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Diffstat (limited to 'src/bluetooth/lecmaccalculator.cpp')
| -rw-r--r-- | src/bluetooth/lecmaccalculator.cpp | 186 |
1 files changed, 186 insertions, 0 deletions
diff --git a/src/bluetooth/lecmaccalculator.cpp b/src/bluetooth/lecmaccalculator.cpp new file mode 100644 index 00000000..1cda9576 --- /dev/null +++ b/src/bluetooth/lecmaccalculator.cpp @@ -0,0 +1,186 @@ +/**************************************************************************** +** +** Copyright (C) 2016 The Qt Company Ltd. +** Contact: https://www.qt.io/licensing/ +** +** This file is part of the QtBluetooth module of the Qt Toolkit. +** +** $QT_BEGIN_LICENSE:LGPL$ +** Commercial License Usage +** Licensees holding valid commercial Qt licenses may use this file in +** accordance with the commercial license agreement provided with the +** Software or, alternatively, in accordance with the terms contained in +** a written agreement between you and The Qt Company. For licensing terms +** and conditions see https://www.qt.io/terms-conditions. For further +** information use the contact form at https://www.qt.io/contact-us. +** +** GNU Lesser General Public License Usage +** Alternatively, this file may be used under the terms of the GNU Lesser +** General Public License version 3 as published by the Free Software +** Foundation and appearing in the file LICENSE.LGPL3 included in the +** packaging of this file. Please review the following information to +** ensure the GNU Lesser General Public License version 3 requirements +** will be met: https://www.gnu.org/licenses/lgpl-3.0.html. +** +** GNU General Public License Usage +** Alternatively, this file may be used under the terms of the GNU +** General Public License version 2.0 or (at your option) the GNU General +** Public license version 3 or any later version approved by the KDE Free +** Qt Foundation. The licenses are as published by the Free Software +** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3 +** included in the packaging of this file. Please review the following +** information to ensure the GNU General Public License requirements will +** be met: https://www.gnu.org/licenses/gpl-2.0.html and +** https://www.gnu.org/licenses/gpl-3.0.html. +** +** $QT_END_LICENSE$ +** +****************************************************************************/ +#include "lecmaccalculator_p.h" + +#include "bluez/bluez_data_p.h" + +#include <QtCore/qbytearray.h> +#include <QtCore/qloggingcategory.h> +#include <QtCore/private/qcore_unix_p.h> + +#include <cstring> +#include <sys/socket.h> +#include <sys/types.h> +#include <unistd.h> + +#ifdef CONFIG_LINUX_CRYPTO_API +#include <linux/if_alg.h> +#endif + +QT_BEGIN_NAMESPACE + +Q_DECLARE_LOGGING_CATEGORY(QT_BT_BLUEZ) + +LeCmacCalculator::LeCmacCalculator() +{ +#ifdef CONFIG_LINUX_CRYPTO_API + m_baseSocket = socket(AF_ALG, SOCK_SEQPACKET, 0); + if (m_baseSocket == -1) { + qCWarning(QT_BT_BLUEZ) << "failed to create first level crypto socket:" + << strerror(errno); + return; + } + sockaddr_alg sa; + using namespace std; + memset(&sa, 0, sizeof sa); + sa.salg_family = AF_ALG; + strcpy(reinterpret_cast<char *>(sa.salg_type), "hash"); + strcpy(reinterpret_cast<char *>(sa.salg_name), "cmac(aes)"); + if (bind(m_baseSocket, reinterpret_cast<sockaddr *>(&sa), sizeof sa) == -1) { + qCWarning(QT_BT_BLUEZ) << "bind() failed