protected override async Task <AuthenticationTicket> AuthenticateCoreAsync()
{
var context = new RetrieveTokenContext(Context, Options);
await Options.Events.RetrieveToken(context);
if (context.Handled)
{
Logger.LogInformation("The default authentication handling was skipped from user code.");
return(context.Ticket);
}
var token = context.Token;
if (string.IsNullOrEmpty(token))
{
// Try to retrieve the access token from the authorization header.
var header = Request.Headers[OAuthIntrospectionConstants.Headers.Authorization];
if (string.IsNullOrEmpty(header))
{
Logger.LogDebug("Authentication was skipped because no bearer token was received.");
return(null);
}
// Ensure that the authorization header contains the mandatory "Bearer" scheme.
// See https://tools.ietf.org/html/rfc6750#section-2.1
if (!header.StartsWith(OAuthIntrospectionConstants.Schemes.Bearer + ' ', StringComparison.OrdinalIgnoreCase))
{
Logger.LogDebug("Authentication was skipped because an incompatible " +
"scheme was used in the 'Authorization' header.");
return(null);
}
// Extract the token from the authorization header.
token = header.Substring(OAuthIntrospectionConstants.Schemes.Bearer.Length + 1).Trim();
if (string.IsNullOrEmpty(token))
{
Logger.LogDebug("Authentication was skipped because the bearer token " +
"was missing from the 'Authorization' header.");
return(null);
}
}
// Try to resolve the authentication ticket from the distributed cache. If none
// can be found, a new introspection request is sent to the authorization server.
var ticket = await RetrieveTicketAsync(token);
if (ticket == null)
{
// Return a failed authentication result if the introspection
// request failed or if the "active" claim was false.
var payload = await GetIntrospectionPayloadAsync(token);
if (payload == null || !payload.Value <bool>(OAuthIntrospectionConstants.Claims.Active))
{
Logger.LogError("Authentication failed because the authorization " +
"server rejected the access token.");
Context.Set(typeof(OAuthIntrospectionError).FullName, new OAuthIntrospectionError
{
Error = OAuthIntrospectionConstants.Errors.InvalidToken,
ErrorDescription = "The access token is not valid."
});
return(null);
}
// Create a new authentication ticket from the introspection
// response returned by the authorization server.
ticket = await CreateTicketAsync(token, payload);
Debug.Assert(ticket != null);
await StoreTicketAsync(token, ticket);
}
// Ensure that the token can be used as an access token.
if (!ValidateTokenUsage(ticket))
{
Logger.LogError("Authentication failed because the token was not an access token.");
Context.Set(typeof(OAuthIntrospectionError).FullName, new OAuthIntrospectionError
{
Error = OAuthIntrospectionConstants.Errors.InvalidToken,
ErrorDescription = "The access token is not valid."
});
return(null);
}
// Ensure that the authentication ticket is still valid.
if (ticket.Properties.ExpiresUtc.HasValue &&
ticket.Properties.ExpiresUtc.Value < Options.SystemClock.UtcNow)
{
Logger.LogError("Authentication failed because the access token was expired.");
Context.Set(typeof(OAuthIntrospectionError).FullName, new OAuthIntrospectionError
{
Error = OAuthIntrospectionConstants.Errors.InvalidToken,
ErrorDescription = "The access token is no longer valid."
});
return(null);
}
// Ensure that the access token was issued
// to be used with this resource server.
if (!ValidateAudience(ticket))
{
Logger.LogError("Authentication failed because the access token " +
"was not valid for this resource server.");
Context.Set(typeof(OAuthIntrospectionError).FullName, new OAuthIntrospectionError
{
Error = OAuthIntrospectionConstants.Errors.InvalidToken,
ErrorDescription = "The access token is not valid for this resource server."
});
return(null);
}
var notification = new ValidateTokenContext(Context, Options, ticket);
await Options.Events.ValidateToken(notification);
// Allow the application code to replace the ticket
// reference from the ValidateToken event.
return(notification.Ticket);
}
/// <summary> /// Invoked when a token is to be parsed from a newly-received request. /// </summary> public virtual Task RetrieveToken(RetrieveTokenContext context) => OnRetrieveToken(context);