Jakub Pawlowski | 72c8dcc | 2019-09-06 16:33:21 +0200 | [diff] [blame] | 1 | /****************************************************************************** |
| 2 | * |
| 3 | * Copyright 2019 The Android Open Source Project |
| 4 | * |
| 5 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 6 | * you may not use this file except in compliance with the License. |
| 7 | * You may obtain a copy of the License at: |
| 8 | * |
| 9 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 10 | * |
| 11 | * Unless required by applicable law or agreed to in writing, software |
| 12 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 13 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 14 | * See the License for the specific language governing permissions and |
| 15 | * limitations under the License. |
| 16 | * |
| 17 | ******************************************************************************/ |
| 18 | |
Jakub Pawlowski | e79714e | 2019-10-14 14:49:55 +0200 | [diff] [blame] | 19 | #include "security/pairing_handler_le.h" |
Jakub Pawlowski | 72c8dcc | 2019-09-06 16:33:21 +0200 | [diff] [blame] | 20 | |
| 21 | namespace bluetooth { |
Jakub Pawlowski | e79714e | 2019-10-14 14:49:55 +0200 | [diff] [blame] | 22 | namespace security { |
Jakub Pawlowski | 72c8dcc | 2019-09-06 16:33:21 +0200 | [diff] [blame] | 23 | |
| 24 | LegacyStage1ResultOrFailure PairingHandlerLe::DoLegacyStage1(const InitialInformations& i, |
| 25 | const PairingRequestView& pairing_request, |
| 26 | const PairingResponseView& pairing_response) { |
| 27 | if (((pairing_request.GetAuthReq() | pairing_response.GetAuthReq()) & AuthReqMaskMitm) == 0) { |
| 28 | // If both devices have not set MITM option, Just Works shall be used |
| 29 | return LegacyJustWorks(); |
| 30 | } |
| 31 | |
| 32 | if (pairing_request.GetOobDataFlag() == OobDataFlag::PRESENT && |
| 33 | pairing_response.GetOobDataFlag() == OobDataFlag::PRESENT) { |
| 34 | // OobDataFlag remote_oob_flag = IAmMaster(i) ? pairing_response.GetOobDataFlag() : |
| 35 | // pairing_request.GetOobDataFlag(); OobDataFlag my_oob_flag = IAmMaster(i) ? pairing_request.GetOobDataFlag() : |
| 36 | // pairing_response.GetOobDataFlag(); |
| 37 | return LegacyOutOfBand(i); |
| 38 | } |
| 39 | |
| 40 | const auto& iom = pairing_request.GetIoCapability(); |
| 41 | const auto& ios = pairing_response.GetIoCapability(); |
| 42 | |
| 43 | if (iom == IoCapability::NO_INPUT_NO_OUTPUT || ios == IoCapability::NO_INPUT_NO_OUTPUT) { |
| 44 | return LegacyJustWorks(); |
| 45 | } |
| 46 | |
| 47 | if ((iom == IoCapability::DISPLAY_ONLY || iom == IoCapability::DISPLAY_YES_NO) && |
| 48 | (ios == IoCapability::DISPLAY_ONLY || ios == IoCapability::DISPLAY_YES_NO)) { |
| 49 | return LegacyJustWorks(); |
| 50 | } |
| 51 | |
| 52 | // This if() should not be needed, these are only combinations left. |
| 53 | if (iom == IoCapability::KEYBOARD_DISPLAY || iom == IoCapability::KEYBOARD_ONLY || |
| 54 | ios == IoCapability::KEYBOARD_DISPLAY || ios == IoCapability::KEYBOARD_ONLY) { |
| 55 | IoCapability my_iocaps = IAmMaster(i) ? iom : ios; |
| 56 | IoCapability remote_iocaps = IAmMaster(i) ? ios : iom; |
| 57 | return LegacyPasskeyEntry(i, my_iocaps, remote_iocaps); |
| 58 | } |
| 59 | |
| 60 | // We went through all possble combinations. |
| 61 | LOG_ALWAYS_FATAL("This should never happen"); |
| 62 | } |
| 63 | |
| 64 | LegacyStage1ResultOrFailure PairingHandlerLe::LegacyJustWorks() { |
