ACLs: Added SessionType and CATs Parameters to SecureSession and Pair…

…ingSession Classes (#12027)

src/credentials/CHIPCert.cpp

@@ -883,7 +883,19 @@ CHIP_ERROR ExtractFabricIdFromCert(const ChipCertificateData & cert, FabricId *
     return CHIP_ERROR_INVALID_ARGUMENT;
 }
 
-CHIP_ERROR ExtractCATsFromOpCert(const ChipCertificateData & opcert, uint32_t * cats, uint8_t catsSize)
+CHIP_ERROR ExtractCATsFromOpCert(const ByteSpan & opcert, CATValues & cats)
+{
+    ChipCertificateSet certSet;
+    ChipCertificateData certData;
+
+    ReturnErrorOnFailure(certSet.Init(&certData, 1));
+
+    ReturnErrorOnFailure(certSet.LoadCert(opcert, BitFlags<CertDecodeFlags>()));
+
+    return ExtractCATsFromOpCert(certData, cats);
+}
+
+CHIP_ERROR ExtractCATsFromOpCert(const ChipCertificateData & opcert, CATValues & cats)
 {
     uint8_t catCount = 0;
     uint8_t certType;
@@ -897,13 +909,17 @@ CHIP_ERROR ExtractCATsFromOpCert(const ChipCertificateData & opcert, uint32_t *
         const auto & rdn = subjectDN.rdn[i];
         if (rdn.mAttrOID == ASN1::kOID_AttributeType_ChipCASEAuthenticatedTag)
         {
-            ReturnErrorCodeIf(catCount == catsSize, CHIP_ERROR_BUFFER_TOO_SMALL);
-            cats[catCount++] = static_cast<uint32_t>(rdn.mChipVal);
+            // This error should never happen in practice because valid NOC cannot have more
+            // than kMaxSubjectCATAttributeCount CATs in its subject. The check that it is
+            // valid NOC was done above.
+            ReturnErrorCodeIf(catCount == cats.size(), CHIP_ERROR_BUFFER_TOO_SMALL);
+            VerifyOrReturnError(CanCastTo<CASEAuthTag>(rdn.mChipVal), CHIP_ERROR_INVALID_ARGUMENT);
+            cats.val[catCount++] = static_cast<CASEAuthTag>(rdn.mChipVal);
         }
     }
-    for (uint8_t i = catCount; i < catsSize; ++i)
+    for (uint8_t i = catCount; i < cats.size(); ++i)
     {
-        cats[i] = 0;
+        cats.val[i] = kUndefinedCAT;
     }
 
     return CHIP_NO_ERROR;

src/credentials/CHIPCert.h

@@ -34,6 +34,7 @@
 #include <lib/asn1/ASN1.h>
 #include <lib/core/CHIPConfig.h>
 #include <lib/core/CHIPTLV.h>
+#include <lib/core/DataModelTypes.h>
 #include <lib/core/PeerId.h>
 #include <lib/support/BitFlags.h>
 #include <lib/support/DLLUtil.h>
@@ -56,6 +57,15 @@ static constexpr uint32_t kMaxCHIPCertDecodeBufLength = kMaxDERCertLength - Cryp
 
 // Muximum number of CASE Authenticated Tags (CAT) in the CHIP certificate subject.
 static constexpr size_t kMaxSubjectCATAttributeCount = CHIP_CONFIG_CERT_MAX_RDN_ATTRIBUTES - 2;
+static constexpr CASEAuthTag kUndefinedCAT           = 0;
+
+struct CATValues
+{
+    CASEAuthTag val[kMaxSubjectCATAttributeCount];
+
+    size_t size() const { return ArraySize(val); }
+};
+static constexpr CATValues kUndefinedCATs = { { Credentials::kUndefinedCAT } };
 
 /** Data Element Tags for the CHIP Certificate
  */
@@ -799,16 +809,26 @@ CHIP_ERROR ExtractFabricIdFromCert(const ChipCertificateData & cert, FabricId *
  */
 CHIP_ERROR ExtractNodeIdFabricIdFromOpCert(const ChipCertificateData & opcert, NodeId * nodeId, FabricId * fabricId);
 
