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RIOT/sys/crypto/3des.c 17.6 KB
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  /*
   * Copyright (C) 2013 Freie Universitรคt Berlin, Computer Systems & Telematics
   *
   * This file is subject to the terms and conditions of the GNU Lesser
   * General Public License v2.1. See the file LICENSE in the top level
   * directory for more details.
   */
  
  /**
   * @ingroup     sys_crypto
   * @{
   *
   * @file
   * @brief       implementation of the 3DES cipher-algorithm
   *
   * @author      Freie Universitaet Berlin, Computer Systems & Telematics
   * @author      Nicolai Schmittberger <nicolai.schmittberger@fu-berlin.de>
   * @author      Tom St Denis <tomstdenis@gmail.com>, http://libtomcrypt.com
   * @author      Dobes Vandermeer
   * @author      Zakaria Kasmi <zkasmi@inf.fu-berlin.de>
   *
   * @date        18.09.2013 14:32:33
   *
   * @note        This implementation is based on a DES implementation included
   *              in the LibTomCrypt modular cryptographic library.
   *              The LibTomCrypt library provides various cryptographic
   *              algorithms in a highly modular and flexible manner.
   *              The library is free for all purposes without any express
   *              guarantee it works.
   *              Tom St Denis, tomstdenis@gmail.com, http://libtomcrypt.com
   *              DES code submitted by Dobes Vandermeer
   * @}
   */
  
  #include <stdio.h>
  #include <stdarg.h>
  #include <string.h>
  #include <stdlib.h>
  #include <stdint.h>
  #include "crypto/3des.h"
  #include "crypto/ciphers.h"
  
  #define ENABLE_DEBUG    (0)
  #include "debug.h"
  
  /*************** GLOBALS ******************/
  /**
   * @brief Interface to the 3DES cipher
   */
  static const cipher_interface_t tripledes_interface = {
      THREEDES_BLOCK_SIZE,
      THREEDES_MAX_KEY_SIZE,
      tripledes_init,
      tripledes_encrypt,
      tripledes_decrypt
  };
  const cipher_id_t CIPHER_3DES = &tripledes_interface;
  
  
  /**
   * @brief struct for the 3DES key expansion
   */
  struct des3_key_s {
      uint32_t ek[3][32];         ///< encryption key
      uint32_t dk[3][32];         ///< decryption key
  } des3_key_s;
  
  /************** PROTOTYPES ***************/
  static void cookey(const uint32_t *raw1, uint32_t *keyout);
  static void deskey(const uint8_t *key, int decrypt, uint32_t *keyout);
  static void desfunc(uint32_t *block, const uint32_t *keys);
  static uint8_t des3_key_setup(const uint8_t *key, struct des3_key_s *dkey);
  
  /*****************************************/
  
  
  /* Use the key schedule specific in the standard (ANSI X3.92-1981) */
  
  static const uint8_t pc1[56] = {
      56, 48, 40, 32, 24, 16,  8,  0, 57, 49, 41, 33, 25, 17,
      9,  1, 58, 50, 42, 34, 26, 18, 10,  2, 59, 51, 43, 35,
      62, 54, 46, 38, 30, 22, 14,  6, 61, 53, 45, 37, 29, 21,
      13,  5, 60, 52, 44, 36, 28, 20, 12,  4, 27, 19, 11,  3
  };
  
  static const uint8_t totrot[16] = {
      1,   2,  4,  6,
      8,  10, 12, 14,
      15, 17, 19, 21,
      23, 25, 27, 28
  };
  
  static const uint8_t pc2[48] = {
      13, 16, 10, 23, 0, 4, 2, 27, 14, 5, 20, 9,
      22, 18, 11, 3, 25, 7, 15, 6, 26, 19, 12, 1,
      40, 51, 30, 36, 46, 54, 29, 39, 50, 44, 32, 47,
      43, 48, 38, 55, 33, 52, 45, 41, 49, 35, 28, 31
  };
  
