Implement md5 hash in crypto library.

lib/crypto/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.
 
 #library('crypto');
 
+#source('hash_utils.dart');
 #source('hmac.dart');
-#source('sha_utils.dart');
+#source('md5.dart');
 #source('sha1.dart');
 #source('sha256.dart');
 
 /**
  * Interface for cryptographic hash functions.
  *
  * The [update] method is used to add data to the hash. The [digest] method
  * is used to extract the message digest.
  *
  * Once the [digest] method has been called no more data can be added using the
@@ skipping 20 matching lines @@
    */
   Hash newInstance();
 
   /**
    * Block size of the hash in bytes.
    */
   int get blockSize();
 }
 
 /**
+ * MD5 hash function implementation.

[Søren Gjesse, 2012/05/03 13:31:12]

We could mention the issues with MD5 here.

[Mads Ager (google), 2012/05/08 08:32:37]

Done.

+ */
+interface MD5 extends Hash default _MD5 {
+  MD5();
+}
+
+/**
  * SHA1 hash function implementation.
  */
 interface SHA1 extends Hash default _SHA1 {
   SHA1();
 }
 
 /**
  * SHA256 hash function implementation.
  */
 interface SHA256 extends Hash default _SHA256 {
@@ skipping 29 matching lines @@
 /**
  * HashExceptions are thrown on invalid use of a Hash
  * object.
  */
 class HashException {
   HashException(String this.message);
   toString() => "HashException: $message";
   String message;
 }