[gssapi-openssh.git] / openssh / rsa.c

/* $OpenBSD: rsa.c,v 1.28 2006/08/03 03:34:42 deraadt Exp $ */
/*
 * Author: Tatu Ylonen <ylo@cs.hut.fi>
 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
 *                    All rights reserved
 *
 * As far as I am concerned, the code I have written for this software
 * can be used freely for any purpose.  Any derived versions of this
 * software must be clearly marked as such, and if the derived work is
 * incompatible with the protocol description in the RFC file, it must be
 * called by a name other than "ssh" or "Secure Shell".
 *
 *
 * Copyright (c) 1999 Niels Provos.  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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 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.
 *
 *
 * Description of the RSA algorithm can be found e.g. from the following
 * sources:
 *
 *   Bruce Schneier: Applied Cryptography.  John Wiley & Sons, 1994.
 *
 *   Jennifer Seberry and Josed Pieprzyk: Cryptography: An Introduction to
 *   Computer Security.  Prentice-Hall, 1989.
 *
 *   Man Young Rhee: Cryptography and Secure Data Communications.  McGraw-Hill,
 *   1994.
 *
 *   R. Rivest, A. Shamir, and L. M. Adleman: Cryptographic Communications
 *   System and Method.  US Patent 4,405,829, 1983.
 *
 *   Hans Riesel: Prime Numbers and Computer Methods for Factorization.
 *   Birkhauser, 1994.
 *
 *   The RSA Frequently Asked Questions document by RSA Data Security,
 *   Inc., 1995.
 *
 *   RSA in 3 lines of perl by Adam Back <aba@atlax.ex.ac.uk>, 1995, as
 * included below:
 *
 *     [gone - had to be deleted - what a pity]
 */

#include "includes.h"

#include <sys/types.h>

#include <stdarg.h>
#include <string.h>

#include "xmalloc.h"
#include "rsa.h"
#include "log.h"

void
rsa_public_encrypt(BIGNUM *out, BIGNUM *in, RSA *key)
{
	u_char *inbuf, *outbuf;
	int len, ilen, olen;

	if (BN_num_bits(key->e) < 2 || !BN_is_odd(key->e))
		fatal("rsa_public_encrypt() exponent too small or not odd");

	olen = BN_num_bytes(key->n);
	outbuf = xmalloc(olen);

	ilen = BN_num_bytes(in);
	inbuf = xmalloc(ilen);
	BN_bn2bin(in, inbuf);

	if ((len = RSA_public_encrypt(ilen, inbuf, outbuf, key,
	    RSA_PKCS1_PADDING)) <= 0)
		fatal("rsa_public_encrypt() failed");

	BN_bin2bn(outbuf, len, out);

	memset(outbuf, 0, olen);
	memset(inbuf, 0, ilen);
	xfree(outbuf);
	xfree(inbuf);
}

int
rsa_private_decrypt(BIGNUM *out, BIGNUM *in, RSA *key)
{
	u_char *inbuf, *outbuf;
	int len, ilen, olen;

	olen = BN_num_bytes(key->n);
	outbuf = xmalloc(olen);

	ilen = BN_num_bytes(in);
	inbuf = xmalloc(ilen);
	BN_bn2bin(in, inbuf);

	if ((len = RSA_private_decrypt(ilen, inbuf, outbuf, key,
	    RSA_PKCS1_PADDING)) <= 0) {
		error("rsa_private_decrypt() failed");
	} else {
		BN_bin2bn(outbuf, len, out);
	}
	memset(outbuf, 0, olen);
	memset(inbuf, 0, ilen);
	xfree(outbuf);
	xfree(inbuf);
	return len;
}

/* calculate p-1 and q-1 */
void
rsa_generate_additional_parameters(RSA *rsa)
{
	BIGNUM *aux;
	BN_CTX *ctx;

	if ((aux = BN_new()) == NULL)
		fatal("rsa_generate_additional_parameters: BN_new failed");
	if ((ctx = BN_CTX_new()) == NULL)
		fatal("rsa_generate_additional_parameters: BN_CTX_new failed");

	BN_sub(aux, rsa->q, BN_value_one());
	BN_mod(rsa->dmq1, rsa->d, aux, ctx);

	BN_sub(aux, rsa->p, BN_value_one());
	BN_mod(rsa->dmp1, rsa->d, aux, ctx);

