/* $OpenBSD: genrsa.c,v 1.23 2025/06/07 08:33:58 tb Exp $ */
/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
 * All rights reserved.
 *
 * This package is an SSL implementation written
 * by Eric Young (eay@cryptsoft.com).
 * The implementation was written so as to conform with Netscapes SSL.
 *
 * This library is free for commercial and non-commercial use as long as
 * the following conditions are aheared to.  The following conditions
 * apply to all code found in this distribution, be it the RC4, RSA,
 * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
 * included with this distribution is covered by the same copyright terms
 * except that the holder is Tim Hudson (tjh@cryptsoft.com).
 *
 * Copyright remains Eric Young's, and as such any Copyright notices in
 * the code are not to be removed.
 * If this package is used in a product, Eric Young should be given attribution
 * as the author of the parts of the library used.
 * This can be in the form of a textual message at program startup or
 * in documentation (online or textual) provided with the package.
 *
 * 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 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 cryptographic software written by
 *     Eric Young (eay@cryptsoft.com)"
 *    The word 'cryptographic' can be left out if the rouines from the library
 *    being used are not cryptographic related :-).
 * 4. If you include any Windows specific code (or a derivative thereof) from
 *    the apps directory (application code) you must include an acknowledgement:
 *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
 *
 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``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 OR 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.
 *
 * The licence and distribution terms for any publically available version or
 * derivative of this code cannot be changed.  i.e. this code cannot simply be
 * copied and put under another distribution licence
 * [including the GNU Public Licence.]
 */

#include <openssl/opensslconf.h>

/* Until the key-gen callbacks are modified to use newer prototypes, we allow
 * deprecated functions for openssl-internal code */
#ifdef OPENSSL_NO_DEPRECATED
#undef OPENSSL_NO_DEPRECATED
#endif


#include <sys/types.h>
#include <sys/stat.h>

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

#include "apps.h"

#include <openssl/bio.h>
#include <openssl/bn.h>
#include <openssl/err.h>
#include <openssl/evp.h>
#include <openssl/pem.h>
#include <openssl/rsa.h>
#include <openssl/x509.h>

#define DEFBITS 2048

static int genrsa_cb(int p, int n, BN_GENCB *cb);

static struct {
        const EVP_CIPHER *enc;
        unsigned long f4;
        char *outfile;
        char *passargout;
} cfg;

static int
set_public_exponent(int argc, char **argv, int *argsused)
{
        char *option = argv[0];

        if (strcmp(option, "-3") == 0)
                cfg.f4 = 3;
        else if (strcmp(option, "-f4") == 0 || strcmp(option, "-F4") == 0)
                cfg.f4 = RSA_F4;
        else
                return (1);

        *argsused = 1;
        return (0);
}

static const EVP_CIPHER *
get_cipher_by_name(char *name)
{
        if (name == NULL || strcmp(name, "") == 0)
                return (NULL);
#ifndef OPENSSL_NO_AES
        else if (strcmp(name, "aes128") == 0)
                return EVP_aes_128_cbc();
        else if (strcmp(name, "aes192") == 0)
                return EVP_aes_192_cbc();
        else if (strcmp(name, "aes256") == 0)
                return EVP_aes_256_cbc();
#endif
#ifndef OPENSSL_NO_CAMELLIA
        else if (strcmp(name, "camellia128") == 0)
                return EVP_camellia_128_cbc();
        else if (strcmp(name, "camellia192") == 0)
                return EVP_camellia_192_cbc();
        else if (strcmp(name, "camellia256") == 0)
                return EVP_camellia_256_cbc();
#endif
#ifndef OPENSSL_NO_DES
        else if (strcmp(name, "des") == 0)
                return EVP_des_cbc();
        else if (strcmp(name, "des3") == 0)
                return EVP_des_ede3_cbc();
#endif
#ifndef OPENSSL_NO_IDEA
        else if (strcmp(name, "idea") == 0)
                return EVP_idea_cbc();
#endif
        else
                return (NULL);
}

static int
set_enc(int argc, char **argv, int *argsused)
{
        char *name = argv[0];

        if (*name++ != '-')
                return (1);

        if ((cfg.enc = get_cipher_by_name(name)) == NULL)
                return (1);

