DiscoveryClient doesn't obey DiscoveryPolicy.Authority

DiscoveryClient allows you to specify a DiscoveryPolicy to aid in validation. However, the first thing it does in DiscoveryClient.GetAsync is overwrite the policy Authority so there’s no way to cause validation to obey the specified Authority.

The use case in which I’m hitting this is multitenancy. I have a multitenant OIDC provider much like Azure AD where the tenant ID in the URL is case-sensitive and contains upper-case letters - https://my.identity.server/TenantIdHere/.well-known/openid-configuration

However, Identity Server forces the base URL to lowercase as the issuer like https://my.identity.server/tenantidhere. I wanted to set the authority in the validation policy to be the “normalized lowercase” version of the URL so validation would work, but that gets overwritten. I also can’t address it by adding to the AdditionalEndpointBaseAddresses because only the authority is used for issuer validation

My current workaround is to disable issuer validation entirely.

[leastprivilege]

yes - sounds good! thanks

[leastprivilege]

…or if you want to make a PR for that - this would probably speed up the process.