FIDO Conformance Tools v1.7.15 fixes

Src/Fido2.Models/AuthenticatorAttestationRawResponse.cs

@@ -15,7 +15,7 @@ public sealed class AuthenticatorAttestationRawResponse
     public byte[] RawId { get; set; }
 
     [JsonPropertyName("type")]
-    public PublicKeyCredentialType Type { get; set; } = PublicKeyCredentialType.PublicKey;
+    public PublicKeyCredentialType? Type { get; set; }
 
     [JsonPropertyName("response")]
     public AttestationResponse Response { get; set; }

Src/Fido2.Models/CredentialCreateOptions.cs

@@ -100,6 +100,7 @@ public static CredentialCreateOptions Create(
                 PubKeyCredParam.ES512,
                 PubKeyCredParam.RS512,
                 PubKeyCredParam.PS512,
+                PubKeyCredParam.RS1,
             },
             AuthenticatorSelection = authenticatorSelection,
             Attestation = attestationConveyancePreference,
@@ -155,6 +156,7 @@ public PubKeyCredParam(COSE.Algorithm alg, PublicKeyCredentialType type = Public
     public static readonly PubKeyCredParam PS384 = new(COSE.Algorithm.PS384);
     public static readonly PubKeyCredParam PS512 = new(COSE.Algorithm.PS512);
     public static readonly PubKeyCredParam Ed25519 = new(COSE.Algorithm.EdDSA);
+    public static readonly PubKeyCredParam RS1 = new(COSE.Algorithm.RS1);
 }
 
 /// <summary>
@@ -212,7 +214,7 @@ public class AuthenticatorSelection
     [JsonPropertyName("residentKey")]
     public ResidentKeyRequirement ResidentKey
     {
-        get => _residentKey;
+        private get => _residentKey;
         set
         {
             _residentKey = value;

Src/Fido2.Models/Objects/AuthenticationExtensionsClientInputs.cs

@@ -12,14 +12,14 @@ public sealed class AuthenticationExtensionsClientInputs
     /// </summary>
     [JsonPropertyName("example.extension.bool")]
     [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingNull)]
-    public object Example { get; set; }
+    public bool? Example { get; set; }
 
     /// <summary>
     /// This extension allows WebAuthn Relying Parties that have previously registered a credential using the legacy FIDO JavaScript APIs to request an assertion.
     /// https://www.w3.org/TR/webauthn/#sctn-appid-extension
     /// </summary>
     [JsonPropertyName("appid")]
-    [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingNull)]
+    [JsonIgnore(Condition = JsonIgnoreCondition.Always)]
     public string AppID { get; set; }
 
     /// <summary>
@@ -36,7 +36,7 @@ public sealed class AuthenticationExtensionsClientInputs
     /// </summary>
     [JsonPropertyName("uvm")]
     [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingNull)]
-    public bool? UserVerificationMethod { get; set; }
+    public bool? UserVerificationMethod { private get; set; }
 
 #nullable enable
     /// <summary>

Src/Fido2.Models/Objects/AuthenticationExtensionsClientOutputs.cs

@@ -9,7 +9,7 @@ public class AuthenticationExtensionsClientOutputs
     /// </summary>
     [JsonPropertyName("example.extension.bool")]
     [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingNull)]
-    public object Example { get; set; }
+    public bool? Example { get; set; }
 
 #nullable enable
 

Src/Fido2/AuthenticatorAssertionResponse.cs

@@ -61,9 +61,10 @@ public async Task<VerifyAssertionResult> VerifyAsync(
         uint storedSignatureCounter,
         IsUserHandleOwnerOfCredentialIdAsync isUserHandleOwnerOfCredId,
         IMetadataService? metadataService,
+        byte[]? requestTokenBindingId,
         CancellationToken cancellationToken = default)
     {
-        BaseVerify(config.FullyQualifiedOrigins, options.Challenge);
+        BaseVerify(config.FullyQualifiedOrigins, options.Challenge, requestTokenBindingId);
 
