ProtobufInspector

A Fiddler extension for decoding Google Protobuf Data in requests and responses.

Files

Protobuf2Json.dll
Inspectors/ProtobufInspector.dll

Usage:

Copy two released files into Fiddler installation folder.

Once the extension is loaded by Fiddler, it will output a log as follows:

How to parse the protobuf data:

1. If Content-Type in request/response headers is "application/x-protobuf" or "application/x-google-protobuf", the extension will regard the contents as "Protobuf" data.
2. The token value of "messageType" in "Content-Type" will be regarded as message type name.
3. The token value of "desc" or "Desc" in "Content-Type" will be regarded as url of descriptorset of the protos.
4. If message type or descriptorset url doesn't exist, the message type name and local proto folder can be provides in Protobuf Inspector View manually and then try to parse the data.
5. Finally, this extension try to decode as raw message just like "protoc --decode-raw" and show it in json-tree view.

References:

https://www.telerik.com/fiddler/add-ons
https://github.com/protocolbuffers/protobuf
https://www.charlesproxy.com/documentation/using-charles/protocol-buffers/
https://github.com/maomaozgw/Protobuf2Fiddler
https://github.com/JonathanJoelBoyd/ProtoMiddler