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Going to host a Linux .NET 8 WebAPI application with App Services Web App.
Problem: When the inbound request url contains a %2F the App Services internal proxy magically converts that to / so when the request hits the application it is a HTTP 404 as that URL is unknown.
Example:
Original value: https://myapp.azure/foo/abc%2Fcba
Expected value: https://myapp.azure/foo/abc%2Fcba
Actual value: https://myapp.azure/foo/abc/cba
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Hi Thanks for the question - yes this is default behaviour - the following should help you https://github.com/Azure/azure-functions-host/pull/9402 same was also referenced here https://github.com/dotnet/aspnetcore/issues/40532
Please let us know if this works for you
Thanks. Unfortunately, I see this behavior as a fundamental problem. The / character was encoded as %2F and that's what url-encoding is designed for, to encode characters that have special meaning.
Excerpt from the URL RFC:
All unsafe characters must always be encoded within a URL. For example, the character "#" must be encoded within URLs even in systems that do not normally deal with fragment or anchor identifiers, so that if the URL is copied into another system that does use them, it will not be necessary to change the URL encoding.
From what I see a workaround is to double encode / but that's still problematic for a number of reasons. I hope it'll get fixed at the proxy level.
As per the issue I quoted above there is a workitem created internally for this - I'll follow it up and let you know what they say
There is an internal backlog item for work to remediate this but currently no dates