Oauth Prompt sign in is success even if we provide wrong value

Prasad_Das-MSFT 

We have added the below OAuthPrompt to waterfall dialog. 

AddDialog(new OAuthPrompt(
nameof(OAuthPrompt),
new OAuthPromptSettings
{
ConnectionName = ConnectionName,
Text = "Please Sign In",
Title = "Sign In",
Timeout = 300000
}));

private async Task<DialogTurnResult> PromptStepAsync(WaterfallStepContext stepContext, CancellationToken cancellationToken)
{
return await stepContext.BeginDialogAsync(nameof(OAuthPrompt), null, cancellationToken);
}

private async Task<DialogTurnResult> LoginStepAsync(WaterfallStepContext stepContext, CancellationToken cancellationToken)
{
// Get the token from the previous step.
var tokenResponse = (TokenResponse)stepContext.Result;

if (tokenResponse?.Token != null)

{

//Here token response is not null even if we provide extra numbers after the actual validation code

}

}