| /* |
| * |
| * Copyright (c) 2020-2022 Project CHIP Authors |
| * All rights reserved. |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| /** |
| * @file |
| * This file implements the CHIP SPAKE2P Session object that provides |
| * APIs for constructing spake2p messages and establishing encryption |
| * keys. |
| * |
| * The protocol for handling pA, pB, cB and cA is defined in SPAKE2 |
| * Plus specifications. |
| * (https://www.ietf.org/id/draft-bar-cfrg-spake2plus-01.html) |
| * |
| */ |
| #include <protocols/secure_channel/PASESession.h> |
| |
| #include <inttypes.h> |
| #include <string.h> |
| |
| #include <lib/core/CHIPEncoding.h> |
| #include <lib/core/CHIPSafeCasts.h> |
| #include <lib/support/BufferWriter.h> |
| #include <lib/support/CHIPMem.h> |
| #include <lib/support/CodeUtils.h> |
| #include <lib/support/SafeInt.h> |
| #include <lib/support/TypeTraits.h> |
| #include <messaging/SessionParameters.h> |
| #include <protocols/Protocols.h> |
| #include <protocols/secure_channel/Constants.h> |
| #include <protocols/secure_channel/StatusReport.h> |
| #include <setup_payload/SetupPayload.h> |
| #include <system/TLVPacketBufferBackingStore.h> |
| #include <tracing/macros.h> |
| #include <transport/SessionManager.h> |
| |
| namespace chip { |
| |
| using namespace Crypto; |
| using namespace Messaging; |
| using namespace Protocols::SecureChannel; |
| |
| const char kSpake2pContext[] = "CHIP PAKE V1 Commissioning"; |
| const char kSpake2pI2RSessionInfo[] = "Commissioning I2R Key"; |
| const char kSpake2pR2ISessionInfo[] = "Commissioning R2I Key"; |
| |
| // Amounts of time to allow for server-side processing of messages. |
| // |
| // These timeout values only allow for the server-side processing and assume that any transport-specific |
| // latency will be added to them. |
| // |
| // The session establishment fails if the response is not received within the resulting timeout window, |
| // which accounts for both transport latency and the server-side latency. |
| static constexpr ExchangeContext::Timeout kExpectedLowProcessingTime = System::Clock::Seconds16(2); |
| static constexpr ExchangeContext::Timeout kExpectedHighProcessingTime = System::Clock::Seconds16(30); |
| |
| PASESession::~PASESession() |
| { |
| // Let's clear out any security state stored in the object, before destroying it. |
| Clear(); |
| } |
| |
| void PASESession::OnSessionReleased() |
| { |
| // Call into our super-class before we clear our state. |
| PairingSession::OnSessionReleased(); |
| Clear(); |
| } |
| |
| void PASESession::Finish() |
| { |
| mPairingComplete = true; |
| PairingSession::Finish(); |
| } |
| |
| void PASESession::Clear() |
| { |
| MATTER_TRACE_SCOPE("Clear", "PASESession"); |
| // This function zeroes out and resets the memory used by the object. |
| // It's done so that no security related information will be leaked. |
| memset(&mPASEVerifier, 0, sizeof(mPASEVerifier)); |
| mNextExpectedMsg.ClearValue(); |
| |
| mSpake2p.Clear(); |
| mCommissioningHash.Clear(); |
| |
| mIterationCount = 0; |
| mSaltLength = 0; |
| if (mSalt != nullptr) |
| { |
| chip::Platform::MemoryFree(mSalt); |
| mSalt = nullptr; |
| } |
| mPairingComplete = false; |
| PairingSession::Clear(); |
| } |
| |
| CHIP_ERROR PASESession::Init(SessionManager & sessionManager, uint32_t setupCode, SessionEstablishmentDelegate * delegate) |
| { |
| MATTER_TRACE_SCOPE("Init", "PASESession"); |
| VerifyOrReturnError(sessionManager.GetSessionKeystore() != nullptr, CHIP_ERROR_INVALID_ARGUMENT); |
| VerifyOrReturnError(delegate != nullptr, CHIP_ERROR_INVALID_ARGUMENT); |
| |
| // Reset any state maintained by PASESession object (in case it's being reused for pairing) |
| Clear(); |
| |
| ReturnErrorOnFailure(mCommissioningHash.Begin()); |
| ReturnErrorOnFailure(mCommissioningHash.AddData(ByteSpan{ Uint8::from_const_char(kSpake2pContext), strlen(kSpake2pContext) })); |
| |
| mDelegate = delegate; |
| ReturnErrorOnFailure(AllocateSecureSession(sessionManager)); |
| VerifyOrReturnError(GetLocalSessionId().HasValue(), CHIP_ERROR_INCORRECT_STATE); |
| ChipLogDetail(SecureChannel, "Assigned local session key ID %u", GetLocalSessionId().Value()); |
| |