         if (Raw.Type != PublicKeyCredentialType.PublicKey)
             throw new Fido2VerificationException(Fido2ErrorCode.InvalidAssertionResponse, Fido2ErrorMessages.AssertionResponseNotPublicKey);
@@ -118,17 +119,19 @@ public async Task<VerifyAssertionResult> VerifyAsync(
         var rpid = Raw.ClientExtensionResults?.AppID ?? false ? options.Extensions?.AppID : options.RpId;
         byte[] hashedRpId = SHA256.HashData(Encoding.UTF8.GetBytes(rpid ?? string.Empty));
         byte[] hash = SHA256.HashData(Raw.Response.ClientDataJson);
+        bool conformanceTesting = metadataService != null && metadataService.ConformanceTesting();
 
         if (!authData.RpIdHash.SequenceEqual(hashedRpId))
             throw new Fido2VerificationException(Fido2ErrorCode.InvalidRpidHash, Fido2ErrorMessages.InvalidRpidHash);
 
-        // 14. Verify that the UP bit of the flags in authData is set.
-        if (!authData.UserPresent)
-            throw new Fido2VerificationException(Fido2ErrorCode.UserPresentFlagNotSet, Fido2ErrorMessages.UserPresentFlagNotSet);
+        // 14. Verify that the UP bit of the flags in authData is set.
+        if (!authData.UserPresent && (!conformanceTesting || options.UserVerification is UserVerificationRequirement.Required))
+            throw new Fido2VerificationException(Fido2ErrorCode.UserPresentFlagNotSet, Fido2ErrorMessages.UserPresentFlagNotSet);
+
+        // 15. If the Relying Party requires user verification for this assertion, verify that the UV bit of the flags in authData is set.
+        if (options.UserVerification is UserVerificationRequirement.Required && !authData.UserVerified)
+            throw new Fido2VerificationException(Fido2ErrorCode.UserVerificationRequirementNotMet, Fido2ErrorMessages.UserVerificationRequirementNotMet);
 
-        // 15. If the Relying Party requires user verification for this assertion, verify that the UV bit of the flags in authData is set.
-        if (options.UserVerification is UserVerificationRequirement.Required && !authData.UserVerified)
-            throw new Fido2VerificationException(Fido2ErrorCode.UserVerificationRequirementNotMet, Fido2ErrorMessages.UserVerificationRequirementNotMet);
 
         // 16. If the credential backup state is used as part of Relying Party business logic or policy, let currentBe and currentBs be the values of the BE and BS bits, respectively, of the flags in authData.
         // Compare currentBe and currentBs with credentialRecord.BE and credentialRecord.BS and apply Relying Party policy, if any.
@@ -211,7 +214,7 @@ public async Task<VerifyAssertionResult> VerifyAsync(
             if (metadataService?.ConformanceTesting() is true && metadataEntry is null && attType != AttestationType.None && fmt is not "fido-u2f")
                 throw new Fido2VerificationException(Fido2ErrorCode.AaGuidNotFound, "AAGUID not found in MDS test metadata");
 
-            TrustAnchor.Verify(metadataEntry, trustPath);
+            TrustAnchor.Verify(metadataEntry, trustPath, metadataService?.ConformanceTesting() is true);
         }
 
         return new VerifyAssertionResult

Src/Fido2/AuthenticatorAttestationResponse.cs

@@ -60,6 +60,7 @@ public async Task<RegisteredPublicKeyCredential> VerifyAsync(
         Fido2Configuration config,
         IsCredentialIdUniqueToUserAsyncDelegate isCredentialIdUniqueToUser,
         IMetadataService? metadataService,
+        byte[]? requestTokenBindingId,
         CancellationToken cancellationToken = default)
     {
         // https://www.w3.org/TR/webauthn/#registering-a-new-credential
@@ -74,7 +75,10 @@ public async Task<RegisteredPublicKeyCredential> VerifyAsync(
 
