/*      $NetBSD: pwhash.c,v 1.16 2019/10/21 02:36:48 jhigh Exp $        */
/*      $OpenBSD: encrypt.c,v 1.16 2002/02/16 21:27:45 millert 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/cdefs.h>

#ifndef lint
__RCSID("$NetBSD: pwhash.c,v 1.16 2019/10/21 02:36:48 jhigh Exp $");
#endif

#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 <limits.h>
#include <login_cap.h>
#include <util.h>

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

#define DO_MAKEKEY 0
#define DO_DES     1
#define DO_MD5     2
#define DO_BLF     3
#define DO_SHA1    4

#ifdef HAVE_ARGON2
#define DO_ARGON2  5
/*
 * Argon2 variant may be specified in /etc/passwd.conf
 * If not found, default to ARGON2_DEFAULT_VARIANT_STR
 * acceptable values are: argon2i, argon2d, argon2id
 */
#define ARGON2_DEFAULT_VARIANT_STR      "argon2id"
#endif /* HAVE_ARGON2 */

__dead static void
usage(void)
{

        (void)fprintf(stderr,
#ifdef HAVE_ARGON2
            "Usage: %s [-km] [-A variant[,params]] [-b rounds] [-S rounds] [-s salt] [-p | string]\n",
#else
            "Usage: %s [-km] [-b rounds] [-S rounds] [-s salt] [-p | string]\n",
#endif /* HAVE_ARGON2 */
            getprogname());
        exit(1);
}

static char *
trim(char *line)
{
        char *ptr;

        for (ptr = &line[strlen(line) - 1]; ptr > line; ptr--) {
                if (!isspace((unsigned char)*ptr))
                        break;
        }
        ptr[1] = '\0';

        for (ptr = line; *ptr && isspace((unsigned char)*ptr); ptr++)
                continue;

        return ptr;
}

static void
print_passwd(char *string, int operation, const char *extra)
{
        char buf[_PASSWORD_LEN];
        char option[LINE_MAX], *key, *opt;
        int error = 0;
        const char *salt = buf;

        switch(operation) {
        case DO_MAKEKEY:
                /*
                 * makekey mode: parse string into separate DES key and salt.
                 */
                if (strlen(string) != 10) {
                        /* To be compatible... */
                        error = EFTYPE;
                        break;
                }
                salt = &string[8];
                break;

        case DO_MD5:
                error = pw_gensalt(buf, _PASSWORD_LEN, "md5", extra);
                break;

        case DO_SHA1:
                error = pw_gensalt(buf, _PASSWORD_LEN, "sha1", extra);
                break;

        case DO_BLF:
                error = pw_gensalt(buf, _PASSWORD_LEN, "blowfish", extra);
                break;

        case DO_DES:
                salt = extra;
                break;

#ifdef HAVE_ARGON2
        case DO_ARGON2:
                /* pwhash -A <variant>[,param]* */
                /* param
                 *    m=<m_cost>
                 *    t=<t_cost>
                 *    p=<threads>
                 */
                snprintf(option, sizeof(option), "%s", extra);
                opt = option;
                key = strsep(&opt, ",");
                error = pw_gensalt(buf, _PASSWORD_LEN, key, opt);
                break;
#endif /* HAVE_ARGON2 */

        default:
                pw_getconf(option, sizeof(option), "default", "localcipher");
                opt = option;
                key = strsep(&opt, ",");
                error = pw_gensalt(buf, _PASSWORD_LEN, key, opt);
                break;
        }

        if (error)
                err(1, "Cannot generate salt");

        (void)fputs(crypt(string, salt), stdout);
}

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

        setprogname(argv[0]);

        if (strcmp(getprogname(), "makekey") == 0)
                operation = DO_MAKEKEY;

#ifdef HAVE_ARGON2
        while ((opt = getopt(argc, argv, "kmpS:s:b:A:")) != -1) {
#else
        while ((opt = getopt(argc, argv, "kmpS:s:b:")) != -1) {
#endif /* HAVE_ARGON2 */
                switch (opt) {
                case 'k':                       /* Stdin/Stdout Unix crypt */
                        if (operation != -1 || prompt)
                                usage();
                        operation = DO_MAKEKEY;
                        break;

                case 'm':                       /* MD5 password hash */
                        if (operation != -1)
                                usage();
                        operation = DO_MD5;
                        extra = NULL;
                        break;

                case 'p':
                        if (operation == DO_MAKEKEY)
                                usage();
                        prompt = 1;
                        break;

                case 'S':                       /* SHA1 password hash */
                        if (operation != -1)
                                usage();
                        operation = DO_SHA1;
                        extra = optarg;
                        break;

                case 's':                       /* Unix crypt (DES) */
                        if (operation != -1 || optarg[0] == '$')
                                usage();
                        operation = DO_DES;
                        extra = optarg;
                        break;

                case 'b':                       /* Blowfish password hash */
                        if (operation != -1)
                                usage();
                        operation = DO_BLF;
                        extra = optarg;
                        break;

#ifdef HAVE_ARGON2
                case 'A':                       /* Argon2 password hash */
                        if (operation != -1)
                                usage();
                        operation = DO_ARGON2;
                        extra = optarg;
                        break;
#endif /* HAVE_ARGON2 */

                default:
                        usage();
                }
        }

        if (((argc - optind) < 1) || operation == DO_MAKEKEY) {
                char line[LINE_MAX], *string;

                if (prompt) {
                        string = getpass("Enter string: ");
                        print_passwd(string, operation, extra);
                        (void)fputc('\n', stdout);
                } else {
                        /* Encrypt stdin to stdout. */
                        while (!feof(stdin) &&
                            (fgets(line, sizeof(line), stdin) != NULL)) {
                                /* Kill the whitesapce. */
                                string = trim(line);
                                if (*string == '\0')
                                        continue;
                                
                                print_passwd(string, operation, extra);

                                if (operation == DO_MAKEKEY) {
                                        (void)fflush(stdout);
                                        break;
                                }
                                (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. */
                (void)memset(argv[optind], 0, strlen(argv[optind]));

                print_passwd(string, operation, extra);

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

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