#### [Abblix\.Oidc\.Server](https://www.abblix.com/en/docs/api/abblix-oidc-server 'index')
### [Abblix\.Oidc\.Server\.Features\.PairwiseIdentifiers](https://www.abblix.com/en/docs/api/abblix-oidc-server/Abblix.Oidc.Server.Features.PairwiseIdentifiers 'Abblix\.Oidc\.Server\.Features\.PairwiseIdentifiers')

## PairwiseSubjectSettingsValidator Class

Fails loudly at startup when the configured seal key cannot key the pairwise seal, instead of letting the
first pairwise token request answer 500\.

```csharp
public sealed class PairwiseSubjectSettingsValidator : Microsoft.Extensions.Options.IValidateOptions<Abblix.Oidc.Server.Features.PairwiseIdentifiers.PairwiseSubjectSettings>
```

Inheritance [System\.Object](https://learn.microsoft.com/en-us/dotnet/api/system.object 'System\.Object') → PairwiseSubjectSettingsValidator

Implements [Microsoft\.Extensions\.Options\.IValidateOptions&lt;](https://learn.microsoft.com/en-us/dotnet/api/microsoft.extensions.options.ivalidateoptions-1 'Microsoft\.Extensions\.Options\.IValidateOptions\`1')[PairwiseSubjectSettings](https://www.abblix.com/en/docs/api/abblix-oidc-server/Abblix.Oidc.Server.Features.PairwiseIdentifiers.PairwiseSubjectSettings 'Abblix\.Oidc\.Server\.Features\.PairwiseIdentifiers\.PairwiseSubjectSettings')[&gt;](https://learn.microsoft.com/en-us/dotnet/api/microsoft.extensions.options.ivalidateoptions-1 'Microsoft\.Extensions\.Options\.IValidateOptions\`1')

### Remarks

The salt is the sole key material of the seal, and the two ways it goes wrong are both quiet. An absent
key leaves the settings carrying null: `required` is a rule of the compiler, and the configuration
binder assigns only the properties whose keys are present, so nothing is raised and nothing is set. A
present but unusable key - not base64, or too short - is refused where it is assigned, but only for an
instance somebody wrote in code.

Downstream, neither is loud either: [SubjectTypeConverter](https://www.abblix.com/en/docs/api/abblix-oidc-server/Abblix.Oidc.Server.Features.PairwiseIdentifiers.SubjectTypeConverter 'Abblix\.Oidc\.Server\.Features\.PairwiseIdentifiers\.SubjectTypeConverter') treats settings it cannot use as
pairwise not being configured, while discovery goes on advertising `pairwise` as a supported subject
type. So a client registered for it is accepted and fails at the token endpoint.