private async Task <bool> InvokeTokenEndpointAsync()
{
if (!HttpMethods.IsPost(Request.Method))
{
Logger.LogError("The token request was rejected because an invalid " +
"HTTP method was specified: {Method}.", Request.Method);
return(await SendTokenResponseAsync(new OpenIdConnectResponse
{
Error = OpenIdConnectConstants.Errors.InvalidRequest,
ErrorDescription = "The specified HTTP method is not valid."
}));
}
// See http://openid.net/specs/openid-connect-core-1_0.html#FormSerialization
if (string.IsNullOrEmpty(Request.ContentType))
{
Logger.LogError("The token request was rejected because the " +
"mandatory 'Content-Type' header was missing.");
return(await SendTokenResponseAsync(new OpenIdConnectResponse
{
Error = OpenIdConnectConstants.Errors.InvalidRequest,
ErrorDescription = "The mandatory 'Content-Type' header must be specified."
}));
}
// May have media/type; charset=utf-8, allow partial match.
if (!Request.ContentType.StartsWith("application/x-www-form-urlencoded", StringComparison.OrdinalIgnoreCase))
{
Logger.LogError("The token request was rejected because an invalid 'Content-Type' " +
"header was specified: {ContentType}.", Request.ContentType);
return(await SendTokenResponseAsync(new OpenIdConnectResponse
{
Error = OpenIdConnectConstants.Errors.InvalidRequest,
ErrorDescription = "The specified 'Content-Type' header is not valid."
}));
}
var request = new OpenIdConnectRequest(await Request.ReadFormAsync(Context.RequestAborted));
// Note: set the message type before invoking the ExtractTokenRequest event.
request.SetProperty(OpenIdConnectConstants.Properties.MessageType,
OpenIdConnectConstants.MessageTypes.TokenRequest);
// Store the token request in the ASP.NET context.
Context.SetOpenIdConnectRequest(request);
var @event = new ExtractTokenRequestContext(Context, Scheme, Options, request);
await Provider.ExtractTokenRequest(@event);
if (@event.Result != null)
{
if (@event.Result.Handled)
{
Logger.LogDebug("The token request was handled in user code.");
return(true);
}
else if (@event.Result.Skipped)
{
Logger.LogDebug("The default token request handling was skipped from user code.");
return(false);
}
}
else if (@event.IsRejected)
{
Logger.LogError("The token request was rejected with the following error: {Error} ; {Description}",
/* Error: */ @event.Error ?? OpenIdConnectConstants.Errors.InvalidRequest,
/* Description: */ @event.ErrorDescription);
return(await SendTokenResponseAsync(new OpenIdConnectResponse
{
Error = @event.Error ?? OpenIdConnectConstants.Errors.InvalidRequest,
ErrorDescription = @event.ErrorDescription,
ErrorUri = @event.ErrorUri
}));
}
Logger.LogInformation("The token request was successfully extracted " +
"from the HTTP request: {Request}.", request);
// Reject token requests missing the mandatory grant_type parameter.
if (string.IsNullOrEmpty(request.GrantType))
{
Logger.LogError("The token request was rejected because the grant type was missing.");
return(await SendTokenResponseAsync(new OpenIdConnectResponse
{
Error = OpenIdConnectConstants.Errors.InvalidRequest,
ErrorDescription = "The mandatory 'grant_type' parameter is missing.",
}));
}
// Reject grant_type=authorization_code requests if the authorization endpoint is disabled.
else if (request.IsAuthorizationCodeGrantType() && !Options.AuthorizationEndpointPath.HasValue)
{
Logger.LogError("The token request was rejected because the authorization code grant was disabled.");
return(await SendTokenResponseAsync(new OpenIdConnectResponse
{
Error = OpenIdConnectConstants.Errors.UnsupportedGrantType,
ErrorDescription = "The authorization code grant is not allowed by this authorization server."
}));
}
// Reject grant_type=authorization_code requests missing the authorization code.
