Removed fixed dependencies

packages/crypto/lib/src/sha1.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.
+
+import 'dart:convert';
+import 'dart:typed_data';
+
+import 'digest.dart';
+import 'hash.dart';
+import 'hash_sink.dart';
+import 'utils.dart';
+
+/// An instance of [Sha1].
+///
+/// This instance provides convenient access to the [SHA-1][rfc] hash function.
+///
+/// [rfc]: http://tools.ietf.org/html/rfc3174
+final sha1 = new Sha1._();
+
+/// An implementation of the [SHA-1][rfc] hash function.
+///
+/// [rfc]: http://tools.ietf.org/html/rfc3174
+class Sha1 extends Hash {
+  @override
+  final int blockSize = 16 * bytesPerWord;
+
+  Sha1._();
+
+  @override
+  ByteConversionSink startChunkedConversion(Sink<Digest> sink) =>
+      new ByteConversionSink.from(new _Sha1Sink(sink));
+}
+
+/// The concrete implementation of [Sha1].
+///
+/// This is separate so that it can extend [HashSink] without leaking additional
+/// public memebers.
+class _Sha1Sink extends HashSink {
+  @override
+  final digest = new Uint32List(5);
+
+  /// The sixteen words from the original chunk, extended to 80 words.
+  ///
+  /// This is an instance variable to avoid re-allocating, but its data isn't
+  /// used across invocations of [updateHash].
+  final Uint32List _extended;
+
+  _Sha1Sink(Sink<Digest> sink)
+      : _extended = new Uint32List(80),
+        super(sink, 16) {
+    digest[0] = 0x67452301;
+    digest[1] = 0xEFCDAB89;
+    digest[2] = 0x98BADCFE;
+    digest[3] = 0x10325476;
+    digest[4] = 0xC3D2E1F0;
+  }
+
+  @override
+  void updateHash(Uint32List chunk) {
+    assert(chunk.length == 16);
+
+    var a = digest[0];
+    var b = digest[1];
+    var c = digest[2];
+    var d = digest[3];
+    var e = digest[4];
+
+    for (var i = 0; i < 80; i++) {
+      if (i < 16) {
+        _extended[i] = chunk[i];
+      } else {
+        _extended[i] = rotl32(
+            _extended[i - 3] ^
+                _extended[i - 8] ^
+                _extended[i - 14] ^
+                _extended[i - 16],
+            1);
+      }
+
+      var newA = add32(add32(rotl32(a, 5), e), _extended[i]);
+      if (i < 20) {
+        newA = add32(add32(newA, (b & c) | (~b & d)), 0x5A827999);
+      } else if (i < 40) {
+        newA = add32(add32(newA, (b ^ c ^ d)), 0x6ED9EBA1);
+      } else if (i < 60) {
+        newA = add32(add32(newA, (b & c) | (b & d) | (c & d)), 0x8F1BBCDC);
+      } else {
+        newA = add32(add32(newA, b ^ c ^ d), 0xCA62C1D6);
+      }
+
+      e = d;
+      d = c;
+      c = rotl32(b, 30);
+      b = a;
+      a = newA & mask32;
+    }
+
+    digest[0] = add32(a, digest[0]);
+    digest[1] = add32(b, digest[1]);
+    digest[2] = add32(c, digest[2]);
+    digest[3] = add32(d, digest[3]);
+    digest[4] = add32(e, digest[4]);
+  }
+}