  
  static const uint32_t SP1[64] = {
      0x01010400UL, 0x00000000UL, 0x00010000UL, 0x01010404UL,
      0x01010004UL, 0x00010404UL, 0x00000004UL, 0x00010000UL,
      0x00000400UL, 0x01010400UL, 0x01010404UL, 0x00000400UL,
      0x01000404UL, 0x01010004UL, 0x01000000UL, 0x00000004UL,
      0x00000404UL, 0x01000400UL, 0x01000400UL, 0x00010400UL,
      0x00010400UL, 0x01010000UL, 0x01010000UL, 0x01000404UL,
      0x00010004UL, 0x01000004UL, 0x01000004UL, 0x00010004UL,
      0x00000000UL, 0x00000404UL, 0x00010404UL, 0x01000000UL,
      0x00010000UL, 0x01010404UL, 0x00000004UL, 0x01010000UL,
      0x01010400UL, 0x01000000UL, 0x01000000UL, 0x00000400UL,
      0x01010004UL, 0x00010000UL, 0x00010400UL, 0x01000004UL,
      0x00000400UL, 0x00000004UL, 0x01000404UL, 0x00010404UL,
      0x01010404UL, 0x00010004UL, 0x01010000UL, 0x01000404UL,
      0x01000004UL, 0x00000404UL, 0x00010404UL, 0x01010400UL,
      0x00000404UL, 0x01000400UL, 0x01000400UL, 0x00000000UL,
      0x00010004UL, 0x00010400UL, 0x00000000UL, 0x01010004UL
  };
  
  static const uint32_t SP2[64] = {
      0x80108020UL, 0x80008000UL, 0x00008000UL, 0x00108020UL,
      0x00100000UL, 0x00000020UL, 0x80100020UL, 0x80008020UL,
      0x80000020UL, 0x80108020UL, 0x80108000UL, 0x80000000UL,
      0x80008000UL, 0x00100000UL, 0x00000020UL, 0x80100020UL,
      0x00108000UL, 0x00100020UL, 0x80008020UL, 0x00000000UL,
      0x80000000UL, 0x00008000UL, 0x00108020UL, 0x80100000UL,
      0x00100020UL, 0x80000020UL, 0x00000000UL, 0x00108000UL,
      0x00008020UL, 0x80108000UL, 0x80100000UL, 0x00008020UL,
      0x00000000UL, 0x00108020UL, 0x80100020UL, 0x00100000UL,
      0x80008020UL, 0x80100000UL, 0x80108000UL, 0x00008000UL,
      0x80100000UL, 0x80008000UL, 0x00000020UL, 0x80108020UL,
      0x00108020UL, 0x00000020UL, 0x00008000UL, 0x80000000UL,
      0x00008020UL, 0x80108000UL, 0x00100000UL, 0x80000020UL,
      0x00100020UL, 0x80008020UL, 0x80000020UL, 0x00100020UL,
      0x00108000UL, 0x00000000UL, 0x80008000UL, 0x00008020UL,
      0x80000000UL, 0x80100020UL, 0x80108020UL, 0x00108000UL
  };
  
  static const uint32_t SP3[64] = {
      0x00000208UL, 0x08020200UL, 0x00000000UL, 0x08020008UL,
      0x08000200UL, 0x00000000UL, 0x00020208UL, 0x08000200UL,
      0x00020008UL, 0x08000008UL, 0x08000008UL, 0x00020000UL,
      0x08020208UL, 0x00020008UL, 0x08020000UL, 0x00000208UL,
      0x08000000UL, 0x00000008UL, 0x08020200UL, 0x00000200UL,
      0x00020200UL, 0x08020000UL, 0x08020008UL, 0x00020208UL,
      0x08000208UL, 0x00020200UL, 0x00020000UL, 0x08000208UL,
      0x00000008UL, 0x08020208UL, 0x00000200UL, 0x08000000UL,
      0x08020200UL, 0x08000000UL, 0x00020008UL, 0x00000208UL,
      0x00020000UL, 0x08020200UL, 0x08000200UL, 0x00000000UL,
      0x00000200UL, 0x00020008UL, 0x08020208UL, 0x08000200UL,
      0x08000008UL, 0x00000200UL, 0x00000000UL, 0x08020008UL,
      0x08000208UL, 0x00020000UL, 0x08000000UL, 0x08020208UL,
      0x00000008UL, 0x00020208UL, 0x00020200UL, 0x08000008UL,
      0x08020000UL, 0x08000208UL, 0x00000208UL, 0x08020000UL,
      0x00020208UL, 0x00000008UL, 0x08020008UL, 0x00020200UL
  };
  
