Change Hash subclasses to be Converters.

lib/src/sha256.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.
 
 library crypto.sha256;
 
+import 'dart:convert';
 import 'dart:typed_data';
 
+import 'digest.dart';
 import 'hash.dart';
-import 'hash_base.dart';
+import 'hash_sink.dart';
 import 'utils.dart';
 
+/// An instance of [SHA256].
+///
+/// This instance provides convenient access to the [SHA256][rfc] hash function.
+///
+/// [rfc]: http://tools.ietf.org/html/rfc6234
+final sha256 = new SHA256();
+
 /// An implementation of the [SHA-256][rfc] hash function.
 ///
 /// [rfc]: http://tools.ietf.org/html/rfc6234
-abstract class SHA256 implements Hash {
-  factory SHA256() = _SHA256;
+///
+/// Note that it's almost always easier to use [sha256] rather than creating a
+/// new instance.
+class SHA256 extends Hash {
+  final int blockSize = 16 * bytesPerWord;
 
-  SHA256 newInstance();
+  @Deprecated("Use the sha256 field instead.")
+  SHA256();
+
+  SHA256 newInstance() => new SHA256();
+
+  ByteConversionSink startChunkedConversion(Sink<Digest> sink) =>
+      new ByteConversionSink.from(new _SHA256Sink(sink));
 }
 
 /// Data from a non-linear function that functions as reproducible noise.
 const List<int> _noise = const [
   0x428a2f98, 0x71374491, 0xb5c0fbcf, 0xe9b5dba5, 0x3956c25b, 0x59f111f1,
   0x923f82a4, 0xab1c5ed5, 0xd807aa98, 0x12835b01, 0x243185be, 0x550c7dc3,
   0x72be5d74, 0x80deb1fe, 0x9bdc06a7, 0xc19bf174, 0xe49b69c1, 0xefbe4786,
   0x0fc19dc6, 0x240ca1cc, 0x2de92c6f, 0x4a7484aa, 0x5cb0a9dc, 0x76f988da,
   0x983e5152, 0xa831c66d, 0xb00327c8, 0xbf597fc7, 0xc6e00bf3, 0xd5a79147,
   0x06ca6351, 0x14292967, 0x27b70a85, 0x2e1b2138, 0x4d2c6dfc, 0x53380d13,
   0x650a7354, 0x766a0abb, 0x81c2c92e, 0x92722c85, 0xa2bfe8a1, 0xa81a664b,
   0xc24b8b70, 0xc76c51a3, 0xd192e819, 0xd6990624, 0xf40e3585, 0x106aa070,
   0x19a4c116, 0x1e376c08, 0x2748774c, 0x34b0bcb5, 0x391c0cb3, 0x4ed8aa4a,
   0x5b9cca4f, 0x682e6ff3, 0x748f82ee, 0x78a5636f, 0x84c87814, 0x8cc70208,
   0x90befffa, 0xa4506ceb, 0xbef9a3f7, 0xc67178f2
 ];
 
 /// The concrete implementation of [SHA256].
 ///
 /// This is separate so that it can extend [HashBase] without leaking additional
 /// public memebers.
-class _SHA256 extends HashBase implements SHA256 {
+class _SHA256Sink extends HashSink {
   final digest = new Uint32List(8);
 
   /// The sixteen words from the original chunk, extended to 64 words.
   ///
   /// This is an instance variable to avoid re-allocating, but its data isn't
   /// used across invocations of [updateHash].
   final Uint32List _extended;
 
-  _SHA256()
+  _SHA256Sink(Sink<Digest> sink)
       : _extended = new Uint32List(64),
-        super(16) {
+        super(sink, 16) {
     // Initial value of the hash parts. First 32 bits of the fractional parts
     // of the square roots of the first 8 prime numbers.
     digest[0] = 0x6a09e667;
     digest[1] = 0xbb67ae85;
     digest[2] = 0x3c6ef372;
     digest[3] = 0xa54ff53a;
     digest[4] = 0x510e527f;
     digest[5] = 0x9b05688c;
     digest[6] = 0x1f83d9ab;
     digest[7] = 0x5be0cd19;
   }
 
-  SHA256 newInstance() => new _SHA256();
-
   // The following helper functions are taken directly from
   // http://tools.ietf.org/html/rfc6234.
 
   _rotr32(int n, int x) => (x >> n) | ((x << (32 - n)) & mask32);
   _ch(int x, int y, int z) => (x & y) ^ ((~x & mask32) & z);
   _maj(int x, int y, int z) => (x & y) ^ (x & z) ^ (y & z);
   _bsig0(int x) => _rotr32(2, x) ^ _rotr32(13, x) ^ _rotr32(22, x);
   _bsig1(int x) => _rotr32(6, x) ^ _rotr32(11, x) ^ _rotr32(25, x);
   _ssig0(int x) => _rotr32(7, x) ^ _rotr32(18, x) ^ (x >> 3);
   _ssig1(int x) => _rotr32(17, x) ^ _rotr32(19, x) ^ (x >> 10);
@@ skipping 42 matching lines @@
     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]);
     digest[5] = add32(f, digest[5]);
     digest[6] = add32(g, digest[6]);
     digest[7] = add32(h, digest[7]);
   }
 }