/* * Author: Sven Gothel * Copyright (c) 2021 Gothel Software e.K. * * Permission is hereby granted, free of charge, to any person obtaining * a copy of this software and associated documentation files (the * "Software"), to deal in the Software without restriction, including * without limitation the rights to use, copy, modify, merge, publish, * distribute, sublicense, and/or sell copies of the Software, and to * permit persons to whom the Software is furnished to do so, subject to * the following conditions: * * The above copyright notice and this permission notice shall be * included in all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */ #ifndef SMPKEYBIN_HPP_ #define SMPKEYBIN_HPP_ #include #include #include #include #include #include #include "SMPTypes.hpp" #include "HCITypes.hpp" namespace direct_bt { class BTDevice; // forward class BTAdapter; // forward /** * Storage for SMP keys including required connection parameter per local adapter and remote device. * * File format version 5. * * Storage for a device's BDAddressAndType, its security connection setup ::BTSecurityLevel + ::SMPIOCapability * and optionally the initiator and responder SMPLongTermKeyInfo (LTK), SMPSignatureResolvingKeyInfo (CSRK) * and SMPLinkKeyInfo (LK) within one file. *

* Since the SMPLongTermKeyInfo (LTK), SMPSignatureResolvingKeyInfo (CSRK) * and SMPLinkKeyInfo (LK) * are optionally set depending on their availability per initiator and responder, * implementation supports mixed mode for certain devices. * E.g. LTK responder key only etc. *

*

* Data is stored in endian::little format, native to Bluetooth. *

*

* Filename as retrieved by SMPKeyBin::getFileBasename() * has the following form `bd_010203040506_C026DA01DAB11.key`: *

    *
  • {@code 'bd_'} prefix
    • *
  • {@code '010203040506'} local {@link EUI48} local adapter address
    • *
  • {@code '_'} separator
    • *
  • {@code 'C026DA01DAB1'} remote {@link EUI48} remote device address
    • *
  • {@code '1'} {@link BDAddressType}
    • *
  • {@code '.key'} suffix
    • * *

