Remove the PakeError message type. (#21239)

It's been gone from the spec for a while; we should remove it from the SDK too.

Fixes #21128

examples/common/tracing/decoder/secure_channel/Decoder.cpp

@@ -35,7 +35,6 @@ constexpr const char * kPBKDFParamResponse = "Password-Based Key Derivation Para
 constexpr const char * kPASE_Pake1         = "Password Authenticated Session Establishment '1'";
 constexpr const char * kPASE_Pake2         = "Password Authenticated Session Establishment '2'";
 constexpr const char * kPASE_Pake3         = "Password Authenticated Session Establishment '3'";
-constexpr const char * kPASE_PakeError     = "Password-authenticated key exchange Error";
 constexpr const char * kCASE_Sigma1        = "Certificate Authenticated Session Establishment Sigma '1'";
 constexpr const char * kCASE_Sigma2        = "Certificate Authenticated Session Establishment Sigma '2'";
 constexpr const char * kCASE_Sigma3        = "Certificate Authenticated Session Establishment Sigma '3'";
@@ -60,7 +59,6 @@ CHIP_ERROR DecodePBDFKParamResponse(TLV::TLVReader & reader);
 CHIP_ERROR DecodePASEPake1(TLV::TLVReader & reader);
 CHIP_ERROR DecodePASEPake2(TLV::TLVReader & reader);
 CHIP_ERROR DecodePASEPake3(TLV::TLVReader & reader);
-CHIP_ERROR DecodePASEPakeError(TLV::TLVReader & reader);
 CHIP_ERROR DecodeCASESigma1(TLV::TLVReader & reader);
 CHIP_ERROR DecodeCASESigma2(TLV::TLVReader & reader);
 CHIP_ERROR DecodeCASESigma3(TLV::TLVReader & reader);
@@ -92,8 +90,6 @@ const char * ToProtocolMessageTypeName(uint8_t protocolCode)
         return kPASE_Pake2;
     case to_underlying(MessageType::PASE_Pake3):
         return kPASE_Pake3;
-    case to_underlying(MessageType::PASE_PakeError):
-        return kPASE_PakeError;
     case to_underlying(MessageType::CASE_Sigma1):
         return kCASE_Sigma1;
     case to_underlying(MessageType::CASE_Sigma2):
@@ -132,8 +128,6 @@ CHIP_ERROR LogAsProtocolMessage(uint8_t protocolCode, const uint8_t * data, size
         return DecodePASEPake2(reader);
     case to_underlying(MessageType::PASE_Pake3):
         return DecodePASEPake3(reader);
-    case to_underlying(MessageType::PASE_PakeError):
-        return DecodePASEPakeError(reader);
     case to_underlying(MessageType::CASE_Sigma1):
         return DecodeCASESigma1(reader);
     case to_underlying(MessageType::CASE_Sigma2):
@@ -323,11 +317,6 @@ CHIP_ERROR DecodePASEPake3(TLV::TLVReader & reader)
     return CHIP_NO_ERROR;
 }
 
-CHIP_ERROR DecodePASEPakeError(TLV::TLVReader & reader)
-{
-    return CHIP_ERROR_NOT_IMPLEMENTED;
-}
-
 CHIP_ERROR DecodeCASESigma1(TLV::TLVReader & reader)
 {
     constexpr uint8_t kInitiatorRandomTag    = 1;

src/messaging/ApplicationExchangeDispatch.cpp

@@ -38,7 +38,6 @@ bool ApplicationExchangeDispatch::MessagePermitted(Protocols::Id protocol, uint8
         case static_cast<uint8_t>(Protocols::SecureChannel::MsgType::PASE_Pake1):
         case static_cast<uint8_t>(Protocols::SecureChannel::MsgType::PASE_Pake2):
         case static_cast<uint8_t>(Protocols::SecureChannel::MsgType::PASE_Pake3):
-        case static_cast<uint8_t>(Protocols::SecureChannel::MsgType::PASE_PakeError):
         case static_cast<uint8_t>(Protocols::SecureChannel::MsgType::CASE_Sigma1):
         case static_cast<uint8_t>(Protocols::SecureChannel::MsgType::CASE_Sigma2):
         case static_cast<uint8_t>(Protocols::SecureChannel::MsgType::CASE_Sigma3):

src/protocols/secure_channel/Constants.h

@@ -60,7 +60,6 @@ enum class MsgType : uint8_t
     PASE_Pake1         = 0x22,
     PASE_Pake2         = 0x23,
     PASE_Pake3         = 0x24,
-    PASE_PakeError     = 0x2F,
 
