[openssh.git] / cipher-aes.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"

/* compatibility with old or broken OpenSSL versions */
#include "openbsd-compat/openssl-compat.h"

#ifdef USE_BUILTIN_RIJNDAEL

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

#define RIJNDAEL_BLOCKSIZE 16
struct ssh_rijndael_ctx
{
	rijndael_ctx	r_ctx;
	u_char		r_iv[RIJNDAEL_BLOCKSIZE];
};

const EVP_CIPHER * evp_rijndael(void);
void ssh_rijndael_iv(EVP_CIPHER_CTX *, int, u_char *, u_int);

static int
ssh_rijndael_init(EVP_CIPHER_CTX *ctx, const u_char *key, const u_char *iv,
    int enc)
{
	struct ssh_rijndael_ctx *c;

	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) {
		if (enc == -1)
			enc = ctx->encrypt;
		rijndael_set_key(&c->r_ctx, (u_char *)key,
		    8*EVP_CIPHER_CTX_key_length(ctx), enc);
	}
	if (iv != NULL)
		memcpy(c->r_iv, iv, RIJNDAEL_BLOCKSIZE);
	return (1);
}

static int
ssh_rijndael_cbc(EVP_CIPHER_CTX *ctx, u_char *dest, const u_char *src,
    u_int len)
{
	struct ssh_rijndael_ctx *c;
	u_char buf[RIJNDAEL_BLOCKSIZE];
	u_char *cprev, *cnow, *plain, *ivp;
	int i, j, blocks = len / RIJNDAEL_BLOCKSIZE;

	if (len == 0)
		return (1);
	if (len % RIJNDAEL_BLOCKSIZE)
		fatal("ssh_rijndael_cbc: bad len %d", len);
	if ((c = EVP_CIPHER_CTX_get_app_data(ctx)) == NULL) {
		error("ssh_rijndael_cbc: no context");
		return (0);
	}
	if (ctx->encrypt) {
		cnow  = dest;
		plain = (u_char *)src;
		cprev = c->r_iv;
		for (i = 0; i < blocks; i++, plain+=RIJNDAEL_BLOCKSIZE,
		    cnow+=RIJNDAEL_BLOCKSIZE) {
			for (j = 0; j < RIJNDAEL_BLOCKSIZE; j++)
				buf[j] = plain[j] ^ cprev[j];
			rijndael_encrypt(&c->r_ctx, buf, cnow);
			cprev = cnow;
		}
		memcpy(c->r_iv, cprev, RIJNDAEL_BLOCKSIZE);
	} else {
		cnow  = (u_char *) (src+len-RIJNDAEL_BLOCKSIZE);
		plain = dest+len-RIJNDAEL_BLOCKSIZE;

		memcpy(buf, cnow, RIJNDAEL_BLOCKSIZE);
		for (i = blocks; i > 0; i--, cnow-=RIJNDAEL_BLOCKSIZE,
		    plain-=RIJNDAEL_BLOCKSIZE) {
			rijndael_decrypt(&c->r_ctx, cnow, plain);
			ivp = (i == 1) ? c->r_iv : cnow-RIJNDAEL_BLOCKSIZE;
			for (j = 0; j < RIJNDAEL_BLOCKSIZE; j++)
				plain[j] ^= ivp[j];
		}
		memcpy(c->r_iv, buf, RIJNDAEL_BLOCKSIZE);
	}
	return (1);
}

static int
ssh_rijndael_cleanup(EVP_CIPHER_CTX *ctx)
{
	struct ssh_rijndael_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
ssh_rijndael_iv(EVP_CIPHER_CTX *evp, int doset, u_char * iv, u_int len)
{
	struct ssh_rijndael_ctx *c;

	if ((c = EVP_CIPHER_CTX_get_app_data(evp)) == NULL)
		fatal("ssh_rijndael_iv: no context");
	if (doset)
		memcpy(c->r_iv, iv, len);
	else
		memcpy(iv, c->r_iv, len);
}

const EVP_CIPHER *
evp_rijndael(void)
{
	static EVP_CIPHER rijndal_cbc;

