| /****************************************************************************** |
| * |
| * Copyright 2019 The Android Open Source Project |
| * |
| * 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. |
| * |
| ******************************************************************************/ |
| |
| #include "security/pairing_handler_le.h" |
| |
| namespace bluetooth { |
| namespace security { |
| |
| LegacyStage1ResultOrFailure PairingHandlerLe::DoLegacyStage1(const InitialInformations& i, |
| const PairingRequestView& pairing_request, |
| const PairingResponseView& pairing_response) { |
| if (((pairing_request.GetAuthReq() | pairing_response.GetAuthReq()) & AuthReqMaskMitm) == 0) { |
| // If both devices have not set MITM option, Just Works shall be used |
| return LegacyJustWorks(); |
| } |
| |
| if (pairing_request.GetOobDataFlag() == OobDataFlag::PRESENT && |
| pairing_response.GetOobDataFlag() == OobDataFlag::PRESENT) { |
| // OobDataFlag remote_oob_flag = IAmMaster(i) ? pairing_response.GetOobDataFlag() : |
| // pairing_request.GetOobDataFlag(); OobDataFlag my_oob_flag = IAmMaster(i) ? pairing_request.GetOobDataFlag() : |
| // pairing_response.GetOobDataFlag(); |
| return LegacyOutOfBand(i); |
| } |
| |
| const auto& iom = pairing_request.GetIoCapability(); |
| const auto& ios = pairing_response.GetIoCapability(); |
| |
| if (iom == IoCapability::NO_INPUT_NO_OUTPUT || ios == IoCapability::NO_INPUT_NO_OUTPUT) { |
| return LegacyJustWorks(); |
| } |
| |
| if ((iom == IoCapability::DISPLAY_ONLY || iom == IoCapability::DISPLAY_YES_NO) && |
| (ios == IoCapability::DISPLAY_ONLY || ios == IoCapability::DISPLAY_YES_NO)) { |
| return LegacyJustWorks(); |
| } |
| |
| // This if() should not be needed, these are only combinations left. |
| if (iom == IoCapability::KEYBOARD_DISPLAY || iom == IoCapability::KEYBOARD_ONLY || |
| ios == IoCapability::KEYBOARD_DISPLAY || ios == IoCapability::KEYBOARD_ONLY) { |
| IoCapability my_iocaps = IAmMaster(i) ? iom : ios; |
| IoCapability remote_iocaps = IAmMaster(i) ? ios : iom; |
| return LegacyPasskeyEntry(i, my_iocaps, remote_iocaps); |
| } |
| |
| // We went through all possble combinations. |
| LOG_ALWAYS_FATAL("This should never happen"); |
| } |
| |
| LegacyStage1ResultOrFailure PairingHandlerLe::LegacyJustWorks() { |
| LOG_INFO("Legacy Just Works start"); |
| return Octet16{0}; |
| } |
| |
| LegacyStage1ResultOrFailure PairingHandlerLe::LegacyPasskeyEntry(const InitialInformations& i, |
| const IoCapability& my_iocaps, |
| const IoCapability& remote_iocaps) { |
| bool i_am_displaying = false; |
| if (my_iocaps == IoCapability::DISPLAY_ONLY || my_iocaps == IoCapability::DISPLAY_YES_NO) { |
| i_am_displaying = true; |
| } else if (IAmMaster(i) && remote_iocaps == IoCapability::KEYBOARD_DISPLAY && |
| my_iocaps == IoCapability::KEYBOARD_DISPLAY) { |
| i_am_displaying = true; |
| } else if (my_iocaps == IoCapability::KEYBOARD_DISPLAY && remote_iocaps == IoCapability::KEYBOARD_ONLY) { |
| i_am_displaying = true; |
| } |
| |
| LOG_INFO("Passkey Entry start %s", i_am_displaying ? "displaying" : "accepting"); |
| |
| uint32_t passkey; |
| if (i_am_displaying) { |
| // generate passkey in a valid range |
| passkey = GenerateRandom(); |
| passkey &= 0x0fffff; /* maximum 20 significant bits */ |
| constexpr uint32_t PASSKEY_MAX = 999999; |
| if (passkey > PASSKEY_MAX) passkey >>= 1; |
| |
| i.ui_handler->DisplayConfirmValue(passkey); |
| } else { |
| i.ui_handler->DisplayEnterPasskeyDialog(); |
