commit 5d3cb4ac585d4a60e547460480a166bd5d9731b6
author Alexander Markov <alexmarkov@google.com> Wed Jul 19 09:56:58 2017 -0700
committer Kevin Moore <kevmoo@users.noreply.github.com> Wed Jul 19 09:56:58 2017 -0700
tree c023f8a119b76686868ae6005989ee236d64fd6a
parent 48f51e09d9a773ce70d58493a53eba655e1c1310

Prepare dart/crypto library for limiting integers to 64 bits in Dart (#37)

* Prepare dart/crypto library for limiting integers to 64 bits in Dart
* Changed version to 2.0.2

CHANGELOG.md

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 36c080a..1417775 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,8 @@
+## 2.0.2
+
+* Prepare `HashSink` implementation for limiting integers to 64 bits in Dart
+  language.
+
 ## 2.0.1
 
 * Support `convert` 2.0.0.

lib/src/hash_sink.dart

diff --git a/lib/src/hash_sink.dart b/lib/src/hash_sink.dart
index 9d70746..369d3e3 100644
--- a/lib/src/hash_sink.dart
+++ b/lib/src/hash_sink.dart
@@ -25,6 +25,10 @@
   /// used across invocations of [_iterate].
   final Uint32List _currentChunk;
 
+  /// Messages with more than 2^64-1 bits are not supported.
+  /// So the maximum length in bytes is (2^64-1)/8.
+  static const _maxMessageLengthInBytes = 0x1fffffffffffffff;
+
   /// The length of the input data so far, in bytes.
   int _lengthInBytes = 0;
 
@@ -121,12 +125,13 @@
       _pendingData.add(0);
     }
 
-    var lengthInBits = _lengthInBytes * bitsPerByte;
-    if (lengthInBits > maxUint64) {
+    if (_lengthInBytes > _maxMessageLengthInBytes) {
       throw new UnsupportedError(
           "Hashing is unsupported for messages with more than 2^64 bits.");
     }
 
+    var lengthInBits = _lengthInBytes * bitsPerByte;
+
     // Add the full length of the input data as a 64-bit value at the end of the
     // hash.
     var offset = _pendingData.length;

lib/src/utils.dart

diff --git a/lib/src/utils.dart b/lib/src/utils.dart
index ec72878..9ac8efc 100644
--- a/lib/src/utils.dart
+++ b/lib/src/utils.dart
@@ -5,9 +5,6 @@
 /// A bitmask that limits an integer to 32 bits.
 const mask32 = 0xFFFFFFFF;
 
-/// The highest value representable by a 64-bit unsigned integer.
-const maxUint64 = 0xFFFFFFFFFFFFFFFF;
-
 /// The number of bits in a byte.
 const bitsPerByte = 8;
 

pubspec.yaml

diff --git a/pubspec.yaml b/pubspec.yaml
index 5a5193f..81ea3c6 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -1,5 +1,5 @@
 name: crypto
-version: 2.0.2-dev
+version: 2.0.2
 author: Dart Team <misc@dartlang.org>
 description: Library of cryptographic functions.
 homepage: https://www.github.com/dart-lang/crypto