/* $OpenBSD: rand.c,v 1.18 2023/07/23 11:39:29 tb Exp $ */
/* ====================================================================
 * Copyright (c) 1998-2001 The OpenSSL Project.  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 acknowledgment:
 *    "This product includes software developed by the OpenSSL Project
 *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
 *
 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
 *    endorse or promote products derived from this software without
 *    prior written permission. For written permission, please contact
 *    openssl-core@openssl.org.
 *
 * 5. Products derived from this software may not be called "OpenSSL"
 *    nor may "OpenSSL" appear in their names without prior written
 *    permission of the OpenSSL Project.
 *
 * 6. Redistributions of any form whatsoever must retain the following
 *    acknowledgment:
 *    "This product includes software developed by the OpenSSL Project
 *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
 *
 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
 * EXPRESSED 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 OpenSSL PROJECT OR
 * ITS CONTRIBUTORS 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.
 * ====================================================================
 *
 * This product includes cryptographic software written by Eric Young
 * (eay@cryptsoft.com).  This product includes software written by Tim
 * Hudson (tjh@cryptsoft.com).
 *
 */

#include <ctype.h>
#include <stdio.h>
#include <string.h>

#include "apps.h"

#include <openssl/bio.h>
#include <openssl/err.h>

static struct {
        int base64;
        int hex;
        char *outfile;
} cfg;

static const struct option rand_options[] = {
        {
                .name = "base64",
                .desc = "Perform base64 encoding on output",
                .type = OPTION_FLAG,
                .opt.flag = &cfg.base64,
        },
        {
                .name = "hex",
                .desc = "Hexadecimal output",
                .type = OPTION_FLAG,
                .opt.flag = &cfg.hex,
        },
        {
                .name = "out",
                .argname = "file",
                .desc = "Write to the given file instead of standard output",
                .type = OPTION_ARG,
                .opt.arg = &cfg.outfile,
        },
        {NULL},
};

static void
rand_usage(void)
{
        fprintf(stderr,
            "usage: rand [-base64 | -hex] [-out file] num\n");
        options_usage(rand_options);
}

int
rand_main(int argc, char **argv)
{
        char *num_bytes = NULL;
        int ret = 1;
        int badopt = 0;
        int num = -1;
        int i, r;
        BIO *out = NULL;

        if (pledge("stdio cpath wpath rpath", NULL) == -1) {
                perror("pledge");
                exit(1);
        }

        memset(&cfg, 0, sizeof(cfg));

        if (options_parse(argc, argv, rand_options, &num_bytes, NULL) != 0) {
                rand_usage();
                return (1);
        }

        if (num_bytes != NULL) {
                r = sscanf(num_bytes, "%d", &num);
                if (r == 0 || num < 0)
                        badopt = 1;
        } else
                badopt = 1;

        if (cfg.hex && cfg.base64)
                badopt = 1;

        if (badopt) {
                rand_usage();
                goto err;
        }

        out = BIO_new(BIO_s_file());
        if (out == NULL)
                goto err;
        if (cfg.outfile != NULL)
                r = BIO_write_filename(out, cfg.outfile);
        else
                r = BIO_set_fp(out, stdout, BIO_NOCLOSE | BIO_FP_TEXT);
        if (r <= 0)
                goto err;
        if (cfg.base64) {
                BIO *b64 = BIO_new(BIO_f_base64());
                if (b64 == NULL)
                        goto err;
                out = BIO_push(b64, out);
        }

        while (num > 0) {
                unsigned char buf[4096];
                int chunk;

                chunk = num;
                if (chunk > (int) sizeof(buf))
                        chunk = sizeof(buf);
                arc4random_buf(buf, chunk);
                if (cfg.hex) {
                        for (i = 0; i < chunk; i++)
                                BIO_printf(out, "%02x", buf[i]);
                } else
                        BIO_write(out, buf, chunk);
                num -= chunk;
        }

        if (cfg.hex)
                BIO_puts(out, "\n");
        (void) BIO_flush(out);

        ret = 0;

 err:
        ERR_print_errors(bio_err);
        BIO_free_all(out);

        return (ret);
}