| Index: mojo/public/dart/third_party/crypto/lib/src/hash_utils.dart
|
| diff --git a/mojo/public/dart/third_party/crypto/lib/src/hash_utils.dart b/mojo/public/dart/third_party/crypto/lib/src/hash_utils.dart
|
| new file mode 100644
|
| index 0000000000000000000000000000000000000000..12bcb0dc78db2edb206be2a041ad2b8d1a2ccaed
|
| --- /dev/null
|
| +++ b/mojo/public/dart/third_party/crypto/lib/src/hash_utils.dart
|
| @@ -0,0 +1,151 @@
|
| +// Copyright (c) 2012, the Dart project authors. Please see the AUTHORS file
|
| +// for details. All rights reserved. Use of this source code is governed by a
|
| +// BSD-style license that can be found in the LICENSE file.
|
| +
|
| +part of crypto;
|
| +
|
| +// Constants.
|
| +const _MASK_8 = 0xff;
|
| +const _MASK_32 = 0xffffffff;
|
| +const _BITS_PER_BYTE = 8;
|
| +const _BYTES_PER_WORD = 4;
|
| +
|
| +// Helper functions used by more than one hasher.
|
| +
|
| +// Rotate left limiting to unsigned 32-bit values.
|
| +int _rotl32(int val, int shift) {
|
| + var mod_shift = shift & 31;
|
| + return ((val << mod_shift) & _MASK_32) |
|
| + ((val & _MASK_32) >> (32 - mod_shift));
|
| +}
|
| +
|
| +// Base class encapsulating common behavior for cryptographic hash
|
| +// functions.
|
| +abstract class _HashBase implements Hash {
|
| + final int _chunkSizeInWords;
|
| + final int _digestSizeInWords;
|
| + final bool _bigEndianWords;
|
| + final Uint32List _currentChunk;
|
| + final Uint32List _h;
|
| + int _lengthInBytes = 0;
|
| + List<int> _pendingData;
|
| + bool _digestCalled = false;
|
| +
|
| + _HashBase(int chunkSizeInWords,
|
| + int digestSizeInWords,
|
| + bool this._bigEndianWords)
|
| + : _pendingData = [],
|
| + _currentChunk = new Uint32List(chunkSizeInWords),
|
| + _h = new Uint32List(digestSizeInWords),
|
| + _chunkSizeInWords = chunkSizeInWords,
|
| + _digestSizeInWords = digestSizeInWords;
|
| +
|
| + // Update the hasher with more data.
|
| + void add(List<int> data) {
|
| + if (_digestCalled) {
|
| + throw new StateError(
|
| + 'Hash update method called after digest was retrieved');
|
| + }
|
| + _lengthInBytes += data.length;
|
| + _pendingData.addAll(data);
|
| + _iterate();
|
| + }
|
| +
|
| + // Finish the hash computation and return the digest string.
|
| + List<int> close() {
|
| + if (_digestCalled) {
|
| + return _resultAsBytes();
|
| + }
|
| + _digestCalled = true;
|
| + _finalizeData();
|
| + _iterate();
|
| + assert(_pendingData.length == 0);
|
| + return _resultAsBytes();
|
| + }
|
| +
|
| + // Returns the block size of the hash in bytes.
|
| + int get blockSize {
|
| + return _chunkSizeInWords * _BYTES_PER_WORD;
|
| + }
|
| +
|
| + // One round of the hash computation.
|
| + void _updateHash(Uint32List m);
|
| +
|
| + // Helper methods.
|
| + int _add32(x, y) => (x + y) & _MASK_32;
|
| + int _roundUp(val, n) => (val + n - 1) & -n;
|
| +
|
| + // Compute the final result as a list of bytes from the hash words.
|
| + List<int> _resultAsBytes() {
|
| + var result = [];
|
| + for (var i = 0; i < _h.length; i++) {
|
| + result.addAll(_wordToBytes(_h[i]));
|
| + }
|
| + return result;
|
| + }
|
| +
|
| + // Converts a list of bytes to a chunk of 32-bit words.
|
| + void _bytesToChunk(List<int> data, int dataIndex) {
|
| + assert((data.length - dataIndex) >= (_chunkSizeInWords * _BYTES_PER_WORD));
|
| +
|
| + for (var wordIndex = 0; wordIndex < _chunkSizeInWords; wordIndex++) {
|
| + var w3 = _bigEndianWords ? data[dataIndex] : data[dataIndex + 3];
|
| + var w2 = _bigEndianWords ? data[dataIndex + 1] : data[dataIndex + 2];
|
| + var w1 = _bigEndianWords ? data[dataIndex + 2] : data[dataIndex + 1];
|
| + var w0 = _bigEndianWords ? data[dataIndex + 3] : data[dataIndex];
|
| + dataIndex += 4;
|
| + var word = (w3 & 0xff) << 24;
|
| + word |= (w2 & _MASK_8) << 16;
|
| + word |= (w1 & _MASK_8) << 8;
|
| + word |= (w0 & _MASK_8);
|
| + _currentChunk[wordIndex] = word;
|
| + }
|
| + }
|
| +
|
| + // Convert a 32-bit word to four bytes.
|
| + List<int> _wordToBytes(int word) {
|
| + List bytes = new List<int>(_BYTES_PER_WORD);
|
| + bytes[0] = (word >> (_bigEndianWords ? 24 : 0)) & _MASK_8;
|
| + bytes[1] = (word >> (_bigEndianWords ? 16 : 8)) & _MASK_8;
|
| + bytes[2] = (word >> (_bigEndianWords ? 8 : 16)) & _MASK_8;
|
| + bytes[3] = (word >> (_bigEndianWords ? 0 : 24)) & _MASK_8;
|
| + return bytes;
|
| + }
|
| +
|
| + // Iterate through data updating the hash computation for each
|
| + // chunk.
|
| + void _iterate() {
|
| + var len = _pendingData.length;
|
| + var chunkSizeInBytes = _chunkSizeInWords * _BYTES_PER_WORD;
|
| + if (len >= chunkSizeInBytes) {
|
| + var index = 0;
|
| + for (; (len - index) >= chunkSizeInBytes; index += chunkSizeInBytes) {
|
| + _bytesToChunk(_pendingData, index);
|
| + _updateHash(_currentChunk);
|
| + }
|
| + _pendingData = _pendingData.sublist(index, len);
|
| + }
|
| + }
|
| +
|
| + // Finalize the data. Add a 1 bit to the end of the message. Expand with
|
| + // 0 bits and add the length of the message.
|
| + void _finalizeData() {
|
| + _pendingData.add(0x80);
|
| + var contentsLength = _lengthInBytes + 9;
|
| + var chunkSizeInBytes = _chunkSizeInWords * _BYTES_PER_WORD;
|
| + var finalizedLength = _roundUp(contentsLength, chunkSizeInBytes);
|
| + var zeroPadding = finalizedLength - contentsLength;
|
| + for (var i = 0; i < zeroPadding; i++) {
|
| + _pendingData.add(0);
|
| + }
|
| + var lengthInBits = _lengthInBytes * _BITS_PER_BYTE;
|
| + assert(lengthInBits < pow(2, 32));
|
| + if (_bigEndianWords) {
|
| + _pendingData.addAll(_wordToBytes(0));
|
| + _pendingData.addAll(_wordToBytes(lengthInBits & _MASK_32));
|
| + } else {
|
| + _pendingData.addAll(_wordToBytes(lengthInBits & _MASK_32));
|
| + _pendingData.addAll(_wordToBytes(0));
|
| + }
|
| + }
|
| +}
|
|
|