workbench/network/WirelessManager/src/crypto/crypto_internal-cipher.c

   1 /*
   2  * Crypto wrapper for internal crypto implementation - Cipher wrappers
   3  * Copyright (c) 2006-2009, Jouni Malinen <j@w1.fi>
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License version 2 as
   7  * published by the Free Software Foundation.
   8  *
   9  * Alternatively, this software may be distributed under the terms of BSD
  10  * license.
  11  *
  12  * See README and COPYING for more details.
  13  */
  14
  15 #include "includes.h"
  16
  17 #include "common.h"
  18 #include "crypto.h"
  19 #include "aes.h"
  20 #include "des_i.h"
  21
  22
  23 struct crypto_cipher {
  24         enum crypto_cipher_alg alg;
  25         union {
  26                 struct {
  27                         size_t used_bytes;
  28                         u8 key[16];
  29                         size_t keylen;
  30                 } rc4;
  31                 struct {
  32                         u8 cbc[32];
  33                         size_t block_size;
  34                         void *ctx_enc;
  35                         void *ctx_dec;
  36                 } aes;
  37                 struct {
  38                         struct des3_key_s key;
  39                         u8 cbc[8];
  40                 } des3;
  41                 struct {
  42                         u32 ek[32];
  43                         u32 dk[32];
  44                         u8 cbc[8];
  45                 } des;
  46         } u;
  47 };
  48
  49
  50 struct crypto_cipher * crypto_cipher_init(enum crypto_cipher_alg alg,
  51                                           const u8 *iv, const u8 *key,
  52                                           size_t key_len)
  53 {
  54         struct crypto_cipher *ctx;
  55
  56         ctx = os_zalloc(sizeof(*ctx));
  57         if (ctx == NULL)
  58                 return NULL;
  59
  60         ctx->alg = alg;
  61
  62         switch (alg) {
  63         case CRYPTO_CIPHER_ALG_RC4:
  64                 if (key_len > sizeof(ctx->u.rc4.key)) {
  65                         os_free(ctx);
  66                         return NULL;
  67                 }
  68                 ctx->u.rc4.keylen = key_len;
  69                 os_memcpy(ctx->u.rc4.key, key, key_len);
  70                 break;
  71         case CRYPTO_CIPHER_ALG_AES:
  72                 if (key_len > sizeof(ctx->u.aes.cbc)) {
  73                         os_free(ctx);
  74                         return NULL;
  75                 }
  76                 ctx->u.aes.ctx_enc = aes_encrypt_init(key, key_len);
  77                 if (ctx->u.aes.ctx_enc == NULL) {
  78                         os_free(ctx);
  79                         return NULL;
  80                 }
  81                 ctx->u.aes.ctx_dec = aes_decrypt_init(key, key_len);
  82                 if (ctx->u.aes.ctx_dec == NULL) {
  83                         aes_encrypt_deinit(ctx->u.aes.ctx_enc);
  84                         os_free(ctx);
  85                         return NULL;
  86                 }
  87                 ctx->u.aes.block_size = key_len;
  88                 os_memcpy(ctx->u.aes.cbc, iv, ctx->u.aes.block_size);
  89                 break;
  90         case CRYPTO_CIPHER_ALG_3DES:
  91                 if (key_len != 24) {
  92                         os_free(ctx);
  93                         return NULL;
  94                 }
  95                 des3_key_setup(key, &ctx->u.des3.key);
  96                 os_memcpy(ctx->u.des3.cbc, iv, 8);
  97                 break;
  98         case CRYPTO_CIPHER_ALG_DES:
  99                 if (key_len != 8) {
 100                         os_free(ctx);
 101                         return NULL;
 102                 }
 103                 des_key_setup(key, ctx->u.des.ek, ctx->u.des.dk);
 104                 os_memcpy(ctx->u.des.cbc, iv, 8);
 105                 break;
 106         default:
 107                 os_free(ctx);
 108                 return NULL;
 109         }
 110
 111         return ctx;
 112 }
 113
 114
 115 int crypto_cipher_encrypt(struct crypto_cipher *ctx, const u8 *plain,
 116                           u8 *crypt, size_t len)
 117 {
 118         size_t i, j, blocks;
 119
 120         switch (ctx->alg) {
 121         case CRYPTO_CIPHER_ALG_RC4:
 122                 if (plain != crypt)
 123                         os_memcpy(crypt, plain, len);
 124                 rc4_skip(ctx->u.rc4.key, ctx->u.rc4.keylen,
 125                          ctx->u.rc4.used_bytes, crypt, len);
 126                 ctx->u.rc4.used_bytes += len;
 127                 break;
 128         case CRYPTO_CIPHER_ALG_AES:
 129                 if (len % ctx->u.aes.block_size)
 130                         return -1;
 131                 blocks = len / ctx->u.aes.block_size;
 132                 for (i = 0; i < blocks; i++) {
 133                         for (j = 0; j < ctx->u.aes.block_size; j++)
 134                                 ctx->u.aes.cbc[j] ^= plain[j];
 135                         aes_encrypt(ctx->u.aes.ctx_enc, ctx->u.aes.cbc,