| 65 | LOG_INFO("Legacy Just Works start"); |
| 66 | return Octet16{0}; |
| 67 | } |
| 68 | |
| 69 | LegacyStage1ResultOrFailure PairingHandlerLe::LegacyPasskeyEntry(const InitialInformations& i, |
| 70 | const IoCapability& my_iocaps, |
| 71 | const IoCapability& remote_iocaps) { |
| 72 | bool i_am_displaying = false; |
| 73 | if (my_iocaps == IoCapability::DISPLAY_ONLY || my_iocaps == IoCapability::DISPLAY_YES_NO) { |
| 74 | i_am_displaying = true; |
| 75 | } else if (IAmMaster(i) && remote_iocaps == IoCapability::KEYBOARD_DISPLAY && |
| 76 | my_iocaps == IoCapability::KEYBOARD_DISPLAY) { |
| 77 | i_am_displaying = true; |
| 78 | } else if (my_iocaps == IoCapability::KEYBOARD_DISPLAY && remote_iocaps == IoCapability::KEYBOARD_ONLY) { |
| 79 | i_am_displaying = true; |
| 80 | } |
| 81 | |
| 82 | LOG_INFO("Passkey Entry start %s", i_am_displaying ? "displaying" : "accepting"); |
| 83 | |
| 84 | uint32_t passkey; |
| 85 | if (i_am_displaying) { |
| 86 | // generate passkey in a valid range |
| 87 | passkey = GenerateRandom(); |
| 88 | passkey &= 0x0fffff; /* maximum 20 significant bits */ |
| 89 | constexpr uint32_t PASSKEY_MAX = 999999; |
| 90 | if (passkey > PASSKEY_MAX) passkey >>= 1; |
| 91 | |
| 92 | i.ui_handler->DisplayConfirmValue(passkey); |
| 93 | } else { |
| 94 | i.ui_handler->DisplayEnterPasskeyDialog(); |
| 95 | std::optional<PairingEvent> response = WaitUiPasskey(); |
| 96 | if (!response) return PairingFailure("Passkey did not arrive!"); |
| 97 | |
| 98 | passkey = response->ui_value; |
| 99 | } |
| 100 | |
| 101 | Octet16 tk{0}; |
| 102 | tk[0] = (uint8_t)(passkey); |
| 103 | tk[1] = (uint8_t)(passkey >> 8); |
| 104 | tk[2] = (uint8_t)(passkey >> 16); |
| 105 | tk[3] = (uint8_t)(passkey >> 24); |
| 106 | |
| 107 | LOG_INFO("Passkey Entry finish"); |
| 108 | return tk; |
| 109 | } |
| 110 | |
| 111 | LegacyStage1ResultOrFailure PairingHandlerLe::LegacyOutOfBand(const InitialInformations& i) { |
| 112 | return i.remote_oob_data->security_manager_tk_value; |
| 113 | } |
| 114 | |
| 115 | StkOrFailure PairingHandlerLe::DoLegacyStage2(const InitialInformations& i, const PairingRequestView& pairing_request, |
| 116 | const PairingResponseView& pairing_response, const Octet16& tk) { |
| 117 | LOG_INFO("Legacy Step 2 start"); |
| 118 | std::vector<uint8_t> preq(pairing_request.begin(), pairing_request.end()); |
| 119 | std::vector<uint8_t> pres(pairing_response.begin(), pairing_response.end()); |
| 120 | |
| 121 | Octet16 mrand, srand; |
| 122 | if (IAmMaster(i)) { |
| 123 | mrand = GenerateRandom<16>(); |
| 124 | |
| 125 | // LOG(INFO) << +(IAmMaster(i)) << " tk = " << base::HexEncode(tk.data(), tk.size()); |
| 126 | // LOG(INFO) << +(IAmMaster(i)) << " mrand = " << base::HexEncode(mrand.data(), mrand.size()); |
| 127 | // LOG(INFO) << +(IAmMaster(i)) << " preq = " << base::HexEncode(preq.data(), preq.size()); |
| 128 | // LOG(INFO) << +(IAmMaster(i)) << " pres = " << base::HexEncode(pres.data(), pres.size()); |
| 129 | // LOG(INFO) << +(IAmMaster(i)) << " i.remote_connection_address_type = " << +i.remote_connection_address_type; |
| 130 | // LOG(INFO) << +(IAmMaster(i)) << " i.i.remote_connection_address.address = " << i.remote_connection_address; |
| 131 | // LOG(INFO) << +(IAmMaster(i)) << " i.my_connection_address_type = " << +i.my_connection_address_type; |
