[crypto] Replace AesCcm128Key with sensitive data buffer

AesCcm128Key, despite its name, is currently only used for Identity Protection Key. Additionally, it has very similar interface to CapacityBoundBuffer. Rename CapacityBoundBuffer to SensitiveDataBuffer to better describe its purpose and add SensitiveDataFixedBuffer for fixed-size contents. Align interfaces of these two and implicit cast operators for better type safety. Finally, replace AesCcm128Key with new IdentityProtectionKey type alias defined as SensitiveDataFixedBuffer< CRYPTO_SYMMETRIC_KEY_LENGTH_BYTES>. Signed-off-by: Damian Krolik <[email protected]>
project-chip · Jan 10, 2023 · 327545e · 327545e
1 parent 682e6a4
commit 327545e
Show file tree

Hide file tree

Showing 31 changed files with 252 additions and 191 deletions.
diff --git a/examples/platform/linux/testing/CustomCSRResponseOperationalKeyStore.cpp b/examples/platform/linux/testing/CustomCSRResponseOperationalKeyStore.cpp
@@ -63,8 +63,8 @@ CHIP_ERROR CustomCSRResponseOperationalKeyStore::ReuseOpKeypair(FabricIndex fabr
 
     // Scope 1: Load up the keypair data from storage
     {
-        // Use a CapacityBoundBuffer to get RAII secret data clearing on scope exit.
-        Crypto::CapacityBoundBuffer<OpKeyTLVMaxSize()> buf;
+        // Use a SensitiveDataBuffer to get RAII secret data clearing on scope exit.
+        Crypto::SensitiveDataBuffer<OpKeyTLVMaxSize()> buf;
 
         // Load up the operational key structure from storage
         uint16_t size = static_cast<uint16_t>(buf.Capacity());

diff --git a/src/controller/AutoCommissioner.cpp b/src/controller/AutoCommissioner.cpp
@@ -450,7 +450,7 @@ Optional<System::Clock::Timeout> AutoCommissioner::GetCommandTimeout(DeviceProxy
     return MakeOptional(timeout);
 }
 
-CHIP_ERROR AutoCommissioner::NOCChainGenerated(ByteSpan noc, ByteSpan icac, ByteSpan rcac, AesCcm128KeySpan ipk,
+CHIP_ERROR AutoCommissioner::NOCChainGenerated(ByteSpan noc, ByteSpan icac, ByteSpan rcac, IdentityProtectionKeySpan ipk,
                                                NodeId adminSubject)
 {
     // Reuse ICA Cert buffer for temporary store Root Cert.

diff --git a/src/controller/AutoCommissioner.h b/src/controller/AutoCommissioner.h
@@ -63,7 +63,7 @@ class AutoCommissioner : public CommissioningDelegate
     ByteSpan GetDAC() const { return ByteSpan(mDAC, mDACLen); }
     ByteSpan GetPAI() const { return ByteSpan(mPAI, mPAILen); }
 
-    CHIP_ERROR NOCChainGenerated(ByteSpan noc, ByteSpan icac, ByteSpan rcac, AesCcm128KeySpan ipk, NodeId adminSubject);
+    CHIP_ERROR NOCChainGenerated(ByteSpan noc, ByteSpan icac, ByteSpan rcac, IdentityProtectionKeySpan ipk, NodeId adminSubject);
     /**
      * The device argument to GetCommandTimeout is the device whose session will
      * be used for sending the relevant command.

diff --git a/src/controller/CHIPDeviceController.cpp b/src/controller/CHIPDeviceController.cpp
@@ -1244,7 +1244,7 @@ void DeviceCommissioner::OnOperationalCertificateSigningRequest(
 }
 
 void DeviceCommissioner::OnDeviceNOCChainGeneration(void * context, CHIP_ERROR status, const ByteSpan & noc, const ByteSpan & icac,
-                                                    const ByteSpan & rcac, Optional<AesCcm128KeySpan> ipk,
+                                                    const ByteSpan & rcac, Optional<IdentityProtectionKeySpan> ipk,
                                                     Optional<NodeId> adminSubject)
 {
     MATTER_TRACE_EVENT_SCOPE("OnDeviceNOCChainGeneration", "DeviceCommissioner");
@@ -1271,7 +1271,7 @@ void DeviceCommissioner::OnDeviceNOCChainGeneration(void * context, CHIP_ERROR s
 
