Allow setting User on ServiceAccountCredential when using GoogleCredential

var creds = GoogleCredential.FromStream(stream).CreateScoped(scopes);

When creating a GoogleCredential from a JSON key for a service account, the resulting UnderlyingCredential (ServiceAccountCredential) provides no way of setting the User property.

The code here looks like it is intending to copy a user over, but no user is ever set. It only derives from the JSON. Maybe we need a method like is provided for adding the scope (CreateScoped).

For now, the only way I can get this to work is to create my own ServiceAccountCredential instead of using GoogleCredential. Basically, I am just copy/pasting the code from the existing DefaultCredentialProvider and adding my User and Scopes.

...

var credentialParameters = NewtonsoftJsonSerializer.Instance.Deserialize<JsonCredentialParameters>(stream);

...

private static ServiceAccountCredential CreateServiceAccountCredentialFromParameters(
    JsonCredentialParameters credentialParameters)
{
    if(credentialParameters.Type != JsonCredentialParameters.ServiceAccountCredentialType ||
        string.IsNullOrEmpty(credentialParameters.ClientEmail) ||
        string.IsNullOrEmpty(credentialParameters.PrivateKey))
    {
        throw new InvalidOperationException("JSON data does not represent a valid service account credential.");
    }

    var initializer = new ServiceAccountCredential.Initializer(credentialParameters.ClientEmail);
    initializer.User = "[e-mail]";
    initializer.Scopes = new List<string>
    {
        DirectoryService.Scope.AdminDirectoryUserReadonly
    };

    return new ServiceAccountCredential(initializer.FromPrivateKey(credentialParameters.PrivateKey));
}

[chrisdunelm]

Yes, exactly. I expect we’ll release a new version to nuget with this fix sometime next week.

[kspearrin]

@chrisdunelm Looks like that will work. I assume the syntax for scopes and user would be?

GoogleCredential.FromStream(stream).CreateScoped(scopes).CreateWithUser(user)