  static const uint32_t SP4[64] = {
      0x00802001UL, 0x00002081UL, 0x00002081UL, 0x00000080UL,
      0x00802080UL, 0x00800081UL, 0x00800001UL, 0x00002001UL,
      0x00000000UL, 0x00802000UL, 0x00802000UL, 0x00802081UL,
      0x00000081UL, 0x00000000UL, 0x00800080UL, 0x00800001UL,
      0x00000001UL, 0x00002000UL, 0x00800000UL, 0x00802001UL,
      0x00000080UL, 0x00800000UL, 0x00002001UL, 0x00002080UL,
      0x00800081UL, 0x00000001UL, 0x00002080UL, 0x00800080UL,
      0x00002000UL, 0x00802080UL, 0x00802081UL, 0x00000081UL,
      0x00800080UL, 0x00800001UL, 0x00802000UL, 0x00802081UL,
      0x00000081UL, 0x00000000UL, 0x00000000UL, 0x00802000UL,
      0x00002080UL, 0x00800080UL, 0x00800081UL, 0x00000001UL,
      0x00802001UL, 0x00002081UL, 0x00002081UL, 0x00000080UL,
      0x00802081UL, 0x00000081UL, 0x00000001UL, 0x00002000UL,
      0x00800001UL, 0x00002001UL, 0x00802080UL, 0x00800081UL,
      0x00002001UL, 0x00002080UL, 0x00800000UL, 0x00802001UL,
      0x00000080UL, 0x00800000UL, 0x00002000UL, 0x00802080UL
  };
  
  static const uint32_t SP5[64] = {
      0x00000100UL, 0x02080100UL, 0x02080000UL, 0x42000100UL,
      0x00080000UL, 0x00000100UL, 0x40000000UL, 0x02080000UL,
      0x40080100UL, 0x00080000UL, 0x02000100UL, 0x40080100UL,
      0x42000100UL, 0x42080000UL, 0x00080100UL, 0x40000000UL,
      0x02000000UL, 0x40080000UL, 0x40080000UL, 0x00000000UL,
      0x40000100UL, 0x42080100UL, 0x42080100UL, 0x02000100UL,
      0x42080000UL, 0x40000100UL, 0x00000000UL, 0x42000000UL,
      0x02080100UL, 0x02000000UL, 0x42000000UL, 0x00080100UL,
      0x00080000UL, 0x42000100UL, 0x00000100UL, 0x02000000UL,
      0x40000000UL, 0x02080000UL, 0x42000100UL, 0x40080100UL,
      0x02000100UL, 0x40000000UL, 0x42080000UL, 0x02080100UL,
      0x40080100UL, 0x00000100UL, 0x02000000UL, 0x42080000UL,
      0x42080100UL, 0x00080100UL, 0x42000000UL, 0x42080100UL,
      0x02080000UL, 0x00000000UL, 0x40080000UL, 0x42000000UL,
      0x00080100UL, 0x02000100UL, 0x40000100UL, 0x00080000UL,
      0x00000000UL, 0x40080000UL, 0x02080100UL, 0x40000100UL
  };
  
  static const uint32_t SP6[64] = {
      0x20000010UL, 0x20400000UL, 0x00004000UL, 0x20404010UL,
      0x20400000UL, 0x00000010UL, 0x20404010UL, 0x00400000UL,
      0x20004000UL, 0x00404010UL, 0x00400000UL, 0x20000010UL,
      0x00400010UL, 0x20004000UL, 0x20000000UL, 0x00004010UL,
      0x00000000UL, 0x00400010UL, 0x20004010UL, 0x00004000UL,
      0x00404000UL, 0x20004010UL, 0x00000010UL, 0x20400010UL,
      0x20400010UL, 0x00000000UL, 0x00404010UL, 0x20404000UL,
      0x00004010UL, 0x00404000UL, 0x20404000UL, 0x20000000UL,
      0x20004000UL, 0x00000010UL, 0x20400010UL, 0x00404000UL,
      0x20404010UL, 0x00400000UL, 0x00004010UL, 0x20000010UL,
      0x00400000UL, 0x20004000UL, 0x20000000UL, 0x00004010UL,
      0x20000010UL, 0x20404010UL, 0x00404000UL, 0x20400000UL,
      0x00404010UL, 0x20404000UL, 0x00000000UL, 0x20400010UL,
      0x00000010UL, 0x00004000UL, 0x20400000UL, 0x00404010UL,
      0x00004000UL, 0x00400010UL, 0x20004010UL, 0x00000000UL,
      0x20404000UL, 0x20000000UL, 0x00400010UL, 0x20004010UL
  };
  
