org.whispersystems.curve25519.java.fe_sq2 Maven / Gradle / Ivy
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Curve25519 library for Java
package org.whispersystems.curve25519.java;
public class fe_sq2 {
//CONVERT #include "fe.h"
//CONVERT #include "long.h"
/*
h = 2 * f * f
Can overlap h with f.
Preconditions:
|f| bounded by 1.65*2^26,1.65*2^25,1.65*2^26,1.65*2^25,etc.
Postconditions:
|h| bounded by 1.01*2^25,1.01*2^24,1.01*2^25,1.01*2^24,etc.
*/
/*
See fe_mul.c for discussion of implementation strategy.
*/
public static void fe_sq2(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];
int f0_2 = 2 * f0;
int f1_2 = 2 * f1;
int f2_2 = 2 * f2;
int f3_2 = 2 * f3;
int f4_2 = 2 * f4;
int f5_2 = 2 * f5;
int f6_2 = 2 * f6;
int f7_2 = 2 * f7;
int f5_38 = 38 * f5; /* 1.959375*2^30 */
int f6_19 = 19 * f6; /* 1.959375*2^30 */
int f7_38 = 38 * f7; /* 1.959375*2^30 */
int f8_19 = 19 * f8; /* 1.959375*2^30 */
int f9_38 = 38 * f9; /* 1.959375*2^30 */
long f0f0 = f0 * (long) f0;
long f0f1_2 = f0_2 * (long) f1;
long f0f2_2 = f0_2 * (long) f2;
long f0f3_2 = f0_2 * (long) f3;
long f0f4_2 = f0_2 * (long) f4;
long f0f5_2 = f0_2 * (long) f5;
long f0f6_2 = f0_2 * (long) f6;
long f0f7_2 = f0_2 * (long) f7;
long f0f8_2 = f0_2 * (long) f8;
long f0f9_2 = f0_2 * (long) f9;
long f1f1_2 = f1_2 * (long) f1;
long f1f2_2 = f1_2 * (long) f2;
long f1f3_4 = f1_2 * (long) f3_2;
long f1f4_2 = f1_2 * (long) f4;
long f1f5_4 = f1_2 * (long) f5_2;
long f1f6_2 = f1_2 * (long) f6;
long f1f7_4 = f1_2 * (long) f7_2;
long f1f8_2 = f1_2 * (long) f8;
long f1f9_76 = f1_2 * (long) f9_38;
long f2f2 = f2 * (long) f2;
long f2f3_2 = f2_2 * (long) f3;
long f2f4_2 = f2_2 * (long) f4;
long f2f5_2 = f2_2 * (long) f5;
long f2f6_2 = f2_2 * (long) f6;
long f2f7_2 = f2_2 * (long) f7;
long f2f8_38 = f2_2 * (long) f8_19;
long f2f9_38 = f2 * (long) f9_38;
long f3f3_2 = f3_2 * (long) f3;
long f3f4_2 = f3_2 * (long) f4;
long f3f5_4 = f3_2 * (long) f5_2;
long f3f6_2 = f3_2 * (long) f6;
long f3f7_76 = f3_2 * (long) f7_38;
long f3f8_38 = f3_2 * (long) f8_19;
long f3f9_76 = f3_2 * (long) f9_38;
long f4f4 = f4 * (long) f4;
long f4f5_2 = f4_2 * (long) f5;
long f4f6_38 = f4_2 * (long) f6_19;
long f4f7_38 = f4 * (long) f7_38;
long f4f8_38 = f4_2 * (long) f8_19;
long f4f9_38 = f4 * (long) f9_38;
long f5f5_38 = f5 * (long) f5_38;
long f5f6_38 = f5_2 * (long) f6_19;
long f5f7_76 = f5_2 * (long) f7_38;
long f5f8_38 = f5_2 * (long) f8_19;
long f5f9_76 = f5_2 * (long) f9_38;
long f6f6_19 = f6 * (long) f6_19;
long f6f7_38 = f6 * (long) f7_38;
long f6f8_38 = f6_2 * (long) f8_19;
long f6f9_38 = f6 * (long) f9_38;
long f7f7_38 = f7 * (long) f7_38;
long f7f8_38 = f7_2 * (long) f8_19;
long f7f9_76 = f7_2 * (long) f9_38;
long f8f8_19 = f8 * (long) f8_19;
long f8f9_38 = f8 * (long) f9_38;
long f9f9_38 = f9 * (long) f9_38;
long h0 = f0f0 +f1f9_76+f2f8_38+f3f7_76+f4f6_38+f5f5_38;
long h1 = f0f1_2+f2f9_38+f3f8_38+f4f7_38+f5f6_38;
long h2 = f0f2_2+f1f1_2 +f3f9_76+f4f8_38+f5f7_76+f6f6_19;
long h3 = f0f3_2+f1f2_2 +f4f9_38+f5f8_38+f6f7_38;
long h4 = f0f4_2+f1f3_4 +f2f2 +f5f9_76+f6f8_38+f7f7_38;
long h5 = f0f5_2+f1f4_2 +f2f3_2 +f6f9_38+f7f8_38;
long h6 = f0f6_2+f1f5_4 +f2f4_2 +f3f3_2 +f7f9_76+f8f8_19;
long h7 = f0f7_2+f1f6_2 +f2f5_2 +f3f4_2 +f8f9_38;
long h8 = f0f8_2+f1f7_4 +f2f6_2 +f3f5_4 +f4f4 +f9f9_38;
long h9 = f0f9_2+f1f8_2 +f2f7_2 +f3f6_2 +f4f5_2;
long carry0;
long carry1;
long carry2;
long carry3;
long carry4;
long carry5;
long carry6;
long carry7;
long carry8;
long carry9;
h0 += h0;
h1 += h1;
h2 += h2;
h3 += h3;
h4 += h4;
h5 += h5;
h6 += h6;
h7 += h7;
h8 += h8;
h9 += h9;
carry0 = (h0 + (long) (1<<25)) >> 26; h1 += carry0; h0 -= carry0 << 26;
carry4 = (h4 + (long) (1<<25)) >> 26; h5 += carry4; h4 -= carry4 << 26;
carry1 = (h1 + (long) (1<<24)) >> 25; h2 += carry1; h1 -= carry1 << 25;
carry5 = (h5 + (long) (1<<24)) >> 25; h6 += carry5; h5 -= carry5 << 25;
carry2 = (h2 + (long) (1<<25)) >> 26; h3 += carry2; h2 -= carry2 << 26;
carry6 = (h6 + (long) (1<<25)) >> 26; h7 += carry6; h6 -= carry6 << 26;
carry3 = (h3 + (long) (1<<24)) >> 25; h4 += carry3; h3 -= carry3 << 25;
carry7 = (h7 + (long) (1<<24)) >> 25; h8 += carry7; h7 -= carry7 << 25;
carry4 = (h4 + (long) (1<<25)) >> 26; h5 += carry4; h4 -= carry4 << 26;
carry8 = (h8 + (long) (1<<25)) >> 26; h9 += carry8; h8 -= carry8 << 26;
carry9 = (h9 + (long) (1<<24)) >> 25; h0 += carry9 * 19; h9 -= carry9 << 25;
carry0 = (h0 + (long) (1<<25)) >> 26; h1 += carry0; h0 -= carry0 << 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;
}
}