hostapd/src/crypto/crypto_internal.c

206 lines
4 KiB
C
Raw Normal View History

/*
* Crypto wrapper for internal crypto implementation
* Copyright (c) 2006-2009, Jouni Malinen <j@w1.fi>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* Alternatively, this software may be distributed under the terms of BSD
* license.
*
* See README and COPYING for more details.
*/
#include "includes.h"
#include "common.h"
#include "crypto.h"
#include "sha1_i.h"
#include "md5_i.h"
struct crypto_hash {
enum crypto_hash_alg alg;
union {
struct MD5Context md5;
struct SHA1Context sha1;
} u;
u8 key[64];
size_t key_len;
};
struct crypto_hash * crypto_hash_init(enum crypto_hash_alg alg, const u8 *key,
size_t key_len)
{
struct crypto_hash *ctx;
u8 k_pad[64];
u8 tk[20];
size_t i;
ctx = os_zalloc(sizeof(*ctx));
if (ctx == NULL)
return NULL;
ctx->alg = alg;
switch (alg) {
case CRYPTO_HASH_ALG_MD5:
MD5Init(&ctx->u.md5);
break;
case CRYPTO_HASH_ALG_SHA1:
SHA1Init(&ctx->u.sha1);
break;
case CRYPTO_HASH_ALG_HMAC_MD5:
if (key_len > sizeof(k_pad)) {
MD5Init(&ctx->u.md5);
MD5Update(&ctx->u.md5, key, key_len);
MD5Final(tk, &ctx->u.md5);
key = tk;
key_len = 16;
}
os_memcpy(ctx->key, key, key_len);
ctx->key_len = key_len;
os_memcpy(k_pad, key, key_len);
os_memset(k_pad + key_len, 0, sizeof(k_pad) - key_len);
for (i = 0; i < sizeof(k_pad); i++)
k_pad[i] ^= 0x36;
MD5Init(&ctx->u.md5);
MD5Update(&ctx->u.md5, k_pad, sizeof(k_pad));
break;
case CRYPTO_HASH_ALG_HMAC_SHA1:
if (key_len > sizeof(k_pad)) {
SHA1Init(&ctx->u.sha1);
SHA1Update(&ctx->u.sha1, key, key_len);
SHA1Final(tk, &ctx->u.sha1);
key = tk;
key_len = 20;
}
os_memcpy(ctx->key, key, key_len);
ctx->key_len = key_len;
os_memcpy(k_pad, key, key_len);
os_memset(k_pad + key_len, 0, sizeof(k_pad) - key_len);
for (i = 0; i < sizeof(k_pad); i++)
k_pad[i] ^= 0x36;
SHA1Init(&ctx->u.sha1);
SHA1Update(&ctx->u.sha1, k_pad, sizeof(k_pad));
break;
default:
os_free(ctx);
return NULL;
}
return ctx;
}
void crypto_hash_update(struct crypto_hash *ctx, const u8 *data, size_t len)
{
if (ctx == NULL)
return;
switch (ctx->alg) {
case CRYPTO_HASH_ALG_MD5:
case CRYPTO_HASH_ALG_HMAC_MD5:
MD5Update(&ctx->u.md5, data, len);
break;
case CRYPTO_HASH_ALG_SHA1:
case CRYPTO_HASH_ALG_HMAC_SHA1:
SHA1Update(&ctx->u.sha1, data, len);
break;
}
}
int crypto_hash_finish(struct crypto_hash *ctx, u8 *mac, size_t *len)
{
u8 k_pad[64];
size_t i;
if (ctx == NULL)
return -2;
if (mac == NULL || len == NULL) {
os_free(ctx);
return 0;
}
switch (ctx->alg) {
case CRYPTO_HASH_ALG_MD5:
if (*len < 16) {
*len = 16;
os_free(ctx);
return -1;
}
*len = 16;
MD5Final(mac, &ctx->u.md5);
break;
case CRYPTO_HASH_ALG_SHA1:
if (*len < 20) {
*len = 20;
os_free(ctx);
return -1;
}
*len = 20;
SHA1Final(mac, &ctx->u.sha1);
break;
case CRYPTO_HASH_ALG_HMAC_MD5:
if (*len < 16) {
*len = 16;
os_free(ctx);
return -1;
}
*len = 16;
MD5Final(mac, &ctx->u.md5);
os_memcpy(k_pad, ctx->key, ctx->key_len);
os_memset(k_pad + ctx->key_len, 0,
sizeof(k_pad) - ctx->key_len);
for (i = 0; i < sizeof(k_pad); i++)
k_pad[i] ^= 0x5c;
MD5Init(&ctx->u.md5);
MD5Update(&ctx->u.md5, k_pad, sizeof(k_pad));
MD5Update(&ctx->u.md5, mac, 16);
MD5Final(mac, &ctx->u.md5);
break;
case CRYPTO_HASH_ALG_HMAC_SHA1:
if (*len < 20) {
*len = 20;
os_free(ctx);
return -1;
}
*len = 20;
SHA1Final(mac, &ctx->u.sha1);
os_memcpy(k_pad, ctx->key, ctx->key_len);
os_memset(k_pad + ctx->key_len, 0,
sizeof(k_pad) - ctx->key_len);
for (i = 0; i < sizeof(k_pad); i++)
k_pad[i] ^= 0x5c;
SHA1Init(&ctx->u.sha1);
SHA1Update(&ctx->u.sha1, k_pad, sizeof(k_pad));
SHA1Update(&ctx->u.sha1, mac, 20);
SHA1Final(mac, &ctx->u.sha1);
break;
}
os_free(ctx);
return 0;
}
int crypto_global_init(void)
{
return 0;
}
void crypto_global_deinit(void)
{
}