/*      $OpenBSD: login_token.c,v 1.17 2021/01/02 20:32:20 millert Exp $        */

/*-
 * Copyright (c) 1995, 1996 Berkeley Software Design, Inc. All rights reserved.
 *
 * 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. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by Berkeley Software Design,
 *      Inc.
 * 4. The name of Berkeley Software Design, Inc.  may not be used to endorse
 *    or promote products derived from this software without specific prior
 *    written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY BERKELEY SOFTWARE DESIGN, INC. ``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 BERKELEY SOFTWARE DESIGN, INC. 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.
 *
 *      BSDI $From: login_token.c,v 1.2 1996/09/04 05:33:05 prb Exp $
 */

#include <sys/types.h>
#include <sys/time.h>
#include <sys/resource.h>

#include <err.h>
#include <readpassphrase.h>
#include <signal.h>
#include <stdlib.h>
#include <stdio.h>
#include <syslog.h>
#include <limits.h>
#include <string.h>
#include <unistd.h>
#include <login_cap.h>
#include <bsd_auth.h>

#include "token.h"

int
main(int argc, char *argv[])
{
        FILE *back = NULL;
        char *username = NULL;
        char *instance;
        char challenge[1024];
        char response[1024];
        char *pp = NULL;
        int c;
        int mode = 0;
        struct rlimit cds;
        sigset_t blockset;

        (void)setpriority(PRIO_PROCESS, 0, 0);

        /* We block keyboard-generated signals during database accesses. */
        sigemptyset(&blockset);
        sigaddset(&blockset, SIGINT);
        sigaddset(&blockset, SIGQUIT);
        sigaddset(&blockset, SIGTSTP);

        openlog(NULL, LOG_ODELAY, LOG_AUTH);

        cds.rlim_cur = 0;
        cds.rlim_max = 0;
        if (setrlimit(RLIMIT_CORE, &cds) == -1)
                syslog(LOG_ERR, "couldn't set core dump size to 0: %m");

        if (pledge("stdio rpath wpath cpath fattr flock getpw tty", NULL) == -1) {
                syslog(LOG_ERR, "pledge: %m");
                exit(1);
        }

        (void)sigprocmask(SIG_BLOCK, &blockset, NULL);
        if (token_init(argv[0]) < 0) {
                syslog(LOG_ERR, "unknown token type");
                errx(1, "unknown token type");
        }
        (void)sigprocmask(SIG_UNBLOCK, &blockset, NULL);

        while ((c = getopt(argc, argv, "ds:v:")) != -1)
                switch (c) {
                case 'd':               /* to remain undocumented */
                        back = stdout;
                        break;
                case 'v':
                        break;
                case 's':       /* service */
                        if (strcmp(optarg, "login") == 0)
                                mode = 0;
                        else if (strcmp(optarg, "challenge") == 0)
                                mode = 1;
                        else if (strcmp(optarg, "response") == 0)
                                mode = 2;
                        else {
                                syslog(LOG_ERR, "%s: invalid service", optarg);
                                exit(1);
                        }
                        break;
                default:
                        syslog(LOG_ERR, "usage error");
                        exit(1);
                }

        switch (argc - optind) {
        case 2:
        case 1:
                username = argv[optind];
                break;
        default:
                syslog(LOG_ERR, "usage error");
                exit(1);
        }


        if (back == NULL && (back = fdopen(3, "r+")) == NULL)  {
                syslog(LOG_ERR, "reopening back channel");
                exit(1);
        }
        if (mode == 2) {
                mode = 0;
                c = -1;
                while (++c < sizeof(challenge) &&
                    read(3, &challenge[c], 1) == 1) {
                        if (challenge[c] == '\0' && ++mode == 2)
                                break;
                        if (challenge[c] == '\0' && mode == 1)
                                pp = challenge + c + 1;
                }
                if (mode < 2) {
                        syslog(LOG_ERR, "protocol error on back channel");
                        exit(1);
                }
        } else {
                (void)sigprocmask(SIG_BLOCK, &blockset, NULL);
                tokenchallenge(username, challenge, sizeof(challenge),
                    tt->proper);
                (void)sigprocmask(SIG_UNBLOCK, &blockset, NULL);
                if (mode == 1) {
                        char *val = auth_mkvalue(challenge);
                        if (val == NULL) {
                                (void)fprintf(back, BI_VALUE " errormsg %s\n",
                                    "unable to allocate memory");
                                (void)fprintf(back, BI_REJECT "\n");
                                exit(1);
                        }
                        fprintf(back, BI_VALUE " challenge %s\n", val);
                        fprintf(back, BI_CHALLENGE "\n");
                        exit(0);
                }

                pp = readpassphrase(challenge, response, sizeof(response), 0);
                if (pp == NULL)
                        exit(1);
                if (*pp == '\0') {
                        char buf[64];
                        snprintf(buf, sizeof(buf), "%s Response [echo on]: ",
                            tt->proper);
                        pp = readpassphrase(buf, response, sizeof(response),
                            RPP_ECHO_ON);
                        if (pp == NULL)
                                exit(1);
                }
        }

        (void)sigprocmask(SIG_BLOCK, &blockset, NULL);
        if (tokenverify(username, challenge, pp) == 0) {
                fprintf(back, BI_AUTH "\n");

                if ((instance = strchr(username, '.'))) {
                        *instance++ = 0;
                        if (strcmp(instance, "root") == 0)
                                fprintf(back, BI_ROOTOKAY "\n");
                }
                fprintf(back, BI_SECURE "\n");
                exit(0);
        }

        fprintf(back, BI_REJECT "\n");
        exit(1);
}