Use relative URIs for core library part-of statements.

tests/standalone/io/hash_utils.dart

+// 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.
+
+/// Hash routines copied from private helpers in dart:io.
+library hashes;
+
+// Constants.
+const _MASK_8 = 0xff;
+const _MASK_32 = 0xffffffff;
+const _BITS_PER_BYTE = 8;
+const _BYTES_PER_WORD = 4;
+const _pow2_32 = 0x100000000;
+
+// Base class encapsulating common behavior for cryptographic hash
+// functions.
+abstract class _HashBase {
+  // Hasher state.
+  final int _chunkSizeInWords;
+  final int _digestSizeInWords;
+  final bool _bigEndianWords;
+  int _lengthInBytes = 0;
+  List<int> _pendingData;
+  List<int> _currentChunk;
+  List<int> _h;
+  bool _digestCalled = false;
+
+  _HashBase(
+      this._chunkSizeInWords, this._digestSizeInWords, this._bigEndianWords)
+      : _pendingData = [] {
+    _currentChunk = new List(_chunkSizeInWords);
+    _h = new List(_digestSizeInWords);
+  }
+
+  // Update the hasher with more data.
+  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;
+  }
+
+  // Create a fresh instance of this Hash.
+  newInstance();
+
+  // One round of the hash computation.
+  _updateHash(List<int> m);
+
+  // Helper methods.
+  _add32(x, y) => (x + y) & _MASK_32;
+  _roundUp(val, n) => (val + n - 1) & -n;
+
+  // 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));
+  }
+
+  // Compute the final result as a list of bytes from the hash words.
+  List<int> _resultAsBytes() {
+    var result = <int>[];
+    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.
+  _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<int> bytes = new List(_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.
+  _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.
+  _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 < _pow2_32);
+    if (_bigEndianWords) {
+      _pendingData.addAll(_wordToBytes(0));
+      _pendingData.addAll(_wordToBytes(lengthInBits & _MASK_32));
+    } else {
+      _pendingData.addAll(_wordToBytes(lengthInBits & _MASK_32));
+      _pendingData.addAll(_wordToBytes(0));
+    }
+  }
+}
+
+// The SHA1 hasher is used to compute an SHA1 message digest.
+class SHA1 extends _HashBase {
+  // Construct a SHA1 hasher object.
+  SHA1()
+      : _w = new List(80),
+        super(16, 5, true) {
+    _h[0] = 0x67452301;
+    _h[1] = 0xEFCDAB89;
+    _h[2] = 0x98BADCFE;
+    _h[3] = 0x10325476;
+    _h[4] = 0xC3D2E1F0;
+  }
+
+  // Returns a new instance of this Hash.
+  SHA1 newInstance() {
+    return new SHA1();
+  }
+
+  // Compute one iteration of the SHA1 algorithm with a chunk of
+  // 16 32-bit pieces.
+  void _updateHash(List<int> m) {
+    assert(m.length == 16);
+
+    var a = _h[0];
+    var b = _h[1];
+    var c = _h[2];
+    var d = _h[3];
+    var e = _h[4];
+
+    for (var i = 0; i < 80; i++) {
+      if (i < 16) {
+        _w[i] = m[i];
+      } else {
+        var n = _w[i - 3] ^ _w[i - 8] ^ _w[i - 14] ^ _w[i - 16];
+        _w[i] = _rotl32(n, 1);
+      }
+      var t = _add32(_add32(_rotl32(a, 5), e), _w[i]);
+      if (i < 20) {
+        t = _add32(_add32(t, (b & c) | (~b & d)), 0x5A827999);
+      } else if (i < 40) {
+        t = _add32(_add32(t, (b ^ c ^ d)), 0x6ED9EBA1);
+      } else if (i < 60) {
+        t = _add32(_add32(t, (b & c) | (b & d) | (c & d)), 0x8F1BBCDC);
+      } else {
+        t = _add32(_add32(t, b ^ c ^ d), 0xCA62C1D6);
+      }
+
+      e = d;
+      d = c;
+      c = _rotl32(b, 30);
+      b = a;
+      a = t & _MASK_32;
+    }
+
+    _h[0] = _add32(a, _h[0]);
+    _h[1] = _add32(b, _h[1]);
+    _h[2] = _add32(c, _h[2]);
+    _h[3] = _add32(d, _h[3]);
+    _h[4] = _add32(e, _h[4]);
+  }
+
+  List<int> _w;
+}