fe_isnegative.java

package im.actor.crypto.primitives.curve25519;

public class fe_isnegative {

//CONVERT #include "fe.h"

/*
return 1 if f is in {1,3,5,...,q-2}
return 0 if f is in {0,2,4,...,q-1}

Preconditions:
   |f| bounded by 1.1*2^26,1.1*2^25,1.1*2^26,1.1*2^25,etc.
*/

public static int fe_isnegative(int[] f)
{
  byte[] s = new byte[32];
  fe_tobytes.fe_tobytes(s,f);
  return s[0] & 1;
}


}