KeyLengthLimit does not support int.MaxValue in Preview 9

[rybkov]

Describe the bug

After update to Preview 9 cannot submit form if KeyLengthLimit set to int.MaxValue

To Reproduce

1. Using this version of ASP.NET Core '3.0.0-preview9.19424.4'
2. Create Default MVC application
3. Create form
4. In services setup
   Services.Configure<FormOptions>( Options => Options.ValueLengthLimit = int.MaxValue ); Services.Configure<FormOptions>( Options => Options.ValueCountLimit = int.MaxValue ); Services.Configure<FormOptions>( Options => Options.KeyLengthLimit = int.MaxValue );
5. Submit a form
6. See error Form key length limit 2147483647 or value length limit 2147483647 exceeded.

Workaround

Setup values to 1_009_100_000 (they might be bigger, but 1_090_000_000 does not work already)

Expected behavior

Preview 8 did not have that issues

[pranavkm]

cc @Tratcher

[Tratcher]

The preview9 change is here: https://github.com/aspnet/AspNetCore/pull/12749/files

You may be hitting an issue here or here were the parser isn't sure yet if it's a measuring a key or value so it adds the limits together. When the limits are both set to int.MaxValue it would overflow and become negative, causing the length check to fail.

Mitigation: Set the limits so their combine size is less than or equal to int.MaxValue.

Did you set int.MaxValue in an attempt to disable the limits? Disabling the limits is strongly discouraged.

[rybkov]

Thank you @Tratcher!
We did not disable it - just in process of migrating 4.7 to Core 3 and setup as it was before.
The limits are pretty high, so we are good and can close the issue.

[Tratcher]

I'll leave it open so we can confirm and address the overflow issue.

[shirhatti]

Given that there's a trivial workaround for this, we're targeting 5.0 for this

[davidfowl]

This should have been nullable.

[Tratcher]

shrug turning it off is a pretty bad idea.

[davidfowl]

And setting it to int.MaxValue isn’t 😆