[openssh.git] / cipher-3des1.c

/*
 * Copyright (c) 2003 Markus Friedl.  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.
 */

#include "includes.h"

#include <openssl/evp.h>
#include "xmalloc.h"
#include "log.h"

#if OPENSSL_VERSION_NUMBER < 0x00906000L
#define SSH_OLD_EVP
#endif

/*
 * This is used by SSH1:
 *
 * What kind of triple DES are these 2 routines?
 *
 * Why is there a redundant initialization vector?
 *
 * If only iv3 was used, then, this would till effect have been
 * outer-cbc. However, there is also a private iv1 == iv2 which
 * perhaps makes differential analysis easier. On the other hand, the
 * private iv1 probably makes the CRC-32 attack ineffective. This is a
 * result of that there is no longer any known iv1 to use when
 * choosing the X block.
 */
struct ssh1_3des_ctx
{
	EVP_CIPHER_CTX	k1, k2, k3;
};

const EVP_CIPHER * evp_ssh1_3des(void);
void ssh1_3des_iv(EVP_CIPHER_CTX *, int, u_char *, int);

static int
ssh1_3des_init(EVP_CIPHER_CTX *ctx, const u_char *key, const u_char *iv,
    int enc)
{
	struct ssh1_3des_ctx *c;
	u_char *k1, *k2, *k3;

	if ((c = EVP_CIPHER_CTX_get_app_data(ctx)) == NULL) {
		c = xmalloc(sizeof(*c));
		EVP_CIPHER_CTX_set_app_data(ctx, c);
	}
	if (key == NULL)
		return (1);
	if (enc == -1)
		enc = ctx->encrypt;
	k1 = k2 = k3 = (u_char *) key;
	k2 += 8;
	if (EVP_CIPHER_CTX_key_length(ctx) >= 16+8) {
		if (enc)
			k3 += 16;
		else
			k1 += 16;
	}
	EVP_CIPHER_CTX_init(&c->k1);
	EVP_CIPHER_CTX_init(&c->k2);
	EVP_CIPHER_CTX_init(&c->k3);
#ifdef SSH_OLD_EVP
	EVP_CipherInit(&c->k1, EVP_des_cbc(), k1, NULL, enc);
	EVP_CipherInit(&c->k2, EVP_des_cbc(), k2, NULL, !enc);
	EVP_CipherInit(&c->k3, EVP_des_cbc(), k3, NULL, enc);
#else
	if (EVP_CipherInit(&c->k1, EVP_des_cbc(), k1, NULL, enc) == 0 ||
	    EVP_CipherInit(&c->k2, EVP_des_cbc(), k2, NULL, !enc) == 0 ||
	    EVP_CipherInit(&c->k3, EVP_des_cbc(), k3, NULL, enc) == 0) {
		memset(c, 0, sizeof(*c));
		xfree(c);
		EVP_CIPHER_CTX_set_app_data(ctx, NULL);
		return (0);
	}
#endif
	return (1);
}

static int
ssh1_3des_cbc(EVP_CIPHER_CTX *ctx, u_char *dest, const u_char *src, u_int len)
{
	struct ssh1_3des_ctx *c;

	if ((c = EVP_CIPHER_CTX_get_app_data(ctx)) == NULL) {
		error("ssh1_3des_cbc: no context");
		return (0);
	}
#ifdef SSH_OLD_EVP
	EVP_Cipher(&c->k1, dest, (u_char *)src, len);
	EVP_Cipher(&c->k2, dest, dest, len);
	EVP_Cipher(&c->k3, dest, dest, len);
#else
	if (EVP_Cipher(&c->k1, dest, (u_char *)src, len) == 0 ||
	    EVP_Cipher(&c->k2, dest, dest, len) == 0 ||
	    EVP_Cipher(&c->k3, dest, dest, len) == 0)
		return (0);
#endif
	return (1);
}

static int
ssh1_3des_cleanup(EVP_CIPHER_CTX *ctx)
{
	struct ssh1_3des_ctx *c;

	if ((c = EVP_CIPHER_CTX_get_app_data(ctx)) != NULL) {
		EVP_CIPHER_CTX_cleanup(&c->k1);
		EVP_CIPHER_CTX_cleanup(&c->k2);
		EVP_CIPHER_CTX_cleanup(&c->k3);
		memset(c, 0, sizeof(*c));
		xfree(c);
		EVP_CIPHER_CTX_set_app_data(ctx, NULL);
	}
	return (1);
}

void
ssh1_3des_iv(EVP_CIPHER_CTX *evp, int doset, u_char *iv, int len)
{
	struct ssh1_3des_ctx *c;

