/*
 * Copyright (c) 2006 Kungliga Tekniska Högskolan
 * (Royal Institute of Technology, Stockholm, Sweden). 
 * 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. Neither the name of the Institute nor the names of its contributors 
 *    may be used to endorse or promote products derived from this software 
 *    without specific prior written permission. 
 *
 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``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 INSTITUTE 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. 
 */

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#ifdef RCSID
RCSID("$Id$");
#endif

#include <stdio.h>

#include <roken.h>
#include <getarg.h>

#include <engine.h>
#include <evp.h>

static void
check_rsa(const unsigned char *in, size_t len, RSA *rsa, int padding)
{
    unsigned char *res, *res2;
    int keylen;

    res = malloc(RSA_size(rsa));
    if (res == NULL)
	errx(1, "res: ENOMEM");

    res2 = malloc(RSA_size(rsa));
    if (res2 == NULL)
	errx(1, "res2: ENOMEM");

    /* signing */

    keylen = RSA_private_encrypt(len, in, res, rsa, padding);
    if (keylen <= 0)
	errx(1, "failed to private encrypt: %d", (int)len, (int)keylen);
    
    if (keylen > RSA_size(rsa))
	errx(1, "keylen > RSA_size(rsa)");
    
    keylen = RSA_public_decrypt(keylen, res, res2, rsa, padding);
    if (keylen <= 0)
	errx(1, "failed to public decrypt: %d", (int)keylen);
    
    if (keylen != len)
	errx(1, "output buffer not same length: %d", (int)keylen);
    
    if (memcmp(res2, in, len) != 0)
	errx(1, "string not the same after decryption");

    /* encryption */

    keylen = RSA_public_encrypt(len, in, res, rsa, padding);
    if (keylen <= 0)
	errx(1, "failed to public encrypt: %d", (int)keylen);
    
    if (keylen > RSA_size(rsa))
	errx(1, "keylen > RSA_size(rsa)");
    
    keylen = RSA_private_decrypt(keylen, res, res2, rsa, padding);
    if (keylen <= 0)
	errx(1, "failed to private decrypt: %d", (int)keylen);

    if (keylen != len)
	errx(1, "output buffer not same length: %d", (int)keylen);
    
    if (memcmp(res2, in, len) != 0)
	errx(1, "string not the same after decryption");

    free(res);
    free(res2);
}

/*
 *
 */

static int version_flag;
static int help_flag;
static char *rsa_key;
static char *id_flag;

static struct getargs args[] = {
    { "id",		0,	arg_string,	&id_flag,
      "selects the engine id", 	"engine-id" },
    { "key",	0,	arg_string,	&rsa_key,
      "rsa key file", NULL },
    { "version",	0,	arg_flag,	&version_flag,
      "print version", NULL },
    { "help",		0,	arg_flag,	&help_flag,
      NULL, 	NULL }
};

static void
usage (int ret)
{
    arg_printusage (args,
		    sizeof(args)/sizeof(*args),
		    NULL,
		    "filename.so");
    exit (ret);
}

int
main(int argc, char **argv)
{
    ENGINE *engine = NULL;
    int i, idx = 0;
    RSA *rsa;

    setprogname(argv[0]);

    if(getarg(args, sizeof(args) / sizeof(args[0]), argc, argv, &idx))
	usage(1);
    
    if (help_flag)
	usage(0);

    if(version_flag){
	print_version(NULL);
	exit(0);
    }

    argc -= idx;
    argv += idx;

    OpenSSL_add_all_algorithms();

    if (argc == 0) {
	OpenSSL_add_all_algorithms();
	ENGINE_load_builtin_engines();
	engine = ENGINE_by_id("builtin");
    } else {
	engine = ENGINE_by_dso(argv[0], id_flag);
    }
    if (engine == NULL)
	errx(1, "ENGINE_by_dso failed");

    if (ENGINE_get_RSA(engine) == NULL)
	return 77;
    
    printf("rsa %s\n", ENGINE_get_RSA(engine)->name);

    if (rsa_key == NULL)
	errx(1, "missing rsa key flag!");

    {
	unsigned char buf[1024 * 4];
	const unsigned char *p;
	size_t size;
	FILE *f;
	
	f = fopen(rsa_key, "r");
	if (f == NULL)
	    err(1, "could not open file %s", rsa_key);
	
	size = fread(buf, 1, sizeof(buf), f);
	if (size == 0)
	    err(1, "failed to read file %s", rsa_key);
	if (size == sizeof(buf))
	    err(1, "key too long in file %s!", rsa_key);
	fclose(f);
	
	p = buf;
	rsa = d2i_RSAPrivateKey(NULL, &p, size);
	if (rsa == NULL)
	    err(1, "failed to parse key in file %s", rsa_key);
	
	RSA_set_method(rsa, ENGINE_get_RSA(engine));
    }


    /*
     * Assuming that you use the RSA key in the distribution, this
     * test will generate a signature have a starting zero and thus
     * will generate a checksum that is 127 byte instead of the
     * checksum that is 128 byte (like the key).
     */
    {
	const unsigned char sha1[20] = {
	    0x6d, 0x33, 0xf9, 0x40, 0x75, 0x5b, 0x4e, 0xc5, 0x90, 0x35, 
	    0x48, 0xab, 0x75, 0x02, 0x09, 0x76, 0x9a, 0xb4, 0x7d, 0x6b
	};

	check_rsa(sha1, sizeof(sha1), rsa, RSA_PKCS1_PADDING);
    }

    for (i = 0; i < 128; i++) {
	unsigned char sha1[20];

	RAND_bytes(sha1, sizeof(sha1));
	check_rsa(sha1, sizeof(sha1), rsa, RSA_PKCS1_PADDING);
    }
    for (i = 0; i < 128; i++) {
	unsigned char des3[21];

	RAND_bytes(des3, sizeof(des3));
	check_rsa(des3, sizeof(des3), rsa, RSA_PKCS1_PADDING);
    }
    for (i = 0; i < 128; i++) {
	unsigned char aes[32];

	RAND_bytes(aes, sizeof(aes));
	check_rsa(aes, sizeof(aes), rsa, RSA_PKCS1_PADDING);
    }

    RSA_free(rsa);

    ENGINE_finish(engine);

    return 0;
}