     // TODO - Verify that the generated root cert matches with commissioner's root cert
     CommissioningDelegate::CommissioningReport report;
-    report.Set<NocChain>(NocChain(noc, icac, rcac, ipk.HasValue() ? ipk.Value() : AesCcm128KeySpan(placeHolderIpk),
+    report.Set<NocChain>(NocChain(noc, icac, rcac, ipk.HasValue() ? ipk.Value() : IdentityProtectionKeySpan(placeHolderIpk),
                                   adminSubject.HasValue() ? adminSubject.Value() : commissioner->GetNodeId()));
     commissioner->CommissioningStageComplete(status, report);
 }
@@ -1325,8 +1325,9 @@ CHIP_ERROR DeviceCommissioner::ProcessCSR(DeviceProxy * proxy, const ByteSpan &
 }
 
 CHIP_ERROR DeviceCommissioner::SendOperationalCertificate(DeviceProxy * device, const ByteSpan & nocCertBuf,
-                                                          const Optional<ByteSpan> & icaCertBuf, const AesCcm128KeySpan ipk,
-                                                          const NodeId adminSubject, Optional<System::Clock::Timeout> timeout)
+                                                          const Optional<ByteSpan> & icaCertBuf,
+                                                          const IdentityProtectionKeySpan ipk, const NodeId adminSubject,
+                                                          Optional<System::Clock::Timeout> timeout)
 {
     MATTER_TRACE_EVENT_SCOPE("SendOperationalCertificate", "DeviceCommissioner");
 

diff --git a/src/controller/CHIPDeviceController.h b/src/controller/CHIPDeviceController.h
@@ -732,7 +732,8 @@ class DLL_EXPORT DeviceCommissioner : public DeviceController,
        The function does not hold a reference to the device object.
      */
     CHIP_ERROR SendOperationalCertificate(DeviceProxy * device, const ByteSpan & nocCertBuf, const Optional<ByteSpan> & icaCertBuf,
-                                          AesCcm128KeySpan ipk, NodeId adminSubject, Optional<System::Clock::Timeout> timeout);
+                                          IdentityProtectionKeySpan ipk, NodeId adminSubject,
+                                          Optional<System::Clock::Timeout> timeout);
     /* This function sends the trusted root certificate to the device.
        The function does not hold a reference to the device object.
      */
@@ -792,7 +793,8 @@ class DLL_EXPORT DeviceCommissioner : public DeviceController,
                                                            Credentials::AttestationVerificationResult result);
 
     static void OnDeviceNOCChainGeneration(void * context, CHIP_ERROR status, const ByteSpan & noc, const ByteSpan & icac,
-                                           const ByteSpan & rcac, Optional<AesCcm128KeySpan> ipk, Optional<NodeId> adminSubject);
+                                           const ByteSpan & rcac, Optional<IdentityProtectionKeySpan> ipk,
+                                           Optional<NodeId> adminSubject);
     static void OnArmFailSafe(void * context,
                               const chip::app::Clusters::GeneralCommissioning::Commands::ArmFailSafeResponse::DecodableType & data);
     static void OnSetRegulatoryConfigResponse(

diff --git a/src/controller/CommissioningDelegate.h b/src/controller/CommissioningDelegate.h
@@ -177,9 +177,9 @@ class CommissioningParameters
     // Epoch key for the identity protection key for the node being commissioned. In the AutoCommissioner, this is set by by the
     // kGenerateNOCChain stage through the OperationalCredentialsDelegate.
     // This value must be set before calling PerformCommissioningStep for the kSendNOC step.
-    const Optional<AesCcm128KeySpan> GetIpk() const
+    const Optional<IdentityProtectionKeySpan> GetIpk() const
     {
-        return mIpk.HasValue() ? Optional<AesCcm128KeySpan>(mIpk.Value().Span()) : Optional<AesCcm128KeySpan>();
+        return mIpk.HasValue() ? Optional<IdentityProtectionKeySpan>(mIpk.Value().Span()) : Optional<IdentityProtectionKeySpan>();
     }
 