	if (len != 24)
		fatal("%s: bad 3des iv length: %d", __func__, len);
	if ((c = EVP_CIPHER_CTX_get_app_data(evp)) == NULL)
		fatal("%s: no 3des context", __func__);
	if (doset) {
		debug3("%s: Installed 3DES IV", __func__);
		memcpy(c->k1.iv, iv, 8);
		memcpy(c->k2.iv, iv + 8, 8);
		memcpy(c->k3.iv, iv + 16, 8);
	} else {
		debug3("%s: Copying 3DES IV", __func__);
		memcpy(iv, c->k1.iv, 8);
		memcpy(iv + 8, c->k2.iv, 8);
		memcpy(iv + 16, c->k3.iv, 8);
	}
}

const EVP_CIPHER *
evp_ssh1_3des(void)
{
	static EVP_CIPHER ssh1_3des;

	memset(&ssh1_3des, 0, sizeof(EVP_CIPHER));
	ssh1_3des.nid = NID_undef;
	ssh1_3des.block_size = 8;
	ssh1_3des.iv_len = 0;
	ssh1_3des.key_len = 16;
	ssh1_3des.init = ssh1_3des_init;
	ssh1_3des.cleanup = ssh1_3des_cleanup;
	ssh1_3des.do_cipher = ssh1_3des_cbc;
#ifndef SSH_OLD_EVP
	ssh1_3des.flags = EVP_CIPH_CBC_MODE | EVP_CIPH_VARIABLE_LENGTH;
#endif
	return (&ssh1_3des);
}
Commit	Line	Data
3b6e3da9	1	/*
	2	* Copyright (c) 2003 Markus Friedl. All rights reserved.
	3	*
	4	* Redistribution and use in source and binary forms, with or without
	5	* modification, are permitted provided that the following conditions
	6	* are met:
	7	* 1. Redistributions of source code must retain the above copyright
	8	* notice, this list of conditions and the following disclaimer.
	9	* 2. Redistributions in binary form must reproduce the above copyright
	10	* notice, this list of conditions and the following disclaimer in the
	11	* documentation and/or other materials provided with the distribution.
	12	*
	13	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
	14	* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
	15	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
	16	* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
	17	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
	18	* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
	19	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
	20	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
	21	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
	22	* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
	23	*/
	24
	25	#include "includes.h"
3b6e3da9	26
	27	#include <openssl/evp.h>
	28	#include "xmalloc.h"
	29	#include "log.h"
	30
0a23d79f	31	#if OPENSSL_VERSION_NUMBER < 0x00906000L
	32	#define SSH_OLD_EVP
	33	#endif
	34
3b6e3da9	35	/*
	36	* This is used by SSH1:
	37	*
	38	* What kind of triple DES are these 2 routines?
	39	*
	40	* Why is there a redundant initialization vector?
	41	*
	42	* If only iv3 was used, then, this would till effect have been
	43	* outer-cbc. However, there is also a private iv1 == iv2 which
	44	* perhaps makes differential analysis easier. On the other hand, the
	45	* private iv1 probably makes the CRC-32 attack ineffective. This is a
	46	* result of that there is no longer any known iv1 to use when
	47	* choosing the X block.
	48	*/
	49	struct ssh1_3des_ctx
	50	{
	51	EVP_CIPHER_CTX k1, k2, k3;
	52	};
	53
	54	const EVP_CIPHER * evp_ssh1_3des(void);
	55	void ssh1_3des_iv(EVP_CIPHER_CTX , int, u_char , int);
	56
	57	static int
	58	ssh1_3des_init(EVP_CIPHER_CTX ctx, const u_char key, const u_char *iv,
	59	int enc)
	60	{
	61	struct ssh1_3des_ctx *c;
	62	u_char k1, k2, *k3;
	63