         // 8. Verify that the value of C.challenge matches the challenge that was sent to the authenticator in the create() call.
         // 9. Verify that the value of C.origin matches the Relying Party's origin.
-        BaseVerify(config.FullyQualifiedOrigins, originalOptions.Challenge);
+        // 9.5. Verify that the value of C.tokenBinding.status matches the state of Token Binding for the TLS connection over which the attestation was obtained.
+        // If Token Binding was used on that TLS connection, also verify that C.tokenBinding.id matches the base64url encoding of the Token Binding ID for the connection.
+        // Validated in BaseVerify.
+        BaseVerify(config.FullyQualifiedOrigins, originalOptions.Challenge, requestTokenBindingId);
 
         if (Raw.Id is null || Raw.Id.Length == 0)
             throw new Fido2VerificationException(Fido2ErrorCode.InvalidAttestationResponse, Fido2ErrorMessages.AttestationResponseIdMissing);
@@ -149,7 +153,7 @@ public async Task<RegisteredPublicKeyCredential> VerifyAsync(
         if (metadataService?.ConformanceTesting() is true && metadataEntry is null && attType != AttestationType.None && AttestationObject.Fmt is not "fido-u2f")
             throw new Fido2VerificationException(Fido2ErrorCode.AaGuidNotFound, "AAGUID not found in MDS test metadata");
 
-        TrustAnchor.Verify(metadataEntry, trustPath);
+        TrustAnchor.Verify(metadataEntry, trustPath, metadataService?.ConformanceTesting() is true);
 
         // 22. Assess the attestation trustworthiness using the outputs of the verification procedure in step 14, as follows:
         //     If self attestation was used, check if self attestation is acceptable under Relying Party policy.
@@ -186,7 +190,7 @@ public async Task<RegisteredPublicKeyCredential> VerifyAsync(
 
         return new RegisteredPublicKeyCredential
         {
-            Type = Raw.Type,
+            Type = Raw.Type.Value,
             Id = authData.AttestedCredentialData.CredentialId,
             PublicKey = authData.AttestedCredentialData.CredentialPublicKey.GetBytes(),
             SignCount = authData.SignCount,
@@ -250,7 +254,7 @@ private async Task<byte[]> DevicePublicKeyRegistrationAsync(
         if (metadataService?.ConformanceTesting() is true && metadataEntry is null && attType != AttestationType.None && devicePublicKeyAuthenticatorOutput.Fmt is not "fido-u2f")
             throw new Fido2VerificationException(Fido2ErrorCode.AaGuidNotFound, "AAGUID not found in MDS test metadata");
 
-        TrustAnchor.Verify(metadataEntry, trustPath);
+        TrustAnchor.Verify(metadataEntry, trustPath, metadataService?.ConformanceTesting() is true);
 
         // Check status reports for authenticator with undesirable status
         var latestStatusReport = metadataEntry?.GetLatestStatusReport();

Src/Fido2/AuthenticatorResponse.cs

@@ -48,6 +48,7 @@ protected AuthenticatorResponse(ReadOnlySpan<byte> utf8EncodedJson)
         Type = response.Type;
         Challenge = response.Challenge;
         Origin = response.Origin;
+        TokenBinding = response.TokenBinding;
     }
 
     public const int MAX_ORIGINS_TO_PRINT = 5;
@@ -62,7 +63,10 @@ protected AuthenticatorResponse(ReadOnlySpan<byte> utf8EncodedJson)
     [JsonPropertyName("origin")]
     public string Origin { get; }
 
