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/* $OpenBSD: crypto.c,v 1.22 2004/06/14 09:55:41 ho Exp $ */
/* $EOM: crypto.c,v 1.32 2000/03/07 20:08:51 niklas Exp $ */
/*
* Copyright (c) 1998 Niels Provos. All rights reserved.
* Copyright (c) 1999, 2000 Niklas Hallqvist. 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.
*/
/*
* This code was written under funding by Ericsson Radio Systems.
*/
#include <sys/param.h>
#include <stdlib.h>
#include <string.h>
#include "sysdep.h"
#include "crypto.h"
#include "log.h"
enum cryptoerr des1_init(struct keystate *, u_int8_t *, u_int16_t);
enum cryptoerr des3_init(struct keystate *, u_int8_t *, u_int16_t);
enum cryptoerr blf_init(struct keystate *, u_int8_t *, u_int16_t);
enum cryptoerr cast_init(struct keystate *, u_int8_t *, u_int16_t);
enum cryptoerr aes_init(struct keystate *, u_int8_t *, u_int16_t);
void des1_encrypt(struct keystate *, u_int8_t *, u_int16_t);
void des1_decrypt(struct keystate *, u_int8_t *, u_int16_t);
void des3_encrypt(struct keystate *, u_int8_t *, u_int16_t);
void des3_decrypt(struct keystate *, u_int8_t *, u_int16_t);
void blf_encrypt(struct keystate *, u_int8_t *, u_int16_t);
void blf_decrypt(struct keystate *, u_int8_t *, u_int16_t);
void cast1_encrypt(struct keystate *, u_int8_t *, u_int16_t);
void cast1_decrypt(struct keystate *, u_int8_t *, u_int16_t);
void aes_encrypt(struct keystate *, u_int8_t *, u_int16_t);
void aes_decrypt(struct keystate *, u_int8_t *, u_int16_t);
struct crypto_xf transforms[] = {
#ifdef USE_DES
{
DES_CBC, "Data Encryption Standard (CBC-Mode)", 8, 8,
BLOCKSIZE, 0,
des1_init,
des1_encrypt, des1_decrypt
},
#endif
#ifdef USE_TRIPLEDES
{
TRIPLEDES_CBC, "Triple-DES (CBC-Mode)", 24, 24,
BLOCKSIZE, 0,
des3_init,
des3_encrypt, des3_decrypt
},
#endif
#ifdef USE_BLOWFISH
{
BLOWFISH_CBC, "Blowfish (CBC-Mode)", 12, 56,
BLOCKSIZE, 0,
blf_init,
blf_encrypt, blf_decrypt
},
#endif
#ifdef USE_CAST
{
CAST_CBC, "CAST (CBC-Mode)", 12, 16,
BLOCKSIZE, 0,
cast_init,
cast1_encrypt, cast1_decrypt
},
#endif
#ifdef USE_AES
{
AES_CBC, "AES (CBC-Mode)", 16, 32,
AES_BLOCK_SIZE, 0,
aes_init,
aes_encrypt, aes_decrypt
},
#endif
};
/* Hmm, the function prototypes for des are really dumb */
#ifdef __OpenBSD__
#define DC (des_cblock *)
#else
#define DC (void *)
#endif
enum cryptoerr
des1_init(struct keystate *ks, u_int8_t *key, u_int16_t len)
{
/* des_set_key returns -1 for parity problems, and -2 for weak keys */
des_set_odd_parity(DC key);
switch (des_set_key(DC key, ks->ks_des[0])) {
case -2:
return EWEAKKEY;
default:
return EOKAY;
}
}
void
des1_encrypt(struct keystate *ks, u_int8_t *d, u_int16_t len)
{
des_cbc_encrypt(DC d, DC d, len, ks->ks_des[0], DC ks->riv,
DES_ENCRYPT);
}
void
des1_decrypt(struct keystate *ks, u_int8_t *d, u_int16_t len)
{
des_cbc_encrypt(DC d, DC d, len, ks->ks_des[0], DC ks->riv,
DES_DECRYPT);
}
#ifdef USE_TRIPLEDES
enum cryptoerr
des3_init(struct keystate *ks, u_int8_t *key, u_int16_t len)
{
des_set_odd_parity(DC key);