| std::optional<PairingEvent> response = WaitUiPasskey(); |
| if (!response) return PairingFailure("Passkey did not arrive!"); |
| |
| passkey = response->ui_value; |
| } |
| |
| Octet16 tk{0}; |
| tk[0] = (uint8_t)(passkey); |
| tk[1] = (uint8_t)(passkey >> 8); |
| tk[2] = (uint8_t)(passkey >> 16); |
| tk[3] = (uint8_t)(passkey >> 24); |
| |
| LOG_INFO("Passkey Entry finish"); |
| return tk; |
| } |
| |
| LegacyStage1ResultOrFailure PairingHandlerLe::LegacyOutOfBand(const InitialInformations& i) { |
| return i.remote_oob_data->security_manager_tk_value; |
| } |
| |
| StkOrFailure PairingHandlerLe::DoLegacyStage2(const InitialInformations& i, const PairingRequestView& pairing_request, |
| const PairingResponseView& pairing_response, const Octet16& tk) { |
| LOG_INFO("Legacy Step 2 start"); |
| std::vector<uint8_t> preq(pairing_request.begin(), pairing_request.end()); |
| std::vector<uint8_t> pres(pairing_response.begin(), pairing_response.end()); |
| |
| Octet16 mrand, srand; |
| if (IAmMaster(i)) { |
| mrand = GenerateRandom<16>(); |
| |
| // LOG(INFO) << +(IAmMaster(i)) << " tk = " << base::HexEncode(tk.data(), tk.size()); |
| // LOG(INFO) << +(IAmMaster(i)) << " mrand = " << base::HexEncode(mrand.data(), mrand.size()); |
| // LOG(INFO) << +(IAmMaster(i)) << " preq = " << base::HexEncode(preq.data(), preq.size()); |
| // LOG(INFO) << +(IAmMaster(i)) << " pres = " << base::HexEncode(pres.data(), pres.size()); |
| // LOG(INFO) << +(IAmMaster(i)) << " i.remote_connection_address_type = " << +i.remote_connection_address_type; |
| // LOG(INFO) << +(IAmMaster(i)) << " i.i.remote_connection_address.address = " << i.remote_connection_address; |
| // LOG(INFO) << +(IAmMaster(i)) << " i.my_connection_address_type = " << +i.my_connection_address_type; |
| // LOG(INFO) << +(IAmMaster(i)) << " i.i.my_connection_address.address = " << i.my_connection_address; |
| Octet16 mconfirm = crypto_toolbox::c1(tk, mrand, preq.data(), pres.data(), i.my_connection_address_type, |
| i.my_connection_address.address, i.remote_connection_address_type, |
| i.remote_connection_address.address); |
| |
| LOG_INFO("Master sends Mconfirm"); |
| SendL2capPacket(i, PairingConfirmBuilder::Create(mconfirm)); |
| |
| LOG_INFO("Master waits for the Sconfirm"); |
| auto sconfirm_pkt = WaitPairingConfirm(); |
| if (std::holds_alternative<PairingFailure>(sconfirm_pkt)) { |
| return std::get<PairingFailure>(sconfirm_pkt); |
| } |
| Octet16 sconfirm = std::get<PairingConfirmView>(sconfirm_pkt).GetConfirmValue(); |
| |
| LOG_INFO("Master sends Mrand"); |
| SendL2capPacket(i, PairingRandomBuilder::Create(mrand)); |
| |
| LOG_INFO("Master waits for Srand"); |
| auto random_pkt = WaitPairingRandom(); |
| if (std::holds_alternative<PairingFailure>(random_pkt)) { |
| return std::get<PairingFailure>(random_pkt); |
| } |
| srand = std::get<PairingRandomView>(random_pkt).GetRandomValue(); |
| |
| // LOG(INFO) << +(IAmMaster(i)) << " tk = " << base::HexEncode(tk.data(), tk.size()); |
| // LOG(INFO) << +(IAmMaster(i)) << " srand = " << base::HexEncode(srand.data(), srand.size()); |
| // LOG(INFO) << +(IAmMaster(i)) << " preq = " << base::HexEncode(preq.data(), preq.size()); |
| // LOG(INFO) << +(IAmMaster(i)) << " pres = " << base::HexEncode(pres.data(), pres.size()); |
| // LOG(INFO) << +(IAmMaster(i)) << " i.my_connection_address_type = " << +i.my_connection_address_type; |
| // LOG(INFO) << +(IAmMaster(i)) << " i.i.my_connection_address.address = " << i.my_connection_address; |
