Saml2: .NET 5: EnvironmentHelpers.IsNetCore bad implementation

Created on 6 Nov 2020 · 16Comments · Source: Sustainsys/Saml2

Hi,
implementation of flag EnvironmentHelpers.IsNetCore in Saml2.Internal and Saml2.Metadata isn't good.
If main application is in .net 5, detection fails and library crashes.

After forking project and fixing bug, library starts to working properly.

bug

Source

Softwaretom007

Most helpful comment

@DavidBasarab ASAP - got piled up with too much work, but working on it.

AndersAbel on 7 Dec 2020

❤3

All 16 comments

Thanks for noticing. .NET 5 is coming and should definitely work. Would you mind sending a pull request with the new detection logic?

Are there any other issues or incompatibilities you've seen so far?

AndersAbel on 9 Nov 2020

Is there a reason this is a runtime check instead of a compile time check @AndersAbel? I could open a PR to change this into a compile time check.

dlemstra on 13 Nov 2020

Hi @AndersAbel, I also ran into this issue. I created a pull request with a fix: https://github.com/Sustainsys/Saml2/pull/1254.

I haven't seen any other issues or incompatibilities so far but will let you know if I do.

creste on 13 Nov 2020

@dlemstra For the .NET Standard target it is not known at compile time if the runtime is .Net Core or .Net Framework. That's the historical reason. But the .NET Standard target might be something to discuss if it's worth keeping - we're already multi-targeting because how .NET Framework does not implement .Net Standard very nicely in some versions.

AndersAbel on 13 Nov 2020

Hi guys!

Any news about this changes?

We are testing net 5.0 and getting this error:

_InvalidCastException: Unable to cast object of type 'System.Security.Cryptography.RSACng' to type 'System.Security.Cryptography.RSACryptoServiceProvider'._

It is related to the EnvironmentHelpers.IsNetCore at AddSignature method in WebSSO/Saml2RedirectBinding.cs:

```queryString += "&SigAlg=" + Uri.EscapeDataString(signingAlgorithmUrl); var signatureDescription = (SignatureDescription)CryptographyExtensions.CreateAlgorithmFromName(signingAlgorithmUrl); HashAlgorithm hashAlg = signatureDescription.CreateDigest(); hashAlg.ComputeHash(Encoding.UTF8.GetBytes(queryString)); AsymmetricSignatureFormatter asymmetricSignatureFormatter = signatureDescription.CreateFormatter( EnvironmentHelpers.IsNetCore ? message.SigningCertificate.PrivateKey : ((RSACryptoServiceProvider)message.SigningCertificate.PrivateKey) .GetSha256EnabledRSACryptoServiceProvider()); byte[] signatureValue = asymmetricSignatureFormatter.CreateSignature(hashAlg); queryString += "&Signature=" + Uri.EscapeDataString(Convert.ToBase64String(signatureValue)); return queryString;