	BN_clear_free(aux);
	BN_CTX_free(ctx);
}
Commit	Line	Data
9108f8d9	1	/* $OpenBSD: rsa.c,v 1.28 2006/08/03 03:34:42 deraadt Exp $ */
3c0ef626	2	/*
	3	* Author: Tatu Ylonen <ylo@cs.hut.fi>
	4	* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
	5	* All rights reserved
	6	*
	7	* As far as I am concerned, the code I have written for this software
	8	* can be used freely for any purpose. Any derived versions of this
	9	* software must be clearly marked as such, and if the derived work is
	10	* incompatible with the protocol description in the RFC file, it must be
	11	* called by a name other than "ssh" or "Secure Shell".
	12	*
	13	*
	14	* Copyright (c) 1999 Niels Provos. All rights reserved.
	15	*
	16	* Redistribution and use in source and binary forms, with or without
	17	* modification, are permitted provided that the following conditions
	18	* are met:
	19	* 1. Redistributions of source code must retain the above copyright
	20	* notice, this list of conditions and the following disclaimer.
	21	* 2. Redistributions in binary form must reproduce the above copyright
	22	* notice, this list of conditions and the following disclaimer in the
	23	* documentation and/or other materials provided with the distribution.
	24	*
	25	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
	26	* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
	27	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
	28	* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
	29	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
	30	* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
	31	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
	32	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
	33	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
	34	* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
	35	*
	36	*
	37	* Description of the RSA algorithm can be found e.g. from the following
	38	* sources:
	39	*
	40	* Bruce Schneier: Applied Cryptography. John Wiley & Sons, 1994.
	41	*
	42	* Jennifer Seberry and Josed Pieprzyk: Cryptography: An Introduction to
	43	* Computer Security. Prentice-Hall, 1989.
	44	*
	45	* Man Young Rhee: Cryptography and Secure Data Communications. McGraw-Hill,
	46	* 1994.
	47	*
	48	* R. Rivest, A. Shamir, and L. M. Adleman: Cryptographic Communications
	49	* System and Method. US Patent 4,405,829, 1983.
	50	*
	51	* Hans Riesel: Prime Numbers and Computer Methods for Factorization.
	52	* Birkhauser, 1994.
	53	*
	54	* The RSA Frequently Asked Questions document by RSA Data Security,
	55	* Inc., 1995.
	56	*
	57	* RSA in 3 lines of perl by Adam Back <aba@atlax.ex.ac.uk>, 1995, as
	58	* included below:
	59	*
	60	* [gone - had to be deleted - what a pity]
	61	*/
	62
	63	#include "includes.h"
3c0ef626	64
9108f8d9	65	#include <sys/types.h>
	66
	67	#include <stdarg.h>
	68	#include <string.h>
	69
	70	#include "xmalloc.h"
3c0ef626	71	#include "rsa.h"
3c0ef626	72	#include "log.h"
3c0ef626	73
	74	void
	75	rsa_public_encrypt(BIGNUM out, BIGNUM in, RSA *key)
	76	{
	77	u_char inbuf, outbuf;
	78	int len, ilen, olen;
	79
	80	if (BN_num_bits(key->e) < 2 \|\| !BN_is_odd(key->e))
	81	fatal("rsa_public_encrypt() exponent too small or not odd");
	82
	83	olen = BN_num_bytes(key->n);
	84	outbuf = xmalloc(olen);
	85
	86	ilen = BN_num_bytes(in);
	87	inbuf = xmalloc(ilen);
	88	BN_bn2bin(in, inbuf);
	89
	90	if ((len = RSA_public_encrypt(ilen, inbuf, outbuf, key,
	91	RSA_PKCS1_PADDING)) <= 0)
	92	fatal("rsa_public_encrypt() failed");
	93
	94	BN_bin2bn(outbuf, len, out);
	95
	96	memset(outbuf, 0, olen);
	97	memset(inbuf, 0, ilen);
	98	xfree(outbuf);
	99	xfree(inbuf);
	100	}
	101
	102	int
	103	rsa_private_decrypt(BIGNUM out, BIGNUM in, RSA *key)
	104	{
	105	u_char inbuf, outbuf;
	106	int len, ilen, olen;
	107
	108	olen = BN_num_bytes(key->n);
	109	outbuf = xmalloc(olen);
	110
	111	ilen = BN_num_bytes(in);
	112	inbuf = xmalloc(ilen);
	113	BN_bn2bin(in, inbuf);
	114
	115	if ((len = RSA_private_decrypt(ilen, inbuf, outbuf, key,
	116	RSA_PKCS1_PADDING)) <= 0) {
	117	error("rsa_private_decrypt() failed");
	118	} else {
	119	BN_bin2bn(outbuf, len, out);
	120	}
	121	memset(outbuf, 0, olen);
	122	memset(inbuf, 0, ilen);
	123	xfree(outbuf);
	124	xfree(inbuf);
	125	return len;
	126	}
	127
e9a17296	128	/* calculate p-1 and q-1 */
3c0ef626	129	void
	130	rsa_generate_additional_parameters(RSA *rsa)
	131	{
	132	BIGNUM *aux;
	133	BN_CTX *ctx;
e9a17296	134
	135	if ((aux = BN_new()) == NULL)
	136	fatal("rsa_generate_additional_parameters: BN_new failed");
	137	if ((ctx = BN_CTX_new()) == NULL)
	138	fatal("rsa_generate_additional_parameters: BN_CTX_new failed");
3c0ef626	139
	140	BN_sub(aux, rsa->q, BN_value_one());
	141	BN_mod(rsa->dmq1, rsa->d, aux, ctx);
	142
	143	BN_sub(aux, rsa->p, BN_value_one());
	144	BN_mod(rsa->dmp1, rsa->d, aux, ctx);
	145
	146	BN_clear_free(aux);
	147	BN_CTX_free(ctx);
	148	}
	149