     // Certificate-based session establishment Message Types
     CASE_Sigma1       = 0x30,

src/protocols/secure_channel/PASESession.cpp

@@ -87,7 +87,7 @@ void PASESession::Clear()
     // It's done so that no security related information will be leaked.
     memset(&mPASEVerifier, 0, sizeof(mPASEVerifier));
     memset(&mKe[0], 0, sizeof(mKe));
-    mNextExpectedMsg = MsgType::PASE_PakeError;
+    mNextExpectedMsg.ClearValue();
 
     mSpake2p.Clear();
     mCommissioningHash.Clear();
@@ -185,8 +185,8 @@ CHIP_ERROR PASESession::WaitForPairing(SessionManager & sessionManager, const Sp
     memmove(mSalt, salt.data(), mSaltLength);
     memmove(&mPASEVerifier, &verifier, sizeof(verifier));
 
-    mIterationCount  = pbkdf2IterCount;
-    mNextExpectedMsg = MsgType::PBKDFParamRequest;
+    mIterationCount = pbkdf2IterCount;
+    mNextExpectedMsg.SetValue(MsgType::PBKDFParamRequest);
     mPairingComplete = false;
     mLocalMRPConfig  = mrpLocalConfig;
 
@@ -234,8 +234,9 @@ void PASESession::OnResponseTimeout(ExchangeContext * ec)
     VerifyOrReturn(ec != nullptr, ChipLogError(SecureChannel, "PASESession::OnResponseTimeout was called by null exchange"));
     VerifyOrReturn(mExchangeCtxt == nullptr || mExchangeCtxt == ec,
                    ChipLogError(SecureChannel, "PASESession::OnResponseTimeout exchange doesn't match"));
+    // If we were waiting for something, mNextExpectedMsg had better have a value.
     ChipLogError(SecureChannel, "PASESession timed out while waiting for a response from the peer. Expected message type was %u",
-                 to_underlying(mNextExpectedMsg));
+                 to_underlying(mNextExpectedMsg.Value()));
     // Discard the exchange so that Clear() doesn't try closing it.  The
     // exchange will handle that.
     DiscardExchange();
@@ -293,7 +294,7 @@ CHIP_ERROR PASESession::SendPBKDFParamRequest()
     ReturnErrorOnFailure(
         mExchangeCtxt->SendMessage(MsgType::PBKDFParamRequest, std::move(req), SendFlags(SendMessageFlags::kExpectResponse)));
 
-    mNextExpectedMsg = MsgType::PBKDFParamResponse;
+    mNextExpectedMsg.SetValue(MsgType::PBKDFParamResponse);
 
     ChipLogDetail(SecureChannel, "Sent PBKDF param request");
 
@@ -418,7 +419,7 @@ CHIP_ERROR PASESession::SendPBKDFParamResponse(ByteSpan initiatorRandom, bool in
         mExchangeCtxt->SendMessage(MsgType::PBKDFParamResponse, std::move(resp), SendFlags(SendMessageFlags::kExpectResponse)));
     ChipLogDetail(SecureChannel, "Sent PBKDF param response");
 
-    mNextExpectedMsg = MsgType::PASE_Pake1;
+    mNextExpectedMsg.SetValue(MsgType::PASE_Pake1);
 
     return CHIP_NO_ERROR;
 }
@@ -545,7 +546,7 @@ CHIP_ERROR PASESession::SendMsg1()
         mExchangeCtxt->SendMessage(MsgType::PASE_Pake1, std::move(msg), SendFlags(SendMessageFlags::kExpectResponse)));
     ChipLogDetail(SecureChannel, "Sent spake2p msg1");
 
-    mNextExpectedMsg = MsgType::PASE_Pake2;
+    mNextExpectedMsg.SetValue(MsgType::PASE_Pake2);
 
     return CHIP_NO_ERROR;
 }
@@ -606,7 +607,7 @@ CHIP_ERROR PASESession::HandleMsg1_and_SendMsg2(System::PacketBufferHandle && ms
         err = mExchangeCtxt->SendMessage(MsgType::PASE_Pake2, std::move(msg2), SendFlags(SendMessageFlags::kExpectResponse));
         SuccessOrExit(err);
 
