/*      $OpenBSD: htpasswd.c,v 1.19 2026/02/18 15:23:36 deraadt Exp $ */
/*
 * Copyright (c) 2014 Florian Obser <florian@openbsd.org>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include <sys/stat.h>

#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <limits.h>
#include <pwd.h>
#include <readpassphrase.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

__dead void     usage(void);
void            nag(char*);

extern char *__progname;

__dead void
usage(void)
{
        fprintf(stderr, "usage:\t%s [file] login\n", __progname);
        fprintf(stderr, "\t%s -I [file]\n", __progname);
        exit(1);
}

#define MAXNAG 5
int nagcount;

int
main(int argc, char** argv)
{
        char tmpl[sizeof("/tmp/htpasswd-XXXXXXXXXX")];
        char hash[_PASSWORD_LEN], pass[1024], pass2[1024];
        char *line = NULL, *login = NULL, *tok;
        int c, fd, loginlen, batch = 0;
        FILE *in = NULL, *out = NULL;
        const char *file = NULL;
        size_t linesize = 0;
        ssize_t linelen;
        mode_t old_umask;

        while ((c = getopt(argc, argv, "I")) != -1) {
                switch (c) {
                case 'I':
                        batch = 1;
                        break;
                default:
                        usage();
                        /* NOT REACHED */
                        break;
                }
        }

        argc -= optind;
        argv += optind;

        if ((batch && argc == 1) || (!batch && argc == 2)) {
                if (unveil(argv[0], "rwc") == -1)
                        err(1, "unveil %s", argv[0]);
                if (unveil("/tmp", "rwc") == -1)
                        err(1, "unveil /tmp");
        }
        if (pledge("stdio rpath wpath cpath flock tty", NULL) == -1)
                err(1, "pledge");

        if (batch) {
                if (argc == 1)
                        file = argv[0];
                else if (argc > 1)
                        usage();
                else if (pledge("stdio", NULL) == -1)
                        err(1, "pledge");

                if ((linelen = getline(&line, &linesize, stdin)) == -1)
                        err(1, "cannot read login:password from stdin");
                line[linelen-1] = '\0';

                if ((tok = strstr(line, ":")) == NULL)
                        errx(1, "cannot find ':' in input");
                *tok++ = '\0';

                if ((loginlen = asprintf(&login, "%s:", line)) == -1)
                        err(1, "asprintf");

                if (strlcpy(pass, tok, sizeof(pass)) >= sizeof(pass))
                        errx(1, "password too long");
        } else {

                switch (argc) {
                case 1:
                        if (pledge("stdio tty", NULL) == -1)
                                err(1, "pledge");
                        if ((loginlen = asprintf(&login, "%s:", argv[0])) == -1)
                                err(1, "asprintf");
                        break;
                case 2:
                        file = argv[0];
                        if ((loginlen = asprintf(&login, "%s:", argv[1])) == -1)
                                err(1, "asprintf");
                        break;
                default:
                        usage();
                        /* NOT REACHED */
                        break;
                }

                if (!readpassphrase("Password: ", pass, sizeof(pass),
                    RPP_ECHO_OFF))
                        err(1, "unable to read password");
                if (!readpassphrase("Retype Password: ", pass2, sizeof(pass2),
                    RPP_ECHO_OFF)) {
                        explicit_bzero(pass, sizeof(pass));
                        err(1, "unable to read password");
                }
                if (strcmp(pass, pass2) != 0) {
                        explicit_bzero(pass, sizeof(pass));
                        explicit_bzero(pass2, sizeof(pass2));
                        errx(1, "passwords don't match");
                }

                explicit_bzero(pass2, sizeof(pass2));
        }

        if (crypt_newhash(pass, "bcrypt,a", hash, sizeof(hash)) != 0)
                err(1, "can't generate hash");
        explicit_bzero(pass, sizeof(pass));

        if (file == NULL)
                printf("%s%s\n", login, hash);
        else {
                if ((in = fopen(file, "r+")) == NULL) {
                        if (errno == ENOENT) {
                                old_umask = umask(S_IXUSR|
                                    S_IWGRP|S_IRGRP|S_IXGRP|
                                    S_IWOTH|S_IROTH|S_IXOTH);
                                if ((out = fopen(file, "w")) == NULL)
                                        err(1, "cannot open password file for"
                                            " reading or writing");
                                umask(old_umask);
                        } else
                                err(1, "cannot open password file for"
                                        " reading or writing");
                } else
                        if (flock(fileno(in), LOCK_EX|LOCK_NB) == -1)
                                errx(1, "cannot lock password file");

                /* file already exits, copy content and filter login out */
                if (out == NULL) {
                        strlcpy(tmpl, "/tmp/htpasswd-XXXXXXXXXX", sizeof(tmpl));
                        if ((fd = mkstemp(tmpl)) == -1)
                                err(1, "mkstemp");

                        if ((out = fdopen(fd, "w+")) == NULL)
                                err(1, "cannot open tempfile");

                        while ((linelen = getline(&line, &linesize, in))
                            != -1) {
                                if (strncmp(line, login, loginlen) != 0) {
                                        if (fprintf(out, "%s", line) == -1)
                                                errx(1, "cannot write to temp "
                                                    "file");
                                        nag(line);
                                }
                        }
                }
                if (fprintf(out, "%s%s\n", login, hash) == -1)
                        errx(1, "cannot write new password hash");

                /* file already exists, overwrite it */
                if (in != NULL) {
                        if (fseek(in, 0, SEEK_SET) == -1)
                                err(1, "cannot seek in password file");
                        if (fseek(out, 0, SEEK_SET) == -1)
                                err(1, "cannot seek in temp file");
                        if (ftruncate(fileno(in), 0) == -1)
                                err(1, "cannot truncate password file");
                        while ((linelen = getline(&line, &linesize, out))
                            != -1)
                                if (fprintf(in, "%s", line) == -1)
                                        errx(1, "cannot write to password "
                                            "file");
                        if (fclose(in) == EOF)
                                err(1, "cannot close password file");
                }
                if (fclose(out) == EOF) {
                        if (in != NULL)
                                err(1, "cannot close temp file");
                        else
                                err(1, "cannot close password file");
                }
                if (in != NULL && unlink(tmpl) == -1)
                        err(1, "cannot delete temp file (%s)", tmpl);
        }
        if (nagcount >= MAXNAG)
                warnx("%d more logins not using bcryt.", nagcount - MAXNAG);
        exit(0);
}

void
nag(char* line)
{
        const char *tok;
        if (strtok(line, ":") != NULL)
                if ((tok = strtok(NULL, ":")) != NULL)
                        if (strncmp(tok, "$2a$", 4) != 0 &&
                             strncmp(tok, "$2b$", 4) != 0) {
                                nagcount++;
                                if (nagcount <= MAXNAG)
                                        warnx("%s doesn't use bcrypt."
                                            " Update the password.", line);
                        }
}