// See https://tools.ietf.org/html/rfc6749#section-4.1.3
else if (request.IsAuthorizationCodeGrantType() && string.IsNullOrEmpty(request.Code))
{
Logger.LogError("The token request was rejected because the authorization code was missing.");
return(await SendTokenResponseAsync(new OpenIdConnectResponse
{
Error = OpenIdConnectConstants.Errors.InvalidRequest,
ErrorDescription = "The mandatory 'code' parameter is missing."
}));
}
// Reject grant_type=refresh_token requests missing the refresh token.
// See https://tools.ietf.org/html/rfc6749#section-6
else if (request.IsRefreshTokenGrantType() && string.IsNullOrEmpty(request.RefreshToken))
{
Logger.LogError("The token request was rejected because the refresh token was missing.");
return(await SendTokenResponseAsync(new OpenIdConnectResponse
{
Error = OpenIdConnectConstants.Errors.InvalidRequest,
ErrorDescription = "The mandatory 'refresh_token' parameter is missing."
}));
}
// Reject grant_type=password requests missing username or password.
// See https://tools.ietf.org/html/rfc6749#section-4.3.2
else if (request.IsPasswordGrantType() && (string.IsNullOrEmpty(request.Username) ||
string.IsNullOrEmpty(request.Password)))
{
Logger.LogError("The token request was rejected because the resource owner credentials were missing.");
return(await SendTokenResponseAsync(new OpenIdConnectResponse
{
Error = OpenIdConnectConstants.Errors.InvalidRequest,
ErrorDescription = "The mandatory 'username' and/or 'password' parameters are missing."
}));
}
// Try to resolve the client credentials specified in the 'Authorization' header.
// If they cannot be extracted, fallback to the client_id/client_secret parameters.
var credentials = Request.Headers.GetClientCredentials();
if (credentials != null)
{
// Reject requests that use multiple client authentication methods.
// See https://tools.ietf.org/html/rfc6749#section-2.3 for more information.
if (!string.IsNullOrEmpty(request.ClientSecret))
{
Logger.LogError("The token request was rejected because multiple client credentials were specified.");
return(await SendTokenResponseAsync(new OpenIdConnectResponse
{
Error = OpenIdConnectConstants.Errors.InvalidRequest,
ErrorDescription = "Multiple client credentials cannot be specified."
}));
}
request.ClientId = credentials?.Key;
request.ClientSecret = credentials?.Value;
}
var context = new ValidateTokenRequestContext(Context, Scheme, Options, request);
await Provider.ValidateTokenRequest(context);
// If the validation context was set as fully validated,
// mark the OpenID Connect request as confidential.
if (context.IsValidated)
{
request.SetProperty(OpenIdConnectConstants.Properties.ConfidentialityLevel,
OpenIdConnectConstants.ConfidentialityLevels.Private);
}
if (context.Result != null)
{
if (context.Result.Handled)
{
Logger.LogDebug("The token request was handled in user code.");
return(true);
}
else if (context.Result.Skipped)
{
Logger.LogDebug("The default token request handling was skipped from user code.");
return(false);
}
}
else if (context.IsRejected)
{
Logger.LogError("The token request was rejected with the following error: {Error} ; {Description}",
/* Error: */ context.Error ?? OpenIdConnectConstants.Errors.InvalidRequest,
/* Description: */ context.ErrorDescription);
return(await SendTokenResponseAsync(new OpenIdConnectResponse
{
Error = context.Error ?? OpenIdConnectConstants.Errors.InvalidRequest,
ErrorDescription = context.ErrorDescription,
ErrorUri = context.ErrorUri
}));
}
// Reject grant_type=client_credentials requests if validation was skipped.
else if (context.IsSkipped && request.IsClientCredentialsGrantType())
{
Logger.LogError("The token request must be fully validated to use the client_credentials grant type.");
return(await SendTokenResponseAsync(new OpenIdConnectResponse
{
Error = OpenIdConnectConstants.Errors.InvalidGrant,
ErrorDescription = "Client authentication is required when using the client credentials grant."