  static const uint32_t SP7[64] = {
      0x00200000UL, 0x04200002UL, 0x04000802UL, 0x00000000UL,
      0x00000800UL, 0x04000802UL, 0x00200802UL, 0x04200800UL,
      0x04200802UL, 0x00200000UL, 0x00000000UL, 0x04000002UL,
      0x00000002UL, 0x04000000UL, 0x04200002UL, 0x00000802UL,
      0x04000800UL, 0x00200802UL, 0x00200002UL, 0x04000800UL,
      0x04000002UL, 0x04200000UL, 0x04200800UL, 0x00200002UL,
      0x04200000UL, 0x00000800UL, 0x00000802UL, 0x04200802UL,
      0x00200800UL, 0x00000002UL, 0x04000000UL, 0x00200800UL,
      0x04000000UL, 0x00200800UL, 0x00200000UL, 0x04000802UL,
      0x04000802UL, 0x04200002UL, 0x04200002UL, 0x00000002UL,
      0x00200002UL, 0x04000000UL, 0x04000800UL, 0x00200000UL,
      0x04200800UL, 0x00000802UL, 0x00200802UL, 0x04200800UL,
      0x00000802UL, 0x04000002UL, 0x04200802UL, 0x04200000UL,
      0x00200800UL, 0x00000000UL, 0x00000002UL, 0x04200802UL,
      0x00000000UL, 0x00200802UL, 0x04200000UL, 0x00000800UL,
      0x04000002UL, 0x04000800UL, 0x00000800UL, 0x00200002UL
  };
  
  static const uint32_t SP8[64] = {
      0x10001040UL, 0x00001000UL, 0x00040000UL, 0x10041040UL,
      0x10000000UL, 0x10001040UL, 0x00000040UL, 0x10000000UL,
      0x00040040UL, 0x10040000UL, 0x10041040UL, 0x00041000UL,
      0x10041000UL, 0x00041040UL, 0x00001000UL, 0x00000040UL,
      0x10040000UL, 0x10000040UL, 0x10001000UL, 0x00001040UL,
      0x00041000UL, 0x00040040UL, 0x10040040UL, 0x10041000UL,
      0x00001040UL, 0x00000000UL, 0x00000000UL, 0x10040040UL,
      0x10000040UL, 0x10001000UL, 0x00041040UL, 0x00040000UL,
      0x00041040UL, 0x00040000UL, 0x10041000UL, 0x00001000UL,
      0x00000040UL, 0x10040040UL, 0x00001000UL, 0x00041040UL,
      0x10001000UL, 0x00000040UL, 0x10000040UL, 0x10040000UL,
      0x10040040UL, 0x10000000UL, 0x00040000UL, 0x10001040UL,
      0x00000000UL, 0x10041040UL, 0x00040040UL, 0x10000040UL,
      0x10040000UL, 0x10001000UL, 0x10001040UL, 0x00000000UL,
      0x10041040UL, 0x00041000UL, 0x00041000UL, 0x00001040UL,
      0x00001040UL, 0x00040040UL, 0x10000000UL, 0x10041000UL
  };
  
  
  int tripledes_init(cipher_context_t *context, const uint8_t *key,
                    uint8_t keySize)
  {
      uint8_t i;
  
      // Make sure that context is large enough. If this is not the case,
      // you should build with -DTHREEDES
      if(CIPHER_MAX_CONTEXT_SIZE < THREEDES_MAX_KEY_SIZE) {
          return CIPHER_ERR_BAD_CONTEXT_SIZE;
      }
  