| // LOG(INFO) << +(IAmMaster(i)) << " i.remote_connection_address_type = " << +i.remote_connection_address_type; |
| // LOG(INFO) << +(IAmMaster(i)) << " i.i.remote_connection_address.address = " << i.remote_connection_address; |
| Octet16 sconfirm_generated = crypto_toolbox::c1(tk, srand, preq.data(), pres.data(), i.my_connection_address_type, |
| i.my_connection_address.address, i.remote_connection_address_type, |
| i.remote_connection_address.address); |
| |
| if (sconfirm != sconfirm_generated) { |
| LOG_INFO("sconfirm does not match generated value"); |
| |
| SendL2capPacket(i, PairingFailedBuilder::Create(PairingFailedReason::CONFIRM_VALUE_FAILED)); |
| return PairingFailure("sconfirm does not match generated value"); |
| } |
| } else { |
| srand = GenerateRandom<16>(); |
| |
| std::vector<uint8_t> preq(pairing_request.begin(), pairing_request.end()); |
| std::vector<uint8_t> pres(pairing_response.begin(), pairing_response.end()); |
| |
| Octet16 sconfirm = crypto_toolbox::c1(tk, srand, preq.data(), pres.data(), i.remote_connection_address_type, |
| i.remote_connection_address.address, i.my_connection_address_type, |
| i.my_connection_address.address); |
| |
| LOG_INFO("Slave waits for the Mconfirm"); |
| auto mconfirm_pkt = WaitPairingConfirm(); |
| if (std::holds_alternative<PairingFailure>(mconfirm_pkt)) { |
| return std::get<PairingFailure>(mconfirm_pkt); |
| } |
| Octet16 mconfirm = std::get<PairingConfirmView>(mconfirm_pkt).GetConfirmValue(); |
| |
| LOG_INFO("Slave sends Sconfirm"); |
| SendL2capPacket(i, PairingConfirmBuilder::Create(sconfirm)); |
| |
| LOG_INFO("Slave waits for Mrand"); |
| auto random_pkt = WaitPairingRandom(); |
| if (std::holds_alternative<PairingFailure>(random_pkt)) { |
| return std::get<PairingFailure>(random_pkt); |
| } |
| mrand = std::get<PairingRandomView>(random_pkt).GetRandomValue(); |
| |
| // LOG(INFO) << +(IAmMaster(i)) << " tk = " << base::HexEncode(tk.data(), tk.size()); |
| // LOG(INFO) << +(IAmMaster(i)) << " mrand = " << base::HexEncode(mrand.data(), mrand.size()); |
| // LOG(INFO) << +(IAmMaster(i)) << " preq = " << base::HexEncode(preq.data(), preq.size()); |
| // LOG(INFO) << +(IAmMaster(i)) << " pres = " << base::HexEncode(pres.data(), pres.size()); |
| // LOG(INFO) << +(IAmMaster(i)) << " i.my_connection_address_type = " << +i.my_connection_address_type; |
| // LOG(INFO) << +(IAmMaster(i)) << " i.i.my_connection_address.address = " << i.my_connection_address; |
| // LOG(INFO) << +(IAmMaster(i)) << " i.remote_connection_address_type = " << +i.remote_connection_address_type; |
| // LOG(INFO) << +(IAmMaster(i)) << " i.i.remote_connection_address.address = " << i.remote_connection_address; |
| Octet16 mconfirm_generated = crypto_toolbox::c1( |
| tk, mrand, preq.data(), pres.data(), i.remote_connection_address_type, i.remote_connection_address.address, |
| i.my_connection_address_type, i.my_connection_address.address); |
| |
| if (mconfirm != mconfirm_generated) { |
| LOG_INFO("mconfirm does not match generated value"); |
| SendL2capPacket(i, PairingFailedBuilder::Create(PairingFailedReason::CONFIRM_VALUE_FAILED)); |
| return PairingFailure("mconfirm does not match generated value"); |
| } |
| |
| LOG_INFO("Slave sends Srand"); |
| SendL2capPacket(i, PairingRandomBuilder::Create(srand)); |
| } |
| |
| LOG_INFO("Legacy stage 2 finish"); |
| |
| /* STK */ |
| return crypto_toolbox::s1(tk, srand, mrand); |
| } |
| } // namespace security |
| } // namespace bluetooth |