| 132 | // LOG(INFO) << +(IAmMaster(i)) << " i.i.my_connection_address.address = " << i.my_connection_address; |
Jakub Pawlowski | a1f13fc | 2019-10-24 20:12:35 +0200 | [diff] [blame] | 133 | Octet16 mconfirm = crypto_toolbox::c1( |
| 134 | tk, mrand, preq.data(), pres.data(), (uint8_t)i.my_connection_address.GetAddressType(), |
| 135 | i.my_connection_address.GetAddress().address, (uint8_t)i.remote_connection_address.GetAddressType(), |
| 136 | i.remote_connection_address.GetAddress().address); |
Jakub Pawlowski | 72c8dcc | 2019-09-06 16:33:21 +0200 | [diff] [blame] | 137 | |
| 138 | LOG_INFO("Master sends Mconfirm"); |
| 139 | SendL2capPacket(i, PairingConfirmBuilder::Create(mconfirm)); |
| 140 | |
| 141 | LOG_INFO("Master waits for the Sconfirm"); |
| 142 | auto sconfirm_pkt = WaitPairingConfirm(); |
| 143 | if (std::holds_alternative<PairingFailure>(sconfirm_pkt)) { |
| 144 | return std::get<PairingFailure>(sconfirm_pkt); |
| 145 | } |
| 146 | Octet16 sconfirm = std::get<PairingConfirmView>(sconfirm_pkt).GetConfirmValue(); |
| 147 | |
| 148 | LOG_INFO("Master sends Mrand"); |
| 149 | SendL2capPacket(i, PairingRandomBuilder::Create(mrand)); |
| 150 | |
| 151 | LOG_INFO("Master waits for Srand"); |
| 152 | auto random_pkt = WaitPairingRandom(); |
| 153 | if (std::holds_alternative<PairingFailure>(random_pkt)) { |
| 154 | return std::get<PairingFailure>(random_pkt); |
| 155 | } |
| 156 | srand = std::get<PairingRandomView>(random_pkt).GetRandomValue(); |
| 157 | |
| 158 | // LOG(INFO) << +(IAmMaster(i)) << " tk = " << base::HexEncode(tk.data(), tk.size()); |
| 159 | // LOG(INFO) << +(IAmMaster(i)) << " srand = " << base::HexEncode(srand.data(), srand.size()); |
| 160 | // LOG(INFO) << +(IAmMaster(i)) << " preq = " << base::HexEncode(preq.data(), preq.size()); |
| 161 | // LOG(INFO) << +(IAmMaster(i)) << " pres = " << base::HexEncode(pres.data(), pres.size()); |
| 162 | // LOG(INFO) << +(IAmMaster(i)) << " i.my_connection_address_type = " << +i.my_connection_address_type; |
| 163 | // LOG(INFO) << +(IAmMaster(i)) << " i.i.my_connection_address.address = " << i.my_connection_address; |
| 164 | // LOG(INFO) << +(IAmMaster(i)) << " i.remote_connection_address_type = " << +i.remote_connection_address_type; |
| 165 | // LOG(INFO) << +(IAmMaster(i)) << " i.i.remote_connection_address.address = " << i.remote_connection_address; |
Jakub Pawlowski | a1f13fc | 2019-10-24 20:12:35 +0200 | [diff] [blame] | 166 | Octet16 sconfirm_generated = crypto_toolbox::c1( |
| 167 | tk, srand, preq.data(), pres.data(), (uint8_t)i.my_connection_address.GetAddressType(), |
| 168 | i.my_connection_address.GetAddress().address, (uint8_t)i.remote_connection_address.GetAddressType(), |
| 169 | i.remote_connection_address.GetAddress().address); |
Jakub Pawlowski | 72c8dcc | 2019-09-06 16:33:21 +0200 | [diff] [blame] | 170 | |
| 171 | if (sconfirm != sconfirm_generated) { |
| 172 | LOG_INFO("sconfirm does not match generated value"); |
| 173 | |
| 174 | SendL2capPacket(i, PairingFailedBuilder::Create(PairingFailedReason::CONFIRM_VALUE_FAILED)); |
| 175 | return PairingFailure("sconfirm does not match generated value"); |
| 176 | } |
| 177 | } else { |
| 178 | srand = GenerateRandom<16>(); |
| 179 | |
| 180 | std::vector<uint8_t> preq(pairing_request.begin(), pairing_request.end()); |
| 181 | std::vector<uint8_t> pres(pairing_response.begin(), pairing_response.end()); |
| 182 | |