	memset(&rijndal_cbc, 0, sizeof(EVP_CIPHER));
	rijndal_cbc.nid = NID_undef;
	rijndal_cbc.block_size = RIJNDAEL_BLOCKSIZE;
	rijndal_cbc.iv_len = RIJNDAEL_BLOCKSIZE;
	rijndal_cbc.key_len = 16;
	rijndal_cbc.init = ssh_rijndael_init;
	rijndal_cbc.cleanup = ssh_rijndael_cleanup;
	rijndal_cbc.do_cipher = ssh_rijndael_cbc;
#ifndef SSH_OLD_EVP
	rijndal_cbc.flags = EVP_CIPH_CBC_MODE | EVP_CIPH_VARIABLE_LENGTH |
	    EVP_CIPH_ALWAYS_CALL_INIT | EVP_CIPH_CUSTOM_IV;
#endif
	return (&rijndal_cbc);
}
#endif /* USE_BUILTIN_RIJNDAEL */
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
3b6e3da9	25	#include "includes.h"
e5146707	26
	27	/* compatibility with old or broken OpenSSL versions */
	28	#include "openbsd-compat/openssl-compat.h"
	29
	30	#ifdef USE_BUILTIN_RIJNDAEL
3b6e3da9	31
	32	#include <openssl/evp.h>
	33	#include "rijndael.h"
	34	#include "xmalloc.h"
	35	#include "log.h"
	36
	37	#define RIJNDAEL_BLOCKSIZE 16
	38	struct ssh_rijndael_ctx
	39	{
	40	rijndael_ctx r_ctx;
	41	u_char r_iv[RIJNDAEL_BLOCKSIZE];
	42	};
	43
	44	const EVP_CIPHER * evp_rijndael(void);
	45	void ssh_rijndael_iv(EVP_CIPHER_CTX , int, u_char , u_int);
	46
	47	static int
	48	ssh_rijndael_init(EVP_CIPHER_CTX ctx, const u_char key, const u_char *iv,
	49	int enc)
	50	{
	51	struct ssh_rijndael_ctx *c;
	52
	53	if ((c = EVP_CIPHER_CTX_get_app_data(ctx)) == NULL) {
	54	c = xmalloc(sizeof(*c));
	55	EVP_CIPHER_CTX_set_app_data(ctx, c);
	56	}
	57	if (key != NULL) {
	58	if (enc == -1)
	59	enc = ctx->encrypt;
	60	rijndael_set_key(&c->r_ctx, (u_char *)key,
	61	8*EVP_CIPHER_CTX_key_length(ctx), enc);
	62	}
	63	if (iv != NULL)
	64	memcpy(c->r_iv, iv, RIJNDAEL_BLOCKSIZE);
	65	return (1);
	66	}
	67
	68	static int
	69	ssh_rijndael_cbc(EVP_CIPHER_CTX ctx, u_char dest, const u_char *src,
	70	u_int len)
	71	{
	72	struct ssh_rijndael_ctx *c;
	73	u_char buf[RIJNDAEL_BLOCKSIZE];
	74	u_char cprev, cnow, plain, ivp;
	75	int i, j, blocks = len / RIJNDAEL_BLOCKSIZE;
	76
	77	if (len == 0)
	78	return (1);
	79	if (len % RIJNDAEL_BLOCKSIZE)
	80	fatal("ssh_rijndael_cbc: bad len %d", len);
	81	if ((c = EVP_CIPHER_CTX_get_app_data(ctx)) == NULL) {
	82	error("ssh_rijndael_cbc: no context");
	83	return (0);
	84	}
	85	if (ctx->encrypt) {
	86	cnow = dest;
	87	plain = (u_char *)src;
	88	cprev = c->r_iv;
	89	for (i = 0; i < blocks; i++, plain+=RIJNDAEL_BLOCKSIZE,
	90	cnow+=RIJNDAEL_BLOCKSIZE) {
	91	for (j = 0; j < RIJNDAEL_BLOCKSIZE; j++)
	92	buf[j] = plain[j] ^ cprev[j];
	93	rijndael_encrypt(&c->r_ctx, buf, cnow);
	94	cprev = cnow;
95	}
96	memcpy(c->r_iv, cprev, RIJNDAEL_BLOCKSIZE);
97	} else {
98	cnow = (u_char *) (src+len-RIJNDAEL_BLOCKSIZE);
99	plain = dest+len-RIJNDAEL_BLOCKSIZE;
100
101	memcpy(buf, cnow, RIJNDAEL_BLOCKSIZE);
102	for (i = blocks; i > 0; i--, cnow-=RIJNDAEL_BLOCKSIZE,
103	plain-=RIJNDAEL_BLOCKSIZE) {
104	rijndael_decrypt(&c->r_ctx, cnow, plain);
105	ivp = (i == 1) ? c->r_iv : cnow-RIJNDAEL_BLOCKSIZE;
106	for (j = 0; j < RIJNDAEL_BLOCKSIZE; j++)
107	plain[j] ^= ivp[j];
108	}
109	memcpy(c->r_iv, buf, RIJNDAEL_BLOCKSIZE);
110	}
111	return (1);
112	}
113
114	static int
115	ssh_rijndael_cleanup(EVP_CIPHER_CTX *ctx)
116	{
117	struct ssh_rijndael_ctx *c;
118
119	if ((c = EVP_CIPHER_CTX_get_app_data(ctx)) != NULL) {
120	memset(c, 0, sizeof(*c));
121	xfree(c);
122	EVP_CIPHER_CTX_set_app_data(ctx, NULL);
123	}
124	return (1);
125	}
126
127	void
128	ssh_rijndael_iv(EVP_CIPHER_CTX evp, int doset, u_char iv, u_int len)
129	{
130	struct ssh_rijndael_ctx *c;
131
132	if ((c = EVP_CIPHER_CTX_get_app_data(evp)) == NULL)
133	fatal("ssh_rijndael_iv: no context");
134	if (doset)
135	memcpy(c->r_iv, iv, len);
136	else
137	memcpy(iv, c->r_iv, len);
138	}
139
140	const EVP_CIPHER *
141	evp_rijndael(void)
142	{
143	static EVP_CIPHER rijndal_cbc;
144
145	memset(&rijndal_cbc, 0, sizeof(EVP_CIPHER));
146	rijndal_cbc.nid = NID_undef;
147	rijndal_cbc.block_size = RIJNDAEL_BLOCKSIZE;
148	rijndal_cbc.iv_len = RIJNDAEL_BLOCKSIZE;
149	rijndal_cbc.key_len = 16;
150	rijndal_cbc.init = ssh_rijndael_init;
151	rijndal_cbc.cleanup = ssh_rijndael_cleanup;
152	rijndal_cbc.do_cipher = ssh_rijndael_cbc;
153	#ifndef SSH_OLD_EVP
154	rijndal_cbc.flags = EVP_CIPH_CBC_MODE \| EVP_CIPH_VARIABLE_LENGTH \|
155	EVP_CIPH_ALWAYS_CALL_INIT \| EVP_CIPH_CUSTOM_IV;
156	#endif
157	return (&rijndal_cbc);
158	}
e5146707	159	#endif /* USE_BUILTIN_RIJNDAEL */