I'm working on a cross platform mobile app that uses HttpClient API for communication with a remote server. To ensure TLS connection with a proper server, I provide ServerCertificateCustomValidationCallback routine with certificate pinning.
This used to work OK on both Android and iOS prior the latest Visual Studio 2019 update from 16.4.6 to 16.5 (and associated updates to mono mac and xamarin ios). Now on iOS, the routine receives "certChain" argument that contains 0 members in ChainElements collection (so I cannot check the issuer certificate). The "certificate" argument contains server's certificate as usual.
Things run normally on Android devices (certChain has both issuer and the server cert).
Have anyone else encountered similar problem? I'll appreciate any help.