private async Task <bool> InvokeTokenEndpointAsync()
{
if (!string.Equals(Request.Method, "POST", StringComparison.OrdinalIgnoreCase))
{
Logger.LogError("The token request was rejected because an invalid " +
"HTTP method was received: {Method}.", Request.Method);
return(await SendTokenResponseAsync(new OpenIdConnectResponse
{
Error = OpenIdConnectConstants.Errors.InvalidRequest,
ErrorDescription = "A malformed token request has been received: make sure to use POST."
}));
}
// 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 = "A malformed token request has been received: " +
"the mandatory 'Content-Type' header was missing from the POST request."
}));
}
// 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 received: {ContentType}.", Request.ContentType);
return(await SendTokenResponseAsync(new OpenIdConnectResponse
{
Error = OpenIdConnectConstants.Errors.InvalidRequest,
ErrorDescription = "A malformed token request has been received: " +
"the 'Content-Type' header contained an unexcepted value. " +
"Make sure to use 'application/x-www-form-urlencoded'."
}));
}
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, Options, request);
await Options.Provider.ExtractTokenRequest(@event);
if (@event.HandledResponse)
{
Logger.LogDebug("The token request was handled in user code.");
return(true);
}
else if (@event.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 was 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 was 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 was 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 " +
"was/were missing from the request message."
}));
}
// When client_id and client_secret are both null, try to extract them from the Authorization header.
// See http://tools.ietf.org/html/rfc6749#section-2.3.1 and
// http://openid.net/specs/openid-connect-core-1_0.html#ClientAuthentication
if (string.IsNullOrEmpty(request.ClientId) && string.IsNullOrEmpty(request.ClientSecret))
{
string header = Request.Headers[HeaderNames.Authorization];
if (!string.IsNullOrEmpty(header) && header.StartsWith("Basic ", StringComparison.OrdinalIgnoreCase))
{
try
{
var value = header.Substring("Basic ".Length).Trim();
var data = Encoding.UTF8.GetString(Convert.FromBase64String(value));
var index = data.IndexOf(':');
if (index >= 0)
{
request.ClientId = data.Substring(0, index);
request.ClientSecret = data.Substring(index + 1);
}
}
catch (FormatException) { }
catch (ArgumentException) { }
}
}
var context = new ValidateTokenRequestContext(Context, Options, request);
await Options.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.HandledResponse)
{
Logger.LogDebug("The token request was handled in user code.");
return(true);
}
else if (context.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 client_credentials."
}));
}
// 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 = "client_id was missing from the token request"
}));
}
// Store the validated client_id as a request property.
request.SetProperty(OpenIdConnectConstants.Properties.ClientId, 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 = "Invalid ticket"
}));
}
// 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 this ticket"
}));
}
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 = "Expired ticket"
}));
}
// 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 = "Ticket does not contain matching client_id"
}));
}
// 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.RedirectUri);
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 = "redirect_uri was missing from the token request"
}));
}
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 = "Authorization code does not contain matching redirect_uri"
}));
}
}
// 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 required 'code_verifier' was missing from the token request."
}));
}
// 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' was invalid."
}));
}
}
if (request.IsRefreshTokenGrantType() && !string.IsNullOrEmpty(request.Resource))
{
// When an explicit resource parameter has been included in the token request
// but was missing from the initial request, the request MUST be rejected.
var resources = ticket.GetResources();
if (!resources.Any())
{
Logger.LogError("The token request was rejected because the 'resource' parameter was not allowed.");
return(await SendTokenResponseAsync(new OpenIdConnectResponse
{
Error = OpenIdConnectConstants.Errors.InvalidGrant,
ErrorDescription = "Token request cannot contain a resource parameter " +
"if the authorization request didn't contain one"
}));
}
// When an explicit resource parameter has been included in the token request,
// the authorization server MUST ensure that it doesn't contain resources
// that were not allowed during the initial authorization/token request.
else if (!new HashSet <string>(resources).IsSupersetOf(request.GetResources()))
{
Logger.LogError("The token request was rejected because the 'resource' parameter was not valid.");
return(await SendTokenResponseAsync(new OpenIdConnectResponse
{
Error = OpenIdConnectConstants.Errors.InvalidGrant,
ErrorDescription = "Token request doesn't contain a valid resource parameter"
}));
}
}
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 = "Token request cannot contain a scope parameter " +
"if the authorization request didn't contain one"
}));
}
// 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 = "Token request doesn't contain a valid scope parameter"
}));
}
}
}
var notification = new HandleTokenRequestContext(Context, Options, request, ticket);
await Options.Provider.HandleTokenRequest(notification);
if (notification.HandledResponse)
{
Logger.LogDebug("The token request was handled in user code.");
return(true);
}
else if (notification.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 grant type is not supported.
if (ticket == null)
{
Logger.LogError("The token request was rejected because no authentication " +
"ticket was returned by application code.");
return(await SendTokenResponseAsync(new OpenIdConnectResponse
{
Error = OpenIdConnectConstants.Errors.UnsupportedGrantType,
ErrorDescription = "The specified grant_type parameter is not supported."
}));
}
// Call HandleSignInAsync to generate a token response.
return(await HandleSignInAsync(ticket));
}