| ReturnErrorCodeIf(setupCode >= (1 << kSetupPINCodeFieldLengthInBits), CHIP_ERROR_INVALID_ARGUMENT); |
| mSetupPINCode = setupCode; |
| |
| return CHIP_NO_ERROR; |
| } |
| |
| CHIP_ERROR PASESession::GeneratePASEVerifier(Spake2pVerifier & verifier, uint32_t pbkdf2IterCount, const ByteSpan & salt, |
| bool useRandomPIN, uint32_t & setupPINCode) |
| { |
| MATTER_TRACE_SCOPE("GeneratePASEVerifier", "PASESession"); |
| |
| if (useRandomPIN) |
| { |
| ReturnErrorOnFailure(DRBG_get_bytes(reinterpret_cast<uint8_t *>(&setupPINCode), sizeof(setupPINCode))); |
| |
| // Passcodes shall be restricted to the values 00000001 to 99999998 in decimal, see 5.1.1.6 |
| setupPINCode = (setupPINCode % kSetupPINCodeMaximumValue) + 1; |
| } |
| |
| return verifier.Generate(pbkdf2IterCount, salt, setupPINCode); |
| } |
| |
| CHIP_ERROR PASESession::SetupSpake2p() |
| { |
| MATTER_TRACE_SCOPE("SetupSpake2p", "PASESession"); |
| uint8_t context[kSHA256_Hash_Length] = { 0 }; |
| MutableByteSpan contextSpan{ context }; |
| |
| ReturnErrorOnFailure(mCommissioningHash.Finish(contextSpan)); |
| ReturnErrorOnFailure(mSpake2p.Init(contextSpan.data(), contextSpan.size())); |
| |
| return CHIP_NO_ERROR; |
| } |
| |
| CHIP_ERROR PASESession::WaitForPairing(SessionManager & sessionManager, const Spake2pVerifier & verifier, uint32_t pbkdf2IterCount, |
| const ByteSpan & salt, Optional<ReliableMessageProtocolConfig> mrpLocalConfig, |
| SessionEstablishmentDelegate * delegate) |
| { |
| // Return early on error here, as we have not initialized any state yet |
| ReturnErrorCodeIf(salt.empty(), CHIP_ERROR_INVALID_ARGUMENT); |
| ReturnErrorCodeIf(salt.data() == nullptr, CHIP_ERROR_INVALID_ARGUMENT); |
| ReturnErrorCodeIf(salt.size() < kSpake2p_Min_PBKDF_Salt_Length || salt.size() > kSpake2p_Max_PBKDF_Salt_Length, |
| CHIP_ERROR_INVALID_ARGUMENT); |
| |
| CHIP_ERROR err = Init(sessionManager, kSetupPINCodeUndefinedValue, delegate); |
| // From here onwards, let's go to exit on error, as some state might have already |
| // been initialized |
| SuccessOrExit(err); |
| |
| mRole = CryptoContext::SessionRole::kResponder; |
| |
| VerifyOrExit(CanCastTo<uint16_t>(salt.size()), err = CHIP_ERROR_INVALID_ARGUMENT); |
| mSaltLength = static_cast<uint16_t>(salt.size()); |
| |
| if (mSalt != nullptr) |
| { |
| chip::Platform::MemoryFree(mSalt); |
| mSalt = nullptr; |
| } |
| |
| mSalt = static_cast<uint8_t *>(chip::Platform::MemoryAlloc(mSaltLength)); |
| VerifyOrExit(mSalt != nullptr, err = CHIP_ERROR_NO_MEMORY); |
| |
| memmove(mSalt, salt.data(), mSaltLength); |
| memmove(&mPASEVerifier, &verifier, sizeof(verifier)); |
| |
| mIterationCount = pbkdf2IterCount; |
| mNextExpectedMsg.SetValue(MsgType::PBKDFParamRequest); |
| mPairingComplete = false; |
| mLocalMRPConfig = mrpLocalConfig.ValueOr(GetDefaultMRPConfig()); |
| |
| ChipLogDetail(SecureChannel, "Waiting for PBKDF param request"); |
| |
| exit: |
| if (err != CHIP_NO_ERROR) |
| { |
| Clear(); |
| } |
| return err; |
| } |
| |
| CHIP_ERROR PASESession::Pair(SessionManager & sessionManager, uint32_t peerSetUpPINCode, |
| Optional<ReliableMessageProtocolConfig> mrpLocalConfig, Messaging::ExchangeContext * exchangeCtxt, |
| SessionEstablishmentDelegate * delegate) |
| { |
| MATTER_TRACE_SCOPE("Pair", "PASESession"); |
| ReturnErrorCodeIf(exchangeCtxt == nullptr, CHIP_ERROR_INVALID_ARGUMENT); |
| CHIP_ERROR err = Init(sessionManager, peerSetUpPINCode, delegate); |
| SuccessOrExit(err); |
| |
| mRole = CryptoContext::SessionRole::kInitiator; |
| |
| mExchangeCtxt.Emplace(*exchangeCtxt); |
| |
| // When commissioning starts, the peer is assumed to be active. |
| mExchangeCtxt.Value()->GetSessionHandle()->AsUnauthenticatedSession()->MarkActiveRx(); |
| |
| mExchangeCtxt.Value()->UseSuggestedResponseTimeout(kExpectedLowProcessingTime); |
| |
| mLocalMRPConfig = mrpLocalConfig.ValueOr(GetDefaultMRPConfig()); |
| |
| err = SendPBKDFParamRequest(); |
| SuccessOrExit(err); |
| |
| mDelegate->OnSessionEstablishmentStarted(); |
| |
| exit: |
| if (err != CHIP_NO_ERROR) |
| { |
| Clear(); |
| } |
| return err; |
| } |
| |
| void PASESession::OnResponseTimeout(ExchangeContext * ec) |
| { |
| MATTER_TRACE_SCOPE("OnResponseTimeout", "PASESession"); |
