[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"
RCSID("$OpenBSD: cipher-3des1.c,v 1.1 2003/05/15 03:08:29 markus Exp $");

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

/*
 * 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) {
		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"
	26	RCSID("$OpenBSD: cipher-3des1.c,v 1.1 2003/05/15 03:08:29 markus Exp $");
	27
	28	#include <openssl/evp.h>
	29	#include "xmalloc.h"
	30	#include "log.h"
	31
	32	/*
	33	* This is used by SSH1:
	34	*
	35	* What kind of triple DES are these 2 routines?
	36	*
	37	* Why is there a redundant initialization vector?
	38	*
	39	* If only iv3 was used, then, this would till effect have been
	40	* outer-cbc. However, there is also a private iv1 == iv2 which
	41	* perhaps makes differential analysis easier. On the other hand, the
	42	* private iv1 probably makes the CRC-32 attack ineffective. This is a
	43	* result of that there is no longer any known iv1 to use when
	44	* choosing the X block.
	45	*/
	46	struct ssh1_3des_ctx
	47	{
	48	EVP_CIPHER_CTX k1, k2, k3;
	49	};
	50
	51	const EVP_CIPHER * evp_ssh1_3des(void);
	52	void ssh1_3des_iv(EVP_CIPHER_CTX , int, u_char , int);
	53
	54	static int
	55	ssh1_3des_init(EVP_CIPHER_CTX ctx, const u_char key, const u_char *iv,
	56	int enc)
	57	{
	58	struct ssh1_3des_ctx *c;
	59	u_char k1, k2, *k3;
	60
	61	if ((c = EVP_CIPHER_CTX_get_app_data(ctx)) == NULL) {
	62	c = xmalloc(sizeof(*c));
	63	EVP_CIPHER_CTX_set_app_data(ctx, c);
	64	}
65	if (key == NULL)
66	return (1);
67	if (enc == -1)
68	enc = ctx->encrypt;
69	k1 = k2 = k3 = (u_char *) key;
70	k2 += 8;
71	if (EVP_CIPHER_CTX_key_length(ctx) >= 16+8) {
72	if (enc)
73	k3 += 16;
74	else
75	k1 += 16;
76	}
77	EVP_CIPHER_CTX_init(&c->k1);
78	EVP_CIPHER_CTX_init(&c->k2);
79	EVP_CIPHER_CTX_init(&c->k3);
80	#ifdef SSH_OLD_EVP
81	EVP_CipherInit(&c->k1, EVP_des_cbc(), k1, NULL, enc);
82	EVP_CipherInit(&c->k2, EVP_des_cbc(), k2, NULL, !enc);
83	EVP_CipherInit(&c->k3, EVP_des_cbc(), k3, NULL, enc);
84	#else
85	if (EVP_CipherInit(&c->k1, EVP_des_cbc(), k1, NULL, enc) == 0 \|\|
86	EVP_CipherInit(&c->k2, EVP_des_cbc(), k2, NULL, !enc) == 0 \|\|
87	EVP_CipherInit(&c->k3, EVP_des_cbc(), k3, NULL, enc) == 0) {
88	memset(c, 0, sizeof(*c));
89	xfree(c);
90	EVP_CIPHER_CTX_set_app_data(ctx, NULL);
91	return (0);
92	}
93	#endif
94	return (1);
95	}
96
97	static int
98	ssh1_3des_cbc(EVP_CIPHER_CTX ctx, u_char dest, const u_char *src, u_int len)
99	{
100	struct ssh1_3des_ctx *c;
101
102	if ((c = EVP_CIPHER_CTX_get_app_data(ctx)) == NULL) {
103	error("ssh1_3des_cbc: no context");
104	return (0);
105	}
106	#ifdef SSH_OLD_EVP
107	EVP_Cipher(&c->k1, dest, (u_char *)src, len);
108	EVP_Cipher(&c->k2, dest, dest, len);
109	EVP_Cipher(&c->k3, dest, dest, len);
110	#else
111	if (EVP_Cipher(&c->k1, dest, (u_char *)src, len) == 0 \|\|
112	EVP_Cipher(&c->k2, dest, dest, len) == 0 \|\|
113	EVP_Cipher(&c->k3, dest, dest, len) == 0)
114	return (0);
115	#endif
116	return (1);
117	}
118
119	static int
120	ssh1_3des_cleanup(EVP_CIPHER_CTX *ctx)
121	{
122	struct ssh1_3des_ctx *c;
123
124	if ((c = EVP_CIPHER_CTX_get_app_data(ctx)) != NULL) {
125	memset(c, 0, sizeof(*c));
126	xfree(c);
127	EVP_CIPHER_CTX_set_app_data(ctx, NULL);
128	}
129	return (1);
130	}
131
132	void
133	ssh1_3des_iv(EVP_CIPHER_CTX evp, int doset, u_char iv, int len)
134	{
135	struct ssh1_3des_ctx *c;
136
137	if (len != 24)
138	fatal("%s: bad 3des iv length: %d", __func__, len);
139	if ((c = EVP_CIPHER_CTX_get_app_data(evp)) == NULL)
140	fatal("%s: no 3des context", __func__);
141	if (doset) {
142	debug3("%s: Installed 3DES IV", __func__);
143	memcpy(c->k1.iv, iv, 8);
144	memcpy(c->k2.iv, iv + 8, 8);
145	memcpy(c->k3.iv, iv + 16, 8);
146	} else {
147	debug3("%s: Copying 3DES IV", __func__);
148	memcpy(iv, c->k1.iv, 8);
149	memcpy(iv + 8, c->k2.iv, 8);
150	memcpy(iv + 16, c->k3.iv, 8);
151	}
152	}
153
154	const EVP_CIPHER *
155	evp_ssh1_3des(void)
156	{
157	static EVP_CIPHER ssh1_3des;
158
159	memset(&ssh1_3des, 0, sizeof(EVP_CIPHER));
160	ssh1_3des.nid = NID_undef;
161	ssh1_3des.block_size = 8;
162	ssh1_3des.iv_len = 0;
163	ssh1_3des.key_len = 16;
164	ssh1_3des.init = ssh1_3des_init;
165	ssh1_3des.cleanup = ssh1_3des_cleanup;
166	ssh1_3des.do_cipher = ssh1_3des_cbc;
167	#ifndef SSH_OLD_EVP
168	ssh1_3des.flags = EVP_CIPH_CBC_MODE \| EVP_CIPH_VARIABLE_LENGTH;
169	#endif
170	return (&ssh1_3des);
171	}