/*
* Copyright 1995-2020 The OpenSSL Project Authors. All Rights Reserved.
*
* Licensed under the Apache License 2.0 (the "License"). You may not use
* this file except in compliance with the License. You can obtain a copy
* in the file LICENSE in the source distribution or at
* https://www.openssl.org/source/license.html
*/
#include <openssl/opensslconf.h>
#include <stdio.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include "apps.h"
#include "progs.h"
#include <openssl/bio.h>
#include <openssl/err.h>
#include <openssl/bn.h>
#include <openssl/rsa.h>
#include <openssl/evp.h>
#include <openssl/x509.h>
#include <openssl/pem.h>
#include <openssl/rand.h>
#define DEFBITS 2048
#define DEFPRIMES 2
static int verbose = 0;
static int genrsa_cb(EVP_PKEY_CTX *ctx);
typedef enum OPTION_choice {
OPT_ERR = -1, OPT_EOF = 0, OPT_HELP,
OPT_3, OPT_F4, OPT_ENGINE,
OPT_OUT, OPT_PASSOUT, OPT_CIPHER, OPT_PRIMES, OPT_VERBOSE,
OPT_R_ENUM, OPT_PROV_ENUM
} OPTION_CHOICE;
const OPTIONS genrsa_options[] = {
{OPT_HELP_STR, 1, '-', "Usage: %s [options] numbits\n"},
OPT_SECTION("General"),
{"help", OPT_HELP, '-', "Display this summary"},
#ifndef OPENSSL_NO_ENGINE
{"engine", OPT_ENGINE, 's', "Use engine, possibly a hardware device"},
#endif
OPT_SECTION("Input"),
{"3", OPT_3, '-', "Use 3 for the E value"},
{"F4", OPT_F4, '-', "Use F4 (0x10001) for the E value"},
{"f4", OPT_F4, '-', "Use F4 (0x10001) for the E value"},
OPT_SECTION("Output"),
{"out", OPT_OUT, '>', "Output the key to specified file"},
{"passout", OPT_PASSOUT, 's', "Output file pass phrase source"},
{"primes", OPT_PRIMES, 'p', "Specify number of primes"},
{"verbose", OPT_VERBOSE, '-', "Verbose output"},
{"", OPT_CIPHER, '-', "Encrypt the output with any supported cipher"},
OPT_R_OPTIONS,
OPT_PROV_OPTIONS,
OPT_PARAMETERS(),
{"numbits", 0, 0, "Size of key in bits"},
{NULL}
};
int genrsa_main(int argc, char **argv)
{
BN_GENCB *cb = BN_GENCB_new();
ENGINE *eng = NULL;
BIGNUM *bn = BN_new();
RSA *rsa;
BIO *out = NULL;
const BIGNUM *e;
EVP_PKEY *pkey = NULL;
EVP_PKEY_CTX *ctx = NULL;
const EVP_CIPHER *enc = NULL;
int ret = 1, num = DEFBITS, private = 0, primes = DEFPRIMES;
unsigned long f4 = RSA_F4;
char *outfile = NULL, *passoutarg = NULL, *passout = NULL;
char *prog, *hexe, *dece;
OPTION_CHOICE o;
unsigned char *ebuf = NULL;
if (bn == NULL || cb == NULL)
goto end;
prog = opt_init(argc, argv, genrsa_options);
while ((o = opt_next()) != OPT_EOF) {
switch (o) {
case OPT_EOF:
case OPT_ERR:
opthelp:
BIO_printf(bio_err, "%s: Use -help for summary.\n", prog);
goto end;
case OPT_HELP:
ret = 0;
opt_help(genrsa_options);
goto end;
case OPT_3:
f4 = RSA_3;
break;
case OPT_F4:
f4 = RSA_F4;
break;
case OPT_OUT:
outfile = opt_arg();
break;
case OPT_ENGINE:
eng = setup_engine(opt_arg(), 0);