-    protected void BaseVerify(IReadOnlySet<string> fullyQualifiedExpectedOrigins, ReadOnlySpan<byte> originalChallenge)
+    [JsonPropertyName("tokenBinding")]
+    public TokenBindingDto? TokenBinding { get; set; }
+
+    protected void BaseVerify(IReadOnlySet<string> fullyQualifiedExpectedOrigins, ReadOnlySpan<byte> originalChallenge, byte[]? requestTokenBindingId)
     {
         if (Type is not "webauthn.create" && Type is not "webauthn.get")
             throw new Fido2VerificationException(Fido2ErrorCode.InvalidAuthenticatorResponse, $"Type must be 'webauthn.create' or 'webauthn.get'. Was '{Type}'");
@@ -79,6 +83,13 @@ protected void BaseVerify(IReadOnlySet<string> fullyQualifiedExpectedOrigins, Re
         // 12. Verify that the value of C.origin matches the Relying Party's origin.
         if (!fullyQualifiedExpectedOrigins.Contains(fullyQualifiedOrigin))
             throw new Fido2VerificationException($"Fully qualified origin {fullyQualifiedOrigin} of {Origin} not equal to fully qualified original origin {string.Join(", ", fullyQualifiedExpectedOrigins.Take(MAX_ORIGINS_TO_PRINT))} ({fullyQualifiedExpectedOrigins.Count})");
+
+        // 13?. Verify that the value of C.tokenBinding.status matches the state of Token Binding for the TLS connection over which the assertion was obtained. 
+        // If Token Binding was used on that TLS connection, also verify that C.tokenBinding.id matches the base64url encoding of the Token Binding ID for the connection.
+        if (TokenBinding != null)
+        {
+            TokenBinding.Verify(requestTokenBindingId);
+        }
     }
 
     /*

Src/Fido2/Extensions/CryptoUtils.cs

@@ -49,7 +49,7 @@ public static HashAlgorithmName HashAlgFromCOSEAlg(COSE.Algorithm alg)
         };
     }
 
-    public static bool ValidateTrustChain(X509Certificate2[] trustPath, X509Certificate2[] attestationRootCertificates)
+    public static bool ValidateTrustChain(X509Certificate2[] trustPath, X509Certificate2[] attestationRootCertificates, bool conformance = false)
     {
         // https://fidoalliance.org/specs/fido-v2.0-id-20180227/fido-metadata-statement-v2.0-id-20180227.html#widl-MetadataStatement-attestationRootCertificates
 
@@ -59,7 +59,9 @@ public static bool ValidateTrustChain(X509Certificate2[] trustPath, X509Certific
         // A trust anchor can be a root certificate, an intermediate CA certificate or even the attestation certificate itself.
 
         // Let's check the simplest case first.  If subject and issuer are the same, and the attestation cert is in the list, that's all the validation we need
-        if (trustPath.Length == 1 && trustPath[0].Subject.Equals(trustPath[0].Issuer, StringComparison.Ordinal))
+
+        // We have the same singular root cert in trustpath and it is in attestationRootCertificates
+        if (trustPath.Length == 1)
         {
             foreach (X509Certificate2 cert in attestationRootCertificates)
             {
@@ -68,7 +70,6 @@ public static bool ValidateTrustChain(X509Certificate2[] trustPath, X509Certific
                     return true;
                 }
             }
-            return false;
         }
 
         // If the attestation cert is not self signed, we will need to build a chain
@@ -101,10 +102,10 @@ public static bool ValidateTrustChain(X509Certificate2[] trustPath, X509Certific
             chain.ChainPolicy.TrustMode = X509ChainTrustMode.CustomRootTrust;
 
             // if the attestation cert has a CDP extension, go ahead and turn on online revocation checking
-            if (!string.IsNullOrEmpty(CDPFromCertificateExts(trustPath[0].Extensions)))
-                chain.ChainPolicy.RevocationMode = X509RevocationMode.Online;
-
-            // don't allow unknown root now that we have a custom root
+            if (!string.IsNullOrEmpty(CDPFromCertificateExts(trustPath[0].Extensions)) && !conformance)
+                chain.ChainPolicy.RevocationMode = X509RevocationMode.Online;
+
+            // don't allow unknown root now that we have a custom root
             chain.ChainPolicy.VerificationFlags = X509VerificationFlags.NoFlag;
 
