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

/*
 * 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"
RCSID("$OpenBSD: rsa.c,v 1.23 2001/06/27 05:42:24 markus Exp $");

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

void
rsa_generate_additional_parameters(RSA *rsa)
{
	BIGNUM *aux;
	BN_CTX *ctx;
	/* Generate additional parameters */
	aux = BN_new();
	ctx = BN_CTX_new();

	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
3c0ef626	1	/*
	2	* Author: Tatu Ylonen <ylo@cs.hut.fi>
	3	* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
	4	* All rights reserved
	5	*
	6	* As far as I am concerned, the code I have written for this software
	7	* can be used freely for any purpose. Any derived versions of this
	8	* software must be clearly marked as such, and if the derived work is
	9	* incompatible with the protocol description in the RFC file, it must be
	10	* called by a name other than "ssh" or "Secure Shell".
	11	*
	12	*
	13	* Copyright (c) 1999 Niels Provos. All rights reserved.
	14	*
	15	* Redistribution and use in source and binary forms, with or without
	16	* modification, are permitted provided that the following conditions
	17	* are met:
	18	* 1. Redistributions of source code must retain the above copyright
	19	* notice, this list of conditions and the following disclaimer.
	20	* 2. Redistributions in binary form must reproduce the above copyright
	21	* notice, this list of conditions and the following disclaimer in the
	22	* documentation and/or other materials provided with the distribution.
	23	*
	24	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
	25	* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
	26	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
	27	* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
	28	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
	29	* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
	30	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
	31	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
	32	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
	33	* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
	34	*
	35	*
	36	* Description of the RSA algorithm can be found e.g. from the following
	37	* sources:
	38	*
	39	* Bruce Schneier: Applied Cryptography. John Wiley & Sons, 1994.
	40	*
	41	* Jennifer Seberry and Josed Pieprzyk: Cryptography: An Introduction to
	42	* Computer Security. Prentice-Hall, 1989.
	43	*
	44	* Man Young Rhee: Cryptography and Secure Data Communications. McGraw-Hill,
	45	* 1994.
	46	*
	47	* R. Rivest, A. Shamir, and L. M. Adleman: Cryptographic Communications
	48	* System and Method. US Patent 4,405,829, 1983.
	49	*
	50	* Hans Riesel: Prime Numbers and Computer Methods for Factorization.
	51	* Birkhauser, 1994.
	52	*
	53	* The RSA Frequently Asked Questions document by RSA Data Security,
	54	* Inc., 1995.
	55	*
	56	* RSA in 3 lines of perl by Adam Back <aba@atlax.ex.ac.uk>, 1995, as
	57	* included below:
	58	*
	59	* [gone - had to be deleted - what a pity]
	60	*/
	61
	62	#include "includes.h"
	63	RCSID("$OpenBSD: rsa.c,v 1.23 2001/06/27 05:42:24 markus Exp $");
	64
65	#include "rsa.h"
66	#include "log.h"
67	#include "xmalloc.h"
68
69	void
70	rsa_public_encrypt(BIGNUM out, BIGNUM in, RSA *key)
71	{
72	u_char inbuf, outbuf;
73	int len, ilen, olen;
74
75	if (BN_num_bits(key->e) < 2 \|\| !BN_is_odd(key->e))
76	fatal("rsa_public_encrypt() exponent too small or not odd");
77
78	olen = BN_num_bytes(key->n);
79	outbuf = xmalloc(olen);
80
81	ilen = BN_num_bytes(in);
82	inbuf = xmalloc(ilen);
83	BN_bn2bin(in, inbuf);
84
85	if ((len = RSA_public_encrypt(ilen, inbuf, outbuf, key,
86	RSA_PKCS1_PADDING)) <= 0)
87	fatal("rsa_public_encrypt() failed");
88
89	BN_bin2bn(outbuf, len, out);
90
91	memset(outbuf, 0, olen);
92	memset(inbuf, 0, ilen);
93	xfree(outbuf);
94	xfree(inbuf);
95	}
96
97	int
98	rsa_private_decrypt(BIGNUM out, BIGNUM in, RSA *key)
99	{
100	u_char inbuf, outbuf;
101	int len, ilen, olen;
102
103	olen = BN_num_bytes(key->n);
104	outbuf = xmalloc(olen);
105
106	ilen = BN_num_bytes(in);
107	inbuf = xmalloc(ilen);
108	BN_bn2bin(in, inbuf);
109
110	if ((len = RSA_private_decrypt(ilen, inbuf, outbuf, key,
111	RSA_PKCS1_PADDING)) <= 0) {
112	error("rsa_private_decrypt() failed");
113	} else {
114	BN_bin2bn(outbuf, len, out);
115	}
116	memset(outbuf, 0, olen);
117	memset(inbuf, 0, ilen);
118	xfree(outbuf);
119	xfree(inbuf);
120	return len;
121	}
122
123	void
124	rsa_generate_additional_parameters(RSA *rsa)
125	{
126	BIGNUM *aux;
127	BN_CTX *ctx;
128	/* Generate additional parameters */
129	aux = BN_new();
130	ctx = BN_CTX_new();
131
132	BN_sub(aux, rsa->q, BN_value_one());
133	BN_mod(rsa->dmq1, rsa->d, aux, ctx);
134
135	BN_sub(aux, rsa->p, BN_value_one());
136	BN_mod(rsa->dmp1, rsa->d, aux, ctx);
137
138	BN_clear_free(aux);
139	BN_CTX_free(ctx);
140	}
141