This week a colleague contacted me with an issue he encountered after upgrading to .NET 8.0. On the project involved we were using the WsFederation middleware to authenticate and interact with ADFS. However after upgrading to .NET 8 and the 8.x version of the Microsoft.AspNetCore.Authentication.WsFederation middleware the trouble began.
Using this version resulted in a change in behavior as suddenly the middleware starts to expect a SAML 2.0 token instead of a SAML 1.1 token that is now issued by our ADFS server:
XmlReadException: IDX30011: Unable to read XML. Expecting XmlReader to be at ns.element: 'urn:oasis:names:tc:SAML:2.0:assertion.Assertion', found: 'urn:oasis:names:tc:SAML:1.0:assertion.Assertion'.
Although I found a post online that it would be technically possible to let ADFS return a SAML 2.0 token through WSTrust, this doesn’t fit in the passive federation scenario we had, so time to look at some alternative solutions.
Attempt 1 – Reverting to an older package version
We first tried to rollback to an older version of the WSFederation middleware but that caused an issue in a transitive dependency. In the project we were using both Microsoft.Data;SqlClient and Microsoft.AspNetCore.Authentication.WsFederation. Both packages reference the Microsoft.IdentityModel.Tokens package as a shared dependency. However as the Microsoft.Data.SqlClient expects at least version 6.35.0 of the package and Microsoft.AspNetCore.Authentication.WsFederation expects at least version 6.10.0, version 6.35.0 of the Microsoft.IdentityModel.Tokens package is used.
Using this version resulted in a MissingMethodException as the Microsoft.IdentityModel.Tokens.InternalValidators.ValidateLifetimeAndIssuerAfterSignatureNotValidatedSaml method no longer exists in this package.
So no luck, we had to try something else...
Attempt 2 - Adding the Microsoft.IdentityModel.Tokens.Saml package
Further investigation brought me to the following issue on GitHub: Authentication.WsFederation breaks with on-premise AD FS use · Issue #52099 · dotnet/aspnetcore
Their was mentioned that explicitly adding the following NuGet package had fixed the issue:
NuGet Gallery | Microsoft.IdentityModel.Tokens.Saml 8.10.0
We followed this advice and indeed that fixed the problem.
On to the next one…
More information
NuGet Gallery | Microsoft.AspNetCore.Authentication.WsFederation 8.0.16
Obtaining a SAML 2.0 assertion from AD FS by using WS-Trust and Integrated Windows Authentication
Authentication.WsFederation breaks with on-premise AD FS use · Issue #52099 · dotnet/aspnetcore