     // Admin subject id used for the case access control entry created if the AddNOC command succeeds. In the AutoCommissioner, this
@@ -321,9 +321,9 @@ class CommissioningParameters
         mIcac.SetValue(icac);
         return *this;
     }
-    CommissioningParameters & SetIpk(const AesCcm128KeySpan ipk)
+    CommissioningParameters & SetIpk(const IdentityProtectionKeySpan ipk)
     {
-        mIpk.SetValue(AesCcm128Key(ipk));
+        mIpk.SetValue(IdentityProtectionKey(ipk));
         return *this;
     }
     CommissioningParameters & SetAdminSubject(const NodeId adminSubject)
@@ -439,7 +439,7 @@ class CommissioningParameters
     Optional<ByteSpan> mRootCert;
     Optional<ByteSpan> mNoc;
     Optional<ByteSpan> mIcac;
-    Optional<AesCcm128Key> mIpk;
+    Optional<IdentityProtectionKey> mIpk;
     Optional<NodeId> mAdminSubject;
     // Items that come from the device in commissioning steps
     Optional<ByteSpan> mAttestationElements;
@@ -484,13 +484,13 @@ struct CSRResponse
 
 struct NocChain
 {
-    NocChain(ByteSpan newNoc, ByteSpan newIcac, ByteSpan newRcac, AesCcm128KeySpan newIpk, NodeId newAdminSubject) :
+    NocChain(ByteSpan newNoc, ByteSpan newIcac, ByteSpan newRcac, IdentityProtectionKeySpan newIpk, NodeId newAdminSubject) :
         noc(newNoc), icac(newIcac), rcac(newRcac), ipk(newIpk), adminSubject(newAdminSubject)
     {}
     ByteSpan noc;
     ByteSpan icac;
     ByteSpan rcac;
-    AesCcm128KeySpan ipk;
+    IdentityProtectionKeySpan ipk;
     NodeId adminSubject;
 };
 

diff --git a/src/controller/ExampleOperationalCredentialsIssuer.cpp b/src/controller/ExampleOperationalCredentialsIssuer.cpp
@@ -386,7 +386,7 @@ CHIP_ERROR ExampleOperationalCredentialsIssuer::GenerateNOCChain(const ByteSpan
     // Prepare IPK to be sent back. A more fully-fledged operational credentials delegate
     // would obtain a suitable key per fabric.
     uint8_t ipkValue[CHIP_CRYPTO_SYMMETRIC_KEY_LENGTH_BYTES];
-    Crypto::AesCcm128KeySpan ipkSpan(ipkValue);
+    Crypto::IdentityProtectionKeySpan ipkSpan(ipkValue);
 
     ReturnErrorCodeIf(defaultIpkSpan.size() != sizeof(ipkValue), CHIP_ERROR_INTERNAL);
     memcpy(&ipkValue[0], defaultIpkSpan.data(), defaultIpkSpan.size());

diff --git a/src/controller/OperationalCredentialsDelegate.h b/src/controller/OperationalCredentialsDelegate.h
@@ -30,7 +30,8 @@ namespace chip {
 namespace Controller {
 
 typedef void (*OnNOCChainGeneration)(void * context, CHIP_ERROR status, const ByteSpan & noc, const ByteSpan & icac,
-                                     const ByteSpan & rcac, Optional<Crypto::AesCcm128KeySpan> ipk, Optional<NodeId> adminSubject);
+                                     const ByteSpan & rcac, Optional<Crypto::IdentityProtectionKeySpan> ipk,
+                                     Optional<NodeId> adminSubject);
 
 constexpr uint32_t kMaxCHIPDERCertLength = 600;
 constexpr size_t kCSRNonceLength         = 32;

diff --git a/src/controller/java/AndroidOperationalCredentialsIssuer.cpp b/src/controller/java/AndroidOperationalCredentialsIssuer.cpp
@@ -297,7 +297,8 @@ CHIP_ERROR AndroidOperationalCredentialsIssuer::CallbackGenerateNOCChain(const B
 }
 
