org.whispersystems.curve25519.java.fe_mul121666 Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of curve25519-java Show documentation

Curve25519 library for Java

There is a newer version: 0.5.0

package org.whispersystems.curve25519.java;

public class fe_mul121666 {

//CONVERT #include "fe.h"
//CONVERT #include "long.h"

/*
h = f * 121666
Can overlap h with f.

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

Postconditions:
   |h| bounded by 1.1*2^25,1.1*2^24,1.1*2^25,1.1*2^24,etc.
*/

public static void fe_mul121666(int[] h,int[] f)
{
  int f0 = f[0];
  int f1 = f[1];
  int f2 = f[2];
  int f3 = f[3];
  int f4 = f[4];
  int f5 = f[5];
  int f6 = f[6];
  int f7 = f[7];
  int f8 = f[8];
  int f9 = f[9];
  long h0 = f0 * (long) 121666;
  long h1 = f1 * (long) 121666;
  long h2 = f2 * (long) 121666;
  long h3 = f3 * (long) 121666;
  long h4 = f4 * (long) 121666;
  long h5 = f5 * (long) 121666;
  long h6 = f6 * (long) 121666;
  long h7 = f7 * (long) 121666;
  long h8 = f8 * (long) 121666;
  long h9 = f9 * (long) 121666;
  long carry0;
  long carry1;
  long carry2;
  long carry3;
  long carry4;
  long carry5;
  long carry6;
  long carry7;
  long carry8;
  long carry9;

  carry9 = (h9 + (long) (1<<24)) >> 25; h0 += carry9 * 19; h9 -= carry9 << 25;
  carry1 = (h1 + (long) (1<<24)) >> 25; h2 += carry1; h1 -= carry1 << 25;
  carry3 = (h3 + (long) (1<<24)) >> 25; h4 += carry3; h3 -= carry3 << 25;
  carry5 = (h5 + (long) (1<<24)) >> 25; h6 += carry5; h5 -= carry5 << 25;
  carry7 = (h7 + (long) (1<<24)) >> 25; h8 += carry7; h7 -= carry7 << 25;

  carry0 = (h0 + (long) (1<<25)) >> 26; h1 += carry0; h0 -= carry0 << 26;
  carry2 = (h2 + (long) (1<<25)) >> 26; h3 += carry2; h2 -= carry2 << 26;
  carry4 = (h4 + (long) (1<<25)) >> 26; h5 += carry4; h4 -= carry4 << 26;
  carry6 = (h6 + (long) (1<<25)) >> 26; h7 += carry6; h6 -= carry6 << 26;
  carry8 = (h8 + (long) (1<<25)) >> 26; h9 += carry8; h8 -= carry8 << 26;

  h[0] = (int)h0;
  h[1] = (int)h1;
  h[2] = (int)h2;
  h[3] = (int)h3;
  h[4] = (int)h4;
  h[5] = (int)h5;
  h[6] = (int)h6;
  h[7] = (int)h7;
  h[8] = (int)h8;
  h[9] = (int)h9;
}


}