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/*
* 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"
#if OPENSSL_VERSION_NUMBER < 0x00907000L
RCSID("$OpenBSD: cipher-aes.c,v 1.1 2003/05/15 03:08:29 markus Exp $");
#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 /* OPENSSL_VERSION_NUMBER */
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