crypto_internal.c

IEEE 802.11a/b/g 服务器端AP

/*
 * WPA Supplicant / Crypto wrapper for internal crypto implementation
 * Copyright (c) 2006-2007, Jouni Malinen <[e-mail]>
 *
 * 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 "md5.h"
#include "sha1.h"
#include "rc4.h"
#include "aes.h"
#include "tls/rsa.h"
#include "tls/bignum.h"
#include "tls/asn1.h"


#ifdef EAP_TLS_FUNCS

#ifdef CONFIG_TLS_INTERNAL

/* from des.c */
struct des3_key_s {
	u32 ek[3][32];
	u32 dk[3][32];
};

void des3_key_setup(const u8 *key, struct des3_key_s *dkey);
void des3_encrypt(const u8 *plain, const struct des3_key_s *key, u8 *crypt);
void des3_decrypt(const u8 *crypt, const struct des3_key_s *key, u8 *plain);


struct MD5Context {
	u32 buf[4];
	u32 bits[2];
	u8 in[64];
};

struct SHA1Context {
	u32 state[5];
	u32 count[2];
	unsigned char buffer[64];
};


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;
}


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];
			size_t block_size;
			void *ctx_enc;
			void *ctx_dec;
		} aes;
		struct {
			struct des3_key_s key;
			u8 cbc[8];
		} des3;
	} 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:
		if (key_len > sizeof(ctx->u.aes.cbc)) {
			os_free(ctx);
			return NULL;
		}
		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;
		}
		ctx->u.aes.block_size = key_len;
		os_memcpy(ctx->u.aes.cbc, iv, ctx->u.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;
	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 % ctx->u.aes.block_size)
			return -1;
		blocks = len / ctx->u.aes.block_size;
		for (i = 0; i < blocks; i++) {
			for (j = 0; j < ctx->u.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,
				  ctx->u.aes.block_size);
			plain += ctx->u.aes.block_size;
			crypt += ctx->u.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;
	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 % ctx->u.aes.block_size)
			return -1;
		blocks = len / ctx->u.aes.block_size;
		for (i = 0; i < blocks; i++) {
			os_memcpy(tmp, crypt, ctx->u.aes.block_size);
			aes_decrypt(ctx->u.aes.ctx_dec, crypt, plain);
			for (j = 0; j < ctx->u.aes.block_size; j++)
				plain[j] ^= ctx->u.aes.cbc[j];
			os_memcpy(ctx->u.aes.cbc, tmp, ctx->u.aes.block_size);
			plain += ctx->u.aes.block_size;
			crypt += ctx->u.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;
	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;