Bug 2363 - System.Uri:CheckHostName: off-by-one error in label length check
Summary: System.Uri:CheckHostName: off-by-one error in label length check
Alias: None
Product: Class Libraries
Classification: Mono
Component: System ()
Version: master
Hardware: All All
: --- normal
Target Milestone: Untriaged
Assignee: Martin Baulig
Depends on:
Reported: 2011-12-06 11:00 UTC by Yves Bastide
Modified: 2012-06-19 21:07 UTC (History)
2 users (show)

Is this bug a regression?: ---
Last known good build:

Possible fix and testcases (1.47 KB, patch)
2011-12-06 11:00 UTC, Yves Bastide

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Description Yves Bastide 2011-12-06 11:00:59 UTC
Created attachment 1001 [details]
Possible fix and testcases

Expected result:

csharp> new Uri("http://3.141592653589793238462643383279502884197169399375105820974944592.com/");

Actual result:

csharp> new Uri("http://3.141592653589793238462643383279502884197169399375105820974944592.com/");
System.UriFormatException: Invalid URI: The hostname could not be parsed.
  at System.Uri.Parse (UriKind kind, System.String uriString) [0x00000] in <filename unknown>:0 
  at System.Uri.ParseUri (UriKind kind) [0x00000] in <filename unknown>:0 
  at System.Uri..ctor (System.String uriString, Boolean dontEscape) [0x00000] in <filename unknown>:0 
  at System.Uri..ctor (System.String uriString) [0x00000] in <filename unknown>:0 
  at Class1.Host (System.Object& $retval) [0x00000] in <filename unknown>:0 
  at Mono.CSharp.Evaluator.Evaluate (System.String input, System.Object& result, System.Boolean& result_set) [0x00000] in <filename unknown>:0 
  at Mono.CSharp.Gui.Shell.Evaluate (System.String s) [0x00000] in <filename unknown>:0

Bug analysis:

The part ("label") 141592653589793238462643383279502884197169399375105820974944592 is 63 chars long; however, System.Uri:IsDomainAddress includes the preceding dot.

Attached are a fix and some unit tests.


Comment 1 Martin Baulig 2012-06-19 21:07:42 UTC
Fixed; commit 330f0eb.

FIXME: We still violate RFC 2181 by not checking the total length of the hostname (maximum 255 bytes), but .NET doesn't check it either.