Resource Owner Password Validation

If you want to use the OAuth 2.0 resource owner password credential grant (aka password), you need to implement and register the IResourceOwnerPasswordValidator interface:

public interface IResourceOwnerPasswordValidator
{
    /// <summary>
    /// Validates the resource owner password credential
    /// </summary>
    /// <param name="context">The context.</param>
    Task ValidateAsync(ResourceOwnerPasswordValidationContext context);
}

On the context you will find already parsed protocol parameters like UserName and Password, but also the raw request if you want to look at other input data.

Your job is then to implement the password validation and set the Result on the context accordingly. See the GrantValidationResult documentation.