Inject dependency into IAuthorizationPolicy

Question

I have a custom IAuthorizationPolicy which has a dependency on a repository

internal class CustomAuthorizationPolicy : IAuthorizationPolicy
{
    private IBaseRepository _baseRepository;

    public CustomAuthorizationPolicy(IBaseRepository baseRepository)
    {
        _baseRepository = baseRepository;
    }
}

It is configured like this in web.config

  <serviceAuthorization principalPermissionMode="Custom">
    <authorizationPolicies>
      <add policyType="CustomAuthorizationPolicy" />
    </authorizationPolicies>
  </serviceAuthorization>

This fails because WCF is not able to inject the required object when the policy is created. It expects a parameterless constructor.

I am using StructureMap and has a custom IInstanceProvider that handles all other dependencies in my application. But I can't get it to handle this situation.

Is this possible to do??

Answer 1

I ended up solving this with the use of a custom ServiceHost and a ServiceHostFactory. The factory sends the IoC container to the servicehost, which adds the new policy with a reference to the container. Now the policy can use the container to get the objects it needs.

public class CustomServiceHost : ServiceHost
{
    public CustomServiceHost(IContainer container, Type serviceType, params Uri[] baseAddresses)
        : base(serviceType, baseAddresses)
    {
        // Keep existing policies
        var policies = new List<IAuthorizationPolicy>();
        if (Authorization.ExternalAuthorizationPolicies != null)
        {
            policies.AddRange(Authorization.ExternalAuthorizationPolicies);
        }

        // Add new policy
        policies.Add(new PasswordAuthorizationPolicy(container));
        Authorization.ExternalAuthorizationPolicies = policies.AsReadOnly();

        // Set correct mode
        this.Authorization.PrincipalPermissionMode = PrincipalPermissionMode.Custom;
    }
}