        *argsused = 1;
        return (0);
}

static const struct option genrsa_options[] = {
        {
                .name = "3",
                .desc = "Use 3 for the E value",
                .type = OPTION_ARGV_FUNC,
                .opt.argvfunc = set_public_exponent,
        },
        {
                .name = "f4",
                .desc = "Use F4 (0x10001) for the E value",
                .type = OPTION_ARGV_FUNC,
                .opt.argvfunc = set_public_exponent,
        },
        {
                .name = "F4",
                .desc = "Use F4 (0x10001) for the E value",
                .type = OPTION_ARGV_FUNC,
                .opt.argvfunc = set_public_exponent,
        },
#ifndef OPENSSL_NO_AES
        {
                .name = "aes128",
                .desc = "Encrypt PEM output with CBC AES",
                .type = OPTION_ARGV_FUNC,
                .opt.argvfunc = set_enc,
        },
        {
                .name = "aes192",
                .desc = "Encrypt PEM output with CBC AES",
                .type = OPTION_ARGV_FUNC,
                .opt.argvfunc = set_enc,
        },
        {
                .name = "aes256",
                .desc = "Encrypt PEM output with CBC AES",
                .type = OPTION_ARGV_FUNC,
                .opt.argvfunc = set_enc,
        },
#endif
#ifndef OPENSSL_NO_CAMELLIA
        {
                .name = "camellia128",
                .desc = "Encrypt PEM output with CBC Camellia",
                .type = OPTION_ARGV_FUNC,
                .opt.argvfunc = set_enc,
        },
        {
                .name = "camellia192",
                .desc = "Encrypt PEM output with CBC Camellia",
                .type = OPTION_ARGV_FUNC,
                .opt.argvfunc = set_enc,
        },
        {
                .name = "camellia256",
                .desc = "Encrypt PEM output with CBC Camellia",
                .type = OPTION_ARGV_FUNC,
                .opt.argvfunc = set_enc,
        },
#endif
#ifndef OPENSSL_NO_DES
        {
                .name = "des",
                .desc = "Encrypt the generated key with DES in CBC mode",
                .type = OPTION_ARGV_FUNC,
                .opt.argvfunc = set_enc,
        },
        {
                .name = "des3",
                .desc = "Encrypt the generated key with DES in EDE CBC mode (168 bit key)",
                .type = OPTION_ARGV_FUNC,
                .opt.argvfunc = set_enc,
        },
#endif
#ifndef OPENSSL_NO_IDEA
        {
                .name = "idea",
                .desc = "Encrypt the generated key with IDEA in CBC mode",
                .type = OPTION_ARGV_FUNC,
                .opt.argvfunc = set_enc,
        },
#endif
        {
                .name = "out",
                .argname = "file",
                .desc = "Output the key to 'file'",
                .type = OPTION_ARG,
                .opt.arg = &cfg.outfile,
        },
        {
                .name = "passout",
                .argname = "arg",
                .desc = "Output file passphrase source",
                .type = OPTION_ARG,
                .opt.arg = &cfg.passargout,
        },
        { NULL },
};

static void
genrsa_usage(void)
{
        fprintf(stderr, "usage: genrsa [-3 | -f4] [-aes128 | -aes192 |");
        fprintf(stderr, " -aes256 |\n");
        fprintf(stderr, "    -camellia128 | -camellia192 | -camellia256 |");
        fprintf(stderr, " -des | -des3 | -idea]\n");
        fprintf(stderr, "    [-out file] [-passout arg] [numbits]\n\n");
        options_usage(genrsa_options);
        fprintf(stderr, "\n");
}

int
genrsa_main(int argc, char **argv)
{
        BN_GENCB *cb = NULL;
        int ret = 1;
        int num = DEFBITS;
        char *numbits = NULL;
        char *passout = NULL;
        BIO *out = NULL;
        BIGNUM *bn = NULL;
        RSA *rsa = NULL;
        char *rsa_e_hex = NULL, *rsa_e_dec = NULL;

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

        if ((bn = BN_new()) == NULL)
                goto err;

        if ((cb = BN_GENCB_new()) == NULL) {
                BIO_printf(bio_err, "Error allocating BN_GENCB object\n");
                goto err;
        }

        BN_GENCB_set(cb, genrsa_cb, bio_err);

        if ((out = BIO_new(BIO_s_file())) == NULL) {
                BIO_printf(bio_err, "unable to create BIO for output\n");
                goto err;
        }

        memset(&cfg, 0, sizeof(cfg));
        cfg.f4 = RSA_F4;

        if (options_parse(argc, argv, genrsa_options, &numbits, NULL) != 0) {
                genrsa_usage();
                goto err;
        }

        if ((numbits != NULL) &&
            ((sscanf(numbits, "%d", &num) == 0) || (num < 0))) {
                genrsa_usage();
                goto err;
        }

        if (!app_passwd(bio_err, NULL, cfg.passargout, NULL,
            &passout)) {
                BIO_printf(bio_err, "Error getting password\n");
                goto err;
        }

        if (cfg.outfile == NULL) {
                BIO_set_fp(out, stdout, BIO_NOCLOSE);
        } else {
                if (BIO_write_filename(out, cfg.outfile) <= 0) {
                        perror(cfg.outfile);
                        goto err;
                }
        }

        BIO_printf(bio_err, "Generating RSA private key, %d bit long modulus\n",
            num);
        rsa = RSA_new();
        if (!rsa)
                goto err;

        if (!BN_set_word(bn, cfg.f4) ||
            !RSA_generate_key_ex(rsa, num, bn, cb))
                goto err;

        if ((rsa_e_hex = BN_bn2hex(RSA_get0_e(rsa))) == NULL)
                goto err;
        if ((rsa_e_dec = BN_bn2dec(RSA_get0_e(rsa))) == NULL)
                goto err;

        BIO_printf(bio_err, "e is %s (0x%s)\n", rsa_e_dec, rsa_e_hex);
        {
                PW_CB_DATA cb_data;
                cb_data.password = passout;
                cb_data.prompt_info = cfg.outfile;
                if (!PEM_write_bio_RSAPrivateKey(out, rsa, cfg.enc,
                    NULL, 0, password_callback, &cb_data))
                        goto err;
        }

        ret = 0;
 err:
        BN_free(bn);
        BN_GENCB_free(cb);
        RSA_free(rsa);
        BIO_free_all(out);
        free(rsa_e_dec);
        free(rsa_e_hex);
        free(passout);

        if (ret != 0)
                ERR_print_errors(bio_err);

        return (ret);
}

static int
genrsa_cb(int p, int n, BN_GENCB *cb)
{
        char c = '*';

        if (p == 0)
                c = '.';
        if (p == 1)
                c = '+';
        if (p == 2)
                c = '*';
        if (p == 3)
                c = '\n';
        BIO_write(BN_GENCB_get_arg(cb), &c, 1);
        (void) BIO_flush(BN_GENCB_get_arg(cb));
        return 1;
}