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* The library is free for all purposes without any express
* guarantee it works.
*
* Tom St Denis, tstdenis82@gmail.com, http://libtom.org
*/
/* calc a value mod 2**b */
int
mp_mod_2d (mp_int * a, int b, mp_int * c)
int x, res;
int x, res;
/* if b is <= 0 then zero the int */
if (b <= 0) {
mp_zero (c);
return MP_OKAY;
}
/* if b is <= 0 then zero the int */
if (b <= 0) {
mp_zero(c);
return MP_OKAY;
}
/* if the modulus is larger than the value than return */
if (b >= (int) (a->used * DIGIT_BIT)) {
res = mp_copy (a, c);
return res;
}
/* if the modulus is larger than the value than return */
if (b >= (int)(a->used * DIGIT_BIT)) {
res = mp_copy(a, c);
return res;
}
/* copy */
if ((res = mp_copy (a, c)) != MP_OKAY) {
return res;
}
/* copy */
if ((res = mp_copy(a, c)) != MP_OKAY) {
return res;
}
/* zero digits above the last digit of the modulus */
for (x = (b / DIGIT_BIT) + (((b % DIGIT_BIT) == 0) ? 0 : 1); x < c->used; x++) {
c->dp[x] = 0;
}
/* clear the digit that is not completely outside/inside the modulus */
c->dp[b / DIGIT_BIT] &=
(mp_digit) ((((mp_digit) 1) << (((mp_digit) b) % DIGIT_BIT)) - ((mp_digit) 1));
mp_clamp (c);
return MP_OKAY;
/* zero digits above the last digit of the modulus */
for (x = (b / DIGIT_BIT) + (((b % DIGIT_BIT) == 0) ? 0 : 1); x < c->used; x++) {
c->dp[x] = 0;
}
/* clear the digit that is not completely outside/inside the modulus */
c->dp[b / DIGIT_BIT] &=
(mp_digit)((((mp_digit) 1) << (((mp_digit) b) % DIGIT_BIT)) - ((mp_digit) 1));
mp_clamp(c);
return MP_OKAY;
}
#endif
/* ref: $Format:%D$ */
/* git commit: $Format:%H$ */
/* commit time: $Format:%ai$ */
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