      //key must be at least 24 Bytes long
      if (keySize < 24) {
          //fill up by concatenating key to as long as needed
          for (i = 0; i < 24; i++) {
              context->context[i] = key[(i % keySize)];
          }
      }
      else {
          for (i = 0; i < 24; i++) {
              context->context[i] = key[i];
          }
      }
  
      return CIPHER_INIT_SUCCESS;
  }
  
  int tripledes_encrypt(const cipher_context_t *context, const uint8_t *plain, uint8_t *crypt)
  {
      int res;
      struct des3_key_s *key = malloc(sizeof(des3_key_s));
      uint32_t work[2];
  
      if (!key) {
          DEBUG("%s:%d in %s: [ERROR] Could NOT malloc space for the des3_key_s struct.\r\n",
                RIOT_FILE_RELATIVE, __LINE__, DEBUG_FUNC);
          return -1;
      }
  
      memset(key, 0, sizeof(des3_key_s));
      res = des3_key_setup(context->context, key);
  
      if (res < 0) {
          DEBUG("%s:%d in %s: [ERROR] des3_key_setup failed with Code %i\r\n",
                RIOT_FILE_RELATIVE, __LINE__, DEBUG_FUNC, res);
          free(key);
          return -2;
      }
  
      work[0] = WPA_GET_BE32(plain);
      work[1] = WPA_GET_BE32(plain + 4);
      desfunc(work, key->ek[0]);
      desfunc(work, key->ek[1]);
      desfunc(work, key->ek[2]);
      WPA_PUT_BE32(crypt, work[0]);
      WPA_PUT_BE32(crypt + 4, work[1]);
  
      free(key);
      return 1;
  }
  
  
  int tripledes_decrypt(const cipher_context_t *context, const uint8_t *crypt, uint8_t *plain)
  {
      int res;
      struct des3_key_s *key = malloc(sizeof(des3_key_s));
      uint32_t work[2];
  
      if (!key) {
          DEBUG("%s:%d in %s: [ERROR] Could NOT malloc space for the des3_key_s struct.\r\n",
                RIOT_FILE_RELATIVE, __LINE__, DEBUG_FUNC);
          return -1;
      }
  
      memset(key, 0, sizeof(des3_key_s));
      res = des3_key_setup(context->context, key);
  
      if (res < 0) {
          DEBUG("%s:%d in %s: [ERROR] des3_key_setup failed with Code %i\r\n",
                RIOT_FILE_RELATIVE, __LINE__, DEBUG_FUNC, res);
          free(key);
          return -2;
      }
  
      work[0] = WPA_GET_BE32(crypt);
      work[1] = WPA_GET_BE32(crypt + 4);
      desfunc(work, key->dk[0]);
      desfunc(work, key->dk[1]);
      desfunc(work, key->dk[2]);
      WPA_PUT_BE32(plain, work[0]);
      WPA_PUT_BE32(plain + 4, work[1]);
  
      free(key);
      return 1;
  }
  
  static void cookey(const uint32_t *raw1, uint32_t *keyout)
  {
      uint32_t *cook;
      uint32_t dough[32];
      int i;
  
      cook = dough;
  
      for (i = 0; i < 16; i++, raw1++) {
          const uint32_t *raw0 = raw1++;
          *cook    = (*raw0 & 0x00fc0000L) << 6;
          *cook   |= (*raw0 & 0x00000fc0L) << 10;
          *cook   |= (*raw1 & 0x00fc0000L) >> 10;
          *cook++ |= (*raw1 & 0x00000fc0L) >> 6;
          *cook    = (*raw0 & 0x0003f000L) << 12;
          *cook   |= (*raw0 & 0x0000003fL) << 16;
          *cook   |= (*raw1 & 0x0003f000L) >> 4;
          *cook++ |= (*raw1 & 0x0000003fL);
      }
  
      memcpy(keyout, dough, sizeof(dough));
  }
  
  
  static void deskey(const uint8_t *key, int decrypt, uint32_t *keyout)
  {
      uint32_t i, j, l, m, kn[32];
      uint8_t pc1m[56], pcr[56];
  
      for (j = 0; j < 56; j++) {
          l = (uint32_t) pc1[j];
          m = l & 7;
          pc1m[j] = (uint8_t)
                    ((key[l >> 3U] & bytebit[m]) == bytebit[m] ? 1 : 0);
      }
  
      for (i = 0; i < 16; i++) {
          if (decrypt) {
              m = (15 - i) << 1;
          }
          else {
              m = i << 1;
          }
  
          uint32_t n = m + 1;
          kn[m] = kn[n] = 0L;
  
          for (j = 0; j < 28; j++) {
              l = j + (uint32_t) totrot[i];
  