+/**
+ * Extract CASE Authenticated Tags from an operational certificate in ByteSpan TLV-encoded form.
+ *
+ * All values in the 'cats' struct will be set either to a valid CAT value or zero (undefined) value.
+ *
+ * @return CHIP_ERROR_INVALID_ARGUMENT if the passed-in cert is not NOC.
+ * @return CHIP_ERROR_BUFFER_TOO_SMALL if there are too many CATs in the NOC
+ */
+CHIP_ERROR ExtractCATsFromOpCert(const ByteSpan & opcert, CATValues & cats);
+
 /**
  * Extract CASE Authenticated Tags from an operational certificate that has already been
  * parsed.
  *
- * All values in the 'cats' array will be set either to a valid CAT value or zero (undefined) value.
+ * All values in the 'cats' struct will be set either to a valid CAT value or to the kUndefinedCAT value.
  *
  * @return CHIP_ERROR_INVALID_ARGUMENT if the passed-in cert is not NOC.
  * @return CHIP_ERROR_BUFFER_TOO_SMALL if the passed-in CATs array is too small.
  */
-CHIP_ERROR ExtractCATsFromOpCert(const ChipCertificateData & opcert, uint32_t * cats, uint8_t catsSize);
+CHIP_ERROR ExtractCATsFromOpCert(const ChipCertificateData & opcert, CATValues & cats);
 
 /**
  * Extract Node ID and Fabric ID from an operational certificate in ByteSpan TLV-encoded

src/credentials/tests/TestChipCert.cpp

@@ -1113,70 +1113,68 @@ static void TestChipCert_ExtractCATsFromOpCert(nlTestSuite * inSuite, void * inC
     struct TestCase
     {
         uint8_t Cert;
-        uint32_t ExpectedCAT[kMaxSubjectCATAttributeCount];
+        CATValues ExpectedCATs;
     };
 
     // clang-format off
     static constexpr TestCase sTestCases[] = {
         // Cert                  CATs
-        // =============================================================
-        {  TestCert::kNode01_01, {          0,          0,          0 } },
-        {  TestCert::kNode01_02, {          0,          0,          0 } },
-        {  TestCert::kNode02_01, {          0,          0,          0 } },
-        {  TestCert::kNode02_02, {          0,          0,          0 } },
-        {  TestCert::kNode02_03, { 0xABCD0001,          0,          0 } },
-        {  TestCert::kNode02_04, { 0xABCE1002, 0xABCD0003,          0 } },
-        {  TestCert::kNode02_05, { 0xABCD0010, 0xABCE1008,          0 } },
-        {  TestCert::kNode02_06, {          0,          0,          0 } },
-        {  TestCert::kNode02_07, {          0,          0,          0 } },
-        {  TestCert::kNode02_08, { 0xABCF00A0, 0xABCD0020, 0xABCE0100 } },
+        // ============================================================================
+        {  TestCert::kNode01_01, { { kUndefinedCAT, kUndefinedCAT, kUndefinedCAT } } },
+        {  TestCert::kNode01_02, { { kUndefinedCAT, kUndefinedCAT, kUndefinedCAT } } },
+        {  TestCert::kNode02_01, { { kUndefinedCAT, kUndefinedCAT, kUndefinedCAT } } },
+        {  TestCert::kNode02_02, { { kUndefinedCAT, kUndefinedCAT, kUndefinedCAT } } },
+        {  TestCert::kNode02_03, { {    0xABCD0001, kUndefinedCAT, kUndefinedCAT } } },
+        {  TestCert::kNode02_04, { {    0xABCE1002,    0xABCD0003, kUndefinedCAT } } },
+        {  TestCert::kNode02_05, { {    0xABCD0010,    0xABCE1008, kUndefinedCAT } } },
+        {  TestCert::kNode02_06, { { kUndefinedCAT, kUndefinedCAT, kUndefinedCAT } } },
+        {  TestCert::kNode02_07, { { kUndefinedCAT, kUndefinedCAT, kUndefinedCAT } } },
+        {  TestCert::kNode02_08, { {    0xABCF00A0,    0xABCD0020,    0xABCE0100 } } },
     };
     // clang-format on
 
     // Test extraction from the raw ByteSpan form.
-    ChipCertificateSet certSet;
     for (auto & testCase : sTestCases)
     {
-        CHIP_ERROR err = certSet.Init(1);
-        NL_TEST_ASSERT(inSuite, err == CHIP_NO_ERROR);
-
-        err = LoadTestCert(certSet, testCase.Cert, sNullLoadFlag, sNullDecodeFlag);
+        ByteSpan cert;
+        CHIP_ERROR err = GetTestCert(testCase.Cert, sNullLoadFlag, cert);
         NL_TEST_ASSERT(inSuite, err == CHIP_NO_ERROR);
 