    * @see BTDevice::setSMPKeyBin() * @see BTDevice::uploadKeys() */ class SMPKeyBin { public: constexpr static const uint16_t VERSION = (uint16_t)0b0101010101010101U + (uint16_t)5U; // bitpattern + version private: uint16_t version; // 2 uint16_t size; // 2 uint64_t ts_creation_sec; // 8 BDAddressAndType localAddress; // 7 BDAddressAndType remoteAddress; // 7 BTSecurityLevel sec_level; // 1 SMPIOCapability io_cap; // 1 SMPKeyType keys_init; // 1 SMPKeyType keys_resp; // 1 SMPLongTermKey ltk_init; // 28 (optional) SMPIdentityResolvingKey irk_init; // 17 (optional) SMPSignatureResolvingKey csrk_init; // 17 (optional) SMPLinkKey lk_init; // 19 (optional) SMPLongTermKey ltk_resp; // 28 (optional) SMPIdentityResolvingKey irk_resp; // 17 (optional) SMPSignatureResolvingKey csrk_resp; // 17 (optional) SMPLinkKey lk_resp; // 19 (optional) // Min-Max: 30 - 190 bytes bool verbose; constexpr uint16_t calcSize() const { uint16_t s = 0; s += sizeof(version); s += sizeof(size); s += sizeof(ts_creation_sec); s += sizeof(localAddress.address); s += sizeof(localAddress.type); s += sizeof(remoteAddress.address); s += sizeof(remoteAddress.type); s += sizeof(sec_level); s += sizeof(io_cap); s += sizeof(keys_init); s += sizeof(keys_resp); if( hasLTKInit() ) { s += sizeof(ltk_init); } if( hasIRKInit() ) { s += sizeof(irk_init); } if( hasCSRKInit() ) { s += sizeof(csrk_init); } if( hasLKInit() ) { s += sizeof(lk_init); } if( hasLTKResp() ) { s += sizeof(ltk_resp); } if( hasIRKResp() ) { s += sizeof(irk_resp); } if( hasCSRKResp() ) { s += sizeof(csrk_resp); } if( hasLKResp() ) { s += sizeof(lk_resp); } return s; } static bool remove_impl(const std::string& fname); public: /** * Create a new SMPKeyBin instance based upon given BTDevice's * BTSecurityLevel, SMPPairingState, PairingMode and LTK keys. * * Returned SMPKeyBin shall be tested if valid via SMPKeyBin::isValid(), * whether the retrieved data from BTDevice is consistent and hence * having BTDevice is a well connected state. * * @param device the BTDevice from which all required data is derived * @return a valid SMPKeyBin instance if properly connected, otherwise an invalid instance. * @see BTDevice * @see isValid() */ static SMPKeyBin create(const BTDevice& device); /** * Create a new SMPKeyBin instance on the fly based upon given BTDevice's * BTSecurityLevel, SMPPairingState, PairingMode and LTK keys. * If valid, instance is stored to a file denoted by `path` and `BTDevice::getAddressAndType()`. * * If BTDevice::getPairingMode() is PairingMode::PRE_PAIRED, an existing file will not be overwritten. * Otherwise, a new key is assumed and an existing file shall be overwritten. * * Method returns `false` if resulting SMPKeyBin is not SMPKeyBin::isValid(). * Otherwise, method returns the SMPKeyBin::write() result. * * @param device the BTDevice from which all required data is derived * @param path the path for the stored SMPKeyBin file. * @param verbose_ set to true to have detailed write processing logged to stderr, otherwise false * @return `true` if file has been successfully written, otherwise `false`. * @see BTDevice * @see Create() * @see write() * @see isValid() */ static bool createAndWrite(const BTDevice& device, const std::string& path, const bool verbose_); /** * Create a new SMPKeyBin instance based upon stored file denoted by `fname`. * * Returned SMPKeyBin shall be tested if valid via SMPKeyBin::isValid(), * whether the read() operation was successful and data is consistent. * * If file is invalid, it is removed. * * @param fname full path of the stored SMPKeyBin file. * @param verbose_ set to true to have detailed read processing logged to stderr, otherwise false * @return valid SMPKeyBin instance if file exist and read successfully, otherwise invalid SMPKeyBin instance. * @see isValid() * @see read() */ static SMPKeyBin read(const std::string& fname, const bool verbose_) { SMPKeyBin smpKeyBin; smpKeyBin.setVerbose( verbose_ ); smpKeyBin.read( fname ); // read failure -> !isValid() return smpKeyBin; } /** * Create a new SMPKeyBin instance based upon the given BTDevice's matching filename, * see SMPKeyBin API doc for filename naming scheme. * * Returned SMPKeyBin shall be tested if valid via SMPKeyBin::isValid(), * whether the read() operation was successful and data is consistent. * * If file is invalid, it is removed. * * @param path directory for the stored SMPKeyBin file. * @param device BTDevice used to derive the filename, see getFilename() * @param verbose_ set to true to have detailed read processing logged to stderr, otherwise false * @return valid SMPKeyBin instance if file exist and read successfully, otherwise invalid SMPKeyBin instance. * @see getFilename() * @see isValid() * @see read() */ static SMPKeyBin read(const std::string& path, const BTDevice& device, const bool verbose_) { return read(getFilename(path, device), verbose_); } static std::vector readAll(const std::string& dname, const bool verbose_); static std::vector readAllForLocalAdapter(const BDAddressAndType& localAddress, const std::string& dname, const bool verbose_); SMPKeyBin(const BDAddressAndType& localAddress_, const BDAddressAndType& remoteAddress_, const BTSecurityLevel sec_level_, const SMPIOCapability io_cap_) : version(VERSION), size(0), ts_creation_sec( jau::getWallClockSeconds() ), localAddress(localAddress_), remoteAddress(remoteAddress_), sec_level(sec_level_), io_cap(io_cap_), keys_init(SMPKeyType::NONE), keys_resp(SMPKeyType::NONE), ltk_init(), irk_init(), csrk_init(), lk_init(), ltk_resp(), irk_resp(), csrk_resp(), lk_resp(), verbose(false) { size = calcSize(); } SMPKeyBin() : version(VERSION), size(0), ts_creation_sec(0), localAddress(), remoteAddress(), sec_level(BTSecurityLevel::UNSET), io_cap(SMPIOCapability::UNSET), keys_init(SMPKeyType::NONE), keys_resp(SMPKeyType::NONE), ltk_init(), irk_init(), csrk_init(), lk_init(), ltk_resp(), irk_resp(), csrk_resp(), lk_resp(), verbose(false) { size = calcSize(); } constexpr bool isVersionValid() const noexcept { return VERSION==version; } constexpr uint16_t getVersion() const noexcept { return version;} constexpr bool isSizeValid() const noexcept { return calcSize() == size;} constexpr uint16_t getSize() const noexcept { return size;} /** Returns the creation timestamp in seconds since Unix epoch */ constexpr uint64_t getCreationTime() const noexcept { return ts_creation_sec; } /** Return the local adapter address. */ constexpr const BDAddressAndType& getLocalAddrAndType() const noexcept { return localAddress; } /** Return the remote device address. */ constexpr const BDAddressAndType& getRemoteAddrAndType() const noexcept { return remoteAddress; } /** Return whether Secure Connection (SC) is being used via LTK keys. */ constexpr bool uses_SC() const noexcept { return ( hasLTKInit() && SMPLongTermKey::Property::NONE != ( getLTKInit().properties & SMPLongTermKey::Property::SC ) ) || ( hasLTKResp() && SMPLongTermKey::Property::NONE != ( getLTKResp().properties & SMPLongTermKey::Property::SC ) ); } constexpr BTSecurityLevel getSecLevel() const noexcept { return sec_level; } constexpr SMPIOCapability getIOCap() const noexcept { return io_cap; } constexpr bool hasLTKInit() const noexcept { return ( SMPKeyType::ENC_KEY & keys_init ) != SMPKeyType::NONE; } constexpr bool hasIRKInit() const noexcept { return ( SMPKeyType::ID_KEY & keys_init ) != SMPKeyType::NONE; } constexpr bool hasCSRKInit() const noexcept { return ( SMPKeyType::SIGN_KEY & keys_init ) != SMPKeyType::NONE; } constexpr bool hasLKInit() const noexcept { return ( SMPKeyType::LINK_KEY & keys_init ) != SMPKeyType::NONE; } constexpr const SMPLongTermKey& getLTKInit() const noexcept { return ltk_init; } constexpr const SMPIdentityResolvingKey& getIRKInit() const noexcept { return irk_init; } constexpr const SMPSignatureResolvingKey& getCSRKInit() const noexcept { return csrk_init; } constexpr const SMPLinkKey& getLKInit() const noexcept { return lk_init; } void setLTKInit(const SMPLongTermKey& v) noexcept { ltk_init = v; keys_init |= SMPKeyType::ENC_KEY; size = calcSize(); } void setIRKInit(const SMPIdentityResolvingKey& v) noexcept { irk_init = v; keys_init |= SMPKeyType::ID_KEY; size = calcSize(); } void setCSRKInit(const SMPSignatureResolvingKey& v) noexcept { csrk_init = v; keys_init |= SMPKeyType::SIGN_KEY; size = calcSize(); } void setLKInit(const SMPLinkKey& v) noexcept { lk_init = v; keys_init |= SMPKeyType::LINK_KEY; size = calcSize(); } constexpr bool hasLTKResp() const noexcept { return ( SMPKeyType::ENC_KEY & keys_resp ) != SMPKeyType::NONE; } constexpr bool hasIRKResp() const noexcept { return ( SMPKeyType::ID_KEY & keys_resp ) != SMPKeyType::NONE; } constexpr bool hasCSRKResp() const noexcept { return ( SMPKeyType::SIGN_KEY & keys_resp ) != SMPKeyType::NONE; } constexpr bool hasLKResp() const noexcept { return ( SMPKeyType::LINK_KEY & keys_resp ) != SMPKeyType::NONE; } constexpr const SMPLongTermKey& getLTKResp() const noexcept { return ltk_resp; } constexpr const SMPIdentityResolvingKey& getIRKResp() const noexcept { return irk_resp; } constexpr const SMPSignatureResolvingKey& getCSRKResp() const noexcept { return csrk_resp; } constexpr const SMPLinkKey& getLKResp() const noexcept { return lk_resp; } void setLTKResp(const SMPLongTermKey& v) noexcept { ltk_resp = v; keys_resp |= SMPKeyType::ENC_KEY; size = calcSize(); } void setIRKResp(const SMPIdentityResolvingKey& v) noexcept { irk_resp = v; keys_resp |= SMPKeyType::ID_KEY; size = calcSize(); } void setCSRKResp(const SMPSignatureResolvingKey& v) noexcept { csrk_resp = v; keys_resp |= SMPKeyType::SIGN_KEY; size = calcSize(); } void setLKResp(const SMPLinkKey& v) noexcept { lk_resp = v; keys_resp |= SMPKeyType::LINK_KEY; size = calcSize(); } void setVerbose(bool v) noexcept { verbose = v; } constexpr bool getVerbose() const noexcept { return verbose; } /** * Returns `true` if * * isVersionValid() && isSizeValid() && * not BTSecurityLevel::UNSET && * not SMPIOCapability::UNSET && * has valid LTK, if at all * */ constexpr bool isValid() const noexcept { return isVersionValid() && isSizeValid() && BTSecurityLevel::UNSET != sec_level && SMPIOCapability::UNSET != io_cap && ( !hasLTKInit() || ltk_init.isValid() ) && ( !hasLTKResp() || ltk_resp.isValid() ) && ( !hasLKInit() || lk_init.isValid() ) && ( !hasLKResp() || lk_resp.isValid() ); } std::string toString() const noexcept; /** * Returns the base filename, see SMPKeyBin API doc for naming scheme. */ std::string getFileBasename() const noexcept; /** * Returns the base filename, see SMPKeyBin API doc for naming scheme. */ static std::string getFileBasename(const BDAddressAndType& localAddress_, const BDAddressAndType& remoteAddress_) noexcept; static std::string getFilename(const std::string& path, const BDAddressAndType& localAddress_, const BDAddressAndType& remoteAddress_) noexcept { return path + "/" + getFileBasename(localAddress_, remoteAddress_); } static std::string getFilename(const std::string& path, const BTDevice& remoteDevice) noexcept ; static bool remove(const std::string& path, const BDAddressAndType& localAddress_, const BDAddressAndType& remoteAddress_) { return remove_impl( getFilename(path, localAddress_, remoteAddress_) ); } static bool remove(const std::string& path, const BTDevice& remoteDevice); std::string getFilename(const std::string& path) const noexcept { return getFilename(path, localAddress, remoteAddress); } bool remove(const std::string& path) { return remove_impl( getFilename(path) ); } bool write(const std::string& path, const bool overwrite) const noexcept; bool read(const std::string& fname); }; } // namespace direct_bt #endif /* SMPKEYBIN_HPP_ */