Code review changes

lib/src/utils.dart

Index: lib/src/utils.dart
diff --git a/lib/src/utils.dart b/lib/src/utils.dart
index 734c58e2687d9706ac1181a40199dc7fee2cb433..bf260eb73a06d38c52e760fe0090c78ba839ba94 100644
--- a/lib/src/utils.dart
+++ b/lib/src/utils.dart
@@ -4,65 +4,16 @@
 
 library oauth2.utils;
 
+import 'dart:convert';
+
+import 'package:crypto/crypto.dart';
+
 /// Adds additional query parameters to [url], overwriting the original
 /// parameters if a name conflict occurs.
 Uri addQueryParameters(Uri url, Map<String, String> parameters) => url.replace(
     queryParameters: new Map.from(url.queryParameters)..addAll(parameters));
 
-/// Like [String.split], but only splits on the first occurrence of the pattern.
-///
-/// This will always return a list of two elements or fewer.
-List<String> split1(String toSplit, String pattern) {
-  if (toSplit.isEmpty) return [];
-
-  var index = toSplit.indexOf(pattern);
-  if (index == -1) return [toSplit];
-  return [toSplit.substring(0, index),
-      toSplit.substring(index + pattern.length)];
-}
-
-/// A WWW-Authenticate header value, parsed as per [RFC 2617][].
-///
-/// [RFC 2617]: http://tools.ietf.org/html/rfc2617
-class AuthenticateHeader {
-  final String scheme;
-  final Map<String, String> parameters;
-
-  AuthenticateHeader(this.scheme, this.parameters);
-
-  /// Parses a header string. Throws a [FormatException] if the header is
-  /// invalid.
-  factory AuthenticateHeader.parse(String header) {
-    var split = split1(header, ' ');
-    if (split.length == 0) {
-      throw new FormatException('Invalid WWW-Authenticate header: "$header"');
-    } else if (split.length == 1 || split[1].trim().isEmpty) {
-      return new AuthenticateHeader(split[0].toLowerCase(), {});
-    }
-    var scheme = split[0].toLowerCase();
-    var paramString = split[1];
-
-    // From http://www.w3.org/Protocols/rfc2616/rfc2616-sec2.html.
-    var tokenChar = r'[^\0-\x1F()<>@,;:\\"/\[\]?={} \t\x7F]';
-    var quotedStringChar = r'(?:[^\0-\x1F\x7F"]|\\.)';
-    var regexp = new RegExp('^ *($tokenChar+)="($quotedStringChar*)" *(, *)?');
-
-    var parameters = {};
-    var match;
-    do {
-      match = regexp.firstMatch(paramString);
-      if (match == null) {
-        throw new FormatException('Invalid WWW-Authenticate header: "$header"');
-      }
-
-      paramString = paramString.substring(match.end);
-      parameters[match.group(1).toLowerCase()] = match.group(2);
-    } while (match.group(3) != null);
-
-    if (!paramString.trim().isEmpty) {
-      throw new FormatException('Invalid WWW-Authenticate header: "$header"');
-    }
-
-    return new AuthenticateHeader(scheme, parameters);
-  }
+String basicAuthHeader(String identifier, String secret) {
+  var userPass = Uri.encodeFull(identifier) + ":" + Uri.encodeFull(secret);
+  return "Basic " + CryptoUtils.bytesToBase64(ASCII.encode(userPass));
 }