File Server: Changed default value for Settings.KeepAlivePeriod to 300 seconds.
File Server: Improved error messages when no SSH server keys or bindings were specified when starting the server.
File System: MountCapableFileSystemProvider allows 'Move' operation between different mounted file system providers.
EWS: Added Ews.Settings.HttpHeaders property to make it possible to specify custom HTTP headers.
EWS: Added EwsMessageInfo.Sensitivity property.
ZIP: Improved Zip64 format detection.
Networking: More meaningful exception is throw when attempting to use HTTP CONNECT proxy with NTLM authentication on platforms that don't support it.
Networking: Optimized timeout infrastructure in ProxySocket.Connect.
TLS Core: Added VerifyMessage signature algorithm logging in TLS 1.3.
TLS Core: Close/Dispose method called on TLS 1.3 socket ensures that all outstanding IO operations are canceled before the control is returned to the caller.
TLS Core: Synchronous methods on TlsSocket wrap TaskCanceledException to TlsException.
Cryptography: Enhanced implicit operator for conversion of Certificate->X509Certificate2 to retain private keys on non-Microsoft Windows platforms as well.
Cryptography: Optimized memory usage in symmetric encryption transformations based on Windows CNG API.
Cryptography: Substantial speed-up of Chacha20/Poly1305 (used in SSH and TLS). Utilizing AVX2 or Advanced NEON SIMD on Microsoft .NET 5.0 (if available).
Common: Accelerated common byte array operations in .NET 5.0 on devices with AVX2 support.