Change DateTime format of OWIN .expiration and .issued dates

Question

I started with the "Individual User Accounts" authentication option when creating a .NET Web API starter template (as described here). The token is being correctly generated, however the ".issued" and ".expires" property are in a non-ISO date format. How do I format them with DateTime.UtcNow.ToString("o") so it's ISO 8601 compliant?

{
  "access_token": "xxx",
  "token_type": "bearer",
  "expires_in": 1199,
  "userName": "[email protected]",
  "Id": "55ab2c33-6c44-4181-a24f-2b1ce044d981",
  ".issued": "Thu, 13 Aug 2015 23:08:11 GMT",
  ".expires": "Thu, 13 Aug 2015 23:28:11 GMT"
}

The template uses a custom OAuthAuthorizationServerProvider and provides a hook to add additional properties to the outgoing token (the 'Id' and 'userName' are my props), but I don't see any way to change existing properties.

I did notice that in the override ofTokenEndpoint, I get a OAuthTokenEndpointContext that has a properties dictionary with the .issued and .expired keys. Trying to change these values, however, has no effect.

Thanks much in advance.

Answer 1

AuthenticationProperties class is defined in Microsoft.Owin.Security namespace in Microsoft.Owin.dll.

The setter of IssuedUtc property does the following (for ExpiresUtc is similar):

this._dictionary[".issued"] = value.Value.ToString("r", (IFormatProvider) CultureInfo.InvariantCulture);

As you can see, when setting the IssuedUtc the .issued field of dictionary is set too, and with "r" format.

You can try to do the following in the TokenEndPoint method:

foreach (KeyValuePair<string, string> property in context.Properties.Dictionary)
{
    if (property.Key == ".issued")
    {
        context.AdditionalResponseParameters.Add(property.Key, context.Properties.IssuedUtc.Value.ToString("o", (IFormatProvider) CultureInfo.InvariantCulture));
    }
    else if (property.Key == ".expires")
    {
        context.AdditionalResponseParameters.Add(property.Key, context.Properties.ExpiresUtc.Value.ToString("o", (IFormatProvider) CultureInfo.InvariantCulture));
    }
    else
    {
        context.AdditionalResponseParameters.Add(property.Key, property.Value);
    }
}

I hope it helps.