tfm_desc.c

开源的目录加密软件

   XFREE(a);
}

static int exptmod(void *a, void *b, void *c, void *d)
{
   LTC_ARGCHK(a != NULL);
   LTC_ARGCHK(b != NULL);
   LTC_ARGCHK(c != NULL);
   LTC_ARGCHK(d != NULL);
   return tfm_to_ltc_error(fp_exptmod(a,b,c,d));
}   

static int isprime(void *a, int *b)
{
   LTC_ARGCHK(a != NULL);
   LTC_ARGCHK(b != NULL);
   *b = (fp_isprime(a) == FP_YES) ? LTC_MP_YES : LTC_MP_NO;
   return CRYPT_OK;
}

#if defined(MECC) && defined(MECC_ACCEL)

static int tfm_ecc_projective_dbl_point(ecc_point *P, ecc_point *R, void *modulus, void *Mp)
{
   fp_int t1, t2;
   fp_digit mp;

   LTC_ARGCHK(P       != NULL);
   LTC_ARGCHK(R       != NULL);
   LTC_ARGCHK(modulus != NULL);
   LTC_ARGCHK(Mp      != NULL);

   mp = *((fp_digit*)Mp);

   fp_init(&t1);
   fp_init(&t2);

   if (P != R) {
      fp_copy(P->x, R->x);
      fp_copy(P->y, R->y);
      fp_copy(P->z, R->z);
   }

   /* t1 = Z * Z */
   fp_sqr(R->z, &t1);
   fp_montgomery_reduce(&t1, modulus, mp);
   /* Z = Y * Z */
   fp_mul(R->z, R->y, R->z);
   fp_montgomery_reduce(R->z, modulus, mp);
   /* Z = 2Z */
   fp_add(R->z, R->z, R->z);
   if (fp_cmp(R->z, modulus) != FP_LT) {
      fp_sub(R->z, modulus, R->z);
   }
   
   /* &t2 = X - T1 */
   fp_sub(R->x, &t1, &t2);
   if (fp_cmp_d(&t2, 0) == FP_LT) {
      fp_add(&t2, modulus, &t2);
   }
   /* T1 = X + T1 */
   fp_add(&t1, R->x, &t1);
   if (fp_cmp(&t1, modulus) != FP_LT) {
      fp_sub(&t1, modulus, &t1);
   }
   /* T2 = T1 * T2 */
   fp_mul(&t1, &t2, &t2);
   fp_montgomery_reduce(&t2, modulus, mp);
   /* T1 = 2T2 */
   fp_add(&t2, &t2, &t1);
   if (fp_cmp(&t1, modulus) != FP_LT) {
      fp_sub(&t1, modulus, &t1);
   }
   /* T1 = T1 + T2 */
   fp_add(&t1, &t2, &t1);
   if (fp_cmp(&t1, modulus) != FP_LT) {
      fp_sub(&t1, modulus, &t1);
   }

   /* Y = 2Y */
   fp_add(R->y, R->y, R->y);
   if (fp_cmp(R->y, modulus) != FP_LT) {
      fp_sub(R->y, modulus, R->y);
   }
   /* Y = Y * Y */
   fp_sqr(R->y, R->y);
   fp_montgomery_reduce(R->y, modulus, mp);
   /* T2 = Y * Y */
   fp_sqr(R->y, &t2);
   fp_montgomery_reduce(&t2, modulus, mp);
   /* T2 = T2/2 */
   if (fp_isodd(&t2)) {
      fp_add(&t2, modulus, &t2);
   }
   fp_div_2(&t2, &t2);
   /* Y = Y * X */
   fp_mul(R->y, R->x, R->y);
   fp_montgomery_reduce(R->y, modulus, mp);

   /* X  = T1 * T1 */
   fp_sqr(&t1, R->x);
   fp_montgomery_reduce(R->x, modulus, mp);
   /* X = X - Y */
   fp_sub(R->x, R->y, R->x);
   if (fp_cmp_d(R->x, 0) == FP_LT) {
      fp_add(R->x, modulus, R->x);
   }
   /* X = X - Y */
   fp_sub(R->x, R->y, R->x);
   if (fp_cmp_d(R->x, 0) == FP_LT) {
      fp_add(R->x, modulus, R->x);
   }

