| /* |
| * 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; |
| } |
| } |