I get a 400 bad request - invalid Url when the length of the request exceeds 320+ characters

Question

Not sure what could be the reason. Added the following in Web.config also. maxUrlLength="1024" maxQueryStringLength="1024" requestPathInvalidCharacters="" maxRequestLength="1024" relaxedUrlToFileSystemMapping="true" I encode the uri parameter and send the request but get a invalid url all the time. Url: http://localhost:51840/api/xxxxxxx/xxxxxxxxxxxx/n4cEF3OM0LC0q8I6OMe0XdHo8evXnoeyC06A%252fL%252fu0a%252f6e0RQrdxl2%252fPkSKNfh4aEQm78TReX1zIfGDB1bgH%252bGBEI%252fBw6i0DwQ6%252b3dk6yjs1UZqqICQye6QqVX8bJT%252fBK7GE8a22FeXJiPVtEgFRmp4WcHc4pIRHaE6QGK28kiASGFfUC9tDdRZhLfmYJsluGpsseSUOc5Inxlf3fTFNe7sg7gixrLTlwhfJIATZWWsPc%252bfo6BITTFA%253d%253d

If I reduce the url to the following it works fine. http://localhost:51840/api/xxxxxxx/xxxxxxxxxxxx/n4cEF3OM0LC0q8I6OMe0XdHo8evXnoeyC06A%252fL%252fu0a%252f6e0RQrdxl2%252fPkSKNfh4aEQm78TReX1zIfGDB1bgH%252bGBEI%252fBw6i0DwQ6%252b3dk6yjs1UZqqICQye6QqVX8bJT%252fBK7GE8a22FeXJiPVtEgFRmp4WcHc4pIRHaE6QGK28kiASGFfUC9tDdRZhLfmYJsluGpsseSUOc5Inxlf3fTFNe7sg7gixrLTlwhfJIATZWWsPc%252bfo6BI

When the last 10+ characters it gives me a bad request. Any help greatly appreciated.

Answer 1

Just documenting my experience:

My issue was the one pointed by @Mark at the question comments:

"by default the maximum url segment length is 260"

He suggested to increase this limit in the registry, but I didn't want this kind of trouble. The suggestion by @Vignesh T worked better:

"Replaced the url segment into a querystring parameter and it worked fine"

In summary, instead of doing:

http://path.to.website/very-long-string-goes-here/

I just did:

http://path.to.website/?key=very-long-string-goes-here

Answer 2

run in powershell

Set-ItemProperty -Path HKLM:\System\CurrentControlSet\Services\HTTP\Parameters -Name UrlSegmentMaxLength -Value 2000 -Type "Dword"

then do net stop http and net start http.

https://blogs.msdn.microsoft.com/amyd/2014/02/06/response-400-bad-request-on-long-url/