   /* Y = Y - X */     
   fp_sub(R->y, R->x, R->y);
   if (fp_cmp_d(R->y, 0) == FP_LT) {
      fp_add(R->y, modulus, R->y);
   }
   /* Y = Y * T1 */
   fp_mul(R->y, &t1, R->y);
   fp_montgomery_reduce(R->y, modulus, mp);
   /* Y = Y - T2 */
   fp_sub(R->y, &t2, R->y);
   if (fp_cmp_d(R->y, 0) == FP_LT) {
      fp_add(R->y, modulus, R->y);
   }
 
   return CRYPT_OK;
}

/**
   Add two ECC points
   @param P        The point to add
   @param Q        The point to add
   @param R        [out] The destination of the double
   @param modulus  The modulus of the field the ECC curve is in
   @param mp       The "b" value from montgomery_setup()
   @return CRYPT_OK on success
*/
static int tfm_ecc_projective_add_point(ecc_point *P, ecc_point *Q, ecc_point *R, void *modulus, void *Mp)
{
   fp_int  t1, t2, x, y, z;
   fp_digit mp;  
   
   LTC_ARGCHK(P       != NULL);
   LTC_ARGCHK(Q       != NULL);
   LTC_ARGCHK(R       != NULL);
   LTC_ARGCHK(modulus != NULL);
   LTC_ARGCHK(Mp      != NULL);

   mp = *((fp_digit*)Mp);

   fp_init(&t1);
   fp_init(&t2);
   fp_init(&x);
   fp_init(&y);
   fp_init(&z);

   /* should we dbl instead? */
   fp_sub(modulus, Q->y, &t1);
   if ( (fp_cmp(P->x, Q->x) == FP_EQ) && 
        (Q->z != NULL && fp_cmp(P->z, Q->z) == FP_EQ) &&
        (fp_cmp(P->y, Q->y) == FP_EQ || fp_cmp(P->y, &t1) == FP_EQ)) {
        return tfm_ecc_projective_dbl_point(P, R, modulus, Mp);
   }

   fp_copy(P->x, &x);
   fp_copy(P->y, &y);
   fp_copy(P->z, &z);

   /* if Z is one then these are no-operations */
   if (Q->z != NULL) {
      /* T1 = Z' * Z' */
      fp_sqr(Q->z, &t1);
      fp_montgomery_reduce(&t1, modulus, mp);
      /* X = X * T1 */
      fp_mul(&t1, &x, &x);
      fp_montgomery_reduce(&x, modulus, mp);
      /* T1 = Z' * T1 */
      fp_mul(Q->z, &t1, &t1);
      fp_montgomery_reduce(&t1, modulus, mp);
      /* Y = Y * T1 */
      fp_mul(&t1, &y, &y);
      fp_montgomery_reduce(&y, modulus, mp);
   }

   /* T1 = Z*Z */
   fp_sqr(&z, &t1);
   fp_montgomery_reduce(&t1, modulus, mp);
   /* T2 = X' * T1 */
   fp_mul(Q->x, &t1, &t2);
   fp_montgomery_reduce(&t2, modulus, mp);
   /* T1 = Z * T1 */
   fp_mul(&z, &t1, &t1);
   fp_montgomery_reduce(&t1, modulus, mp);
   /* T1 = Y' * T1 */
   fp_mul(Q->y, &t1, &t1);
   fp_montgomery_reduce(&t1, modulus, mp);

   /* Y = Y - T1 */
   fp_sub(&y, &t1, &y);
   if (fp_cmp_d(&y, 0) == FP_LT) {
      fp_add(&y, modulus, &y);
   }
   /* T1 = 2T1 */
   fp_add(&t1, &t1, &t1);
   if (fp_cmp(&t1, modulus) != FP_LT) {
      fp_sub(&t1, modulus, &t1);
   }
   /* T1 = Y + T1 */
   fp_add(&t1, &y, &t1);
   if (fp_cmp(&t1, modulus) != FP_LT) {
      fp_sub(&t1, modulus, &t1);
   }
   /* X = X - T2 */
   fp_sub(&x, &t2, &x);
   if (fp_cmp_d(&x, 0) == FP_LT) {
      fp_add(&x, modulus, &x);
   }
   /* T2 = 2T2 */
   fp_add(&t2, &t2, &t2);
   if (fp_cmp(&t2, modulus) != FP_LT) {
      fp_sub(&t2, modulus, &t2);
   }
   /* T2 = X + T2 */
   fp_add(&t2, &x, &t2);
   if (fp_cmp(&t2, modulus) != FP_LT) {
      fp_sub(&t2, modulus, &t2);
   }