| VerifyOrReturn(ec != nullptr, ChipLogError(SecureChannel, "PASESession::OnResponseTimeout was called by null exchange")); |
| VerifyOrReturn(!mExchangeCtxt.HasValue() || &mExchangeCtxt.Value().Get() == 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.Value())); |
| MATTER_TRACE_COUNTER("PASETimeout"); |
| // Discard the exchange so that Clear() doesn't try closing it. The |
| // exchange will handle that. |
| DiscardExchange(); |
| Clear(); |
| // Do this last in case the delegate frees us. |
| NotifySessionEstablishmentError(CHIP_ERROR_TIMEOUT); |
| } |
| |
| CHIP_ERROR PASESession::DeriveSecureSession(CryptoContext & session) const |
| { |
| VerifyOrReturnError(mPairingComplete, CHIP_ERROR_INCORRECT_STATE); |
| |
| SessionKeystore & keystore = *mSessionManager->GetSessionKeystore(); |
| AutoReleaseSymmetricKey<HkdfKeyHandle> hkdfKey(keystore); |
| |
| ReturnErrorOnFailure(mSpake2p.GetKeys(keystore, hkdfKey.KeyHandle())); |
| ReturnErrorOnFailure(session.InitFromSecret(keystore, hkdfKey.KeyHandle(), ByteSpan{} /* salt */, |
| CryptoContext::SessionInfoType::kSessionEstablishment, mRole)); |
| |
| return CHIP_NO_ERROR; |
| } |
| |
| CHIP_ERROR PASESession::SendPBKDFParamRequest() |
| { |
| MATTER_TRACE_SCOPE("SendPBKDFParamRequest", "PASESession"); |
| |
| VerifyOrReturnError(GetLocalSessionId().HasValue(), CHIP_ERROR_INCORRECT_STATE); |
| |
| ReturnErrorOnFailure(DRBG_get_bytes(mPBKDFLocalRandomData, sizeof(mPBKDFLocalRandomData))); |
| |
| const size_t max_msg_len = TLV::EstimateStructOverhead(kPBKDFParamRandomNumberSize, // initiatorRandom, |
| sizeof(uint16_t), // initiatorSessionId |
| sizeof(PasscodeId), // passcodeId, |
| sizeof(uint8_t), // hasPBKDFParameters |
| SessionParameters::kEstimatedTLVSize // Session Parameters |
| ); |
| |
| System::PacketBufferHandle req = System::PacketBufferHandle::New(max_msg_len); |
| VerifyOrReturnError(!req.IsNull(), CHIP_ERROR_NO_MEMORY); |
| |
| System::PacketBufferTLVWriter tlvWriter; |
| tlvWriter.Init(std::move(req)); |
| |
| TLV::TLVType outerContainerType = TLV::kTLVType_NotSpecified; |
| ReturnErrorOnFailure(tlvWriter.StartContainer(TLV::AnonymousTag(), TLV::kTLVType_Structure, outerContainerType)); |
| ReturnErrorOnFailure(tlvWriter.PutBytes(TLV::ContextTag(1), mPBKDFLocalRandomData, sizeof(mPBKDFLocalRandomData))); |
| ReturnErrorOnFailure(tlvWriter.Put(TLV::ContextTag(2), GetLocalSessionId().Value())); |
| ReturnErrorOnFailure(tlvWriter.Put(TLV::ContextTag(3), kDefaultCommissioningPasscodeId)); |
| ReturnErrorOnFailure(tlvWriter.PutBoolean(TLV::ContextTag(4), mHavePBKDFParameters)); |
| |
| ReturnErrorOnFailure(EncodeSessionParameters(TLV::ContextTag(5), mLocalMRPConfig, tlvWriter)); |
| |
| ReturnErrorOnFailure(tlvWriter.EndContainer(outerContainerType)); |
| ReturnErrorOnFailure(tlvWriter.Finalize(&req)); |
| |
| // Update commissioning hash with the pbkdf2 param request that's being sent. |
| ReturnErrorOnFailure(mCommissioningHash.AddData(ByteSpan{ req->Start(), req->DataLength() })); |
| |
| ReturnErrorOnFailure(mExchangeCtxt.Value()->SendMessage(MsgType::PBKDFParamRequest, std::move(req), |
| SendFlags(SendMessageFlags::kExpectResponse))); |
| |
| mNextExpectedMsg.SetValue(MsgType::PBKDFParamResponse); |
| |
| ChipLogDetail(SecureChannel, "Sent PBKDF param request"); |
| |
| return CHIP_NO_ERROR; |
| } |
| |
| CHIP_ERROR PASESession::HandlePBKDFParamRequest(System::PacketBufferHandle && msg) |
| { |
| MATTER_TRACE_SCOPE("HandlePBKDFParamRequest", "PASESession"); |
| CHIP_ERROR err = CHIP_NO_ERROR; |
| |
| System::PacketBufferTLVReader tlvReader; |
| TLV::TLVType containerType = TLV::kTLVType_Structure; |
| |
| uint16_t initiatorSessionId; |
| uint8_t initiatorRandom[kPBKDFParamRandomNumberSize]; |
| |
| uint32_t decodeTagIdSeq = 0; |
| PasscodeId passcodeId = kDefaultCommissioningPasscodeId; |
| bool hasPBKDFParameters = false; |
| |
| ChipLogDetail(SecureChannel, "Received PBKDF param request"); |
| |
| SuccessOrExit(err = mCommissioningHash.AddData(ByteSpan{ msg->Start(), msg->DataLength() })); |
| |
| tlvReader.Init(std::move(msg)); |
| SuccessOrExit(err = tlvReader.Next(containerType, TLV::AnonymousTag())); |
