Darwin: Allow partial validation of DAC and CD (for external cloud or…

… custom app based validation)

src/darwin/Framework/CHIP/MTRDeviceController.h

@@ -124,6 +124,10 @@ typedef void (^MTRDeviceConnectionCallback)(MTRBaseDevice * _Nullable device, NS
  * Sets this MTRDeviceController to use the given issuer for issuing operational certs. By default, the MTRDeviceController uses an
  * internal issuer.
  *
+ * When a nocChainIssuer is set, the device commissioner will delegate verification to the chip::Credentials::PartialDACVerifier so
+ * that DAC chain and CD validation can be performed by custom code triggered by MTRNOCChainIssuer.onNOCChainGenerationNeeded().
+ * Otherwise, the device commissioner uses the chip::Credentials::DefaultDACVerifier
+ *
  * @param[in] nocChainIssuer the NOC Chain issuer to use for issuer operational certs
  *
  * @param[in] queue The queue on which the callbacks will be delivered

src/darwin/Framework/CHIP/MTRDeviceController.mm

@@ -47,6 +47,7 @@
 #include <controller/CommissioningWindowOpener.h>
 #include <credentials/FabricTable.h>
 #include <credentials/GroupDataProvider.h>
+#include <credentials/attestation_verifier/DacOnlyPartialAttestationVerifier.h>
 #include <credentials/attestation_verifier/DefaultDeviceAttestationVerifier.h>
 #include <lib/core/CHIPVendorIdentifiers.hpp>
 #include <platform/PlatformManager.h>
@@ -77,6 +78,7 @@ @interface MTRDeviceController ()
 @property (atomic, readonly) dispatch_queue_t chipWorkQueue;
 
 @property (readonly) chip::Controller::DeviceCommissioner * cppCommissioner;
+@property (readonly) chip::Credentials::PartialDACVerifier * partialDACVerifier;
 @property (readonly) MTRDevicePairingDelegateBridge * pairingDelegateBridge;
 @property (readonly) MTROperationalCredentialsDelegate * operationalCredentialsDelegate;
 @property (readonly) MTRP256KeypairBridge signingKeypairBridge;
@@ -664,7 +666,12 @@ - (void)setNocChainIssuer:(id<MTRNOCChainIssuer>)nocChainIssuer queue:(dispatch_
     dispatch_sync(_chipWorkQueue, ^{
         VerifyOrReturn([self checkIsRunning]);
 
-        self->_operationalCredentialsDelegate->SetNocChainIssuer(nocChainIssuer, queue);
+        if (nocChainIssuer != nil) {
+            self->_operationalCredentialsDelegate->SetNocChainIssuer(nocChainIssuer, queue);
+            self->_cppCommissioner->SetDeviceAttestationVerifier(_partialDACVerifier);
+        } else {
+            self->_cppCommissioner->SetDeviceAttestationVerifier(chip::Credentials::GetDeviceAttestationVerifier());
+        }
     });
 }