              if (l < 28) {
                  pcr[j] = pc1m[l];
              }
              else {
                  pcr[j] = pc1m[l - 28];
              }
          }
  
          for (/* j = 28 */; j < 56; j++) {
              l = j + (uint32_t) totrot[i];
  
              if (l < 56) {
                  pcr[j] = pc1m[l];
              }
              else {
                  pcr[j] = pc1m[l - 28];
              }
          }
  
          for (j = 0; j < 24; j++) {
              if ((int) pcr[(int) pc2[j]] != 0) {
                  kn[m] |= bigbyte[j];
              }
  
              if ((int) pcr[(int) pc2[j + 24]] != 0) {
                  kn[n] |= bigbyte[j];
              }
          }
      }
  
      cookey(kn, keyout);
  }
  
  
  static void desfunc(uint32_t *block, const uint32_t *keys)
  {
      uint32_t work, right, leftt;
      int cur_round;
  
      leftt = block[0];
      right = block[1];
  
      work = ((leftt >> 4)  ^ right) & 0x0f0f0f0fL;
      right ^= work;
      leftt ^= (work << 4);
  
      work = ((leftt >> 16) ^ right) & 0x0000ffffL;
      right ^= work;
      leftt ^= (work << 16);
  
      work = ((right >> 2)  ^ leftt) & 0x33333333L;
      leftt ^= work;
      right ^= (work << 2);
  
      work = ((right >> 8)  ^ leftt) & 0x00ff00ffL;
      leftt ^= work;
      right ^= (work << 8);
  
      right = ROLc(right, 1);
      work = (leftt ^ right) & 0xaaaaaaaaL;
  
      leftt ^= work;
      right ^= work;
      leftt = ROLc(leftt, 1);
  
      for (cur_round = 0; cur_round < 8; cur_round++) {
          work  = RORc(right, 4) ^ *keys++;
          leftt ^= SP7[work        & 0x3fL]
                   ^ SP5[(work >>  8) & 0x3fL]
                   ^ SP3[(work >> 16) & 0x3fL]
                   ^ SP1[(work >> 24) & 0x3fL];
          work  = right ^ *keys++;
          leftt ^= SP8[ work        & 0x3fL]
                   ^  SP6[(work >>  8) & 0x3fL]
                   ^  SP4[(work >> 16) & 0x3fL]
                   ^  SP2[(work >> 24) & 0x3fL];
  
          work = RORc(leftt, 4) ^ *keys++;
          right ^= SP7[ work        & 0x3fL]
                   ^  SP5[(work >>  8) & 0x3fL]
                   ^  SP3[(work >> 16) & 0x3fL]
                   ^  SP1[(work >> 24) & 0x3fL];
          work  = leftt ^ *keys++;
          right ^= SP8[ work        & 0x3fL]
                   ^  SP6[(work >>  8) & 0x3fL]
                   ^  SP4[(work >> 16) & 0x3fL]
                   ^  SP2[(work >> 24) & 0x3fL];
      }
  
      right = RORc(right, 1);
      work = (leftt ^ right) & 0xaaaaaaaaL;
      leftt ^= work;
      right ^= work;
      leftt = RORc(leftt, 1);
      work = ((leftt >> 8) ^ right) & 0x00ff00ffL;
      right ^= work;
      leftt ^= (work << 8);
      /* -- */
      work = ((leftt >> 2) ^ right) & 0x33333333L;
      right ^= work;
      leftt ^= (work << 2);
      work = ((right >> 16) ^ leftt) & 0x0000ffffL;
      leftt ^= work;
      right ^= (work << 16);
      work = ((right >> 4) ^ leftt) & 0x0f0f0f0fL;
      leftt ^= work;
      right ^= (work << 4);
  
      block[0] = right;
      block[1] = leftt;
  }
  
  static uint8_t des3_key_setup(const uint8_t *key, struct des3_key_s *dkey)
  {
      deskey(key, 0, dkey->ek[0]);
      deskey(key + 8, 1, dkey->ek[1]);
      deskey(key + 16, 0, dkey->ek[2]);
  
      deskey(key, 1, dkey->dk[2]);
      deskey(key + 8, 0, dkey->dk[1]);
      deskey(key + 16, 1, dkey->dk[0]);
      return 1;
  }