des_set_odd_parity(DC(key + 8));
des_set_odd_parity(DC(key + 16));
/* As of the draft Tripe-DES does not check for weak keys */
des_set_key(DC key, ks->ks_des[0]);
des_set_key(DC(key + 8), ks->ks_des[1]);
des_set_key(DC(key + 16), ks->ks_des[2]);
return EOKAY;
}
void
des3_encrypt(struct keystate *ks, u_int8_t *data, u_int16_t len)
{
u_int8_t iv[MAXBLK];
memcpy(iv, ks->riv, ks->xf->blocksize);
des_ede3_cbc_encrypt(DC data, DC data, len, ks->ks_des[0],
ks->ks_des[1], ks->ks_des[2], DC iv, DES_ENCRYPT);
}
void
des3_decrypt(struct keystate *ks, u_int8_t *data, u_int16_t len)
{
u_int8_t iv[MAXBLK];
memcpy(iv, ks->riv, ks->xf->blocksize);
des_ede3_cbc_encrypt(DC data, DC data, len, ks->ks_des[0],
ks->ks_des[1], ks->ks_des[2], DC iv, DES_DECRYPT);
}
#undef DC
#endif /* USE_TRIPLEDES */
#ifdef USE_BLOWFISH
enum cryptoerr
blf_init(struct keystate *ks, u_int8_t *key, u_int16_t len)
{
blf_key(&ks->ks_blf, key, len);
return EOKAY;
}
void
blf_encrypt(struct keystate *ks, u_int8_t *data, u_int16_t len)
{
u_int16_t i, blocksize = ks->xf->blocksize;
u_int8_t *iv = ks->liv;
u_int32_t xl, xr;
memcpy(iv, ks->riv, blocksize);
for (i = 0; i < len; data += blocksize, i += blocksize) {
XOR64(data, iv);
xl = GET_32BIT_BIG(data);
xr = GET_32BIT_BIG(data + 4);
Blowfish_encipher(&ks->ks_blf, &xl, &xr);
SET_32BIT_BIG(data, xl);
SET_32BIT_BIG(data + 4, xr);
SET64(iv, data);
}
}
void
blf_decrypt(struct keystate *ks, u_int8_t *data, u_int16_t len)
{
u_int16_t i, blocksize = ks->xf->blocksize;
u_int32_t xl, xr;
data += len - blocksize;
for (i = len - blocksize; i >= blocksize; data -= blocksize,
i -= blocksize) {
xl = GET_32BIT_BIG(data);
xr = GET_32BIT_BIG(data + 4);
Blowfish_decipher(&ks->ks_blf, &xl, &xr);
SET_32BIT_BIG(data, xl);
SET_32BIT_BIG(data + 4, xr);
XOR64(data, data - blocksize);
}
xl = GET_32BIT_BIG(data);
xr = GET_32BIT_BIG(data + 4);
Blowfish_decipher(&ks->ks_blf, &xl, &xr);
SET_32BIT_BIG(data, xl);
SET_32BIT_BIG(data + 4, xr);
XOR64(data, ks->riv);
}
#endif /* USE_BLOWFISH */
#ifdef USE_CAST
enum cryptoerr
cast_init(struct keystate *ks, u_int8_t *key, u_int16_t len)
{
cast_setkey(&ks->ks_cast, key, len);
return EOKAY;
}
void
cast1_encrypt(struct keystate *ks, u_int8_t *data, u_int16_t len)
{
u_int16_t i, blocksize = ks->xf->blocksize;
u_int8_t *iv = ks->liv;
memcpy(iv, ks->riv, blocksize);
for (i = 0; i < len; data += blocksize, i += blocksize) {
XOR64(data, iv);
cast_encrypt(&ks->ks_cast, data, data);
SET64(iv, data);
}
}
void
cast1_decrypt(struct keystate *ks, u_int8_t *data, u_int16_t len)
{
u_int16_t i, blocksize = ks->xf->blocksize;
data += len - blocksize;
for (i = len - blocksize; i >= blocksize; data -= blocksize,
i -= blocksize) {
cast_decrypt(&ks->ks_cast, data, data);
XOR64(data, data - blocksize);
}
cast_decrypt(&ks->ks_cast, data, data);
XOR64(data, ks->riv);
}
#endif /* USE_CAST */
#ifdef USE_AES
enum cryptoerr
aes_init(struct keystate *ks, u_int8_t *key, u_int16_t len)
{
AES_set_encrypt_key(key, len << 3, &ks->ks_aes[0]);
