Rebex Security Releases

Released: Aug 5, 2021

Updates in R5.4


  • Cryptography: Fixed Certificate.FriendlyName setter in .NET 5.0 on non-Windows platforms.

Released: Jun 18, 2021

Updates in R5.3


  • Cryptography: Added support for private keys using PBKDF2 with HMAC/SHA-2 (RFC 8018 / PKCS #5 v2.1).
  • Cryptography: Optimized creation of algorithm objects in CNG layer.


  • Cryptography: Fixed detection of FIPS-only systems on Microsoft .NET Framework 4.8.

Released: May 9, 2021

Updates in R5.2


  • Cryptography: Added ChaCha20Poly1305 class that implements ChaCha20/Poly1305 with an API that resembles Microsoft .NET's AesGcm class.
  • Cryptography: Added support for loading ECDSA certificates from PFX/P12 files in Microsoft .NET 5.0 and .NET Standard 2.1 on Linux and Apple macOS.
  • Cryptography: Added support for saving to PFX/P12 files for certificates with temporarily associated private keys in .NET 5.0 and .NET Standard 2.1 on Linux and macOS.
  • Cryptography: Improved ChaCha20/Poly...

Released: Mar 3, 2021

Updates in R5.1


  • All: Changed release naming scheme ('R5.1' instead of '2020 R5.1').
  • 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...

Released: Nov 10, 2020

Updates in 2020 R5


  • All: Added support for Microsoft .NET 5.0.
  • Cryptography: Added built-in support for Ed25519 algorithm.
  • Cryptography: Added Rebex.Security.Cryptography.AesGcm class (equivalent to .NET 5.0's AesGcm class, but available on all platforms including .NET Framework 3.5).
  • Cryptography: Added SetOtherNames/GetOtherNames methods to CertificateInfo class ('Other Name' support in SANs).
  • Cryptography: AsymmetricKeyAlgorithm.ImportKey method can initialize Ed25519 key from seed (in addition to...

Released: Sep 30, 2020

Updates in 2020 R4


  • All: Rebex assemblies targeting Microsoft .NET Standard 2.1 have been fully tested on Microsoft .NET 5.0 RC1 and are suitable to be used in production on Microsoft's latest .NET platform.
  • Cryptography: Added Ed25519 support to Certificate class. (Not yet supported by the built-in certificate validator due to lack of support in Microsoft Windows and Microsoft .NET).
  • Cryptography: Prohibited usage of Chacha20/Poly1305 in TLS 1.3 in FIPS-only mode. (Already prohibited in TLS 1.2 or earlier...

Released: Jul 14, 2020

Updates in 2020 R3


  • All: Added binaries targeting Microsoft .NET Standard 2.1.
  • Cryptography: Memory usage optimizations in CNG layer.
  • Cryptography: On Microsoft Windows 10 and Microsoft Windows Server 2016 or higher, Microsoft CNG API is used for classic Diffie-Hellman calculations instead of legacy Microsoft CryptoAPI.
  • Cryptography: Optimized disposing of temporary keys in Certificate class.


  • Cryptography: Fixed encoding of ECDSA signatures in PKCS #7 CertificationRequest structure.

Released: May 24, 2020

Updates in 2020 R2


  • Cryptography: Added ContentInfo.ToStream() method.
  • Cryptography: Enhanced Certificate.LoadDerWithKey to support RSASSA-PSS and RSAES-OAEP for RSA keys.
  • Cryptography: Improved AsymmetricKeyAlgorithm to support RSASSA-PSS and RSAES-OAEP with keys loaded via ImportKey method.
  • Cryptography: Optimized Certificate and CertificateChain class to only consume native resources when needed.
  • Cryptography: Optimized CNG handles cleanup.


  • Cryptography: Fixed AsymmetricKeyAlgorithm...

Released: Mar 25, 2020

Updates in 2020 R1.1


  • Common: Added DiffieHellmanNative class to Rebex.Common.Native assembly (speeds up Diffie-Hellman calculations on Xamarin.Android).

Released: Feb 21, 2020

Updates in 2020 R1


  • .NET Standard 2.0 on Xamarin.Android and Xamarin.iOS - Rebex binaries targeting .NET Standard 2.0 are now supported on Xamarin.Android and Xamarin.iOS. Previously-available binaries targeting specific Xamarin platforms have been deprecated, and .NET Standard 2.0 binaries should be used instead.
  • Native X25519 elliptic curve support on Windows 10 - On Windows 10, Windows Server 2016 and Windows Server 2019, Rebex components using ECDH key exchange in TLS or SSH now support X25519 curve...