}));
}
// At this stage, client_id cannot be null for grant_type=authorization_code requests,
// as it must either be set in the ValidateTokenRequest notification
// by the developer or manually flowed by non-confidential client applications.
// See https://tools.ietf.org/html/rfc6749#section-4.1.3
if (request.IsAuthorizationCodeGrantType() && string.IsNullOrEmpty(context.ClientId))
{
Logger.LogError("The token request was rejected because the mandatory 'client_id' was missing.");
return(await SendTokenResponseAsync(new OpenIdConnectResponse
{
Error = OpenIdConnectConstants.Errors.InvalidRequest,
ErrorDescription = "The mandatory 'client_id' parameter is missing."
}));
}
// Store the validated client_id as a request property.
request.SetProperty(OpenIdConnectConstants.Properties.ValidatedClientId, context.ClientId);
Logger.LogInformation("The token request was successfully validated.");
AuthenticationTicket ticket = null;
// See http://tools.ietf.org/html/rfc6749#section-4.1
// and http://tools.ietf.org/html/rfc6749#section-4.1.3 (authorization code grant).
// See http://tools.ietf.org/html/rfc6749#section-6 (refresh token grant).
if (request.IsAuthorizationCodeGrantType() || request.IsRefreshTokenGrantType())
{
ticket = request.IsAuthorizationCodeGrantType() ?
await DeserializeAuthorizationCodeAsync(request.Code, request) :
await DeserializeRefreshTokenAsync(request.RefreshToken, request);
if (ticket == null)
{
Logger.LogError("The token request was rejected because the " +
"authorization code or the refresh token was invalid.");
return(await SendTokenResponseAsync(new OpenIdConnectResponse
{
Error = OpenIdConnectConstants.Errors.InvalidGrant,
ErrorDescription = request.IsAuthorizationCodeGrantType() ?
"The specified authorization code is invalid." :
"The specified refresh token is invalid."
}));
}
// If the client was fully authenticated when retrieving its refresh token,
// the current request must be rejected if client authentication was not enforced.
if (request.IsRefreshTokenGrantType() && !context.IsValidated && ticket.IsConfidential())
{
Logger.LogError("The token request was rejected because client authentication " +
"was required to use the confidential refresh token.");
return(await SendTokenResponseAsync(new OpenIdConnectResponse
{
Error = OpenIdConnectConstants.Errors.InvalidGrant,
ErrorDescription = "Client authentication is required to use the specified refresh token."
}));
}
if (ticket.Properties.ExpiresUtc.HasValue &&
ticket.Properties.ExpiresUtc < Options.SystemClock.UtcNow)
{
Logger.LogError("The token request was rejected because the " +
"authorization code or the refresh token was expired.");
return(await SendTokenResponseAsync(new OpenIdConnectResponse
{
Error = OpenIdConnectConstants.Errors.InvalidGrant,
ErrorDescription = request.IsAuthorizationCodeGrantType() ?
"The specified authorization code is no longer valid." :
"The specified refresh token is no longer valid."
}));
}
// Note: presenters may be empty during a grant_type=refresh_token request if the refresh token
// was issued to a public client but cannot be null for an authorization code grant request.
var presenters = ticket.GetPresenters();
if (request.IsAuthorizationCodeGrantType() && !presenters.Any())
{
throw new InvalidOperationException("The presenters list cannot be extracted from the authorization code.");
}
// Ensure the authorization code/refresh token was issued to the client application making the token request.
// Note: when using the refresh token grant, client_id is optional but must validated if present.
// As a consequence, this check doesn't depend on the actual status of client authentication.