Jakub Pawlowski | a1f13fc | 2019-10-24 20:12:35 +0200 | [diff] [blame] | 183 | Octet16 sconfirm = crypto_toolbox::c1( |
| 184 | tk, srand, preq.data(), pres.data(), (uint8_t)i.remote_connection_address.GetAddressType(), |
| 185 | i.remote_connection_address.GetAddress().address, (uint8_t)i.my_connection_address.GetAddressType(), |
| 186 | i.my_connection_address.GetAddress().address); |
Jakub Pawlowski | 72c8dcc | 2019-09-06 16:33:21 +0200 | [diff] [blame] | 187 | |
| 188 | LOG_INFO("Slave waits for the Mconfirm"); |
| 189 | auto mconfirm_pkt = WaitPairingConfirm(); |
| 190 | if (std::holds_alternative<PairingFailure>(mconfirm_pkt)) { |
| 191 | return std::get<PairingFailure>(mconfirm_pkt); |
| 192 | } |
| 193 | Octet16 mconfirm = std::get<PairingConfirmView>(mconfirm_pkt).GetConfirmValue(); |
| 194 | |
| 195 | LOG_INFO("Slave sends Sconfirm"); |
| 196 | SendL2capPacket(i, PairingConfirmBuilder::Create(sconfirm)); |
| 197 | |
| 198 | LOG_INFO("Slave waits for Mrand"); |
| 199 | auto random_pkt = WaitPairingRandom(); |
| 200 | if (std::holds_alternative<PairingFailure>(random_pkt)) { |
| 201 | return std::get<PairingFailure>(random_pkt); |
| 202 | } |
| 203 | mrand = std::get<PairingRandomView>(random_pkt).GetRandomValue(); |
| 204 | |
| 205 | // LOG(INFO) << +(IAmMaster(i)) << " tk = " << base::HexEncode(tk.data(), tk.size()); |
| 206 | // LOG(INFO) << +(IAmMaster(i)) << " mrand = " << base::HexEncode(mrand.data(), mrand.size()); |
| 207 | // LOG(INFO) << +(IAmMaster(i)) << " preq = " << base::HexEncode(preq.data(), preq.size()); |
| 208 | // LOG(INFO) << +(IAmMaster(i)) << " pres = " << base::HexEncode(pres.data(), pres.size()); |
| 209 | // LOG(INFO) << +(IAmMaster(i)) << " i.my_connection_address_type = " << +i.my_connection_address_type; |
| 210 | // LOG(INFO) << +(IAmMaster(i)) << " i.i.my_connection_address.address = " << i.my_connection_address; |
| 211 | // LOG(INFO) << +(IAmMaster(i)) << " i.remote_connection_address_type = " << +i.remote_connection_address_type; |
| 212 | // LOG(INFO) << +(IAmMaster(i)) << " i.i.remote_connection_address.address = " << i.remote_connection_address; |
| 213 | Octet16 mconfirm_generated = crypto_toolbox::c1( |
Jakub Pawlowski | a1f13fc | 2019-10-24 20:12:35 +0200 | [diff] [blame] | 214 | tk, mrand, preq.data(), pres.data(), (uint8_t)i.remote_connection_address.GetAddressType(), |
| 215 | i.remote_connection_address.GetAddress().address, (uint8_t)i.my_connection_address.GetAddressType(), |
| 216 | i.my_connection_address.GetAddress().address); |
Jakub Pawlowski | 72c8dcc | 2019-09-06 16:33:21 +0200 | [diff] [blame] | 217 | |
| 218 | if (mconfirm != mconfirm_generated) { |
| 219 | LOG_INFO("mconfirm does not match generated value"); |
| 220 | SendL2capPacket(i, PairingFailedBuilder::Create(PairingFailedReason::CONFIRM_VALUE_FAILED)); |
| 221 | return PairingFailure("mconfirm does not match generated value"); |
| 222 | } |
| 223 | |
| 224 | LOG_INFO("Slave sends Srand"); |
| 225 | SendL2capPacket(i, PairingRandomBuilder::Create(srand)); |
| 226 | } |
| 227 | |
| 228 | LOG_INFO("Legacy stage 2 finish"); |
| 229 | |
| 230 | /* STK */ |
| 231 | return crypto_toolbox::s1(tk, srand, mrand); |
| 232 | } |
Jakub Pawlowski | e79714e | 2019-10-14 14:49:55 +0200 | [diff] [blame] | 233 | } // namespace security |
Jakub Pawlowski | 72c8dcc | 2019-09-06 16:33:21 +0200 | [diff] [blame] | 234 | } // namespace bluetooth |