 CHIP_ERROR AndroidOperationalCredentialsIssuer::NOCChainGenerated(CHIP_ERROR status, const ByteSpan & noc, const ByteSpan & icac,
-                                                                  const ByteSpan & rcac, Optional<Crypto::AesCcm128KeySpan> ipk,
+                                                                  const ByteSpan & rcac,
+                                                                  Optional<Crypto::IdentityProtectionKeySpan> ipk,
                                                                   Optional<NodeId> adminSubject)
 {
     ReturnErrorCodeIf(mOnNOCCompletionCallback == nullptr, CHIP_ERROR_INCORRECT_STATE);
@@ -384,7 +385,7 @@ CHIP_ERROR AndroidOperationalCredentialsIssuer::LocalGenerateNOCChain(const Byte
     // Prepare IPK to be sent back. A more fully-fledged operational credentials delegate
     // would obtain a suitable key per fabric.
     uint8_t ipkValue[CHIP_CRYPTO_SYMMETRIC_KEY_LENGTH_BYTES];
-    Crypto::AesCcm128KeySpan ipkSpan(ipkValue);
+    Crypto::IdentityProtectionKeySpan ipkSpan(ipkValue);
 
     ReturnErrorCodeIf(defaultIpkSpan.size() != sizeof(ipkValue), CHIP_ERROR_INTERNAL);
 

diff --git a/src/controller/java/AndroidOperationalCredentialsIssuer.h b/src/controller/java/AndroidOperationalCredentialsIssuer.h
@@ -53,7 +53,7 @@ class DLL_EXPORT AndroidOperationalCredentialsIssuer : public OperationalCredent
                                 Callback::Callback<OnNOCChainGeneration> * onCompletion) override;
 
     CHIP_ERROR NOCChainGenerated(CHIP_ERROR status, const ByteSpan & noc, const ByteSpan & icac, const ByteSpan & rcac,
-                                 Optional<Crypto::AesCcm128KeySpan> ipk, Optional<NodeId> adminSubject);
+                                 Optional<Crypto::IdentityProtectionKeySpan> ipk, Optional<NodeId> adminSubject);
 
     void SetUseJavaCallbackForNOCRequest(bool useJavaCallbackForNOCRequest)
     {

diff --git a/src/controller/java/CHIPDeviceController-JNI.cpp b/src/controller/java/CHIPDeviceController-JNI.cpp
@@ -202,9 +202,9 @@ JNI_METHOD(jint, onNOCChainGeneration)
     // use ipk and adminSubject from CommissioningParameters if not set in ControllerParams
     CommissioningParameters commissioningParams = wrapper->GetCommissioningParameters();
 
-    Optional<Crypto::AesCcm128KeySpan> ipkOptional;
+    Optional<Crypto::IdentityProtectionKeySpan> ipkOptional;
     uint8_t ipkValue[CHIP_CRYPTO_SYMMETRIC_KEY_LENGTH_BYTES];
-    Crypto::AesCcm128KeySpan ipkTempSpan(ipkValue);
+    Crypto::IdentityProtectionKeySpan ipkTempSpan(ipkValue);
 
     jbyteArray ipk = (jbyteArray) env->CallObjectMethod(controllerParams, getIpk);
     if (ipk != nullptr)

diff --git a/src/controller/python/ChipDeviceController-IssueNocChain.cpp b/src/controller/python/ChipDeviceController-IssueNocChain.cpp
@@ -50,7 +50,7 @@ PyChipError pychip_DeviceController_IssueNOCChain(chip::Controller::DeviceCommis
 }
 
 void pychip_DeviceController_IssueNOCChainCallback(void * context, CHIP_ERROR status, const ByteSpan & noc, const ByteSpan & icac,
-                                                   const ByteSpan & rcac, Optional<Crypto::AesCcm128KeySpan> ipk,
+                                                   const ByteSpan & rcac, Optional<Crypto::IdentityProtectionKeySpan> ipk,
                                                    Optional<NodeId> adminSubject)
 {
     if (pychip_DeviceController_IssueNOCChainCallbackPythonCallbackFunct == nullptr)
@@ -65,8 +65,8 @@ void pychip_DeviceController_IssueNOCChainCallback(void * context, CHIP_ERROR st
     MutableByteSpan chipIcacSpan;
     MutableByteSpan chipRcacSpan;
 
