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pkg/dev_compiler/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;
-}