             // now, verify chain again with all checks turned on

Src/Fido2/Fido2.cs

@@ -66,10 +66,11 @@ public async Task<MakeNewCredentialResult> MakeNewCredentialAsync(
         AuthenticatorAttestationRawResponse attestationResponse,
         CredentialCreateOptions originalOptions,
         IsCredentialIdUniqueToUserAsyncDelegate isCredentialIdUniqueToUser,
+        byte[]? requestTokenBindingId = null,
         CancellationToken cancellationToken = default)
     {
         var parsedResponse = AuthenticatorAttestationResponse.Parse(attestationResponse);
-        var success = await parsedResponse.VerifyAsync(originalOptions, _config, isCredentialIdUniqueToUser, _metadataService, cancellationToken);
+        var success = await parsedResponse.VerifyAsync(originalOptions, _config, isCredentialIdUniqueToUser, _metadataService, requestTokenBindingId, cancellationToken);
 
         // todo: Set Errormessage etc.
         return new MakeNewCredentialResult(
@@ -111,6 +112,7 @@ public async Task<VerifyAssertionResult> MakeAssertionAsync(
         IReadOnlyList<byte[]> storedDevicePublicKeys,
         uint storedSignatureCounter,
         IsUserHandleOwnerOfCredentialIdAsync isUserHandleOwnerOfCredentialIdCallback,
+        byte[]? requestTokenBindingId = null,
         CancellationToken cancellationToken = default)
     {
         var parsedResponse = AuthenticatorAssertionResponse.Parse(assertionResponse);
@@ -122,6 +124,7 @@ public async Task<VerifyAssertionResult> MakeAssertionAsync(
                                                       storedSignatureCounter,
                                                       isUserHandleOwnerOfCredentialIdCallback,
                                                       _metadataService,
+                                                      requestTokenBindingId,
                                                       cancellationToken);
 
         return result;

Src/Fido2/IFido2.cs

@@ -20,12 +20,14 @@ Task<VerifyAssertionResult> MakeAssertionAsync(
         IReadOnlyList<byte[]> storedDevicePublicKeys,
         uint storedSignatureCounter,
         IsUserHandleOwnerOfCredentialIdAsync isUserHandleOwnerOfCredentialIdCallback,
+        byte[]? requestTokenBindingId = null,
         CancellationToken cancellationToken = default);
 
     Task<MakeNewCredentialResult> MakeNewCredentialAsync(
         AuthenticatorAttestationRawResponse attestationResponse,
         CredentialCreateOptions originalOptions,
         IsCredentialIdUniqueToUserAsyncDelegate isCredentialIdUniqueToUser,
+        byte[]? requestTokenBindingId = null,
         CancellationToken cancellationToken = default);
 
     CredentialCreateOptions RequestNewCredential(

Src/Fido2/TokenBindingDto.cs

@@ -0,0 +1,41 @@
+using System.Text.Json.Serialization;
+
+namespace Fido2NetLib
+{
+    public class TokenBindingDto
+    {
+        /// <summary>
+        /// Either "present" or "supported". https://www.w3.org/TR/webauthn/#enumdef-tokenbindingstatus
+        /// supported: Indicates the client supports token binding, but it was not negotiated when communicating with the Relying Party.
+        /// present: Indicates token binding was used when communicating with the Relying Party. In this case, the id member MUST be present
+        /// </summary>
+        [JsonPropertyName("status")]
+        public string? Status { get; set; }
+
+        /// <summary>
+        /// This member MUST be present if status is present, and MUST a base64url encoding of the Token Binding ID that was used when communicating with the Relying Party.
+        /// </summary>
+        [JsonPropertyName("id")]
+        public string? Id { get; set; }
+
+        public void Verify(byte[]? requestTokenbinding)
+        {
+            // validation by the FIDO conformance tool (more than spec says)
+            switch (Status)
+            {
+                case "present":
+                    if (string.IsNullOrEmpty(Id))
+                        throw new Fido2VerificationException("TokenBinding status was present but Id is missing");
+                    var b64 = Base64Url.Encode(requestTokenbinding);
+                    if (Id != b64)
+                        throw new Fido2VerificationException("Tokenbinding Id does not match");
+                    break;
+                case "supported":
+                case "not-supported":
+                    break;
+                default:
+                    throw new Fido2VerificationException("Malformed tokenbinding status field");
+            }
+        }
+    }
+}