-    Crypto::AesCcm128KeySpan ipkData;
-    ipkData = ipk.ValueOr(Crypto::AesCcm128KeySpan());
+    Crypto::IdentityProtectionKeySpan ipkData;
+    ipkData = ipk.ValueOr(Crypto::IdentityProtectionKeySpan());
 
     CHIP_ERROR err = status;
     if (err != CHIP_NO_ERROR)

diff --git a/src/credentials/CHIPCert.cpp b/src/credentials/CHIPCert.cpp
@@ -296,7 +296,7 @@ CHIP_ERROR ChipCertificateSet::VerifySignature(const ChipCertificateData * cert,
 
     VerifyOrReturnError((cert != nullptr) && (caCert != nullptr), CHIP_ERROR_INVALID_ARGUMENT);
     ReturnErrorOnFailure(signature.SetLength(cert->mSignature.size()));
-    memcpy(signature, cert->mSignature.data(), cert->mSignature.size());
+    memcpy(signature.Bytes(), cert->mSignature.data(), cert->mSignature.size());
 
     memcpy(caPublicKey, caCert->mPublicKey.data(), caCert->mPublicKey.size());
 

diff --git a/src/credentials/CertificationDeclaration.cpp b/src/credentials/CertificationDeclaration.cpp
@@ -475,7 +475,7 @@ CHIP_ERROR EncodeSignerInfo(const ByteSpan & signerKeyId, const P256ECDSASignatu
 
             uint8_t asn1SignatureBuf[kMax_ECDSA_Signature_Length_Der];
             MutableByteSpan asn1Signature(asn1SignatureBuf);
-            ReturnErrorOnFailure(EcdsaRawSignatureToAsn1(kP256_FE_Length, ByteSpan(signature, signature.Length()), asn1Signature));
+            ReturnErrorOnFailure(EcdsaRawSignatureToAsn1(kP256_FE_Length, signature.Span(), asn1Signature));
 
             // signature OCTET STRING
             ReturnErrorOnFailure(writer.PutOctetString(asn1Signature.data(), static_cast<uint16_t>(asn1Signature.size())));
@@ -539,7 +539,7 @@ CHIP_ERROR DecodeSignerInfo(ASN1Reader & reader, ByteSpan & signerKeyId, P256ECD
             // signature OCTET STRING
             ASN1_PARSE_ELEMENT(kASN1TagClass_Universal, kASN1UniversalTag_OctetString);
 
-            MutableByteSpan signatureSpan(signature, signature.Capacity());
+            MutableByteSpan signatureSpan(signature.Bytes(), signature.Capacity());
             ReturnErrorOnFailure(
                 EcdsaAsn1SignatureToRaw(kP256_FE_Length, ByteSpan(reader.GetValue(), reader.GetValueLen()), signatureSpan));
             ReturnErrorOnFailure(signature.SetLength(signatureSpan.size()));

diff --git a/src/credentials/tests/TestCertificationDeclaration.cpp b/src/credentials/tests/TestCertificationDeclaration.cpp
@@ -363,7 +363,7 @@ static void TestCD_CMSSignAndVerify(nlTestSuite * inSuite, void * inContext)
     // Test with known key
     P256Keypair keypair2;
     P256SerializedKeypair serializedKeypair;
-    memcpy(serializedKeypair, sTestCMS_SignerSerializedKeypair, sizeof(sTestCMS_SignerSerializedKeypair));
+    memcpy(serializedKeypair.Bytes(), sTestCMS_SignerSerializedKeypair, sizeof(sTestCMS_SignerSerializedKeypair));
     serializedKeypair.SetLength(sizeof(sTestCMS_SignerSerializedKeypair));
     cdContentIn   = ByteSpan(sTestCMS_CDContent02);
     signedMessage = MutableByteSpan(signedMessageBuf);

diff --git a/src/credentials/tests/TestFabricTable.cpp b/src/credentials/tests/TestFabricTable.cpp
@@ -89,8 +89,8 @@ static CHIP_ERROR LoadTestFabric_Node01_01(nlTestSuite * inSuite, FabricTable &
     static Crypto::P256Keypair opKey_Node01_01;
 
