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/*
* Crypto wrapper for internal crypto implementation - Cipher wrappers
* Copyright (c) 2006-2009, Jouni Malinen <j@w1.fi>
*
* This software may be distributed under the terms of the BSD license.
* See README for more details.
*/
#include "includes.h"
#include "common.h"
#include "crypto.h"
#include "aes.h"
#include "des_i.h"
struct crypto_cipher {
enum crypto_cipher_alg alg;
union {
struct {
size_t used_bytes;
u8 key[16];
size_t keylen;
} rc4;
struct {
u8 cbc[32];
void *ctx_enc;
void *ctx_dec;
} aes;
struct {
struct des3_key_s key;
u8 cbc[8];
} des3;
struct {
u32 ek[32];
u32 dk[32];
u8 cbc[8];
} des;
} u;
};
struct crypto_cipher * crypto_cipher_init(enum crypto_cipher_alg alg,
const u8 *iv, const u8 *key,
size_t key_len)
{
struct crypto_cipher *ctx;
ctx = os_zalloc(sizeof(*ctx));
if (ctx == NULL)
return NULL;
ctx->alg = alg;
switch (alg) {
case CRYPTO_CIPHER_ALG_RC4:
if (key_len > sizeof(ctx->u.rc4.key)) {
os_free(ctx);
return NULL;
}
ctx->u.rc4.keylen = key_len;
os_memcpy(ctx->u.rc4.key, key, key_len);
break;
case CRYPTO_CIPHER_ALG_AES:
ctx->u.aes.ctx_enc = aes_encrypt_init(key, key_len);
if (ctx->u.aes.ctx_enc == NULL) {
os_free(ctx);
return NULL;
}
ctx->u.aes.ctx_dec = aes_decrypt_init(key, key_len);
if (ctx->u.aes.ctx_dec == NULL) {
aes_encrypt_deinit(ctx->u.aes.ctx_enc);
os_free(ctx);
return NULL;
}
os_memcpy(ctx->u.aes.cbc, iv, AES_BLOCK_SIZE);
break;
case CRYPTO_CIPHER_ALG_3DES:
if (key_len != 24) {
os_free(ctx);
return NULL;
}
des3_key_setup(key, &ctx->u.des3.key);
os_memcpy(ctx->u.des3.cbc, iv, 8);
break;
case CRYPTO_CIPHER_ALG_DES:
if (key_len != 8) {
os_free(ctx);
return NULL;
}
des_key_setup(key, ctx->u.des.ek, ctx->u.des.dk);
os_memcpy(ctx->u.des.cbc, iv, 8);
break;
default:
os_free(ctx);
return NULL;
}
return ctx;
}
int crypto_cipher_encrypt(struct crypto_cipher *ctx, const u8 *plain,
u8 *crypt, size_t len)
{
size_t i, j, blocks;
switch (ctx->alg) {
case CRYPTO_CIPHER_ALG_RC4:
if (plain != crypt)
os_memcpy(crypt, plain, len);
rc4_skip(ctx->u.rc4.key, ctx->u.rc4.keylen,
ctx->u.rc4.used_bytes, crypt, len);
ctx->u.rc4.used_bytes += len;
break;
case CRYPTO_CIPHER_ALG_AES:
if (len % AES_BLOCK_SIZE)
return -1;
blocks = len / AES_BLOCK_SIZE;
for (i = 0; i < blocks; i++) {
for (j = 0; j < AES_BLOCK_SIZE; j++)
ctx->u.aes.cbc[j] ^= plain[j];
aes_encrypt(ctx->u.aes.ctx_enc, ctx->u.aes.cbc,
ctx->u.aes.cbc);
os_memcpy(crypt, ctx->u.aes.cbc, AES_BLOCK_SIZE);
plain += AES_BLOCK_SIZE;
crypt += AES_BLOCK_SIZE;
}
break;
case CRYPTO_CIPHER_ALG_3DES:
if (len % 8)
return -1;
blocks = len / 8;
for (i = 0; i < blocks; i++) {
for (j = 0; j < 8; j++)
ctx->u.des3.cbc[j] ^= plain[j];
des3_encrypt(ctx->u.des3.cbc, &ctx->u.des3.key,
ctx->u.des3.cbc);
os_memcpy(crypt, ctx->u.des3.cbc, 8);
plain += 8;
crypt += 8;
}
break;
case CRYPTO_CIPHER_ALG_DES:
if (len % 8)
return -1;
blocks = len / 8;
for (i = 0; i < blocks; i++) {
for (j = 0; j < 8; j++)
ctx->u.des3.cbc[j] ^= plain[j];
des_block_encrypt(ctx->u.des.cbc, ctx->u.des.ek,
ctx->u.des.cbc);
os_memcpy(crypt, ctx->u.des.cbc, 8);
plain += 8;
crypt += 8;
}
break;
default:
return -1;
}
return 0;
}
int crypto_cipher_decrypt(struct crypto_cipher *ctx, const u8 *crypt,
u8 *plain, size_t len)
{
size_t i, j, blocks;
u8 tmp[32];
switch (ctx->alg) {
case CRYPTO_CIPHER_ALG_RC4:
if (plain != crypt)
os_memcpy(plain, crypt, len);
rc4_skip(ctx->u.rc4.key, ctx->u.rc4.keylen,
ctx->u.rc4.used_bytes, plain, len);
ctx->u.rc4.used_bytes += len;
break;
case CRYPTO_CIPHER_ALG_AES:
if (len % AES_BLOCK_SIZE)
return -1;
blocks = len / AES_BLOCK_SIZE;
for (i = 0; i < blocks; i++) {
os_memcpy(tmp, crypt, AES_BLOCK_SIZE);
aes_decrypt(ctx->u.aes.ctx_dec, crypt, plain);
for (j = 0; j < AES_BLOCK_SIZE; j++)
plain[j] ^= ctx->u.aes.cbc[j];
os_memcpy(ctx->u.aes.cbc, tmp, AES_BLOCK_SIZE);
plain += AES_BLOCK_SIZE;
crypt += AES_BLOCK_SIZE;
}
break;
case CRYPTO_CIPHER_ALG_3DES:
if (len % 8)
return -1;
blocks = len / 8;
for (i = 0; i < blocks; i++) {
os_memcpy(tmp, crypt, 8);
des3_decrypt(crypt, &ctx->u.des3.key, plain);
for (j = 0; j < 8; j++)
plain[j] ^= ctx->u.des3.cbc[j];
os_memcpy(ctx->u.des3.cbc, tmp, 8);
plain += 8;
crypt += 8;
}
break;
case CRYPTO_CIPHER_ALG_DES:
if (len % 8)
return -1;
blocks = len / 8;
for (i = 0; i < blocks; i++) {
os_memcpy(tmp, crypt, 8);
des_block_decrypt(crypt, ctx->u.des.dk, plain);
for (j = 0; j < 8; j++)
plain[j] ^= ctx->u.des.cbc[j];
os_memcpy(ctx->u.des.cbc, tmp, 8);
plain += 8;
crypt += 8;
}
break;
default:
return -1;
}
return 0;
}
void crypto_cipher_deinit(struct crypto_cipher *ctx)
{
switch (ctx->alg) {
case CRYPTO_CIPHER_ALG_AES:
aes_encrypt_deinit(ctx->u.aes.ctx_enc);
aes_decrypt_deinit(ctx->u.aes.ctx_dec);
break;
case CRYPTO_CIPHER_ALG_3DES:
break;
default:
break;
}
os_free(ctx);
}
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