/* $OpenBSD: dsaparam.c,v 1.2 2014/08/28 14:23:52 jsing 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>	/* for OPENSSL_NO_DSA */

/* 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 <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>

#include "apps.h"

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

/* -inform arg	- input format - default PEM (DER or PEM)
 * -outform arg - output format - default PEM
 * -in arg	- input file - default stdin
 * -out arg	- output file - default stdout
 * -noout
 * -text
 * -C
 * -noout
 * -genkey
 *  #ifdef GENCB_TEST
 * -timebomb n  - interrupt keygen after <n> seconds
 *  #endif
 */

#ifdef GENCB_TEST

static int stop_keygen_flag = 0;

static void
timebomb_sigalarm(int foo)
{
	stop_keygen_flag = 1;
}

#endif

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

int dsaparam_main(int, char **);

int
dsaparam_main(int argc, char **argv)
{
	DSA *dsa = NULL;
	int i, badops = 0, text = 0;
	BIO *in = NULL, *out = NULL;
	int informat, outformat, noout = 0, C = 0, ret = 1;
	char *infile, *outfile, *prog;
	int numbits = -1, num, genkey = 0;
#ifndef OPENSSL_NO_ENGINE
	char *engine = NULL;
#endif
#ifdef GENCB_TEST
	const char *errstr = NULL;
	int timebomb = 0;
#endif

	infile = NULL;
	outfile = NULL;
	informat = FORMAT_PEM;
	outformat = FORMAT_PEM;

	prog = argv[0];
	argc--;
	argv++;
	while (argc >= 1) {
		if (strcmp(*argv, "-inform") == 0) {
			if (--argc < 1)
				goto bad;
			informat = str2fmt(*(++argv));
		} else if (strcmp(*argv, "-outform") == 0) {
			if (--argc < 1)
				goto bad;
			outformat = str2fmt(*(++argv));
		} else if (strcmp(*argv, "-in") == 0) {
			if (--argc < 1)
				goto bad;
			infile = *(++argv);
		} else if (strcmp(*argv, "-out") == 0) {
			if (--argc < 1)
				goto bad;
			outfile = *(++argv);
		}
#ifndef OPENSSL_NO_ENGINE
		else if (strcmp(*argv, "-engine") == 0) {
			if (--argc < 1)
				goto bad;
			engine = *(++argv);
		}
#endif
#ifdef GENCB_TEST
		else if (strcmp(*argv, "-timebomb") == 0) {
			if (--argc < 1)
				goto bad;
			timebomb = strtonum(*(++argv), 0, INT_MAX, &errstr);
			if (errstr)
				goto bad;
		}
#endif
		else if (strcmp(*argv, "-text") == 0)
			text = 1;
		else if (strcmp(*argv, "-C") == 0)
			C = 1;
		else if (strcmp(*argv, "-genkey") == 0) {
			genkey = 1;
		} else if (strcmp(*argv, "-noout") == 0)
			noout = 1;
		else if (sscanf(*argv, "%d", &num) == 1) {
			/* generate a key */
			numbits = num;
		} else {
			BIO_printf(bio_err, "unknown option %s\n", *argv);
			badops = 1;
			break;
		}
		argc--;
		argv++;
	}

	if (badops) {
bad:
		BIO_printf(bio_err, "%s [options] [bits] <infile >outfile\n", prog);
		BIO_printf(bio_err, "where options are\n");
		BIO_printf(bio_err, " -inform arg   input format - DER or PEM\n");
		BIO_printf(bio_err, " -outform arg  output format - DER or PEM\n");
		BIO_printf(bio_err, " -in arg       input file\n");
		BIO_printf(bio_err, " -out arg      output file\n");
		BIO_printf(bio_err, " -text         print as text\n");
		BIO_printf(bio_err, " -C            Output C code\n");
		BIO_printf(bio_err, " -noout        no output\n");
		BIO_printf(bio_err, " -genkey       generate a DSA key\n");
#ifndef OPENSSL_NO_ENGINE
		BIO_printf(bio_err, " -engine e     use engine e, possibly a hardware device.\n");
#endif
#ifdef GENCB_TEST
		BIO_printf(bio_err, " -timebomb n   interrupt keygen after <n> seconds\n");
#endif
		BIO_printf(bio_err, " number        number of bits to use for generating private key\n");
		goto end;
	}

	in = BIO_new(BIO_s_file());
	out = BIO_new(BIO_s_file());
	if ((in == NULL) || (out == NULL)) {
		ERR_print_errors(bio_err);
		goto end;
	}
	if (infile == NULL)
		BIO_set_fp(in, stdin, BIO_NOCLOSE);
	else {
		if (BIO_read_filename(in, infile) <= 0) {
			perror(infile);
			goto end;
		}
	}
	if (outfile == NULL) {
		BIO_set_fp(out, stdout, BIO_NOCLOSE);
	} else {
		if (BIO_write_filename(out, outfile) <= 0) {
			perror(outfile);
			goto end;
		}
	}