     FabricIndex fabricIndex;
-    memcpy((uint8_t *) (opKeysSerialized), TestCerts::sTestCert_Node01_01_PublicKey, TestCerts::sTestCert_Node01_01_PublicKey_Len);
-    memcpy((uint8_t *) (opKeysSerialized) + TestCerts::sTestCert_Node01_01_PublicKey_Len, TestCerts::sTestCert_Node01_01_PrivateKey,
+    memcpy(opKeysSerialized.Bytes(), TestCerts::sTestCert_Node01_01_PublicKey, TestCerts::sTestCert_Node01_01_PublicKey_Len);
+    memcpy(opKeysSerialized.Bytes() + TestCerts::sTestCert_Node01_01_PublicKey_Len, TestCerts::sTestCert_Node01_01_PrivateKey,
            TestCerts::sTestCert_Node01_01_PrivateKey_Len);
 
     ByteSpan rcacSpan(TestCerts::sTestCert_Root01_Chip, TestCerts::sTestCert_Root01_Chip_Len);
@@ -119,8 +119,8 @@ static CHIP_ERROR LoadTestFabric_Node01_02(nlTestSuite * inSuite, FabricTable &
     FabricIndex fabricIndex;
     static Crypto::P256Keypair opKey_Node01_02;
 
-    memcpy((uint8_t *) (opKeysSerialized), TestCerts::sTestCert_Node01_02_PublicKey, TestCerts::sTestCert_Node01_02_PublicKey_Len);
-    memcpy((uint8_t *) (opKeysSerialized) + TestCerts::sTestCert_Node01_02_PublicKey_Len, TestCerts::sTestCert_Node01_02_PrivateKey,
+    memcpy(opKeysSerialized.Bytes(), TestCerts::sTestCert_Node01_02_PublicKey, TestCerts::sTestCert_Node01_02_PublicKey_Len);
+    memcpy(opKeysSerialized.Bytes() + TestCerts::sTestCert_Node01_02_PublicKey_Len, TestCerts::sTestCert_Node01_02_PrivateKey,
            TestCerts::sTestCert_Node01_02_PrivateKey_Len);
 
     ByteSpan rcacSpan(TestCerts::sTestCert_Root01_Chip, TestCerts::sTestCert_Root01_Chip_Len);
@@ -151,8 +151,8 @@ static CHIP_ERROR LoadTestFabric_Node02_01(nlTestSuite * inSuite, FabricTable &
     FabricIndex fabricIndex;
     static Crypto::P256Keypair opKey_Node02_01;
 
-    memcpy((uint8_t *) (opKeysSerialized), TestCerts::sTestCert_Node02_01_PublicKey, TestCerts::sTestCert_Node02_01_PublicKey_Len);
-    memcpy((uint8_t *) (opKeysSerialized) + TestCerts::sTestCert_Node02_01_PublicKey_Len, TestCerts::sTestCert_Node02_01_PrivateKey,
+    memcpy(opKeysSerialized.Bytes(), TestCerts::sTestCert_Node02_01_PublicKey, TestCerts::sTestCert_Node02_01_PublicKey_Len);
+    memcpy(opKeysSerialized.Bytes() + TestCerts::sTestCert_Node02_01_PublicKey_Len, TestCerts::sTestCert_Node02_01_PrivateKey,
            TestCerts::sTestCert_Node02_01_PrivateKey_Len);
 
     ByteSpan rcacSpan(TestCerts::sTestCert_Root02_Chip, TestCerts::sTestCert_Root02_Chip_Len);