| SuccessOrExit(err = tlvReader.EnterContainer(containerType)); |
| |
| SuccessOrExit(err = tlvReader.Next()); |
| VerifyOrExit(TLV::TagNumFromTag(tlvReader.GetTag()) == ++decodeTagIdSeq, err = CHIP_ERROR_INVALID_TLV_TAG); |
| SuccessOrExit(err = tlvReader.GetBytes(initiatorRandom, sizeof(initiatorRandom))); |
| |
| SuccessOrExit(err = tlvReader.Next()); |
| VerifyOrExit(TLV::TagNumFromTag(tlvReader.GetTag()) == ++decodeTagIdSeq, err = CHIP_ERROR_INVALID_TLV_TAG); |
| SuccessOrExit(err = tlvReader.Get(initiatorSessionId)); |
| |
| ChipLogDetail(SecureChannel, "Peer assigned session ID %d", initiatorSessionId); |
| SetPeerSessionId(initiatorSessionId); |
| |
| SuccessOrExit(err = tlvReader.Next()); |
| VerifyOrExit(TLV::TagNumFromTag(tlvReader.GetTag()) == ++decodeTagIdSeq, err = CHIP_ERROR_INVALID_TLV_TAG); |
| SuccessOrExit(err = tlvReader.Get(passcodeId)); |
| VerifyOrExit(passcodeId == kDefaultCommissioningPasscodeId, err = CHIP_ERROR_INVALID_PASE_PARAMETER); |
| |
| SuccessOrExit(err = tlvReader.Next()); |
| VerifyOrExit(TLV::TagNumFromTag(tlvReader.GetTag()) == ++decodeTagIdSeq, err = CHIP_ERROR_INVALID_TLV_TAG); |
| SuccessOrExit(err = tlvReader.Get(hasPBKDFParameters)); |
| |
| if (tlvReader.Next() != CHIP_END_OF_TLV) |
| { |
| SuccessOrExit(err = DecodeMRPParametersIfPresent(TLV::ContextTag(5), tlvReader)); |
| mExchangeCtxt.Value()->GetSessionHandle()->AsUnauthenticatedSession()->SetRemoteSessionParameters( |
| GetRemoteSessionParameters()); |
| } |
| |
| err = SendPBKDFParamResponse(ByteSpan(initiatorRandom), hasPBKDFParameters); |
| SuccessOrExit(err); |
| |
| mDelegate->OnSessionEstablishmentStarted(); |
| |
| exit: |
| |
| if (err != CHIP_NO_ERROR) |
| { |
| SendStatusReport(mExchangeCtxt, kProtocolCodeInvalidParam); |
| } |
| return err; |
| } |
| |
| CHIP_ERROR PASESession::SendPBKDFParamResponse(ByteSpan initiatorRandom, bool initiatorHasPBKDFParams) |
| { |
| MATTER_TRACE_SCOPE("SendPBKDFParamResponse", "PASESession"); |
| |
| VerifyOrReturnError(GetLocalSessionId().HasValue(), CHIP_ERROR_INCORRECT_STATE); |
| |
| ReturnErrorOnFailure(DRBG_get_bytes(mPBKDFLocalRandomData, sizeof(mPBKDFLocalRandomData))); |
| |
| const size_t max_msg_len = |
| TLV::EstimateStructOverhead(kPBKDFParamRandomNumberSize, // initiatorRandom |
| kPBKDFParamRandomNumberSize, // responderRandom |
| sizeof(uint16_t), // responderSessionId |
| TLV::EstimateStructOverhead(sizeof(uint32_t), mSaltLength), // pbkdf_parameters |
| SessionParameters::kEstimatedTLVSize // Session Parameters |
| ); |
| |
| System::PacketBufferHandle resp = System::PacketBufferHandle::New(max_msg_len); |
| VerifyOrReturnError(!resp.IsNull(), CHIP_ERROR_NO_MEMORY); |
| |
| System::PacketBufferTLVWriter tlvWriter; |
| tlvWriter.Init(std::move(resp)); |
| |
| TLV::TLVType outerContainerType = TLV::kTLVType_NotSpecified; |
| ReturnErrorOnFailure(tlvWriter.StartContainer(TLV::AnonymousTag(), TLV::kTLVType_Structure, outerContainerType)); |
| // The initiator random value is being sent back in the response as required by the specifications |
| ReturnErrorOnFailure(tlvWriter.Put(TLV::ContextTag(1), initiatorRandom)); |
| ReturnErrorOnFailure(tlvWriter.PutBytes(TLV::ContextTag(2), mPBKDFLocalRandomData, sizeof(mPBKDFLocalRandomData))); |
| ReturnErrorOnFailure(tlvWriter.Put(TLV::ContextTag(3), GetLocalSessionId().Value())); |
| |
| if (!initiatorHasPBKDFParams) |
| { |
| TLV::TLVType pbkdfParamContainer; |
| ReturnErrorOnFailure(tlvWriter.StartContainer(TLV::ContextTag(4), TLV::kTLVType_Structure, pbkdfParamContainer)); |
| ReturnErrorOnFailure(tlvWriter.Put(TLV::ContextTag(1), mIterationCount)); |
| ReturnErrorOnFailure(tlvWriter.PutBytes(TLV::ContextTag(2), mSalt, mSaltLength)); |
| ReturnErrorOnFailure(tlvWriter.EndContainer(pbkdfParamContainer)); |
| } |
| |
| ReturnErrorOnFailure(EncodeSessionParameters(TLV::ContextTag(5), mLocalMRPConfig, tlvWriter)); |
| |
| ReturnErrorOnFailure(tlvWriter.EndContainer(outerContainerType)); |
| ReturnErrorOnFailure(tlvWriter.Finalize(&resp)); |
| |
| // Update commissioning hash with the pbkdf2 param response that's being sent. |
| ReturnErrorOnFailure(mCommissioningHash.AddData(ByteSpan{ resp->Start(), resp->DataLength() })); |
