        if ((flags & (PAM_ESTABLISH_CRED | PAM_REINITIALIZE_CRED)) != 0)
                res = smbfs_keychain_add(uid, dom, user, pw);

        if ((flags & PAM_DELETE_CRED) != 0)
                res = smbfs_keychain_del(uid, dom, user);

        /*
         * map errors to user messages and PAM return codes.
         */
        switch (res) {
        case SMB_KEYCHAIN_SUCCESS:
                if (debug)
                        __pam_log(LOG_AUTH | LOG_DEBUG,
                            "smbfs password successfully stored for %s", user);
                break;

        case SMB_KEYCHAIN_BADPASSWD:
                __pam_log(LOG_AUTH | LOG_ERR, "smbfs password is invalid");
                break;

        case SMB_KEYCHAIN_BADDOMAIN:
                __pam_log(LOG_AUTH | LOG_ERR,
                    "%s: smbfs domain %s is invalid", service, dom);
                break;

        case SMB_KEYCHAIN_BADUSER:
                __pam_log(LOG_AUTH | LOG_ERR, "smbfs user %s is invalid", user);
                break;

        case SMB_KEYCHAIN_NODRIVER:
                __pam_log(LOG_AUTH | LOG_ERR,
                    "driver open failed (%s), smbfs password not stored",
                    strerror(errno));
                break;

        case SMB_KEYCHAIN_UNKNOWN:
                __pam_log(LOG_AUTH | LOG_ERR,
                    "Unexpected failure, smbfs password not stored");
                break;

        default:
                __pam_log(LOG_AUTH | LOG_ERR,
                    "driver ioctl failed (%s), smbfs password not stored",
                    strerror(errno));
                break;
        }

        return (PAM_IGNORE);
}