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com.google.gwt.emul.java.security.SHA256Digest Maven / Gradle / Ivy
/*
* Copyright 2016 Google Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may not
* use this file except in compliance with the License. You may obtain a copy of
* the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations under
* the License.
*/
package java.security;
import java.util.Arrays;
/**
* SHA256 implementation for GWT.
*/
public class SHA256Digest extends MessageDigest {
private static final int WORD_LENGTH = 32;
private static final int[] K = {
0x428a2f98, 0x71374491, 0xb5c0fbcf, 0xe9b5dba5, 0x3956c25b, 0x59f111f1, 0x923f82a4,
0xab1c5ed5, 0xd807aa98, 0x12835b01, 0x243185be, 0x550c7dc3, 0x72be5d74, 0x80deb1fe,
0x9bdc06a7, 0xc19bf174, 0xe49b69c1, 0xefbe4786, 0x0fc19dc6, 0x240ca1cc, 0x2de92c6f,
0x4a7484aa, 0x5cb0a9dc, 0x76f988da, 0x983e5152, 0xa831c66d, 0xb00327c8, 0xbf597fc7,
0xc6e00bf3, 0xd5a79147, 0x06ca6351, 0x14292967, 0x27b70a85, 0x2e1b2138, 0x4d2c6dfc,
0x53380d13, 0x650a7354, 0x766a0abb, 0x81c2c92e, 0x92722c85, 0xa2bfe8a1, 0xa81a664b,
0xc24b8b70, 0xc76c51a3, 0xd192e819, 0xd6990624, 0xf40e3585, 0x106aa070, 0x19a4c116,
0x1e376c08, 0x2748774c, 0x34b0bcb5, 0x391c0cb3, 0x4ed8aa4a, 0x5b9cca4f, 0x682e6ff3,
0x748f82ee, 0x78a5636f, 0x84c87814, 0x8cc70208, 0x90befffa, 0xa4506ceb, 0xbef9a3f7,
0xc67178f2
};
private static final int[] H = {
0x6a09e667, 0xbb67ae85, 0x3c6ef372, 0xa54ff53a,
0x510e527f, 0x9b05688c, 0x1f83d9ab, 0x5be0cd19
};
private int[] hash;
private byte[] wordBuffer;
private int wordOff;
private int[] blockBuffer;
private int blockOff;
private long byteCounter;
SHA256Digest() {
super("SHA-256");
hash = new int[8];
wordBuffer = new byte[4];
blockBuffer = new int[64];
engineReset();
}
@Override
protected void engineReset() {
System.arraycopy(H, 0, hash, 0, 8);
Arrays.fill(wordBuffer, (byte) 0);
Arrays.fill(blockBuffer, 0);
wordOff = 0;
blockOff = 0;
byteCounter = 0;
}
@Override
protected void engineUpdate(byte input) {
wordBuffer[wordOff] = input;
wordOff++;
byteCounter++;
if (wordOff == 4) {
updateWord();
wordOff = 0;
}
}
@Override
protected void engineUpdate(byte[] input, int inOff, int len) {
for (int i = 0; i < len; i++) {
engineUpdate(input[inOff + i]);
}
}
@Override
protected byte[] engineDigest() {
doPadding();
byte[] result = new byte[32];
for (int i = 0; i < 8; i++) {
int2bytes(hash[i], result, i * 4);
}
engineReset();
return result;
}
private void int2bytes(int input, byte[] output, int outOff) {
output[outOff] = (byte) ((input >>> 24) & 0xff);
output[outOff + 1] = (byte) ((input >>> 16) & 0xff);
output[outOff + 2] = (byte) ((input >>> 8) & 0xff);
output[outOff + 3] = (byte) (input & 0xff);
}
private void doPadding() {
long length = byteCounter << 3;
engineUpdate((byte) 128);
while (wordOff != 0) {
engineUpdate((byte) 0);
}
Arrays.fill(blockBuffer, blockOff, 64, 0);
if (blockOff > 14) {
computeBlock();
Arrays.fill(blockBuffer, 0);
}
blockBuffer[14] = (int) (length >>> 32);
blockBuffer[15] = enforceOverflow((int) length);
computeBlock();
}
private void updateWord() {
blockBuffer[blockOff] = ((wordBuffer[0] & 0xff) << 24) | ((wordBuffer[1] & 0xff) << 16)
| ((wordBuffer[2] & 0xff) << 8) | (wordBuffer[3] & 0xff);
blockOff++;
if (blockOff == 16) {
computeBlock();
}
}
private void computeBlock() {
// Prepare message schedule.
for (int t = 16; t < blockBuffer.length; t++) {
blockBuffer[t] = enforceOverflow(sigma1(blockBuffer[t - 2]) + blockBuffer[t - 7]
+ sigma0(blockBuffer[t - 15]) + blockBuffer[t - 16]);
}
// Init working variables with hash value from previously round.
int a = hash[0];
int b = hash[1];
int c = hash[2];
int d = hash[3];
int e = hash[4];
int f = hash[5];
int g = hash[6];
int h = hash[7];
for (int t = 0; t < 64; t++) {
int t1 = h + sum1(e) + ch(e, f, g) + K[t] + blockBuffer[t];
int t2 = sum0(a) + maj(a, b, c);
h = g;
g = f;
f = e;
e = enforceOverflow(d + t1);
d = c;
c = b;
b = a;
a = enforceOverflow(t1 + t2);
}
// Compute intermediate hash.
hash[0] = enforceOverflow(a + hash[0]);
hash[1] = enforceOverflow(b + hash[1]);
hash[2] = enforceOverflow(c + hash[2]);
hash[3] = enforceOverflow(d + hash[3]);
hash[4] = enforceOverflow(e + hash[4]);
hash[5] = enforceOverflow(f + hash[5]);
hash[6] = enforceOverflow(g + hash[6]);
hash[7] = enforceOverflow(h + hash[7]);
blockOff = 0;
}
private int sum0(int x) {
return rightRotate(x, 2) ^ rightRotate(x, 13) ^ rightRotate(x, 22);
}
private int sum1(int x) {
return rightRotate(x, 6) ^ rightRotate(x, 11) ^ rightRotate(x, 25);
}
private int sigma0(int x) {
return rightRotate(x, 7) ^ rightRotate(x, 18) ^ (x >>> 3);
}
private int sigma1(int x) {
return rightRotate(x, 17) ^ rightRotate(x, 19) ^ (x >>> 10);
}
private int rightRotate(int x, int n) {
return (x >>> n) | enforceOverflow(x << (WORD_LENGTH - n));
}
private int ch(int x, int y, int z) {
return enforceOverflow(((x & y) ^ ((~x) & z)));
}
private int maj(int x, int y, int z) {
return (x & y) ^ (x & z) ^ (y & z);
}
// GWT emulates integer with double and doesn't overflow. Enfore it by a integer mask.
private int enforceOverflow(int input) {
return input & 0xffffffff;
}
}
