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Omitting a forward slash from http domain produces Bad HTTP request line

See original GitHub issue

Problem Description

Running a GET request for “http://wikipedia.com” will produce the following output: 35.176.198.120:43784: clientconnect << Bad HTTP request line: b'GET http://wikipedia.com HTTP/1.1' ::ffff:35.176.198.120:43784: request -> HTTP protocol error in client request: Bad HTTP request line: b'GET http://wikipedia.com HTTP/1.1' 35.176.198.120:43784: clientdisconnect

The request status, headers and body are as follows for the client: 400 <CIMultiDictProxy('Server': 'mitmproxy 5.3.0', 'Connection': 'close', 'Content-Length': '306', 'Content-Type': 'text/html')> b'<html>\n <head>\n <title>400 Bad Request</title>\n </head>\n <body>\n <h1>400 Bad Request</h1>\n <p>HttpSyntaxException("Bad HTTP request line: b'GET http://wikipedia.com HTTP/1.1'")</p>\n </body>\n </html>

Running a GET request for “http://wikipedia.com/” will not produce this error. Nor will “https://wikipedia.com”. Curl runs the problematic URL fine as it appends the missing trailing slash before running the request which can be seen by printing flow.request.url.

Steps to reproduce the behavior:

Start mitmproxy using “mitmdump -s proxy_server.py --set block_global=false”
Run a GET request with mitm proxy as the request proxy for “http://wikipedia.com”.

System Information

Mitmproxy: 5.3.0 Python: 3.7.9 OpenSSL: OpenSSL 1.1.1h 22 Sep 2020 Platform: Linux-4.14.203-156.332.amzn2.x86_64-x86_64-with-glibc2.2.5

Issue Analytics

State:
Created 3 years ago
Comments:7 (6 by maintainers)

Top GitHub Comments

1reaction

dlbascommented, Feb 13, 2021

This generally sounds good to me. Have you checked if there is more current guidance in any of the 72xx HTTP RFCs?

This document (RFC 7230) says that providing “/” as a path in case of empty URI’s path component is a MUST.

0reactions

mhilscommented, Mar 5, 2021

@pdelagrave: you’re encouraged to switch to master (we do have binaries for dev snapshots as well) and report more bugs there 😃

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