Forces OAuth 2.0 to consider empty parameters to be absent, per the spec requirement.

2 files changed, 28 insertions, 0 deletions

diff --git a/src/DotNetOpenAuth/Messaging/Channel.cs b/src/DotNetOpenAuth/Messaging/Channel.cs
index 800d49d..7ae045f 100644
--- a/src/DotNetOpenAuth/Messaging/Channel.cs
+++ b/src/DotNetOpenAuth/Messaging/Channel.cs
@@ -720,6 +720,7 @@ namespace DotNetOpenAuth.Messaging {
 		protected virtual IProtocolMessage Receive(Dictionary<string, string> fields, MessageReceivingEndpoint recipient) {
 			Contract.Requires<ArgumentNullException>(fields != null);
 
+			this.FilterReceivedFields(fields);
 			IProtocolMessage message = this.MessageFactory.GetNewRequestMessage(recipient, fields);
 
 			// If there was no data, or we couldn't recognize it as a message, abort.
@@ -1216,6 +1217,14 @@ namespace DotNetOpenAuth.Messaging {
 		}
 
 		/// <summary>
+		/// Allows preprocessing and validation of message data before an appropriate message type is
+		/// selected or deserialized.
+		/// </summary>
+		/// <param name="fields">The received message data.</param>
+		protected virtual void FilterReceivedFields(IDictionary<string, string> fields) {
+		}
+
+		/// <summary>
 		/// Customizes the binding element order for outgoing and incoming messages.
 		/// </summary>
 		/// <param name="outgoingOrder">The outgoing order.</param>
diff --git a/src/DotNetOpenAuth/OAuth2/ChannelElements/OAuth2ChannelBase.cs b/src/DotNetOpenAuth/OAuth2/ChannelElements/OAuth2ChannelBase.cs
index d9f33a0..d53e7ef 100644
--- a/src/DotNetOpenAuth/OAuth2/ChannelElements/OAuth2ChannelBase.cs
+++ b/src/DotNetOpenAuth/OAuth2/ChannelElements/OAuth2ChannelBase.cs
@@ -47,5 +47,24 @@ namespace DotNetOpenAuth.OAuth2.ChannelElements {
 		internal OAuth2ChannelBase(params IChannelBindingElement[] channelBindingElements)
 			: base(MessageTypes, Versions, channelBindingElements) {
 		}
+
+		/// <summary>
+		/// Allows preprocessing and validation of message data before an appropriate message type is
+		/// selected or deserialized.
+		/// </summary>
+		/// <param name="fields">The received message data.</param>
+		protected override void FilterReceivedFields(IDictionary<string, string> fields) {
+			base.FilterReceivedFields(fields);
+
+			// Apply the OAuth 2.0 section 2.1 requirement:
+			// Parameters sent without a value MUST be treated as if they were omitted from the request.
+			// The authorization server SHOULD ignore unrecognized request parameters.
+			var emptyKeys = from pair in fields
+							where String.IsNullOrEmpty(pair.Value)
+							select pair.Key;
+			foreach (string emptyKey in emptyKeys.ToList()) {
+				fields.Remove(emptyKey);
+			}
+		}
 	}
 }