safer.c

该压缩包中包括 tom的加密函数库及pdf说明 ,以及Rinick s ECC：椭圆曲线非对称加密密钥生成器

/* LibTomCrypt, modular cryptographic library -- Tom St Denis
 *
 * LibTomCrypt is a library that 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, [e-mail], http://libtomcrypt.org
 */

/*******************************************************************************
*
* FILE:           safer.c
*
* DESCRIPTION:    block-cipher algorithm SAFER (Secure And Fast Encryption
*                 Routine) in its four versions: SAFER K-64, SAFER K-128,
*                 SAFER SK-64 and SAFER SK-128.
*
* AUTHOR:         Richard De Moliner ([e-mail])
*                 Signal and Information Processing Laboratory
*                 Swiss Federal Institute of Technology
*                 CH-8092 Zuerich, Switzerland
*
* DATE:           September 9, 1995
*
* CHANGE HISTORY:
*
*******************************************************************************/

#include <tomcrypt.h>

#ifdef SAFER

const struct ltc_cipher_descriptor 
   safer_k64_desc = {
   "safer-k64", 
   8, 8, 8, 8, SAFER_K64_DEFAULT_NOF_ROUNDS,
   &safer_k64_setup,
   &safer_ecb_encrypt,
   &safer_ecb_decrypt,
   &safer_k64_test,
   &safer_done,
   &safer_64_keysize,
   NULL, NULL, NULL, NULL, NULL, NULL, NULL
   },

   safer_sk64_desc = {
   "safer-sk64",
   9, 8, 8, 8, SAFER_SK64_DEFAULT_NOF_ROUNDS,
   &safer_sk64_setup,
   &safer_ecb_encrypt,
   &safer_ecb_decrypt,
   &safer_sk64_test,
   &safer_done,
   &safer_64_keysize,
   NULL, NULL, NULL, NULL, NULL, NULL, NULL
   },

   safer_k128_desc = {
   "safer-k128",
   10, 16, 16, 8, SAFER_K128_DEFAULT_NOF_ROUNDS,
   &safer_k128_setup,
   &safer_ecb_encrypt,
   &safer_ecb_decrypt,
   &safer_sk128_test,
   &safer_done,
   &safer_128_keysize,
   NULL, NULL, NULL, NULL, NULL, NULL, NULL
   },

   safer_sk128_desc = {
   "safer-sk128",
   11, 16, 16, 8, SAFER_SK128_DEFAULT_NOF_ROUNDS,
   &safer_sk128_setup,
   &safer_ecb_encrypt,
   &safer_ecb_decrypt,
   &safer_sk128_test,
   &safer_done,
   &safer_128_keysize,
   NULL, NULL, NULL, NULL, NULL, NULL, NULL
   };

/******************* Constants ************************************************/
/* #define TAB_LEN      256  */

/******************* Assertions ***********************************************/

/******************* Macros ***************************************************/
#define ROL8(x, n)   ((unsigned char)((unsigned int)(x) << (n)\
                                     |(unsigned int)((x) & 0xFF) >> (8 - (n))))
#define EXP(x)       safer_ebox[(x) & 0xFF]
#define LOG(x)       safer_lbox[(x) & 0xFF]
#define PHT(x, y)    { y += x; x += y; }
#define IPHT(x, y)   { x -= y; y -= x; }

/******************* Types ****************************************************/
extern const unsigned char safer_ebox[], safer_lbox[];

#ifdef LTC_CLEAN_STACK
static void _Safer_Expand_Userkey(const unsigned char *userkey_1,
                                 const unsigned char *userkey_2,
                                 unsigned int nof_rounds,
                                 int strengthened,
                                 safer_key_t key)
#else
static void Safer_Expand_Userkey(const unsigned char *userkey_1,
                                 const unsigned char *userkey_2,
                                 unsigned int nof_rounds,
                                 int strengthened,
                                 safer_key_t key)
#endif
{   unsigned int i, j, k;
    unsigned char ka[SAFER_BLOCK_LEN + 1];
    unsigned char kb[SAFER_BLOCK_LEN + 1];