#ifndef OPENSSL_NO_ENGINE
	setup_engine(bio_err, engine, 0);
#endif

	if (numbits > 0) {
		BN_GENCB cb;
		BN_GENCB_set(&cb, dsa_cb, bio_err);
		dsa = DSA_new();
		if (!dsa) {
			BIO_printf(bio_err, "Error allocating DSA object\n");
			goto end;
		}
		BIO_printf(bio_err, "Generating DSA parameters, %d bit long prime\n", num);
		BIO_printf(bio_err, "This could take some time\n");
#ifdef GENCB_TEST
		if (timebomb > 0) {
			struct sigaction act;
			act.sa_handler = timebomb_sigalarm;
			act.sa_flags = 0;
			BIO_printf(bio_err, "(though I'll stop it if not done within %d secs)\n",
			    timebomb);
			if (sigaction(SIGALRM, &act, NULL) != 0) {
				BIO_printf(bio_err, "Error, couldn't set SIGALRM handler\n");
				goto end;
			}
			alarm(timebomb);
		}
#endif
		if (!DSA_generate_parameters_ex(dsa, num, NULL, 0, NULL, NULL, &cb)) {
#ifdef GENCB_TEST
			if (stop_keygen_flag) {
				BIO_printf(bio_err, "DSA key generation time-stopped\n");
				/* This is an asked-for behaviour! */
				ret = 0;
				goto end;
			}
#endif
			ERR_print_errors(bio_err);
			BIO_printf(bio_err, "Error, DSA key generation failed\n");
			goto end;
		}
	} else if (informat == FORMAT_ASN1)
		dsa = d2i_DSAparams_bio(in, NULL);
	else if (informat == FORMAT_PEM)
		dsa = PEM_read_bio_DSAparams(in, NULL, NULL, NULL);
	else {
		BIO_printf(bio_err, "bad input format specified\n");
		goto end;
	}
	if (dsa == NULL) {
		BIO_printf(bio_err, "unable to load DSA parameters\n");
		ERR_print_errors(bio_err);
		goto end;
	}
	if (text) {
		DSAparams_print(out, dsa);
	}
	if (C) {
		unsigned char *data;
		int l, len, bits_p;

		len = BN_num_bytes(dsa->p);
		bits_p = BN_num_bits(dsa->p);
		data = malloc(len + 20);
		if (data == NULL) {
			perror("malloc");
			goto end;
		}
		l = BN_bn2bin(dsa->p, data);
		printf("static unsigned char dsa%d_p[] = {", bits_p);
		for (i = 0; i < l; i++) {
			if ((i % 12) == 0)
				printf("\n\t");
			printf("0x%02X, ", data[i]);
		}
		printf("\n\t};\n");

		l = BN_bn2bin(dsa->q, data);
		printf("static unsigned char dsa%d_q[] = {", bits_p);
		for (i = 0; i < l; i++) {
			if ((i % 12) == 0)
				printf("\n\t");
			printf("0x%02X, ", data[i]);
		}
		printf("\n\t};\n");

		l = BN_bn2bin(dsa->g, data);
		printf("static unsigned char dsa%d_g[] = {", bits_p);
		for (i = 0; i < l; i++) {
			if ((i % 12) == 0)
				printf("\n\t");
			printf("0x%02X, ", data[i]);
		}
		free(data);
		printf("\n\t};\n\n");

		printf("DSA *get_dsa%d()\n\t{\n", bits_p);
		printf("\tDSA *dsa;\n\n");
		printf("\tif ((dsa = DSA_new()) == NULL) return(NULL);\n");
		printf("\tdsa->p = BN_bin2bn(dsa%d_p, sizeof(dsa%d_p), NULL);\n",
		    bits_p, bits_p);
		printf("\tdsa->q = BN_bin2bn(dsa%d_q, sizeof(dsa%d_q), NULL);\n",
		    bits_p, bits_p);
		printf("\tdsa->g = BN_bin2bn(dsa%d_g, sizeof(dsa%d_g), NULL);\n",
		    bits_p, bits_p);
		printf("\tif ((dsa->p == NULL) || (dsa->q == NULL) || (dsa->g == NULL))\n");
		printf("\t\t{ DSA_free(dsa); return(NULL); }\n");
		printf("\treturn(dsa);\n\t}\n");
	}
	if (!noout) {
		if (outformat == FORMAT_ASN1)
			i = i2d_DSAparams_bio(out, dsa);
		else if (outformat == FORMAT_PEM)
			i = PEM_write_bio_DSAparams(out, dsa);
		else {
			BIO_printf(bio_err, "bad output format specified for outfile\n");
			goto end;
		}
		if (!i) {
			BIO_printf(bio_err, "unable to write DSA parameters\n");
			ERR_print_errors(bio_err);
			goto end;
		}
	}
	if (genkey) {
		DSA *dsakey;

		if ((dsakey = DSAparams_dup(dsa)) == NULL)
			goto end;
		if (!DSA_generate_key(dsakey)) {
			ERR_print_errors(bio_err);
			DSA_free(dsakey);
			goto end;
		}
		if (outformat == FORMAT_ASN1)
			i = i2d_DSAPrivateKey_bio(out, dsakey);
		else if (outformat == FORMAT_PEM)
			i = PEM_write_bio_DSAPrivateKey(out, dsakey, NULL, NULL, 0, NULL, NULL);
		else {
			BIO_printf(bio_err, "bad output format specified for outfile\n");
			DSA_free(dsakey);
			goto end;
		}
		DSA_free(dsakey);
	}
	ret = 0;

end:
	BIO_free(in);
	if (out != NULL)
		BIO_free_all(out);
	if (dsa != NULL)
		DSA_free(dsa);

	return (ret);
}

static int
dsa_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(cb->arg, &c, 1);
	(void) BIO_flush(cb->arg);
#ifdef GENCB_TEST
	if (stop_keygen_flag)
		return 0;
#endif
	return 1;
}