 136                                     ctx->u.aes.cbc);
 137                         os_memcpy(crypt, ctx->u.aes.cbc,
 138                                   ctx->u.aes.block_size);
 139                         plain += ctx->u.aes.block_size;
 140                         crypt += ctx->u.aes.block_size;
 141                 }
 142                 break;
 143         case CRYPTO_CIPHER_ALG_3DES:
 144                 if (len % 8)
 145                         return -1;
 146                 blocks = len / 8;
 147                 for (i = 0; i < blocks; i++) {
 148                         for (j = 0; j < 8; j++)
 149                                 ctx->u.des3.cbc[j] ^= plain[j];
 150                         des3_encrypt(ctx->u.des3.cbc, &ctx->u.des3.key,
 151                                      ctx->u.des3.cbc);
 152                         os_memcpy(crypt, ctx->u.des3.cbc, 8);
 153                         plain += 8;
 154                         crypt += 8;
 155                 }
 156                 break;
 157         case CRYPTO_CIPHER_ALG_DES:
 158                 if (len % 8)
 159                         return -1;
 160                 blocks = len / 8;
 161                 for (i = 0; i < blocks; i++) {
 162                         for (j = 0; j < 8; j++)
 163                                 ctx->u.des3.cbc[j] ^= plain[j];
 164                         des_block_encrypt(ctx->u.des.cbc, ctx->u.des.ek,
 165                                           ctx->u.des.cbc);
 166                         os_memcpy(crypt, ctx->u.des.cbc, 8);
 167                         plain += 8;
 168                         crypt += 8;
 169                 }
 170                 break;
 171         default:
 172                 return -1;
 173         }
 174
 175         return 0;
 176 }
 177
 178
 179 int crypto_cipher_decrypt(struct crypto_cipher *ctx, const u8 *crypt,
 180                           u8 *plain, size_t len)
 181 {
 182         size_t i, j, blocks;
 183         u8 tmp[32];
 184
 185         switch (ctx->alg) {
 186         case CRYPTO_CIPHER_ALG_RC4:
 187                 if (plain != crypt)
 188                         os_memcpy(plain, crypt, len);
 189                 rc4_skip(ctx->u.rc4.key, ctx->u.rc4.keylen,
 190                          ctx->u.rc4.used_bytes, plain, len);
 191                 ctx->u.rc4.used_bytes += len;
 192                 break;
 193         case CRYPTO_CIPHER_ALG_AES:
 194                 if (len % ctx->u.aes.block_size)
 195                         return -1;
 196                 blocks = len / ctx->u.aes.block_size;
 197                 for (i = 0; i < blocks; i++) {
 198                         os_memcpy(tmp, crypt, ctx->u.aes.block_size);
 199                         aes_decrypt(ctx->u.aes.ctx_dec, crypt, plain);
 200                         for (j = 0; j < ctx->u.aes.block_size; j++)
 201                                 plain[j] ^= ctx->u.aes.cbc[j];
 202                         os_memcpy(ctx->u.aes.cbc, tmp, ctx->u.aes.block_size);
 203                         plain += ctx->u.aes.block_size;
 204                         crypt += ctx->u.aes.block_size;
 205                 }
 206                 break;
 207         case CRYPTO_CIPHER_ALG_3DES:
 208                 if (len % 8)
 209                         return -1;
 210                 blocks = len / 8;
 211                 for (i = 0; i < blocks; i++) {
 212                         os_memcpy(tmp, crypt, 8);
 213                         des3_decrypt(crypt, &ctx->u.des3.key, plain);
 214                         for (j = 0; j < 8; j++)
 215                                 plain[j] ^= ctx->u.des3.cbc[j];
 216                         os_memcpy(ctx->u.des3.cbc, tmp, 8);
 217                         plain += 8;
 218                         crypt += 8;
 219                 }
 220                 break;
 221         case CRYPTO_CIPHER_ALG_DES:
 222                 if (len % 8)
 223                         return -1;
 224                 blocks = len / 8;
 225                 for (i = 0; i < blocks; i++) {
 226                         os_memcpy(tmp, crypt, 8);
 227                         des_block_decrypt(crypt, ctx->u.des.dk, plain);
 228                         for (j = 0; j < 8; j++)
 229                                 plain[j] ^= ctx->u.des.cbc[j];
 230                         os_memcpy(ctx->u.des.cbc, tmp, 8);
 231                         plain += 8;
 232                         crypt += 8;
 233                 }
 234                 break;
 235         default:
 236                 return -1;
 237         }
 238
 239         return 0;
 240 }
 241
 242
 243 void crypto_cipher_deinit(struct crypto_cipher *ctx)
 244 {
 245         switch (ctx->alg) {
 246         case CRYPTO_CIPHER_ALG_AES:
 247                 aes_encrypt_deinit(ctx->u.aes.ctx_enc);
 248                 aes_decrypt_deinit(ctx->u.aes.ctx_dec);
 249                 break;
 250         case CRYPTO_CIPHER_ALG_3DES:
 251                 break;
 252         default:
 253                 break;
 254         }
 255         os_free(ctx);
 256 }