Migrate dart2js stubs for dart:io

tool/input_sdk/lib/io/crypto.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.
+
+part of dart.io;
+
+class _CryptoUtils {
+  static const int PAD = 61; // '='
+  static const int CR = 13;  // '\r'
+  static const int LF = 10;  // '\n'
+  static const int LINE_LENGTH = 76;
+
+  static const String _encodeTable =
+      "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
+
+  static const String _encodeTableUrlSafe =
+      "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-_";
+
+  // Lookup table used for finding Base 64 alphabet index of a given byte.
+  // -2 : Outside Base 64 alphabet.
+  // -1 : '\r' or '\n'
+  //  0 : = (Padding character).
+  // >0 : Base 64 alphabet index of given byte.
+  static const List<int> _decodeTable =
+      const [ -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -1, -2, -2, -1, -2, -2,
+              -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2,
+              -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, 62, -2, 62, -2, 63,
+              52, 53, 54, 55, 56, 57, 58, 59, 60, 61, -2, -2, -2,  0, -2, -2,
+              -2,  0,  1,  2,  3,  4,  5,  6,  7,  8,  9, 10, 11, 12, 13, 14,
+              15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, -2, -2, -2, -2, 63,
+              -2, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40,
+              41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, -2, -2, -2, -2, -2,
+              -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2,
+              -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2,
+              -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2,
+              -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2,
+              -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2,
+              -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2,
+              -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2,
+              -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2 ];
+
+  static String bytesToHex(List<int> bytes) {
+    var result = new StringBuffer();
+    for (var part in bytes) {
+      result.write('${part < 16 ? '0' : ''}${part.toRadixString(16)}');
+    }
+    return result.toString();
+  }
+
+  static String bytesToBase64(List<int> bytes,
+                              [bool urlSafe = false,
+                               bool addLineSeparator = false]) {
+    int len = bytes.length;
+    if (len == 0) {
+      return "";
+    }
+    final String lookup = urlSafe ? _encodeTableUrlSafe : _encodeTable;
+    // Size of 24 bit chunks.
+    final int remainderLength = len.remainder(3);
+    final int chunkLength = len - remainderLength;
+    // Size of base output.
+    int outputLen = ((len ~/ 3) * 4) + ((remainderLength > 0) ? 4 : 0);
+    // Add extra for line separators.
+    if (addLineSeparator) {
+      outputLen += ((outputLen - 1) ~/ LINE_LENGTH) << 1;
+    }
+    List<int> out = new List<int>(outputLen);
+
+    // Encode 24 bit chunks.
+    int j = 0, i = 0, c = 0;
+    while (i < chunkLength) {
+      int x = ((bytes[i++] << 16) & 0xFFFFFF) |
+              ((bytes[i++] << 8) & 0xFFFFFF) |
+                bytes[i++];
+      out[j++] = lookup.codeUnitAt(x >> 18);
+      out[j++] = lookup.codeUnitAt((x >> 12) & 0x3F);
+      out[j++] = lookup.codeUnitAt((x >> 6)  & 0x3F);
+      out[j++] = lookup.codeUnitAt(x & 0x3f);
+      // Add optional line separator for each 76 char output.
+      if (addLineSeparator && ++c == 19 && j < outputLen - 2) {
+          out[j++] = CR;
+          out[j++] = LF;
+          c = 0;
+      }
+    }
+
+    // If input length if not a multiple of 3, encode remaining bytes and
+    // add padding.
+    if (remainderLength == 1) {
+      int x = bytes[i];
+      out[j++] = lookup.codeUnitAt(x >> 2);
+      out[j++] = lookup.codeUnitAt((x << 4) & 0x3F);
+      out[j++] = PAD;
+      out[j++] = PAD;
+    } else if (remainderLength == 2) {
+      int x = bytes[i];
+      int y = bytes[i + 1];
+      out[j++] = lookup.codeUnitAt(x >> 2);
+      out[j++] = lookup.codeUnitAt(((x << 4) | (y >> 4)) & 0x3F);
+      out[j++] = lookup.codeUnitAt((y << 2) & 0x3F);
+      out[j++] = PAD;
+    }
+
+    return new String.fromCharCodes(out);
+  }
+
+  static List<int> base64StringToBytes(String input,
+                                       [bool ignoreInvalidCharacters = true]) {
+    int len = input.length;
+    if (len == 0) {
+      return new List<int>(0);
+    }
+
+    // Count '\r', '\n' and illegal characters, For illegal characters,
+    // if [ignoreInvalidCharacters] is false, throw an exception.
+    int extrasLen = 0;
+    for (int i = 0; i < len; i++) {
+      int c = _decodeTable[input.codeUnitAt(i)];
+      if (c < 0) {
+        extrasLen++;
+        if(c == -2 && !ignoreInvalidCharacters) {
+          throw new FormatException('Invalid character: ${input[i]}');
+        }
+      }
+    }
+
+    if ((len - extrasLen) % 4 != 0) {
+      throw new FormatException('''Size of Base 64 characters in Input
+          must be a multiple of 4. Input: $input''');
+    }
+
+    // Count pad characters, ignore illegal characters at the end.
