Ensure credProtect level 3 uses high security wrapping by default

python_tests/ctap/test_credprotect.py

@@ -211,6 +211,40 @@ def test_low_sec_credprotect(self):
                                      'up': False
                                  })
 
+    def test_credprotect_three_creation_requires_pin_when_pin_set(self):
+        pin = secrets.token_hex(8)
+        ClientPin(self.ctap2).set_pin(pin)
+
+        params = dict(self.basic_makecred_params)
+        params['extensions'] = {
+            "credProtect": CredProtectExtension.POLICY.REQUIRED
+        }
+
+        with self.assertRaises(CtapError) as e:
+            self.ctap2.make_credential(**params)
+
+        self.assertEqual(CtapError.ERR.PIN_REQUIRED, e.exception.code)
+
+
+class MaximumComplianceCredProtectTestCase(CredProtectTestCase):
+    def setUp(self, install_params=None) -> None:
+        if install_params is None:
+            install_params = bytes([0xA2, 0x00, 0xF5, 0x01, 0xF5])
+        super().setUp(install_params=install_params)
+
+    def test_level_three_can_use_low_security_when_explicitly_enabled(self):
+        pin = secrets.token_hex(8)
+        ClientPin(self.ctap2).set_pin(pin)
+
+        params = dict(self.basic_makecred_params)
+        params['extensions'] = {
+            "credProtect": CredProtectExtension.POLICY.REQUIRED
+        }
+
+        res = self.ctap2.make_credential(**params)
+        self.assertEqual(CredProtectExtension.POLICY.REQUIRED,
+                         res.auth_data.extensions.get('credProtect'))
+
 
 class CredProtectDeletionTestCase(CredManagementBaseTestCase):
     @parameterized.expand([

src/main/java/us/q3q/fido2/FIDO2Applet.java

@@ -1068,7 +1068,8 @@ private void makeCredential(APDU apdu, short lc, byte[] buffer) {
                     effectiveCredBlobLen = 0;
                 }
 
-                final boolean lowSecForRK = USE_LOW_SECURITY_FOR_SOME_RKS && credProtectLevel < 3;
+                final boolean lowSecForRK = (USE_LOW_SECURITY_FOR_SOME_RKS && credProtectLevel < 3)
+                        || LOW_SECURITY_MAXIMUM_COMPLIANCE;
                 final boolean lowSecWasUsed = encodeCredentialID(apdu, (ECPrivateKey) ecKeyPair.getPrivate(),
                         scratchRPIDHashBuffer, scratchRPIDHashOffset,
                         scratchCredBuffer, scratchCredOffset,
@@ -1119,7 +1120,8 @@ private void makeCredential(APDU apdu, short lc, byte[] buffer) {
             }
         } else {
             // Non-resident credProtect Level 3 creds still need to use the high security key (to require PIN auth)
-            final boolean credMayUseLowSecurityForDiscoverable = credProtectLevel < 3;
+            final boolean credMayUseLowSecurityForDiscoverable = credProtectLevel < 3
+                    || LOW_SECURITY_MAXIMUM_COMPLIANCE;
             encodeCredentialID(apdu, (ECPrivateKey) ecKeyPair.getPrivate(),
                     scratchRPIDHashBuffer, scratchRPIDHashOffset,
                     scratchCredBuffer, scratchCredOffset,
@@ -1772,13 +1774,18 @@ private boolean encodeCredentialID(APDU apdu, ECPrivateKey privKey,
                                        byte[] rpIdHashBuffer, short rpIdHashOffset,
                                        byte[] outBuffer, short outOffset,
                                        short rkNum, boolean lowSecurity, byte credProtectLevel) {
+        final boolean lowSecurityExplicitlyRequested = lowSecurity;
         if (rkNum >= 0 && !USE_LOW_SECURITY_FOR_SOME_RKS) {
             lowSecurity = false;
         }
-        // use low security even for RKs if LOW_SECURITY_MAXIMUM_COMPLIANCE
-        if (LOW_SECURITY_MAXIMUM_COMPLIANCE) {
+        // use low security even for RKs if LOW_SECURITY_MAXIMUM_COMPLIANCE is explicitly requested
+        if (LOW_SECURITY_MAXIMUM_COMPLIANCE && (lowSecurity || credProtectLevel < 3)) {
             lowSecurity = true;
         }
+        // regardless of anything else, default to the high-sec key for credProtect-level-3 creds unless explicitly requested
+        if (credProtectLevel == 3 && !lowSecurityExplicitlyRequested) {
+            lowSecurity = false;
+        }
         // regardless of anything else, opportunistically use the high-sec key for credProtect-level-3 creds
         final byte pinProtocolInUse = transientStorage.getPinProtocolInUse();
         if (credProtectLevel == 3 && (pinProtocolInUse == 1 || pinProtocolInUse == 2)) {
@@ -6826,7 +6833,7 @@ private FIDO2Applet(byte[] array, short offset, byte length) {
         // set up parameters
         // first, defaults
         attestationSwitchingEnabled = false;
-        LOW_SECURITY_MAXIMUM_COMPLIANCE = true;
+        LOW_SECURITY_MAXIMUM_COMPLIANCE = false;
         FORCE_ALWAYS_UV = false;
         USE_LOW_SECURITY_FOR_SOME_RKS = true;
         PROTECT_AGAINST_MALICIOUS_RESETS = false;