| ReturnErrorOnFailure(SetupSpake2p()); |
| |
| ReturnErrorOnFailure(mExchangeCtxt.Value()->SendMessage(MsgType::PBKDFParamResponse, std::move(resp), |
| SendFlags(SendMessageFlags::kExpectResponse))); |
| ChipLogDetail(SecureChannel, "Sent PBKDF param response"); |
| |
| mNextExpectedMsg.SetValue(MsgType::PASE_Pake1); |
| |
| return CHIP_NO_ERROR; |
| } |
| |
| CHIP_ERROR PASESession::HandlePBKDFParamResponse(System::PacketBufferHandle && msg) |
| { |
| MATTER_TRACE_SCOPE("HandlePBKDFParamResponse", "PASESession"); |
| CHIP_ERROR err = CHIP_NO_ERROR; |
| |
| System::PacketBufferTLVReader tlvReader; |
| TLV::TLVType containerType = TLV::kTLVType_Structure; |
| |
| uint16_t responderSessionId; |
| uint8_t random[kPBKDFParamRandomNumberSize]; |
| |
| uint32_t decodeTagIdSeq = 0; |
| ByteSpan salt; |
| uint8_t serializedWS[kSpake2p_WS_Length * 2] = { 0 }; |
| |
| ChipLogDetail(SecureChannel, "Received PBKDF param response"); |
| |
| SuccessOrExit(err = mCommissioningHash.AddData(ByteSpan{ msg->Start(), msg->DataLength() })); |
| |
| tlvReader.Init(std::move(msg)); |
| SuccessOrExit(err = tlvReader.Next(containerType, TLV::AnonymousTag())); |
| SuccessOrExit(err = tlvReader.EnterContainer(containerType)); |
| |
| SuccessOrExit(err = tlvReader.Next()); |
| VerifyOrExit(TLV::TagNumFromTag(tlvReader.GetTag()) == ++decodeTagIdSeq, err = CHIP_ERROR_INVALID_TLV_TAG); |
| // Initiator's random value |
| SuccessOrExit(err = tlvReader.GetBytes(random, sizeof(random))); |
| VerifyOrExit(ByteSpan(random).data_equal(ByteSpan(mPBKDFLocalRandomData)), err = CHIP_ERROR_INVALID_PASE_PARAMETER); |
| |
| SuccessOrExit(err = tlvReader.Next()); |
| VerifyOrExit(TLV::TagNumFromTag(tlvReader.GetTag()) == ++decodeTagIdSeq, err = CHIP_ERROR_INVALID_TLV_TAG); |
| // Responder's random value |
| SuccessOrExit(err = tlvReader.GetBytes(random, sizeof(random))); |
| |
| SuccessOrExit(err = tlvReader.Next()); |
| VerifyOrExit(TLV::TagNumFromTag(tlvReader.GetTag()) == ++decodeTagIdSeq, err = CHIP_ERROR_INVALID_TLV_TAG); |
| SuccessOrExit(err = tlvReader.Get(responderSessionId)); |
| |
| ChipLogDetail(SecureChannel, "Peer assigned session ID %d", responderSessionId); |
| SetPeerSessionId(responderSessionId); |
| |
| if (mHavePBKDFParameters) |
| { |
| if (tlvReader.Next() != CHIP_END_OF_TLV) |
| { |
| SuccessOrExit(err = DecodeMRPParametersIfPresent(TLV::ContextTag(5), tlvReader)); |
| mExchangeCtxt.Value()->GetSessionHandle()->AsUnauthenticatedSession()->SetRemoteSessionParameters( |
| GetRemoteSessionParameters()); |
| } |
| |
| // TODO - Add a unit test that exercises mHavePBKDFParameters path |
| salt = ByteSpan(mSalt, mSaltLength); |
| } |
| else |
| { |
| SuccessOrExit(err = tlvReader.Next()); |
| SuccessOrExit(err = tlvReader.EnterContainer(containerType)); |
| decodeTagIdSeq = 0; |
| |
| SuccessOrExit(err = tlvReader.Next()); |
| VerifyOrExit(TLV::TagNumFromTag(tlvReader.GetTag()) == ++decodeTagIdSeq, err = CHIP_ERROR_INVALID_TLV_TAG); |
| SuccessOrExit(err = tlvReader.Get(mIterationCount)); |
| |
| SuccessOrExit(err = tlvReader.Next()); |
| VerifyOrExit(TLV::TagNumFromTag(tlvReader.GetTag()) == ++decodeTagIdSeq, err = CHIP_ERROR_INVALID_TLV_TAG); |
| SuccessOrExit(err = tlvReader.Get(salt)); |
| |
| SuccessOrExit(err = tlvReader.ExitContainer(containerType)); |
| |
| if (tlvReader.Next() != CHIP_END_OF_TLV) |
| { |
| SuccessOrExit(err = DecodeMRPParametersIfPresent(TLV::ContextTag(5), tlvReader)); |
| mExchangeCtxt.Value()->GetSessionHandle()->AsUnauthenticatedSession()->SetRemoteSessionParameters( |
| GetRemoteSessionParameters()); |
| } |
| } |
| |
| err = SetupSpake2p(); |
| SuccessOrExit(err); |
| |
| err = Spake2pVerifier::ComputeWS(mIterationCount, salt, mSetupPINCode, serializedWS, sizeof(serializedWS)); |
| SuccessOrExit(err); |
| |
| err = mSpake2p.BeginProver(nullptr, 0, nullptr, 0, &serializedWS[0], kSpake2p_WS_Length, &serializedWS[kSpake2p_WS_Length], |
| kSpake2p_WS_Length); |
| SuccessOrExit(err); |
| |
| err = SendMsg1(); |
| SuccessOrExit(err); |
| |
| exit: |
| if (err != CHIP_NO_ERROR) |
| { |
| SendStatusReport(mExchangeCtxt, kProtocolCodeInvalidParam); |
| } |
| return err; |
| } |
| |
| CHIP_ERROR PASESession::SendMsg1() |