+    int padLength = 0;
+    for (int i = len - 1; i >= 0; i--) {
+      int currentCodeUnit = input.codeUnitAt(i);
+      if (_decodeTable[currentCodeUnit] > 0) break;
+      if (currentCodeUnit == PAD) padLength++;
+    }
+    int outputLen = (((len - extrasLen) * 6) >> 3) - padLength;
+    List<int> out = new List<int>(outputLen);
+
+    for (int i = 0, o = 0; o < outputLen;) {
+      // Accumulate 4 valid 6 bit Base 64 characters into an int.
+      int x = 0;
+      for (int j = 4; j > 0;) {
+        int c = _decodeTable[input.codeUnitAt(i++)];
+        if (c >= 0) {
+          x = ((x << 6) & 0xFFFFFF) | c;
+          j--;
+        }
+      }
+      out[o++] = x >> 16;
+      if (o < outputLen) {
+        out[o++] = (x >> 8) & 0xFF;
+        if (o < outputLen) out[o++] = x & 0xFF;
+      }
+    }
+    return out;
+  }
+
+}
+
+// Constants.
+const _MASK_8 = 0xff;
+const _MASK_32 = 0xffffffff;
+const _BITS_PER_BYTE = 8;
+const _BYTES_PER_WORD = 4;
+
+// 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.
+  _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.
+  _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.
+  _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 < 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));
+    }
+  }
+}
+
+// The MD5 hasher is used to compute an MD5 message digest.
+class _MD5 extends _HashBase {
+  _MD5() : super(16, 4, false) {
+    _h[0] = 0x67452301;
+    _h[1] = 0xefcdab89;
+    _h[2] = 0x98badcfe;
+    _h[3] = 0x10325476;
+  }
+
+  // Returns a new instance of this Hash.
+  _MD5 newInstance() {
+    return new _MD5();
+  }
+
+  static const _k = const [
+    0xd76aa478, 0xe8c7b756, 0x242070db, 0xc1bdceee, 0xf57c0faf, 0x4787c62a,
+    0xa8304613, 0xfd469501, 0x698098d8, 0x8b44f7af, 0xffff5bb1, 0x895cd7be,
+    0x6b901122, 0xfd987193, 0xa679438e, 0x49b40821, 0xf61e2562, 0xc040b340,
+    0x265e5a51, 0xe9b6c7aa, 0xd62f105d, 0x02441453, 0xd8a1e681, 0xe7d3fbc8,
+    0x21e1cde6, 0xc33707d6, 0xf4d50d87, 0x455a14ed, 0xa9e3e905, 0xfcefa3f8,
+    0x676f02d9, 0x8d2a4c8a, 0xfffa3942, 0x8771f681, 0x6d9d6122, 0xfde5380c,
+    0xa4beea44, 0x4bdecfa9, 0xf6bb4b60, 0xbebfbc70, 0x289b7ec6, 0xeaa127fa,
+    0xd4ef3085, 0x04881d05, 0xd9d4d039, 0xe6db99e5, 0x1fa27cf8, 0xc4ac5665,
+    0xf4292244, 0x432aff97, 0xab9423a7, 0xfc93a039, 0x655b59c3, 0x8f0ccc92,
+    0xffeff47d, 0x85845dd1, 0x6fa87e4f, 0xfe2ce6e0, 0xa3014314, 0x4e0811a1,
+    0xf7537e82, 0xbd3af235, 0x2ad7d2bb, 0xeb86d391 ];
+
+  static const _r = const [
+    7, 12, 17, 22, 7, 12, 17, 22, 7, 12, 17, 22, 7, 12, 17, 22, 5,  9, 14,
+    20, 5,  9, 14, 20, 5,  9, 14, 20, 5,  9, 14, 20, 4, 11, 16, 23, 4, 11,
+    16, 23, 4, 11, 16, 23, 4, 11, 16, 23, 6, 10, 15, 21, 6, 10, 15, 21, 6,
+    10, 15, 21, 6, 10, 15, 21 ];
+
+  // Compute one iteration of the MD5 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 t0;
+    var t1;
+
+    for (var i = 0; i < 64; i++) {
+      if (i < 16) {
+        t0 = (b & c) | ((~b & _MASK_32) & d);
+        t1 = i;
+      } else if (i < 32) {
+        t0 = (d & b) | ((~d & _MASK_32) & c);
+        t1 = ((5 * i) + 1) % 16;
+      } else if (i < 48) {
+        t0 = b ^ c ^ d;
+        t1 = ((3 * i) + 5) % 16;
+      } else {
+        t0 = c ^ (b | (~d & _MASK_32));
+        t1 = (7 * i) % 16;
+      }
+
+      var temp = d;
+      d = c;
+      c = b;
+      b = _add32(b, _rotl32(_add32(_add32(a, t0),
+                                   _add32(_k[i], m[t1])),
+                            _r[i]));
+      a = temp;
+    }
+
+    _h[0] = _add32(a, _h[0]);
+    _h[1] = _add32(b, _h[1]);
+    _h[2] = _add32(c, _h[2]);
+    _h[3] = _add32(d, _h[3]);
+  }
+}
+
+// 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;
+}