AES_set_decrypt_key(key, len << 3, &ks->ks_aes[1]);
return EOKAY;
}
void
aes_encrypt(struct keystate *ks, u_int8_t *data, u_int16_t len)
{
u_int8_t iv[MAXBLK];
memcpy(iv, ks->riv, ks->xf->blocksize);
AES_cbc_encrypt(data, data, len, &ks->ks_aes[0], iv, AES_ENCRYPT);
}
void
aes_decrypt(struct keystate *ks, u_int8_t *data, u_int16_t len)
{
u_int8_t iv[MAXBLK];
memcpy(iv, ks->riv, ks->xf->blocksize);
AES_cbc_encrypt(data, data, len, &ks->ks_aes[1], iv, AES_DECRYPT);
}
#endif /* USE_AES */
struct crypto_xf *
crypto_get(enum transform id)
{
size_t i;
for (i = 0; i < sizeof transforms / sizeof transforms[0]; i++)
if (id == transforms[i].id)
return &transforms[i];
return 0;
}
struct keystate *
crypto_init(struct crypto_xf *xf, u_int8_t *key, u_int16_t len,
enum cryptoerr *err)
{
struct keystate *ks;
if (len < xf->keymin || len > xf->keymax) {
LOG_DBG((LOG_CRYPTO, 10, "crypto_init: invalid key length %d",
len));
*err = EKEYLEN;
return 0;
}
ks = calloc(1, sizeof *ks);
if (!ks) {
log_error("crypto_init: calloc (1, %lu) failed",
(unsigned long)sizeof *ks);
*err = ENOCRYPTO;
return 0;
}
ks->xf = xf;
/* Setup the IV. */
ks->riv = ks->iv;
ks->liv = ks->iv2;
LOG_DBG_BUF((LOG_CRYPTO, 40, "crypto_init: key", key, len));
*err = xf->init(ks, key, len);
if (*err != EOKAY) {
LOG_DBG((LOG_CRYPTO, 30, "crypto_init: weak key found for %s",
xf->name));
free(ks);
return 0;
}
return ks;
}
void
crypto_update_iv(struct keystate *ks)
{
u_int8_t *tmp;
tmp = ks->riv;
ks->riv = ks->liv;
ks->liv = tmp;
LOG_DBG_BUF((LOG_CRYPTO, 50, "crypto_update_iv: updated IV", ks->riv,
ks->xf->blocksize));
}
void
crypto_init_iv(struct keystate *ks, u_int8_t *buf, size_t len)
{
memcpy(ks->riv, buf, len);
LOG_DBG_BUF((LOG_CRYPTO, 50, "crypto_init_iv: initialized IV", ks->riv,
len));
}
void
crypto_encrypt(struct keystate *ks, u_int8_t *buf, u_int16_t len)
{
LOG_DBG_BUF((LOG_CRYPTO, 10, "crypto_encrypt: before encryption", buf,
len));
ks->xf->encrypt(ks, buf, len);
memcpy(ks->liv, buf + len - ks->xf->blocksize, ks->xf->blocksize);
LOG_DBG_BUF((LOG_CRYPTO, 30, "crypto_encrypt: after encryption", buf,
len));
}
void
crypto_decrypt(struct keystate *ks, u_int8_t *buf, u_int16_t len)
{
LOG_DBG_BUF((LOG_CRYPTO, 10, "crypto_decrypt: before decryption", buf,
len));
/*
* XXX There is controversy about the correctness of updating the IV
* like this.
*/
memcpy(ks->liv, buf + len - ks->xf->blocksize, ks->xf->blocksize);
ks->xf->decrypt(ks, buf, len);
LOG_DBG_BUF((LOG_CRYPTO, 30, "crypto_decrypt: after decryption", buf,
len));
}
/* Make a copy of the keystate pointed to by OKS. */
struct keystate *
crypto_clone_keystate(struct keystate *oks)
{
struct keystate *ks;
ks = malloc(sizeof *ks);
if (!ks) {
log_error("crypto_clone_keystate: malloc (%lu) failed",
(unsigned long)sizeof *ks);
return 0;
}
memcpy(ks, oks, sizeof *ks);
if (oks->riv == oks->iv) {
ks->riv = ks->iv;
ks->liv = ks->iv2;
} else {
ks->riv = ks->iv2;
ks->liv = ks->iv;
}
return ks;
}
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