public async Task ValidateAsync(ExtensionGrantValidationContext context)
{
var provider = context.Request.Raw.Get("provider");
if (provider.IsEmpty())
{
context.Result = new GrantValidationResult(TokenRequestErrors.InvalidRequest, "invalid provider");
return;
}
var providerType = (ProviderType)Enum.Parse(typeof(ProviderType), provider, true);
if (!Enum.IsDefined(typeof(ProviderType), providerType))
{
context.Result = new GrantValidationResult(TokenRequestErrors.InvalidRequest, "invalid provider");
return;
}
var token = context.Request.Raw.Get("external_token");
if (token.IsEmpty())
{
context.Result = new GrantValidationResult(TokenRequestErrors.InvalidRequest, "invalid external token");
return;
}
var userInfo = await _providers[providerType].GetUserInfoAsync(token);
if (userInfo == null)
{
context.Result = new GrantValidationResult(TokenRequestErrors.InvalidRequest, "couldn't retrieve user info from specified provider, please make sure that access token is not expired.");
return;
}
context.Result = await _userProcessor.ExecuteAsync(userInfo, provider);
}