HashedSharedSecretValidator does not catch null value

[MPapst]

The HashedSharedSecretValidator does not check for nulls before trying to Convert from Base64.

Issue / Steps to reproduce the problem

Good question. Actually I do not know what is causing this.

I added to a working instance of IdentityServer4 (v2.4.0) a MVC Client as described in the samples. Whenever I try to Authenticate from that MVC Client, I am getting an HTML Error Page send back to the Client using Post instead of the Json Token.
I already tried the sample MVC Client and the same happens, so it seems to be related to the IdentityServer configuration(?).

Nevertheless - as I am still investigating this issue offline - a better exception message could have already helped me finding the position.

Relevant parts of the log file

[15:18:50 VRB] Calling into client configuration validator: IdentityServer4.Validation.DefaultClientConfigurationValidator
[15:18:50 DBG] client configuration validation for client ManagementAPIClient succeeded.
[15:18:50 FTL] Unhandled exception: Value cannot be null.
Parameter name: s
System.ArgumentNullException: Value cannot be null.
Parameter name: s
   at System.Convert.FromBase64String(String s)
   at IdentityServer4.Validation.HashedSharedSecretValidator.ValidateAsync(IEnumerable`1 secrets, ParsedSecret parsedSecret) in C:\local\identity\server4\IdentityServer4\src\IdentityServer4\src\Validation\Default\HashedSharedSecretValidator.cs:line 71
   at IdentityServer4.Validation.SecretValidator.ValidateAsync(ParsedSecret parsedSecret, IEnumerable`1 secrets) in C:\local\identity\server4\IdentityServer4\src\IdentityServer4\src\Validation\Default\SecretValidator.cs:line 59
   at IdentityServer4.Validation.ClientSecretValidator.ValidateAsync(HttpContext context) in C:\local\identity\server4\IdentityServer4\src\IdentityServer4\src\Validation\Default\ClientSecretValidator.cs:line 83
   at IdentityServer4.Endpoints.TokenEndpoint.ProcessTokenRequestAsync(HttpContext context) in C:\local\identity\server4\IdentityServer4\src\IdentityServer4\src\Endpoints\TokenEndpoint.cs:line 78
   at IdentityServer4.Endpoints.TokenEndpoint.ProcessAsync(HttpContext context) in C:\local\identity\server4\IdentityServer4\src\IdentityServer4\src\Endpoints\TokenEndpoint.cs:line 70
   at IdentityServer4.Hosting.IdentityServerMiddleware.Invoke(HttpContext context, IEndpointRouter router, IUserSession session, IEventService events) in C:\local\identity\server4\IdentityServer4\src\IdentityServer4\src\Hosting\IdentityServerMiddleware.cs:line 54

[brockallen]

Fixed. Thanks.

[lock]

This thread has been automatically locked since there has not been any recent activity after it was closed. Please open a new issue for related bugs.