| { |
| MATTER_TRACE_SCOPE("SendMsg1", "PASESession"); |
| const size_t max_msg_len = TLV::EstimateStructOverhead(kMAX_Point_Length); |
| System::PacketBufferHandle msg = System::PacketBufferHandle::New(max_msg_len); |
| VerifyOrReturnError(!msg.IsNull(), CHIP_ERROR_NO_MEMORY); |
| |
| System::PacketBufferTLVWriter tlvWriter; |
| tlvWriter.Init(std::move(msg)); |
| |
| TLV::TLVType outerContainerType = TLV::kTLVType_NotSpecified; |
| ReturnErrorOnFailure(tlvWriter.StartContainer(TLV::AnonymousTag(), TLV::kTLVType_Structure, outerContainerType)); |
| |
| uint8_t X[kMAX_Point_Length]; |
| size_t X_len = sizeof(X); |
| |
| constexpr uint8_t kPake1_pA = 1; |
| |
| ReturnErrorOnFailure(mSpake2p.ComputeRoundOne(nullptr, 0, X, &X_len)); |
| VerifyOrReturnError(X_len == sizeof(X), CHIP_ERROR_INTERNAL); |
| ReturnErrorOnFailure(tlvWriter.Put(TLV::ContextTag(kPake1_pA), ByteSpan(X))); |
| ReturnErrorOnFailure(tlvWriter.EndContainer(outerContainerType)); |
| ReturnErrorOnFailure(tlvWriter.Finalize(&msg)); |
| |
| ReturnErrorOnFailure( |
| mExchangeCtxt.Value()->SendMessage(MsgType::PASE_Pake1, std::move(msg), SendFlags(SendMessageFlags::kExpectResponse))); |
| ChipLogDetail(SecureChannel, "Sent spake2p msg1"); |
| |
| mNextExpectedMsg.SetValue(MsgType::PASE_Pake2); |
| |
| return CHIP_NO_ERROR; |
| } |
| |
| CHIP_ERROR PASESession::HandleMsg1_and_SendMsg2(System::PacketBufferHandle && msg1) |
| { |
| MATTER_TRACE_SCOPE("HandleMsg1_and_SendMsg2", "PASESession"); |
| CHIP_ERROR err = CHIP_NO_ERROR; |
| |
| uint8_t Y[kMAX_Point_Length]; |
| size_t Y_len = sizeof(Y); |
| |
| uint8_t verifier[kMAX_Hash_Length]; |
| size_t verifier_len = kMAX_Hash_Length; |
| |
| ChipLogDetail(SecureChannel, "Received spake2p msg1"); |
| MATTER_TRACE_SCOPE("Pake1", "PASESession"); |
| |
| System::PacketBufferTLVReader tlvReader; |
| TLV::TLVType containerType = TLV::kTLVType_Structure; |
| |
| const uint8_t * X; |
| size_t X_len = 0; |
| |
| tlvReader.Init(std::move(msg1)); |
| SuccessOrExit(err = tlvReader.Next(containerType, TLV::AnonymousTag())); |
| SuccessOrExit(err = tlvReader.EnterContainer(containerType)); |
| |
| SuccessOrExit(err = tlvReader.Next()); |
| VerifyOrExit(TLV::TagNumFromTag(tlvReader.GetTag()) == 1, err = CHIP_ERROR_INVALID_TLV_TAG); |
| X_len = tlvReader.GetLength(); |
| SuccessOrExit(err = tlvReader.GetDataPtr(X)); |
| SuccessOrExit(err = mSpake2p.BeginVerifier(nullptr, 0, nullptr, 0, mPASEVerifier.mW0, kP256_FE_Length, mPASEVerifier.mL, |
| kP256_Point_Length)); |
| |
| SuccessOrExit(err = mSpake2p.ComputeRoundOne(X, X_len, Y, &Y_len)); |
| VerifyOrReturnError(Y_len == sizeof(Y), CHIP_ERROR_INTERNAL); |
| SuccessOrExit(err = mSpake2p.ComputeRoundTwo(X, X_len, verifier, &verifier_len)); |
| msg1 = nullptr; |
| |
| { |
| const size_t max_msg_len = TLV::EstimateStructOverhead(Y_len, verifier_len); |
| constexpr uint8_t kPake2_pB = 1; |
| constexpr uint8_t kPake2_cB = 2; |
| |
| System::PacketBufferHandle msg2 = System::PacketBufferHandle::New(max_msg_len); |
| VerifyOrExit(!msg2.IsNull(), err = CHIP_ERROR_NO_MEMORY); |
| |
| System::PacketBufferTLVWriter tlvWriter; |
| tlvWriter.Init(std::move(msg2)); |
| |
| TLV::TLVType outerContainerType = TLV::kTLVType_NotSpecified; |
| SuccessOrExit(err = tlvWriter.StartContainer(TLV::AnonymousTag(), TLV::kTLVType_Structure, outerContainerType)); |
| SuccessOrExit(err = tlvWriter.Put(TLV::ContextTag(kPake2_pB), ByteSpan(Y))); |
| SuccessOrExit(err = tlvWriter.Put(TLV::ContextTag(kPake2_cB), ByteSpan(verifier, verifier_len))); |
| SuccessOrExit(err = tlvWriter.EndContainer(outerContainerType)); |
| SuccessOrExit(err = tlvWriter.Finalize(&msg2)); |
| |
| err = |
| mExchangeCtxt.Value()->SendMessage(MsgType::PASE_Pake2, std::move(msg2), SendFlags(SendMessageFlags::kExpectResponse)); |
| SuccessOrExit(err); |
| |
| mNextExpectedMsg.SetValue(MsgType::PASE_Pake3); |
| } |
| |
| ChipLogDetail(SecureChannel, "Sent spake2p msg2"); |
| MATTER_TRACE_COUNTER("Pake2"); |
| |
| exit: |
| |
| if (err != CHIP_NO_ERROR) |
| { |
| SendStatusReport(mExchangeCtxt, kProtocolCodeInvalidParam); |
| } |
| return err; |
| } |
| |
| CHIP_ERROR PASESession::HandleMsg2_and_SendMsg3(System::PacketBufferHandle && msg2) |
