void bigint_reduce(bigint_t* a, const bigint_t* r);
void bigint_expmod_u(bigint_t* dest, const bigint_t* a, const bigint_t* exp, const bigint_t* r);
void bigint_gcdext(bigint_t* gcd, bigint_t* a, bigint_t* b, const bigint_t* x, const bigint_t* y);
void bigint_reduce(bigint_t* a, const bigint_t* r);
void bigint_expmod_u(bigint_t* dest, const bigint_t* a, const bigint_t* exp, const bigint_t* r);
void bigint_gcdext(bigint_t* gcd, bigint_t* a, bigint_t* b, const bigint_t* x, const bigint_t* y);
-void bigint_inverse(bigint_t* dest, bigint_t* a, bigint_t* m);
-
+void bigint_inverse(bigint_t* dest, const bigint_t* a, const bigint_t* m);
+void bigint_changeendianess(bigint_t* a);