// See https://tools.ietf.org/html/rfc6749#section-6
// and http://openid.net/specs/openid-connect-core-1_0.html#RefreshingAccessToken
if (!string.IsNullOrEmpty(context.ClientId) && presenters.Any() &&
!presenters.Contains(context.ClientId, StringComparer.Ordinal))
{
Logger.LogError("The token request was rejected because the authorization " +
"code was issued to a different client application.");
return(await SendTokenResponseAsync(new OpenIdConnectResponse
{
Error = OpenIdConnectConstants.Errors.InvalidGrant,
ErrorDescription = request.IsAuthorizationCodeGrantType() ?
"The specified authorization code cannot be used by this client application." :
"The specified refresh token cannot be used by this client application."
}));
}
// Validate the redirect_uri flowed by the client application during this token request.
// Note: for pure OAuth2 requests, redirect_uri is only mandatory if the authorization request
// contained an explicit redirect_uri. OpenID Connect requests MUST include a redirect_uri
// but the specifications allow proceeding the token request without returning an error
// if the authorization request didn't contain an explicit redirect_uri.
// See https://tools.ietf.org/html/rfc6749#section-4.1.3
// and http://openid.net/specs/openid-connect-core-1_0.html#TokenRequestValidation
var address = ticket.GetProperty(OpenIdConnectConstants.Properties.OriginalRedirectUri);
if (request.IsAuthorizationCodeGrantType() && !string.IsNullOrEmpty(address))
{
if (string.IsNullOrEmpty(request.RedirectUri))
{
Logger.LogError("The token request was rejected because the mandatory 'redirect_uri' " +
"parameter was missing from the grant_type=authorization_code request.");
return(await SendTokenResponseAsync(new OpenIdConnectResponse
{
Error = OpenIdConnectConstants.Errors.InvalidRequest,
ErrorDescription = "The mandatory 'redirect_uri' parameter is missing."
}));
}
else if (!string.Equals(address, request.RedirectUri, StringComparison.Ordinal))
{
Logger.LogError("The token request was rejected because the 'redirect_uri' " +
"parameter didn't correspond to the expected value.");
return(await SendTokenResponseAsync(new OpenIdConnectResponse
{
Error = OpenIdConnectConstants.Errors.InvalidGrant,
ErrorDescription = "The specified 'redirect_uri' parameter doesn't match the client " +
"redirection endpoint the authorization code was initially sent to."
}));
}
}
// If a code challenge was initially sent in the authorization request and associated with the
// code, validate the code verifier to ensure the token request is sent by a legit caller.
var challenge = ticket.GetProperty(OpenIdConnectConstants.Properties.CodeChallenge);
if (request.IsAuthorizationCodeGrantType() && !string.IsNullOrEmpty(challenge))
{
// Get the code verifier from the token request.
// If it cannot be found, return an invalid_grant error.
var verifier = request.CodeVerifier;
if (string.IsNullOrEmpty(verifier))
{
Logger.LogError("The token request was rejected because the required 'code_verifier' " +
"parameter was missing from the grant_type=authorization_code request.");
return(await SendTokenResponseAsync(new OpenIdConnectResponse
{
Error = OpenIdConnectConstants.Errors.InvalidRequest,
ErrorDescription = "The mandatory 'code_verifier' parameter is missing."
}));
}
// Note: the code challenge method is always validated when receiving the authorization request.
var method = ticket.GetProperty(OpenIdConnectConstants.Properties.CodeChallengeMethod);
Debug.Assert(string.IsNullOrEmpty(method) ||
string.Equals(method, OpenIdConnectConstants.CodeChallengeMethods.Plain, StringComparison.Ordinal) ||
string.Equals(method, OpenIdConnectConstants.CodeChallengeMethods.Sha256, StringComparison.Ordinal),
"The specified code challenge method should be supported.");
// If the S256 challenge method was used, compute the hash corresponding to the code verifier.
if (string.Equals(method, OpenIdConnectConstants.CodeChallengeMethods.Sha256, StringComparison.Ordinal))
{
using (var algorithm = SHA256.Create())
{
// Compute the SHA-256 hash of the code verifier and encode it using base64-url.
