// 
// Decompiled by Procyon v0.6.0
// 

package com.google.crypto.tink.internal;

import java.math.BigInteger;

final class Ed25519Constants
{
    static final long[] D;
    static final long[] D2;
    static final long[] SQRTM1;
    static final Ed25519.CachedXYT[][] B_TABLE;
    static final Ed25519.CachedXYT[] B2;
    private static final BigInteger P_BI;
    private static final BigInteger D_BI;
    private static final BigInteger D2_BI;
    private static final BigInteger SQRTM1_BI;
    
    private static BigInteger recoverX(final BigInteger y) {
        final BigInteger xx = y.pow(2).subtract(BigInteger.ONE).multiply(Ed25519Constants.D_BI.multiply(y.pow(2)).add(BigInteger.ONE).modInverse(Ed25519Constants.P_BI));
        BigInteger x = xx.modPow(Ed25519Constants.P_BI.add(BigInteger.valueOf(3L)).divide(BigInteger.valueOf(8L)), Ed25519Constants.P_BI);
        if (!x.pow(2).subtract(xx).mod(Ed25519Constants.P_BI).equals(BigInteger.ZERO)) {
            x = x.multiply(Ed25519Constants.SQRTM1_BI).mod(Ed25519Constants.P_BI);
        }
        if (x.testBit(0)) {
            x = Ed25519Constants.P_BI.subtract(x);
        }
        return x;
    }
    
    private static Point edwards(final Point a, final Point b) {
        final Point o = new Point();
        final BigInteger xxyy = Ed25519Constants.D_BI.multiply(a.x.multiply(b.x).multiply(a.y).multiply(b.y)).mod(Ed25519Constants.P_BI);
        o.x = a.x.multiply(b.y).add(b.x.multiply(a.y)).multiply(BigInteger.ONE.add(xxyy).modInverse(Ed25519Constants.P_BI)).mod(Ed25519Constants.P_BI);
        o.y = a.y.multiply(b.y).add(a.x.multiply(b.x)).multiply(BigInteger.ONE.subtract(xxyy).modInverse(Ed25519Constants.P_BI)).mod(Ed25519Constants.P_BI);
        return o;
    }
    
    private static byte[] toLittleEndian(final BigInteger n) {
        final byte[] b = new byte[32];
        final byte[] nBytes = n.toByteArray();
        System.arraycopy(nBytes, 0, b, 32 - nBytes.length, nBytes.length);
        for (int i = 0; i < b.length / 2; ++i) {
            final byte t = b[i];
            b[i] = b[b.length - i - 1];
            b[b.length - i - 1] = t;
        }
        return b;
    }
    
    private static Ed25519.CachedXYT getCachedXYT(final Point p) {
        return new Ed25519.CachedXYT(Field25519.expand(toLittleEndian(p.y.add(p.x).mod(Ed25519Constants.P_BI))), Field25519.expand(toLittleEndian(p.y.subtract(p.x).mod(Ed25519Constants.P_BI))), Field25519.expand(toLittleEndian(Ed25519Constants.D2_BI.multiply(p.x).multiply(p.y).mod(Ed25519Constants.P_BI))));
    }
    
    private Ed25519Constants() {
    }
    
    static {
        P_BI = BigInteger.valueOf(2L).pow(255).subtract(BigInteger.valueOf(19L));
        D_BI = BigInteger.valueOf(-121665L).multiply(BigInteger.valueOf(121666L).modInverse(Ed25519Constants.P_BI)).mod(Ed25519Constants.P_BI);
        D2_BI = BigInteger.valueOf(2L).multiply(Ed25519Constants.D_BI).mod(Ed25519Constants.P_BI);
        SQRTM1_BI = BigInteger.valueOf(2L).modPow(Ed25519Constants.P_BI.subtract(BigInteger.ONE).divide(BigInteger.valueOf(4L)), Ed25519Constants.P_BI);
        final Point b = new Point();
        b.y = BigInteger.valueOf(4L).multiply(BigInteger.valueOf(5L).modInverse(Ed25519Constants.P_BI)).mod(Ed25519Constants.P_BI);
        b.x = recoverX(b.y);
        D = Field25519.expand(toLittleEndian(Ed25519Constants.D_BI));
        D2 = Field25519.expand(toLittleEndian(Ed25519Constants.D2_BI));
        SQRTM1 = Field25519.expand(toLittleEndian(Ed25519Constants.SQRTM1_BI));
        Point bi = b;
        B_TABLE = new Ed25519.CachedXYT[32][8];
        for (int i = 0; i < 32; ++i) {
            Point bij = bi;
            for (int j = 0; j < 8; ++j) {
                Ed25519Constants.B_TABLE[i][j] = getCachedXYT(bij);
                bij = edwards(bij, bi);
            }
            for (int j = 0; j < 8; ++j) {
                bi = edwards(bi, bi);
            }
        }
        bi = b;
        final Point b2 = edwards(b, b);
        B2 = new Ed25519.CachedXYT[8];
        for (int k = 0; k < 8; ++k) {
            Ed25519Constants.B2[k] = getCachedXYT(bi);
            bi = edwards(bi, b2);
        }
    }
    
    private static class Point
    {
        private BigInteger x;
        private BigInteger y;
    }
}