| { |
| MATTER_TRACE_SCOPE("HandleMsg2_and_SendMsg3", "PASESession"); |
| CHIP_ERROR err = CHIP_NO_ERROR; |
| |
| uint8_t verifier[kMAX_Hash_Length]; |
| size_t verifier_len = kMAX_Hash_Length; |
| |
| System::PacketBufferHandle resp; |
| |
| ChipLogDetail(SecureChannel, "Received spake2p msg2"); |
| |
| System::PacketBufferTLVReader tlvReader; |
| TLV::TLVType containerType = TLV::kTLVType_Structure; |
| |
| const uint8_t * Y; |
| size_t Y_len = 0; |
| |
| const uint8_t * peer_verifier; |
| size_t peer_verifier_len = 0; |
| |
| uint32_t decodeTagIdSeq = 0; |
| |
| tlvReader.Init(std::move(msg2)); |
| SuccessOrExit(err = tlvReader.Next(containerType, TLV::AnonymousTag())); |
| SuccessOrExit(err = tlvReader.EnterContainer(containerType)); |
| |
| SuccessOrExit(err = tlvReader.Next()); |
| VerifyOrExit(TLV::TagNumFromTag(tlvReader.GetTag()) == ++decodeTagIdSeq, err = CHIP_ERROR_INVALID_TLV_TAG); |
| Y_len = tlvReader.GetLength(); |
| SuccessOrExit(err = tlvReader.GetDataPtr(Y)); |
| |
| SuccessOrExit(err = tlvReader.Next()); |
| VerifyOrExit(TLV::TagNumFromTag(tlvReader.GetTag()) == ++decodeTagIdSeq, err = CHIP_ERROR_INVALID_TLV_TAG); |
| peer_verifier_len = tlvReader.GetLength(); |
| SuccessOrExit(err = tlvReader.GetDataPtr(peer_verifier)); |
| |
| SuccessOrExit(err = mSpake2p.ComputeRoundTwo(Y, Y_len, verifier, &verifier_len)); |
| |
| SuccessOrExit(err = mSpake2p.KeyConfirm(peer_verifier, peer_verifier_len)); |
| msg2 = nullptr; |
| |
| { |
| const size_t max_msg_len = TLV::EstimateStructOverhead(verifier_len); |
| constexpr uint8_t kPake3_cB = 1; |
| |
| System::PacketBufferHandle msg3 = System::PacketBufferHandle::New(max_msg_len); |
| VerifyOrExit(!msg3.IsNull(), err = CHIP_ERROR_NO_MEMORY); |
| |
| System::PacketBufferTLVWriter tlvWriter; |
| tlvWriter.Init(std::move(msg3)); |
| |
| TLV::TLVType outerContainerType = TLV::kTLVType_NotSpecified; |
| SuccessOrExit(err = tlvWriter.StartContainer(TLV::AnonymousTag(), TLV::kTLVType_Structure, outerContainerType)); |
| SuccessOrExit(err = tlvWriter.Put(TLV::ContextTag(kPake3_cB), ByteSpan(verifier, verifier_len))); |
| SuccessOrExit(err = tlvWriter.EndContainer(outerContainerType)); |
| SuccessOrExit(err = tlvWriter.Finalize(&msg3)); |
| |
| err = |
| mExchangeCtxt.Value()->SendMessage(MsgType::PASE_Pake3, std::move(msg3), SendFlags(SendMessageFlags::kExpectResponse)); |
| SuccessOrExit(err); |
| |
| mNextExpectedMsg.SetValue(MsgType::StatusReport); |
| } |
| ChipLogDetail(SecureChannel, "Sent spake2p msg3"); |
| |
| exit: |
| |
| if (err != CHIP_NO_ERROR) |
| { |
| SendStatusReport(mExchangeCtxt, kProtocolCodeInvalidParam); |
| } |
| return err; |
| } |
| |
| CHIP_ERROR PASESession::HandleMsg3(System::PacketBufferHandle && msg) |
| { |
| MATTER_TRACE_SCOPE("HandleMsg3", "PASESession"); |
| CHIP_ERROR err = CHIP_NO_ERROR; |
| |
| ChipLogDetail(SecureChannel, "Received spake2p msg3"); |
| MATTER_TRACE_COUNTER("Pake3"); |
| |
| mNextExpectedMsg.ClearValue(); |
| |
| System::PacketBufferTLVReader tlvReader; |
| TLV::TLVType containerType = TLV::kTLVType_Structure; |
| |
| const uint8_t * peer_verifier; |
| size_t peer_verifier_len = 0; |
| |
| tlvReader.Init(std::move(msg)); |
| SuccessOrExit(err = tlvReader.Next(containerType, TLV::AnonymousTag())); |
| SuccessOrExit(err = tlvReader.EnterContainer(containerType)); |
| |
| SuccessOrExit(err = tlvReader.Next()); |
| VerifyOrExit(TLV::TagNumFromTag(tlvReader.GetTag()) == 1, err = CHIP_ERROR_INVALID_TLV_TAG); |
| peer_verifier_len = tlvReader.GetLength(); |
| SuccessOrExit(err = tlvReader.GetDataPtr(peer_verifier)); |
| |
| VerifyOrExit(peer_verifier_len == kMAX_Hash_Length, err = CHIP_ERROR_INVALID_MESSAGE_LENGTH); |
| |
| SuccessOrExit(err = mSpake2p.KeyConfirm(peer_verifier, peer_verifier_len)); |
| |
| // Send confirmation to peer that we succeeded so they can start using the session. |
| SendStatusReport(mExchangeCtxt, kProtocolCodeSuccess); |
| |
| Finish(); |
| exit: |
| |
| if (err != CHIP_NO_ERROR) |
| { |
| SendStatusReport(mExchangeCtxt, kProtocolCodeInvalidParam); |
| } |
| return err; |
| } |
| |
| void PASESession::OnSuccessStatusReport() |
| { |
| Finish(); |
| } |
| |
