/*      $OpenBSD: encrypt.c,v 1.52 2022/02/10 13:06:46 robert Exp $     */

/*
 * Copyright (c) 1996, Jason Downs.  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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``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(S) 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/types.h>
#include <ctype.h>
#include <err.h>
#include <errno.h>
#include <pwd.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <login_cap.h>
#include <limits.h>
#include <readpassphrase.h>

/*
 * Very simple little program, for encrypting passwords from the command
 * line.  Useful for scripts and such.
 */

extern char *__progname;

static void __dead      usage(void);
static void             print_passwd(char *, int, char *);

#define DO_BLF          0

static void __dead
usage(void)
{

        (void)fprintf(stderr,
            "usage: %s [-b rounds] [-c class] [-p | string]\n",
            __progname);
        exit(1);
}

static void
print_passwd(char *string, int operation, char *extra)
{
        char buffer[_PASSWORD_LEN];
        const char *pref;
        char prefbuf[64];

        if (operation == DO_BLF) {
                if (snprintf(prefbuf, sizeof(prefbuf), "blowfish,%s", extra) >=
                    sizeof(prefbuf))
                        errx(1, "pref too long");
                pref = prefbuf;
        } else {
                login_cap_t *lc;

                if ((lc = login_getclass(extra)) == NULL)
                        errx(1, "unable to get login class `%s'",
                            extra ? (char *)extra : "default");
                pref = login_getcapstr(lc, "localcipher", NULL, NULL);
        }
        if (crypt_newhash(string, pref, buffer, sizeof(buffer)) != 0)
                err(1, "can't generate hash");

        fputs(buffer, stdout);
}

int
main(int argc, char **argv)
{
        int opt;
        int operation = -1;
        int prompt = 0;
        char *extra = NULL;     /* Store login class or number of rounds */
        const char *errstr;

        if (unveil(_PATH_LOGIN_CONF, "r") == -1)
                err(1, "unveil %s", _PATH_LOGIN_CONF);
        if (unveil(_PATH_LOGIN_CONF ".db", "r") == -1)
                err(1, "unveil %s.db", _PATH_LOGIN_CONF);
        if (unveil(_PATH_LOGIN_CONF_D, "r") == -1)
                err(1, "unveil %s", _PATH_LOGIN_CONF_D);
        if (pledge("stdio rpath tty", NULL) == -1)
                err(1, "pledge");

        while ((opt = getopt(argc, argv, "pb:c:")) != -1) {
                switch (opt) {
                case 'p':
                        prompt = 1;
                        break;
                case 'b':                       /* Blowfish password hash */
                        if (operation != -1)
                                usage();
                        operation = DO_BLF;
                        if (strcmp(optarg, "a") != 0) {
                                (void)strtonum(optarg, 4, 31, &errstr);
                                if (errstr != NULL)
                                        errx(1, "rounds is %s: %s", errstr,
                                            optarg);
                        }
                        extra = optarg;
                        break;
                case 'c':                       /* user login class */
                        extra = optarg;
                        operation = -1;
                        break;
                default:
                        usage();
                }
        }

        if (((argc - optind) < 1)) {
                char line[BUFSIZ];
                char string[1024];

                if (prompt) {
                        if (readpassphrase("Enter string: ", string,
                            sizeof(string), RPP_ECHO_OFF) == NULL)
                                err(1, "readpassphrase");
                        print_passwd(string, operation, extra);
                        (void)fputc('\n', stdout);
                        explicit_bzero(string, sizeof(string));
                } else {
                        size_t len;
                        /* Encrypt stdin to stdout. */
                        while (!feof(stdin) &&
                            (fgets(line, sizeof(line), stdin) != NULL)) {
                                len = strlen(line);
                                if (len == 0 || line[0] == '\n')
                                        continue;
                                if (line[len - 1] == '\n')
                                        line[len - 1] = '\0';

                                print_passwd(line, operation, extra);

                                (void)fputc('\n', stdout);
                        }
                }
        } else {
                char *string;

                /* can't combine -p with a supplied string */
                if (prompt)
                        usage();

                /* Perhaps it isn't worth worrying about, but... */
                if ((string = strdup(argv[optind])) == NULL)
                        err(1, NULL);
                /* Wipe the argument. */
                explicit_bzero(argv[optind], strlen(argv[optind]));

                print_passwd(string, operation, extra);

                (void)fputc('\n', stdout);

                /* Wipe our copy, before we free it. */
                freezero(string, strlen(string));
        }
        return 0;
}