-        uint32_t cats[kMaxSubjectCATAttributeCount];
-        err = ExtractCATsFromOpCert(certSet.GetCertSet()[0], cats, ArraySize(cats));
+        CATValues cats;
+        err = ExtractCATsFromOpCert(cert, cats);
         NL_TEST_ASSERT(inSuite, err == CHIP_NO_ERROR);
-        NL_TEST_ASSERT(inSuite, memcmp(cats, testCase.ExpectedCAT, sizeof(cats)) == 0);
-
-        certSet.Release();
+        NL_TEST_ASSERT(inSuite, memcmp(&cats, &testCase.ExpectedCATs, sizeof(cats)) == 0);
     }
 
-    // Error case: trying to extract CAT from Root Cert.
+    // Test extraction from the parsed form.
+    ChipCertificateSet certSet;
+    for (auto & testCase : sTestCases)
     {
         CHIP_ERROR err = certSet.Init(1);
         NL_TEST_ASSERT(inSuite, err == CHIP_NO_ERROR);
 
-        err = LoadTestCert(certSet, TestCert::kRoot01, sNullLoadFlag, sNullDecodeFlag);
+        err = LoadTestCert(certSet, testCase.Cert, sNullLoadFlag, sNullDecodeFlag);
         NL_TEST_ASSERT(inSuite, err == CHIP_NO_ERROR);
 
-        uint32_t cats[kMaxSubjectCATAttributeCount];
-        err = ExtractCATsFromOpCert(certSet.GetCertSet()[0], cats, ArraySize(cats));
-        NL_TEST_ASSERT(inSuite, err == CHIP_ERROR_INVALID_ARGUMENT);
+        CATValues cats;
+        err = ExtractCATsFromOpCert(certSet.GetCertSet()[0], cats);
+        NL_TEST_ASSERT(inSuite, err == CHIP_NO_ERROR);
+        NL_TEST_ASSERT(inSuite, memcmp(&cats, &testCase.ExpectedCATs, sizeof(cats)) == 0);
 
         certSet.Release();
     }
 
-    // Error case: CAT array is too small.
+    // Error case: trying to extract CAT from Root Cert.
     {
         CHIP_ERROR err = certSet.Init(1);
         NL_TEST_ASSERT(inSuite, err == CHIP_NO_ERROR);
 
-        err = LoadTestCert(certSet, TestCert::kNode02_08, sNullLoadFlag, sNullDecodeFlag);
+        err = LoadTestCert(certSet, TestCert::kRoot01, sNullLoadFlag, sNullDecodeFlag);
         NL_TEST_ASSERT(inSuite, err == CHIP_NO_ERROR);
 
-        uint32_t cats[kMaxSubjectCATAttributeCount - 1];
-        err = ExtractCATsFromOpCert(certSet.GetCertSet()[0], cats, ArraySize(cats));
-        NL_TEST_ASSERT(inSuite, err == CHIP_ERROR_BUFFER_TOO_SMALL);
+        CATValues cats;
+        err = ExtractCATsFromOpCert(certSet.GetCertSet()[0], cats);
+        NL_TEST_ASSERT(inSuite, err == CHIP_ERROR_INVALID_ARGUMENT);
 
         certSet.Release();
     }
@@ -1276,7 +1274,7 @@ static const nlTest sTests[] = {
     NL_TEST_DEF("Test CHIP Verify Generated Cert Chain", TestChipCert_VerifyGeneratedCerts),
     NL_TEST_DEF("Test CHIP Verify Generated Cert Chain No ICA", TestChipCert_VerifyGeneratedCertsNoICA),
     NL_TEST_DEF("Test extracting PeerId from node certificate", TestChipCert_ExtractPeerId),
-    NL_TEST_DEF("Test extracting CAST Authenticated Tags from node certificate", TestChipCert_ExtractCATsFromOpCert),
+    NL_TEST_DEF("Test extracting CASE Authenticated Tags from node certificate", TestChipCert_ExtractCATsFromOpCert),
     NL_TEST_DEF("Test extracting PublicKey and SKID from chip certificate", TestChipCert_ExtractPublicKeyAndSKID),
     NL_TEST_SENTINEL()
 };

src/lib/core/DataModelTypes.h

@@ -28,6 +28,7 @@ namespace chip {
 
 typedef uint8_t ActionId;
 typedef uint32_t AttributeId;
+typedef uint32_t CASEAuthTag;
 typedef uint32_t ClusterId;
 typedef uint8_t ClusterStatus;
 typedef uint32_t CommandId;

src/lib/core/NodeId.h

@@ -40,11 +40,8 @@ constexpr NodeId kMinTemporaryLocalId = 0xFFFF'FFFE'0000'0000ULL;
 constexpr NodeId kMaxTemporaryLocalId = 0xFFFF'FFFE'FFFF'FFFEULL;
 constexpr NodeId kPlaceholderNodeId   = 0xFFFF'FFFE'FFFF'FFFFULL;
 