   /* if Z' != 1 */
   if (Q->z != NULL) {
      /* Z = Z * Z' */
      fp_mul(&z, Q->z, &z);
      fp_montgomery_reduce(&z, modulus, mp);
   }

   /* Z = Z * X */
   fp_mul(&z, &x, &z);
   fp_montgomery_reduce(&z, modulus, mp);

   /* T1 = T1 * X  */
   fp_mul(&t1, &x, &t1);
   fp_montgomery_reduce(&t1, modulus, mp);
   /* X = X * X */
   fp_sqr(&x, &x);
   fp_montgomery_reduce(&x, modulus, mp);
   /* T2 = T2 * x */
   fp_mul(&t2, &x, &t2);
   fp_montgomery_reduce(&t2, modulus, mp);
   /* T1 = T1 * X  */
   fp_mul(&t1, &x, &t1);
   fp_montgomery_reduce(&t1, modulus, mp);
 
   /* X = Y*Y */
   fp_sqr(&y, &x);
   fp_montgomery_reduce(&x, modulus, mp);
   /* X = X - T2 */
   fp_sub(&x, &t2, &x);
   if (fp_cmp_d(&x, 0) == FP_LT) {
      fp_add(&x, modulus, &x);
   }

   /* T2 = T2 - X */
   fp_sub(&t2, &x, &t2);
   if (fp_cmp_d(&t2, 0) == FP_LT) {
      fp_add(&t2, modulus, &t2);
   } 
   /* T2 = T2 - X */
   fp_sub(&t2, &x, &t2);
   if (fp_cmp_d(&t2, 0) == FP_LT) {
      fp_add(&t2, modulus, &t2);
   }
   /* T2 = T2 * Y */
   fp_mul(&t2, &y, &t2);
   fp_montgomery_reduce(&t2, modulus, mp);
   /* Y = T2 - T1 */
   fp_sub(&t2, &t1, &y);
   if (fp_cmp_d(&y, 0) == FP_LT) {
      fp_add(&y, modulus, &y);
   }
   /* Y = Y/2 */
   if (fp_isodd(&y)) {
      fp_add(&y, modulus, &y);
   }
   fp_div_2(&y, &y);

   fp_copy(&x, R->x);
   fp_copy(&y, R->y);
   fp_copy(&z, R->z);
   
   return CRYPT_OK;
}


#endif

const ltc_math_descriptor tfm_desc = {

   "TomsFastMath",
   (int)DIGIT_BIT,

   &init,
   &init_copy,
   &deinit,

   &neg,
   &copy,

   &set_int,
   &get_int,
   &get_digit,
   &get_digit_count,
   &compare,
   &compare_d,
   &count_bits,
   &count_lsb_bits,
   &twoexpt,

   &read_radix,
   &write_radix,
   &unsigned_size,
   &unsigned_write,
   &unsigned_read,

   &add,
   &addi,
   &sub,
   &subi,
   &mul,
   &muli,
   &sqr,
   &divide,
   &div_2,
   &modi,
   &gcd,
   &lcm,

   &mulmod,
   &sqrmod,
   &invmod,

   &montgomery_setup,
   &montgomery_normalization,
   &montgomery_reduce,
   &montgomery_deinit,

   &exptmod,
   &isprime,

#ifdef MECC
#ifdef MECC_FP
   &ltc_ecc_fp_mulmod,
#else
   &ltc_ecc_mulmod,
#endif /* MECC_FP */
#ifdef MECC_ACCEL
   &tfm_ecc_projective_add_point,
   &tfm_ecc_projective_dbl_point,
#else
   &ltc_ecc_projective_add_point,
   &ltc_ecc_projective_dbl_point,
#endif
   &ltc_ecc_map,
#else
   NULL, NULL, NULL, NULL,
#endif

#ifdef MRSA
   &rsa_make_key,
   &rsa_exptmod,
#else
   NULL, NULL
#endif
   
};


#endif

/* $Source: /cvs/libtom/libtomcrypt/src/math/tfm_desc.c,v $ */
/* $Revision: 1.23 $ */
/* $Date: 2006/06/09 22:17:53 $ */