Teach dart_package to understand the packages/ subdirectory

third_party/dart-packages/crypto/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.
-
-/**
- * Cryptographic algorithms, with support for hash functions such as
- * SHA-1, SHA-256, HMAC, and MD5.
- */
-library crypto;
-
-import 'dart:math';
-
-part 'src/crypto_utils.dart';
-part 'src/hash_utils.dart';
-part 'src/hmac.dart';
-part 'src/md5.dart';
-part 'src/sha1.dart';
-part 'src/sha256.dart';
-
-/**
- * Interface for cryptographic hash functions.
- *
- * The [add] method is used to add data to the hash. The [close] method
- * is used to extract the message digest.
- *
- * Once the [close] method has been called no more data can be added using the
- * [add] method. If [add] is called after the first call to [close] a
- * HashException is thrown.
- *
- * If multiple instances of a given Hash is needed the [newInstance]
- * method can provide a new instance.
- */
-// TODO(floitsch): make Hash implement Sink, EventSink or similar.
-abstract class Hash {
-  /**
-   * Add a list of bytes to the hash computation.
-   */
-  void add(List<int> data);
-
-  /**
-   * Finish the hash computation and extract the message digest as
-   * a list of bytes.
-   */
-  List<int> close();
-
-  /**
-   * Returns a new instance of this hash function.
-   */
-  Hash newInstance();
-
-  /**
-   * Internal block size of the hash in bytes.
-   *
-   * This is exposed for use by the HMAC class which needs to know the
-   * block size for the [Hash] it is using.
-   */
-  int get blockSize;
-}
-
-/**
- * Utility methods for working with message digests.
- */
-class CryptoUtils {
-  /**
-   * Convert a list of bytes (for example a message digest) into a hex
-   * string.
-   */
-  static String bytesToHex(List<int> bytes) {
-    return _CryptoUtils.bytesToHex(bytes);
-  }
-
-  /**
-   * Converts a list of bytes into a Base 64 encoded string.
-   *
-   * The list can be any list of integers in the range 0..255,
-   * for example a message digest.
-   *
-   * If [addLineSeparator] is true, the resulting string will  be
-   * broken into lines of 76 characters, separated by "\r\n".
-   *
-   * If [urlSafe] is true, the result is URL and filename safe.
-   *
-   * Based on [RFC 4648](http://tools.ietf.org/html/rfc4648)
-   *
-   */
-  static String bytesToBase64(List<int> bytes,
-                              {bool urlSafe : false,
-                               bool addLineSeparator : false}) {
-    return _CryptoUtils.bytesToBase64(bytes,
-                                      urlSafe,
-                                      addLineSeparator);
-  }
-
-
-  /**
-   * Converts a Base 64 encoded String into list of bytes.
-   *
-   * Decoder ignores "\r\n" sequences from input.
-   *
-   * Accepts both URL safe and unsafe Base 64 encoded strings.
-   *
-   * Throws a FormatException exception if input contains invalid characters.
-   *
-   * Based on [RFC 4648](http://tools.ietf.org/html/rfc4648)
-   */
-  static List<int> base64StringToBytes(String input) {
-    return _CryptoUtils.base64StringToBytes(input);
-  }
-}