// See https://tools.ietf.org/html/rfc7636#section-4.6 for more information.
var hash = algorithm.ComputeHash(Encoding.ASCII.GetBytes(request.CodeVerifier));
verifier = Base64UrlEncoder.Encode(hash);
}
}
// Compare the verifier and the code challenge: if the two don't match, return an error.
// Note: to prevent timing attacks, a time-constant comparer is always used.
if (!OpenIdConnectServerHelpers.AreEqual(verifier, challenge))
{
Logger.LogError("The token request was rejected because the 'code_verifier' was invalid.");
return(await SendTokenResponseAsync(new OpenIdConnectResponse
{
Error = OpenIdConnectConstants.Errors.InvalidGrant,
ErrorDescription = "The specified 'code_verifier' parameter is invalid."
}));
}
}
if (request.IsRefreshTokenGrantType() && !string.IsNullOrEmpty(request.Scope))
{
// When an explicit scope parameter has been included in the token request
// but was missing from the initial request, the request MUST be rejected.
// See http://tools.ietf.org/html/rfc6749#section-6
var scopes = ticket.GetScopes();
if (!scopes.Any())
{
Logger.LogError("The token request was rejected because the 'scope' parameter was not allowed.");
return(await SendTokenResponseAsync(new OpenIdConnectResponse
{
Error = OpenIdConnectConstants.Errors.InvalidGrant,
ErrorDescription = "The 'scope' parameter is not valid in this context."
}));
}
// When an explicit scope parameter has been included in the token request,
// the authorization server MUST ensure that it doesn't contain scopes
// that were not allowed during the initial authorization/token request.
// See https://tools.ietf.org/html/rfc6749#section-6
else if (!new HashSet <string>(scopes).IsSupersetOf(request.GetScopes()))
{
Logger.LogError("The token request was rejected because the 'scope' parameter was not valid.");
return(await SendTokenResponseAsync(new OpenIdConnectResponse
{
Error = OpenIdConnectConstants.Errors.InvalidGrant,
ErrorDescription = "The specified 'scope' parameter is invalid."
}));
}
}
}
var notification = new HandleTokenRequestContext(Context, Scheme, Options, request, ticket);
await Provider.HandleTokenRequest(notification);
if (notification.Result != null)
{
if (notification.Result.Handled)
{
Logger.LogDebug("The token request was handled in user code.");
return(true);
}
else if (notification.Result.Skipped)
{
Logger.LogDebug("The default token request handling was skipped from user code.");
return(false);
}
}
else if (notification.IsRejected)
{
Logger.LogError("The token request was rejected with the following error: {Error} ; {Description}",
/* Error: */ notification.Error ?? OpenIdConnectConstants.Errors.InvalidGrant,
/* Description: */ notification.ErrorDescription);
return(await SendTokenResponseAsync(new OpenIdConnectResponse
{
Error = notification.Error ?? OpenIdConnectConstants.Errors.InvalidGrant,
ErrorDescription = notification.ErrorDescription,
ErrorUri = notification.ErrorUri
}));
}
// Flow the changes made to the ticket.
ticket = notification.Ticket;
// Ensure an authentication ticket has been provided or return
// an error code indicating that the request was rejected.
if (ticket == null)
{
Logger.LogError("The token request was rejected because it was not handled by the user code.");
return(await SendTokenResponseAsync(new OpenIdConnectResponse
{
Error = OpenIdConnectConstants.Errors.InvalidRequest,
ErrorDescription = "The token request was rejected by the authorization server."
}));
}
return(await SignInAsync(ticket));
}
/// <summary> /// Represents an event called for each request to the token endpoint to give the user code /// a chance to manually extract the token request from the ambient HTTP context. /// </summary> /// <param name="context">The context instance associated with this event.</param> /// <returns>A <see cref="Task"/> that can be used to monitor the asynchronous operation.</returns> public virtual Task ExtractTokenRequest(ExtractTokenRequestContext context) => OnExtractTokenRequest(context);