break;
case OPT_R_CASES:
if (!opt_rand(o))
goto end;
break;
case OPT_PROV_CASES:
if (!opt_provider(o))
goto end;
break;
case OPT_PASSOUT:
passoutarg = opt_arg();
break;
case OPT_CIPHER:
if (!opt_cipher(opt_unknown(), &enc))
goto end;
break;
case OPT_PRIMES:
if (!opt_int(opt_arg(), &primes))
goto end;
break;
case OPT_VERBOSE:
verbose = 1;
break;
}
}
argc = opt_num_rest();
argv = opt_rest();
if (argc == 1) {
if (!opt_int(argv[0], &num) || num <= 0)
goto end;
if (num > OPENSSL_RSA_MAX_MODULUS_BITS)
BIO_printf(bio_err,
"Warning: It is not recommended to use more than %d bit for RSA keys.\n"
" Your key size is %d! Larger key size may behave not as expected.\n",
OPENSSL_RSA_MAX_MODULUS_BITS, num);
} else if (argc > 0) {
BIO_printf(bio_err, "Extra arguments given.\n");
goto opthelp;
}
private = 1;
if (!app_passwd(NULL, passoutarg, NULL, &passout)) {
BIO_printf(bio_err, "Error getting password\n");
goto end;
}
out = bio_open_owner(outfile, FORMAT_PEM, private);
if (out == NULL)
goto end;
if (!init_gen_str(&ctx, "RSA", eng, 0))
goto end;
EVP_PKEY_CTX_set_cb(ctx, genrsa_cb);
EVP_PKEY_CTX_set_app_data(ctx, bio_err);
if (EVP_PKEY_CTX_set_rsa_keygen_bits(ctx, num) <= 0) {
BIO_printf(bio_err, "Error setting RSA length\n");
goto end;
}
if (!BN_set_word(bn, f4)) {
BIO_printf(bio_err, "Error allocating RSA public exponent\n");
goto end;
}
if (EVP_PKEY_CTX_set_rsa_keygen_pubexp(ctx, bn) <= 0) {
BIO_printf(bio_err, "Error setting RSA public exponent\n");
goto end;
}
if (EVP_PKEY_CTX_set_rsa_keygen_primes(ctx, primes) <= 0) {
BIO_printf(bio_err, "Error setting number of primes\n");
goto end;
}
if (verbose)
BIO_printf(bio_err, "Generating RSA private key, %d bit long modulus (%d primes)\n",
num, primes);
if (!EVP_PKEY_keygen(ctx, &pkey)) {
BIO_printf(bio_err, "Error generating RSA key\n");
goto end;
}
if (verbose) {
if ((rsa = EVP_PKEY_get0_RSA(pkey)) != NULL) {
RSA_get0_key(rsa, NULL, &e, NULL);
} else {
BIO_printf(bio_err, "Error cannot access RSA e\n");
goto end;
}
hexe = BN_bn2hex(e);
dece = BN_bn2dec(e);
if (hexe && dece) {
BIO_printf(bio_err, "e is %s (0x%s)\n", dece, hexe);
}
OPENSSL_free(hexe);
OPENSSL_free(dece);
}
if (!PEM_write_bio_PrivateKey(out, pkey, enc, NULL, 0, NULL, passout))
goto end;
ret = 0;
end:
BN_free(bn);
BN_GENCB_free(cb);
EVP_PKEY_CTX_free(ctx);
EVP_PKEY_free(pkey);
BIO_free_all(out);
release_engine(eng);
OPENSSL_free(passout);
OPENSSL_free(ebuf);
if (ret != 0)
ERR_print_errors(bio_err);
return ret;
}
static int genrsa_cb(EVP_PKEY_CTX *ctx)
{
char c = '*';
BIO *b = EVP_PKEY_CTX_get_app_data(ctx);
int p = EVP_PKEY_CTX_get_keygen_info(ctx, 0);
if (!verbose)
return 1;
if (p == 0)
c = '.';
if (p == 1)
c = '+';
if (p == 2)
c = '*';
if (p == 3)
c = '\n';
BIO_write(b, &c, 1);
(void)BIO_flush(b);
return 1;
}