| CHIP_ERROR PASESession::OnFailureStatusReport(Protocols::SecureChannel::GeneralStatusCode generalCode, uint16_t protocolCode, |
| Optional<uintptr_t> protocolData) |
| { |
| CHIP_ERROR err = CHIP_NO_ERROR; |
| switch (protocolCode) |
| { |
| case kProtocolCodeInvalidParam: |
| err = CHIP_ERROR_INVALID_PASE_PARAMETER; |
| break; |
| |
| default: |
| err = CHIP_ERROR_INTERNAL; |
| break; |
| }; |
| ChipLogError(SecureChannel, "Received error (protocol code %d) during PASE process: %" CHIP_ERROR_FORMAT, protocolCode, |
| err.Format()); |
| return err; |
| } |
| |
| CHIP_ERROR PASESession::ValidateReceivedMessage(ExchangeContext * exchange, const PayloadHeader & payloadHeader, |
| const System::PacketBufferHandle & msg) |
| { |
| VerifyOrReturnError(exchange != nullptr, CHIP_ERROR_INVALID_ARGUMENT); |
| |
| // mExchangeCtxt can be nullptr if this is the first message (PBKDFParamRequest) received by PASESession |
| // via UnsolicitedMessageHandler. The exchange context is allocated by exchange manager and provided |
| // to the handler (PASESession object). |
| if (mExchangeCtxt.HasValue()) |
| { |
| if (&mExchangeCtxt.Value().Get() != exchange) |
| { |
| ReturnErrorOnFailure(CHIP_ERROR_INVALID_ARGUMENT); |
| } |
| } |
| else |
| { |
| mExchangeCtxt.Emplace(*exchange); |
| } |
| |
| if (!mExchangeCtxt.Value()->GetSessionHandle()->IsUnauthenticatedSession()) |
| { |
| ChipLogError(SecureChannel, "PASESession received PBKDFParamRequest over encrypted session. Ignoring."); |
| return CHIP_ERROR_INCORRECT_STATE; |
| } |
| |
| mExchangeCtxt.Value()->UseSuggestedResponseTimeout(kExpectedHighProcessingTime); |
| |
| VerifyOrReturnError(!msg.IsNull(), CHIP_ERROR_INVALID_ARGUMENT); |
| VerifyOrReturnError((mNextExpectedMsg.HasValue() && payloadHeader.HasMessageType(mNextExpectedMsg.Value())) || |
| payloadHeader.HasMessageType(MsgType::StatusReport), |
| CHIP_ERROR_INVALID_MESSAGE_TYPE); |
| |
| return CHIP_NO_ERROR; |
| } |
| |
| CHIP_ERROR PASESession::OnUnsolicitedMessageReceived(const PayloadHeader & payloadHeader, ExchangeDelegate *& newDelegate) |
| { |
| // Handle messages by myself |
| newDelegate = this; |
| return CHIP_NO_ERROR; |
| } |
| |
| CHIP_ERROR PASESession::OnMessageReceived(ExchangeContext * exchange, const PayloadHeader & payloadHeader, |
| System::PacketBufferHandle && msg) |
| { |
| MATTER_TRACE_SCOPE("OnMessageReceived", "PASESession"); |
| CHIP_ERROR err = ValidateReceivedMessage(exchange, payloadHeader, msg); |
| MsgType msgType = static_cast<MsgType>(payloadHeader.GetMessageType()); |
| SuccessOrExit(err); |
| |
| #if CHIP_CONFIG_SLOW_CRYPTO |
| if (msgType == MsgType::PBKDFParamRequest || msgType == MsgType::PBKDFParamResponse || msgType == MsgType::PASE_Pake1 || |
| msgType == MsgType::PASE_Pake2 || msgType == MsgType::PASE_Pake3) |
| { |
| SuccessOrExit(err = mExchangeCtxt.Value()->FlushAcks()); |
| } |
| #endif // CHIP_CONFIG_SLOW_CRYPTO |
| |
| switch (msgType) |
| { |
| case MsgType::PBKDFParamRequest: |
| err = HandlePBKDFParamRequest(std::move(msg)); |
| break; |
| |
| case MsgType::PBKDFParamResponse: |
| err = HandlePBKDFParamResponse(std::move(msg)); |
| break; |
| |
| case MsgType::PASE_Pake1: |
| err = HandleMsg1_and_SendMsg2(std::move(msg)); |
| break; |
| |
| case MsgType::PASE_Pake2: |
| err = HandleMsg2_and_SendMsg3(std::move(msg)); |
| break; |
| |
| case MsgType::PASE_Pake3: |
| err = HandleMsg3(std::move(msg)); |
| break; |
| |
| case MsgType::StatusReport: |
| err = |
| HandleStatusReport(std::move(msg), mNextExpectedMsg.HasValue() && (mNextExpectedMsg.Value() == MsgType::StatusReport)); |
| break; |
| |
| default: |
| err = CHIP_ERROR_INVALID_MESSAGE_TYPE; |
| break; |
| }; |
| |
| exit: |
| |
| // Call delegate to indicate pairing failure |
| if (err != CHIP_NO_ERROR) |
| { |
| // Discard the exchange so that Clear() doesn't try closing it. The |
| // exchange will handle that. |
| DiscardExchange(); |
| Clear(); |
| ChipLogError(SecureChannel, "Failed during PASE session setup: %" CHIP_ERROR_FORMAT, err.Format()); |
| MATTER_TRACE_COUNTER("PASEFail"); |
| // Do this last in case the delegate frees us. |
| NotifySessionEstablishmentError(err); |
| } |
| return err; |
| } |
| |
| } // namespace chip |
