www.pudn.com > serpent.rar > ecb_vk.c

/* 
  $Id: ecb_vk.c,v 1.7 1998/06/07 08:15:40 fms Exp $ 
 
  # This file is part of the C reference implementation of Serpent. 
  # 
  # Written by Frank Stajano, 
  # Olivetti Oracle Research Laboratory  and 
  # Cambridge University Computer Laboratory . 
  #  
  # (c) 1998 Olivetti Oracle Research Laboratory (ORL) 
  # 
  # Original (Python) Serpent reference development started on 1998 02 12. 
  # C implementation development started on 1998 03 04. 
  # 
  # Serpent cipher invented by Ross Anderson, Eli Biham, Lars Knudsen. 
  # Serpent is a candidate for the Advanced Encryption Standard. 
 
*/ 
 
/* -------------------------------------------------- */ 
#include "serpent-api.h" 
#include "serpent-aux.h" 
/* -------------------------------------------------- */ 
EMBED_RCS(ecb_vk_c, 
          "$Id: ecb_vk.c,v 1.7 1998/06/07 08:15:40 fms Exp $") 
 
 
int main(void) { 
  int i, bitsPerShortKey, result; 
  BLOCK plainText, cipherText, recoveredPlainText; 
  char asciiKey[HEX_DIGITS_PER_KEY+1]; 
  keyInstance key; 
  cipherInstance cipher; 
 
  printHeader("ecb_vk", "Electronic Codebook (ECB) Mode", 
              "Variable Key Known Answer Tests"); 
 
  for(bitsPerShortKey=BITS_PER_SHORTEST_KEY; bitsPerShortKey<=BITS_PER_KEY; 
      bitsPerShortKey+=BITS_PER_KEY_STEP) { 
    result = stringToWords("00000000000000000000000000000000", plainText, 
                           WORDS_PER_BLOCK); 
    if (result != TRUE) goto error; 
 
    printf("KEYSIZE=%d\n\n", bitsPerShortKey); 
    render("PT=", plainText, WORDS_PER_BLOCK); 
    printf("\n"); 
 
    /* Construct (backwards) an ascii key of all 0s, of length 
       bitsPerShortKey bits. */ 
    i=bitsPerShortKey/BITS_PER_HEX_DIGIT; 
    asciiKey[i] = 0; /* terminating null */  
    for (i--; i >=0; i--) { 
      asciiKey[i] = '0'; 
    } 
 
    result = cipherInit(&cipher, MODE_ECB, 0); 
    if (result != TRUE) goto error; 
 
    for(i=bitsPerShortKey-1; i>=0; i--) { 
 
      /* assert: asciiKey is all 0s, and has the right length. */ 
 
      /* prepare key for this round: in the ascii big-endian 
         representation, set bit number i.  */ 
      asciiKey[(bitsPerShortKey-1-i)/BITS_PER_HEX_DIGIT] =  
        hex(1 << (i%BITS_PER_HEX_DIGIT)); 
      result = makeKey(&key, DIR_ENCRYPT, bitsPerShortKey, asciiKey); 
      if (result != TRUE) goto error; 
       
      /* restore ascii key for next round */ 
      asciiKey[(bitsPerShortKey-1-i)/BITS_PER_HEX_DIGIT] = '0'; 
      /* assert: asciiKey is all 0s again */ 
 
      /* assert: key.userKey has a 1 bit in its ith position */ 
      printf("I=%d\n", bitsPerShortKey-i); 
      render("KEY=", key.userKey, bitsPerShortKey/BITS_PER_WORD); 
       
      /* encrypt */ 
      key.direction = DIR_ENCRYPT; 
      result = blockEncrypt(&cipher, &key, (BYTE*) plainText, BITS_PER_BLOCK, 
                            (BYTE*) cipherText); 
      if (result < 0) { 
        goto error; 
      } else if (result != BITS_PER_BLOCK) { 
        result = BAD_NUMBER_OF_BITS_PROCESSED; 
        goto error; 
      } 
      render("CT=", cipherText, WORDS_PER_BLOCK); 
 
      /* decrypt and see if it comes out the same */ 
      key.direction = DIR_DECRYPT; 
      result = blockDecrypt(&cipher, &key, (BYTE*) cipherText, BITS_PER_BLOCK, 
                            (BYTE*) recoveredPlainText); 
      if (result < 0) { 
        goto error; 
      } else if (result != BITS_PER_BLOCK) { 
        result = BAD_NUMBER_OF_BITS_PROCESSED; 
        goto error; 
      } 
 
      if (memcmp((BYTE*)plainText, (BYTE*)recoveredPlainText, 
                 BYTES_PER_BLOCK)) { 
        result = DECRYPTION_MISMATCH; 
        goto error; 
      } 
 
      printf("\n"); 
    } 
    printf("==========\n\n"); 
  } 
  exit(0); 
 
error: 
  printf("Error %d (sorry, see serpent-api.h to see what this means)\n", 
         result); 
  exit(result); 
}