    if (SAFER_MAX_NOF_ROUNDS < nof_rounds)
        nof_rounds = SAFER_MAX_NOF_ROUNDS;
    *key++ = (unsigned char)nof_rounds;
    ka[SAFER_BLOCK_LEN] = (unsigned char)0;
    kb[SAFER_BLOCK_LEN] = (unsigned char)0;
    k = 0;
    for (j = 0; j < SAFER_BLOCK_LEN; j++) {
        ka[j] = ROL8(userkey_1[j], 5);
        ka[SAFER_BLOCK_LEN] ^= ka[j];
        kb[j] = *key++ = userkey_2[j];
        kb[SAFER_BLOCK_LEN] ^= kb[j];
    }
    for (i = 1; i <= nof_rounds; i++) {
        for (j = 0; j < SAFER_BLOCK_LEN + 1; j++) {
            ka[j] = ROL8(ka[j], 6);
            kb[j] = ROL8(kb[j], 6);
        }
        if (strengthened) {
           k = 2 * i - 1;
           while (k >= (SAFER_BLOCK_LEN + 1)) { k -= SAFER_BLOCK_LEN + 1; }
        }
        for (j = 0; j < SAFER_BLOCK_LEN; j++) {
            if (strengthened) {
                *key++ = (ka[k]
                                + safer_ebox[(int)safer_ebox[(int)((18 * i + j + 1)&0xFF)]]) & 0xFF;
                if (++k == (SAFER_BLOCK_LEN + 1)) { k = 0; }
            } else {
                *key++ = (ka[j] + safer_ebox[(int)safer_ebox[(int)((18 * i + j + 1)&0xFF)]]) & 0xFF;
            }
        }
        if (strengthened) {
           k = 2 * i;
           while (k >= (SAFER_BLOCK_LEN + 1)) { k -= SAFER_BLOCK_LEN + 1; }
        }
        for (j = 0; j < SAFER_BLOCK_LEN; j++) {
            if (strengthened) {
                *key++ = (kb[k]
                                + safer_ebox[(int)safer_ebox[(int)((18 * i + j + 10)&0xFF)]]) & 0xFF;
                if (++k == (SAFER_BLOCK_LEN + 1)) { k = 0; }
            } else {
                *key++ = (kb[j] + safer_ebox[(int)safer_ebox[(int)((18 * i + j + 10)&0xFF)]]) & 0xFF;
            }
        }
    }
    
#ifdef LTC_CLEAN_STACK
    zeromem(ka, sizeof(ka));
    zeromem(kb, sizeof(kb));
#endif
}

#ifdef LTC_CLEAN_STACK
static void Safer_Expand_Userkey(const unsigned char *userkey_1,
                                 const unsigned char *userkey_2,
                                 unsigned int nof_rounds,
                                 int strengthened,
                                 safer_key_t key)
{
   _Safer_Expand_Userkey(userkey_1, userkey_2, nof_rounds, strengthened, key);
   burn_stack(sizeof(unsigned char) * (2 * (SAFER_BLOCK_LEN + 1)) + sizeof(unsigned int)*2);
}
#endif

int safer_k64_setup(const unsigned char *key, int keylen, int numrounds, symmetric_key *skey)
{
   LTC_ARGCHK(key != NULL);
   LTC_ARGCHK(skey != NULL);

   if (numrounds != 0 && (numrounds < 6 || numrounds > SAFER_MAX_NOF_ROUNDS)) {
      return CRYPT_INVALID_ROUNDS;
   }

   if (keylen != 8) {
      return CRYPT_INVALID_KEYSIZE;
   }

   Safer_Expand_Userkey(key, key, (unsigned int)(numrounds != 0 ?numrounds:SAFER_K64_DEFAULT_NOF_ROUNDS), 0, skey->safer.key);
   return CRYPT_OK;
}
   
int safer_sk64_setup(const unsigned char *key, int keylen, int numrounds, symmetric_key *skey)
{
   LTC_ARGCHK(key != NULL);
   LTC_ARGCHK(skey != NULL);

   if (numrounds != 0 && (numrounds < 6 || numrounds > SAFER_MAX_NOF_ROUNDS)) {
      return CRYPT_INVALID_ROUNDS;
   }

   if (keylen != 8) {
      return CRYPT_INVALID_KEYSIZE;
   }

   Safer_Expand_Userkey(key, key, (unsigned int)(numrounds != 0 ?numrounds:SAFER_SK64_DEFAULT_NOF_ROUNDS), 1, skey->safer.key);
   return CRYPT_OK;
}

int safer_k128_setup(const unsigned char *key, int keylen, int numrounds, symmetric_key *skey)
{
   LTC_ARGCHK(key != NULL);
   LTC_ARGCHK(skey != NULL);

   if (numrounds != 0 && (numrounds < 6 || numrounds > SAFER_MAX_NOF_ROUNDS)) {
      return CRYPT_INVALID_ROUNDS;
   }

   if (keylen != 16) {
      return CRYPT_INVALID_KEYSIZE;
   }

   Safer_Expand_Userkey(key, key+8, (unsigned int)(numrounds != 0 ?numrounds:SAFER_K128_DEFAULT_NOF_ROUNDS), 0, skey->safer.key);
   return CRYPT_OK;
}

int safer_sk128_setup(const unsigned char *key, int keylen, int numrounds, symmetric_key *skey)
{
   LTC_ARGCHK(key != NULL);
   LTC_ARGCHK(skey != NULL);

   if (numrounds != 0 && (numrounds < 6 || numrounds > SAFER_MAX_NOF_ROUNDS)) {
      return CRYPT_INVALID_ROUNDS;
   }

   if (keylen != 16) {
      return CRYPT_INVALID_KEYSIZE;
   }

   Safer_Expand_Userkey(key, key+8, (unsigned int)(numrounds != 0?numrounds:SAFER_SK128_DEFAULT_NOF_ROUNDS), 1, skey->safer.key);