-constexpr NodeId kMinCASEAuthTag1 = 0xFFFF'FFFD'0000'0000ULL;
-constexpr NodeId kMaxCASEAuthTag1 = 0xFFFF'FFFD'FFFF'FFFFULL;
-
-constexpr NodeId kMinCASEAuthTag2 = 0xFFFF'FFFC'0000'0000ULL;
-constexpr NodeId kMaxCASEAuthTag2 = 0xFFFF'FFFC'FFFF'FFFFULL;
+constexpr NodeId kMinCASEAuthTag = 0xFFFF'FFFD'0000'0000ULL;
+constexpr NodeId kMaxCASEAuthTag = 0xFFFF'FFFD'FFFF'FFFFULL;
 
 constexpr NodeId kMinPAKEKeyId = 0xFFFF'FFFB'0000'0000ULL;
 constexpr NodeId kMaxPAKEKeyId = 0xFFFF'FFFB'FFFF'FFFFULL;

src/protocols/secure_channel/CASESession.cpp

@@ -1,3 +1,4 @@
+
 /*
  *
  *    Copyright (c) 2021 Project CHIP Authors
@@ -91,6 +92,7 @@ static constexpr ExchangeContext::Timeout kSigma_Response_Timeout = System::Cloc
 
 CASESession::CASESession()
 {
+    SetSecureSessionType(Transport::SecureSession::Type::kCASE);
     mTrustedRootId = CertificateKeyId();
 }
 
@@ -174,8 +176,12 @@ CHIP_ERROR CASESession::ToSerializable(CASESessionSerializable & serializable)
     serializable.mMessageDigestLen = LittleEndian::HostSwap16(static_cast<uint16_t>(sizeof(mMessageDigest)));
     serializable.mVersion          = kCASESessionVersion;
     serializable.mPeerNodeId       = LittleEndian::HostSwap64(peerNodeId);
-    serializable.mLocalSessionId   = LittleEndian::HostSwap16(GetLocalSessionId());
-    serializable.mPeerSessionId    = LittleEndian::HostSwap16(GetPeerSessionId());
+    for (size_t i = 0; i < serializable.mPeerCATs.size(); i++)
+    {
+        serializable.mPeerCATs.val[i] = LittleEndian::HostSwap32(GetPeerCATs().val[i]);
+    }
+    serializable.mLocalSessionId = LittleEndian::HostSwap16(GetLocalSessionId());
+    serializable.mPeerSessionId  = LittleEndian::HostSwap16(GetPeerSessionId());
 
     memcpy(serializable.mResumptionId, mResumptionId, sizeof(mResumptionId));
     memcpy(serializable.mSharedSecret, mSharedSecret, mSharedSecret.Length());
@@ -198,6 +204,12 @@ CHIP_ERROR CASESession::FromSerializable(const CASESessionSerializable & seriali
     memcpy(mMessageDigest, serializable.mMessageDigest, length);
 
     SetPeerNodeId(LittleEndian::HostSwap64(serializable.mPeerNodeId));
+    Credentials::CATValues peerCATs;
+    for (size_t i = 0; i < serializable.mPeerCATs.size(); i++)
+    {
+        peerCATs.val[i] = LittleEndian::HostSwap32(serializable.mPeerCATs.val[i]);
+    }
+    SetPeerCATs(peerCATs);
     SetLocalSessionId(LittleEndian::HostSwap16(serializable.mLocalSessionId));
     SetPeerSessionId(LittleEndian::HostSwap16(serializable.mPeerSessionId));
 
@@ -863,6 +875,11 @@ CHIP_ERROR CASESession::HandleSigma2(System::PacketBufferHandle && msg)
     SuccessOrExit(err = decryptedDataTlvReader.Next(TLV::kTLVType_ByteString, TLV::ContextTag(kTag_TBEData_ResumptionID)));
     SuccessOrExit(err = decryptedDataTlvReader.GetBytes(mResumptionId, static_cast<uint32_t>(sizeof(mResumptionId))));
 
