sha1 static method

Uint8List sha1(List<int> message)

Implementation

static Uint8List sha1(List<int> message) {
  final List<int> padded = List<int>.from(message)..add(0x80);
  while (padded.length % 64 != 56) {
    padded.add(0);
  }
  final int bitLength = message.length * 8;
  for (int i = 7; i >= 0; i--) {
    padded.add((bitLength >>> (8 * i)) & 0xFF);
  }
  int h0 = 0x67452301;
  int h1 = 0xEFCDAB89;
  int h2 = 0x98BADCFE;
  int h3 = 0x10325476;
  int h4 = 0xC3D2E1F0;
  final List<int> words = List<int>.filled(80, 0);
  for (int chunk = 0; chunk < padded.length; chunk += 64) {
    for (int i = 0; i < 16; i++) {
      words[i] = (padded[chunk + i * 4] << 24) | (padded[chunk + i * 4 + 1] << 16) | (padded[chunk + i * 4 + 2] << 8) | padded[chunk + i * 4 + 3];
    }
    for (int i = 16; i < 80; i++) {
      final int value = words[i - 3] ^ words[i - 8] ^ words[i - 14] ^ words[i - 16];
      words[i] = ((value << 1) | (value >>> 31)) & 0xFFFFFFFF;
    }
    int a = h0;
    int b = h1;
    int c = h2;
    int d = h3;
    int e = h4;
    for (int i = 0; i < 80; i++) {
      int f;
      int k;
      if (i < 20) {
        f = (b & c) | (~b & d);
        k = 0x5A827999;
      } else if (i < 40) {
        f = b ^ c ^ d;
        k = 0x6ED9EBA1;
      } else if (i < 60) {
        f = (b & c) | (b & d) | (c & d);
        k = 0x8F1BBCDC;
      } else {
        f = b ^ c ^ d;
        k = 0xCA62C1D6;
      }
      final int temp = (((a << 5) | (a >>> 27)) + (f & 0xFFFFFFFF) + e + k + words[i]) & 0xFFFFFFFF;
      e = d;
      d = c;
      c = ((b << 30) | (b >>> 2)) & 0xFFFFFFFF;
      b = a;
      a = temp;
    }
    h0 = (h0 + a) & 0xFFFFFFFF;
    h1 = (h1 + b) & 0xFFFFFFFF;
    h2 = (h2 + c) & 0xFFFFFFFF;
    h3 = (h3 + d) & 0xFFFFFFFF;
    h4 = (h4 + e) & 0xFFFFFFFF;
  }
  final Uint8List out = Uint8List(20);
  final List<int> values = <int>[h0, h1, h2, h3, h4];
  for (int i = 0; i < 5; i++) {
    out[i * 4] = (values[i] >>> 24) & 0xFF;
    out[i * 4 + 1] = (values[i] >>> 16) & 0xFF;
    out[i * 4 + 2] = (values[i] >>> 8) & 0xFF;
    out[i * 4 + 3] = values[i] & 0xFF;
  }
  return out;
}