	64	if ((c = EVP_CIPHER_CTX_get_app_data(ctx)) == NULL) {
	65	c = xmalloc(sizeof(*c));
	66	EVP_CIPHER_CTX_set_app_data(ctx, c);
	67	}
	68	if (key == NULL)
	69	return (1);
	70	if (enc == -1)
	71	enc = ctx->encrypt;
	72	k1 = k2 = k3 = (u_char *) key;
	73	k2 += 8;
	74	if (EVP_CIPHER_CTX_key_length(ctx) >= 16+8) {
	75	if (enc)
	76	k3 += 16;
	77	else
	78	k1 += 16;
	79	}
	80	EVP_CIPHER_CTX_init(&c->k1);
	81	EVP_CIPHER_CTX_init(&c->k2);
	82	EVP_CIPHER_CTX_init(&c->k3);
	83	#ifdef SSH_OLD_EVP
	84	EVP_CipherInit(&c->k1, EVP_des_cbc(), k1, NULL, enc);
	85	EVP_CipherInit(&c->k2, EVP_des_cbc(), k2, NULL, !enc);
	86	EVP_CipherInit(&c->k3, EVP_des_cbc(), k3, NULL, enc);
	87	#else
	88	if (EVP_CipherInit(&c->k1, EVP_des_cbc(), k1, NULL, enc) == 0 \|\|
	89	EVP_CipherInit(&c->k2, EVP_des_cbc(), k2, NULL, !enc) == 0 \|\|
	90	EVP_CipherInit(&c->k3, EVP_des_cbc(), k3, NULL, enc) == 0) {
	91	memset(c, 0, sizeof(*c));
	92	xfree(c);
	93	EVP_CIPHER_CTX_set_app_data(ctx, NULL);
	94	return (0);
	95	}
	96	#endif
	97	return (1);
	98	}
99
100	static int
101	ssh1_3des_cbc(EVP_CIPHER_CTX ctx, u_char dest, const u_char *src, u_int len)
102	{
103	struct ssh1_3des_ctx *c;
104
105	if ((c = EVP_CIPHER_CTX_get_app_data(ctx)) == NULL) {
106	error("ssh1_3des_cbc: no context");
107	return (0);
108	}
109	#ifdef SSH_OLD_EVP
110	EVP_Cipher(&c->k1, dest, (u_char *)src, len);
111	EVP_Cipher(&c->k2, dest, dest, len);
112	EVP_Cipher(&c->k3, dest, dest, len);
113	#else
114	if (EVP_Cipher(&c->k1, dest, (u_char *)src, len) == 0 \|\|
115	EVP_Cipher(&c->k2, dest, dest, len) == 0 \|\|
116	EVP_Cipher(&c->k3, dest, dest, len) == 0)
117	return (0);
118	#endif
119	return (1);
120	}
121
122	static int
123	ssh1_3des_cleanup(EVP_CIPHER_CTX *ctx)
124	{
125	struct ssh1_3des_ctx *c;
126
127	if ((c = EVP_CIPHER_CTX_get_app_data(ctx)) != NULL) {
1dd5f021	128	EVP_CIPHER_CTX_cleanup(&c->k1);
	129	EVP_CIPHER_CTX_cleanup(&c->k2);
	130	EVP_CIPHER_CTX_cleanup(&c->k3);
3b6e3da9	131	memset(c, 0, sizeof(*c));
	132	xfree(c);
	133	EVP_CIPHER_CTX_set_app_data(ctx, NULL);
	134	}
	135	return (1);
	136	}
	137
	138	void
	139	ssh1_3des_iv(EVP_CIPHER_CTX evp, int doset, u_char iv, int len)
	140	{
	141	struct ssh1_3des_ctx *c;
	142
	143	if (len != 24)
	144	fatal("%s: bad 3des iv length: %d", __func__, len);
	145	if ((c = EVP_CIPHER_CTX_get_app_data(evp)) == NULL)
	146	fatal("%s: no 3des context", __func__);
	147	if (doset) {
	148	debug3("%s: Installed 3DES IV", __func__);
	149	memcpy(c->k1.iv, iv, 8);
	150	memcpy(c->k2.iv, iv + 8, 8);
	151	memcpy(c->k3.iv, iv + 16, 8);
	152	} else {
	153	debug3("%s: Copying 3DES IV", __func__);
	154	memcpy(iv, c->k1.iv, 8);
	155	memcpy(iv + 8, c->k2.iv, 8);
	156	memcpy(iv + 16, c->k3.iv, 8);
	157	}
	158	}
	159
	160	const EVP_CIPHER *
	161	evp_ssh1_3des(void)
	162	{
	163	static EVP_CIPHER ssh1_3des;
	164
	165	memset(&ssh1_3des, 0, sizeof(EVP_CIPHER));
	166	ssh1_3des.nid = NID_undef;
	167	ssh1_3des.block_size = 8;
	168	ssh1_3des.iv_len = 0;
	169	ssh1_3des.key_len = 16;
	170	ssh1_3des.init = ssh1_3des_init;
	171	ssh1_3des.cleanup = ssh1_3des_cleanup;
	172	ssh1_3des.do_cipher = ssh1_3des_cbc;
	173	#ifndef SSH_OLD_EVP
	174	ssh1_3des.flags = EVP_CIPH_CBC_MODE \| EVP_CIPH_VARIABLE_LENGTH;
	175	#endif
	176	return (&ssh1_3des);
	177	}