FastSymApi

The FastSymApi server is a Fast API server designed for debugging and development environments. It allows users to download and cache symbols from Microsoft, Google, and Mozilla symbol servers. Additionally, users can easily add support for other symbol servers.

When clients connect to FastSymApi and attempt to download a symbol, the server first checks if the symbol exists within its ./fastsymapi/symbols cache. If found, the server returns the symbol; otherwise, it responds with a status 404 and proceeds to download the symbol. On subsequent requests, if the symbol is already downloaded and cached, the server returns it, either compressed using GZIP or decompressed based on the presence of the Accept-Encoding: gzip header. GZIP compression reduces bandwidth usage and improves download speed for clients.

FastSymApi has been tested and works with the following tools:

• x64dbg
• WinDbg
• Symchk

Supports the following symbol servers:

• http://msdl.microsoft.com/download/symbols
• http://chromium-browser-symsrv.commondatastorage.googleapis.com
• http://symbols.mozilla.org

Setup FastSymApi

Clone the repository

git clone https://github.com/P1tt1cus/FastSymApi

Install the requirements

pip install requirements.txt 

Start the server

uvicorn fastsymapi:app --host 0.0.0.0 --port 80 

Debug Mode

uvicorn fastsymapi:app --reload 

Run Tests

pytest fastsymapi_tests.py

Configure x64dbg

options >> preferences >> misc

Symbol store

http://FastSymApiServerIp/

Configure WinDbg

.sympath srv*C:\symbols*http://FastSymApiServerIp/