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src/ltc/ciphers/safer/safer.c  view on Meta::CPAN

#ifdef LTC_SAFER

#ifndef LTC_SAFER_TAB_C
#define LTC_SAFER_TAB_C
#include "safer_tab.c"
#endif

const struct ltc_cipher_descriptor safer_k64_desc = {
   "safer-k64",
   8, 8, 8, 8, LTC_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, NULL, NULL, NULL, NULL, NULL, NULL, NULL
   },

   safer_sk64_desc = {
   "safer-sk64",
   9, 8, 8, 8, LTC_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, NULL, NULL, NULL, NULL, NULL, NULL, NULL
   },

   safer_k128_desc = {
   "safer-k128",
   10, 16, 16, 8, LTC_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, NULL, NULL, NULL, NULL, NULL, NULL, NULL
   },

   safer_sk128_desc = {
   "safer-sk128",
   11, 16, 16, 8, LTC_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, 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 ****************************************************/

#ifdef LTC_CLEAN_STACK
static void s_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[LTC_SAFER_BLOCK_LEN + 1];
    unsigned char kb[LTC_SAFER_BLOCK_LEN + 1];

    if (LTC_SAFER_MAX_NOF_ROUNDS < nof_rounds) {
        nof_rounds = LTC_SAFER_MAX_NOF_ROUNDS;
    }
    *key++ = (unsigned char)nof_rounds;
    ka[LTC_SAFER_BLOCK_LEN] = (unsigned char)0;
    kb[LTC_SAFER_BLOCK_LEN] = (unsigned char)0;
    k = 0;
    for (j = 0; j < LTC_SAFER_BLOCK_LEN; j++) {
        ka[j] = ROL8(userkey_1[j], 5);
        ka[LTC_SAFER_BLOCK_LEN] ^= ka[j];
        kb[j] = *key++ = userkey_2[j];
        kb[LTC_SAFER_BLOCK_LEN] ^= kb[j];
    }
    for (i = 1; i <= nof_rounds; i++) {
        for (j = 0; j < LTC_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 >= (LTC_SAFER_BLOCK_LEN + 1)) { k -= LTC_SAFER_BLOCK_LEN + 1; }
        }
        for (j = 0; j < LTC_SAFER_BLOCK_LEN; j++) {
            if (strengthened) {
                *key++ = (ka[k]
                                + safer_ebox[(int)safer_ebox[(int)((18 * i + j + 1)&0xFF)]]) & 0xFF;
                if (++k == (LTC_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 >= (LTC_SAFER_BLOCK_LEN + 1)) { k -= LTC_SAFER_BLOCK_LEN + 1; }