Xamarin Studio 6 and iOS Certificate error

Profile pictureToni Petrina
Published on 2016-06-141 min read
  • #xamarin
  • #ios

Xamarin Studio 6 is here and it broke some people's code including ours. The error happens when using HttpClient to connect to a web service using TLS. Here is a part of the exception:

System.Net.WebException: Error: TrustFailure (CertificateUnknown) ---> Mono.Security.Interface.TlsException: CertificateUnknown at Security.Tls.MobileAuthenticatedStream.ProcessAuthentication (System.Net.LazyAsyncResult lazyResult) [0x00077] in /Users/builder/data/lanes/3339/39ebb778/source/maccore/src/Security/Tls/MobileAuthenticatedStream.cs:206

iOS Build settings

To fix this, go to iOS project settings and change the SSL/TLS implementation from Apple TLS (default) to Mono (TLS v1.0) as seen on the image below.

This should fix the issue and you can continue using Xamarin Studio 6 instead of downgrading to 5.2.0.

Happy coding!

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