+    // Retrieve peer CASE Authenticated Tags (CATs) from peer's NOC.
+    Credentials::CATValues peerCATs;
+    SuccessOrExit(err = ExtractCATsFromOpCert(responderNOC, peerCATs));
+    SetPeerCATs(peerCATs);
+
 exit:
     if (err != CHIP_NO_ERROR)
     {
@@ -1120,6 +1137,11 @@ CHIP_ERROR CASESession::HandleSigma3(System::PacketBufferHandle && msg)
 
     SuccessOrExit(err = mCommissioningHash.Finish(messageDigestSpan));
 
+    // Retrieve peer CASE Authenticated Tags (CATs) from peer's NOC.
+    Credentials::CATValues peerCATs;
+    SuccessOrExit(err = ExtractCATsFromOpCert(initiatorNOC, peerCATs));
+    SetPeerCATs(peerCATs);
+
     SendStatusReport(mExchangeCtxt, kProtocolCodeSuccess);
 
     // TODO: Set timestamp on the new session, to allow selecting a least-recently-used session for eviction

src/protocols/secure_channel/CASESession.h

@@ -68,6 +68,7 @@ struct CASESessionSerializable
     uint16_t mMessageDigestLen;
     uint8_t mMessageDigest[Crypto::kSHA256_Hash_Length];
     NodeId mPeerNodeId;
+    Credentials::CATValues mPeerCATs;
     uint16_t mLocalSessionId;
     uint16_t mPeerSessionId;
     uint8_t mResumptionId[kCASEResumptionIDSize];

src/protocols/secure_channel/PASESession.cpp

@@ -70,7 +70,10 @@ using PBKDF2_sha256_crypto = PBKDF2_sha256HSM;
 using PBKDF2_sha256_crypto = PBKDF2_sha256;
 #endif
 
-PASESession::PASESession() {}
+PASESession::PASESession()
+{
+    SetSecureSessionType(Transport::SecureSession::Type::kPASE);
+}
 
 PASESession::~PASESession()
 {

src/protocols/secure_channel/tests/TestCASESession.cpp

@@ -153,6 +153,11 @@ void CASE_SecurePairingWaitTest(nlTestSuite * inSuite, void * inContext)
     TestCASESessionIPK pairing;
     FabricTable fabrics;
 
+    NL_TEST_ASSERT(inSuite, pairing.GetSecureSessionType() == SecureSession::Type::kCASE);
+    Credentials::CATValues peerCATs;
+    peerCATs = pairing.GetPeerCATs();
+    NL_TEST_ASSERT(inSuite, memcmp(&peerCATs, &kUndefinedCATs, sizeof(Credentials::CATValues)) == 0);
+
     NL_TEST_ASSERT(inSuite, pairing.ListenForSessionEstablishment(0, nullptr, nullptr) == CHIP_ERROR_INVALID_ARGUMENT);
     NL_TEST_ASSERT(inSuite, pairing.ListenForSessionEstablishment(0, nullptr, &delegate) == CHIP_ERROR_INVALID_ARGUMENT);
     NL_TEST_ASSERT(inSuite, pairing.ListenForSessionEstablishment(0, &fabrics, &delegate) == CHIP_NO_ERROR);

src/protocols/secure_channel/tests/TestPASESession.cpp

@@ -1,6 +1,6 @@
 /*
  *
- *    Copyright (c) 2020 Project CHIP Authors
+ *    Copyright (c) 2020-2021 Project CHIP Authors
  *    All rights reserved.
  *
  *    Licensed under the Apache License, Version 2.0 (the "License");
@@ -101,6 +101,11 @@ void SecurePairingWaitTest(nlTestSuite * inSuite, void * inContext)
     TestSecurePairingDelegate delegate;
     PASESession pairing;
 
+    NL_TEST_ASSERT(inSuite, pairing.GetSecureSessionType() == SecureSession::Type::kPASE);
+    Credentials::CATValues peerCATs;
+    peerCATs = pairing.GetPeerCATs();
+    NL_TEST_ASSERT(inSuite, memcmp(&peerCATs, &Credentials::kUndefinedCATs, sizeof(Credentials::CATValues)) == 0);
+
     gLoopback.Reset();
 
     NL_TEST_ASSERT(inSuite, pairing.WaitForPairing(1234, 500, ByteSpan(nullptr, 0), 0, &delegate) == CHIP_ERROR_INVALID_ARGUMENT);