dotnet/aspnetcore

HttpRuleParser GetExpressionLength allows invalid characters.

Open

#2,694 opened on Jan 2, 2018

View on GitHub
 (1 comment) (0 reactions) (0 assignees)C# (37,933 stars) (10,653 forks)batch import
affected-fewarea-networkingbugfeature-http-abstractionshelp wantedseverity-minor

Description

From @jkotalik on Tuesday, August 22, 2017 4:19:40 PM

@Tratcher and I discovered that GetExpressionLength in HttpRuleParser allows invalid characters (including control characters in expressions. GetExpressionLength mentions that we don't really care about the content of a quoted string, however it seems appropriate that if a quoted string has an invalid character, it should throw on parsing here, not in Kestrel (or whatever server).

This would be a breaking change, as it would introduce a new place where an exception is thrown, however it is probably the right behavior.

Copied from original issue: aspnet/HttpAbstractions#923

Contributor guide

Tech stack
csharp
Domain
backend
Issue type
bug
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
3
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
1-3 hours
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
stale
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
mostly clear
Prerequisites
understanding of HTTP parsingC# programming
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
30
Research direction
The issue is in the GetExpressionLength method in HttpRuleParser.cs. The method currently allows invalid characters in quoted strings. To fix, refer to RFC 7230 for valid characters, and consider adding validation that throws an exception for invalid characters. This is a breaking change, so review existing tests and discuss with maintainers. The file is located at src/Microsoft.Net.Http.Headers/HttpRuleParser.cs.
HttpRuleParser GetExpressionLength allows invalid characters. · dotnet/aspnetcore#2694 | Good First Issue