-        mNextExpectedMsg = MsgType::PASE_Pake3;
+        mNextExpectedMsg.SetValue(MsgType::PASE_Pake3);
     }
 
     ChipLogDetail(SecureChannel, "Sent spake2p msg2");
@@ -682,7 +683,7 @@ CHIP_ERROR PASESession::HandleMsg2_and_SendMsg3(System::PacketBufferHandle && ms
         err = mExchangeCtxt->SendMessage(MsgType::PASE_Pake3, std::move(msg3), SendFlags(SendMessageFlags::kExpectResponse));
         SuccessOrExit(err);
 
-        mNextExpectedMsg = MsgType::StatusReport;
+        mNextExpectedMsg.SetValue(MsgType::StatusReport);
     }
 
     ChipLogDetail(SecureChannel, "Sent spake2p msg3");
@@ -703,8 +704,7 @@ CHIP_ERROR PASESession::HandleMsg3(System::PacketBufferHandle && msg)
 
     ChipLogDetail(SecureChannel, "Received spake2p msg3");
 
-    // We will set NextExpectedMsg to PASE_PakeError in all cases
-    mNextExpectedMsg = MsgType::PASE_PakeError;
+    mNextExpectedMsg.ClearValue();
 
     System::PacketBufferTLVReader tlvReader;
     TLV::TLVType containerType = TLV::kTLVType_Structure;
@@ -784,7 +784,8 @@ CHIP_ERROR PASESession::ValidateReceivedMessage(ExchangeContext * exchange, cons
     }
 
     VerifyOrReturnError(!msg.IsNull(), CHIP_ERROR_INVALID_ARGUMENT);
-    VerifyOrReturnError(payloadHeader.HasMessageType(mNextExpectedMsg) || payloadHeader.HasMessageType(MsgType::StatusReport),
+    VerifyOrReturnError((mNextExpectedMsg.HasValue() && payloadHeader.HasMessageType(mNextExpectedMsg.Value())) ||
+                            payloadHeader.HasMessageType(MsgType::StatusReport),
                         CHIP_ERROR_INVALID_MESSAGE_TYPE);
 
     return CHIP_NO_ERROR;
@@ -835,7 +836,8 @@ CHIP_ERROR PASESession::OnMessageReceived(ExchangeContext * exchange, const Payl
         break;
 
     case MsgType::StatusReport:
-        err = HandleStatusReport(std::move(msg), mNextExpectedMsg == MsgType::StatusReport);
+        err =
+            HandleStatusReport(std::move(msg), mNextExpectedMsg.HasValue() && (mNextExpectedMsg.Value() == MsgType::StatusReport));
         break;
 
     default:

src/protocols/secure_channel/PASESession.h

@@ -210,7 +210,8 @@ class DLL_EXPORT PASESession : public Messaging::UnsolicitedMessageHandler,
 
     void Finish();
 
-    Protocols::SecureChannel::MsgType mNextExpectedMsg = Protocols::SecureChannel::MsgType::PASE_PakeError;
+    // mNextExpectedMsg is set when we are expecting a message.
+    Optional<Protocols::SecureChannel::MsgType> mNextExpectedMsg;
 
 #ifdef ENABLE_HSM_SPAKE
     Spake2pHSM_P256_SHA256_HKDF_HMAC mSpake2p;

src/protocols/secure_channel/SessionEstablishmentExchangeDispatch.cpp

@@ -40,7 +40,6 @@ bool SessionEstablishmentExchangeDispatch::MessagePermitted(Protocols::Id protoc
         case static_cast<uint8_t>(Protocols::SecureChannel::MsgType::PASE_Pake1):
         case static_cast<uint8_t>(Protocols::SecureChannel::MsgType::PASE_Pake2):
         case static_cast<uint8_t>(Protocols::SecureChannel::MsgType::PASE_Pake3):
-        case static_cast<uint8_t>(Protocols::SecureChannel::MsgType::PASE_PakeError):
         case static_cast<uint8_t>(Protocols::SecureChannel::MsgType::CASE_Sigma1):
         case static_cast<uint8_t>(Protocols::SecureChannel::MsgType::CASE_Sigma2):
         case static_cast<uint8_t>(Protocols::SecureChannel::MsgType::CASE_Sigma3):