for crypto socket:" << strerror(errno); + return; + } +#else // CONFIG_LINUX_CRYPTO_API + qCWarning(QT_BT_BLUEZ) << "Linux crypto API not present, CMAC verification will fail."; +#endif +} + +LeCmacCalculator::~LeCmacCalculator() +{ + if (m_baseSocket != -1) + close(m_baseSocket); +} + +QByteArray LeCmacCalculator::createFullMessage(const QByteArray &message, quint32 signCounter) +{ + // Spec v4.2, Vol 3, Part H, 2.4.5 + QByteArray fullMessage = message; + fullMessage.resize(fullMessage.count() + sizeof signCounter); + putBtData(signCounter, fullMessage.data() + message.count()); + return fullMessage; +} + +quint64 LeCmacCalculator::calculateMac(const QByteArray &message, const quint128 &csrk) const +{ +#ifdef CONFIG_LINUX_CRYPTO_API + if (m_baseSocket == -1) + return false; + quint128 csrkMsb; + std::reverse_copy(std::begin(csrk.data), std::end(csrk.data), std::begin(csrkMsb.data)); + qCDebug(QT_BT_BLUEZ) << "CSRK (MSB):" << QByteArray(reinterpret_cast<char *>(csrkMsb.data), + sizeof csrkMsb).toHex(); + if (setsockopt(m_baseSocket, 279 /* SOL_ALG */, ALG_SET_KEY, csrkMsb.data, sizeof csrkMsb) == -1) { + qCWarning(QT_BT_BLUEZ) << "setsockopt() failed for crypto socket:" << strerror(errno); + return 0; + } + + class SocketWrapper + { + public: + SocketWrapper(int socket) : m_socket(socket) {} + ~SocketWrapper() { + if (m_socket != -1) + close(m_socket); + } + + int value() const { return m_socket; } + private: + int m_socket; + }; + SocketWrapper cryptoSocket(accept(m_baseSocket, nullptr, 0)); + if (cryptoSocket.value() == -1) { + qCWarning(QT_BT_BLUEZ) << "accept() failed for crypto socket:" << strerror(errno); + return 0; + } + + QByteArray messageSwapped(message.count(), Qt::Uninitialized); + std::reverse_copy(message.begin(), message.end(), messageSwapped.begin()); + qint64 totalBytesWritten = 0; + do { + const qint64 bytesWritten = qt_safe_write(cryptoSocket.value(), + messageSwapped.constData() + totalBytesWritten, + messageSwapped.count() - totalBytesWritten); + if (bytesWritten == -1) { + qCWarning(QT_BT_BLUEZ) << "writing to crypto socket failed:" << strerror(errno); + return 0; + } + totalBytesWritten += bytesWritten; + } while (totalBytesWritten < messageSwapped.count()); + quint64 mac; + quint8 * const macPtr = reinterpret_cast<quint8 *>(&mac); + qint64 totalBytesRead = 0; + do { + const qint64 bytesRead = qt_safe_read(cryptoSocket.value(), macPtr + totalBytesRead, + sizeof mac - totalBytesRead); + if (bytesRead == -1) { + qCWarning(QT_BT_BLUEZ) << "reading from crypto socket failed:" << strerror(errno); + return 0; + } + totalBytesRead += bytesRead; + } while (totalBytesRead < qint64(sizeof mac)); + return qFromBigEndian(mac); +#else // CONFIG_LINUX_CRYPTO_API + Q_UNUSED(message); + Q_UNUSED(csrk); + qCWarning(QT_BT_BLUEZ) << "CMAC calculation failed due to missing Linux crypto API."; + return 0; +#endif +} + +bool LeCmacCalculator::verify(const QByteArray &message, const quint128 &csrk, + quint64 expectedMac) const +{ +#ifdef CONFIG_LINUX_CRYPTO_API + const quint64 actualMac = calculateMac(message, csrk); + if (actualMac != expectedMac) { + qCWarning(QT_BT_BLUEZ) << hex << "signature verification failed: calculated mac:" + << actualMac << "expected mac:" << expectedMac; + return false; + } + return true; +#else // CONFIG_LINUX_CRYPTO_API + Q_UNUSED(message); + Q_UNUSED(csrk); + Q_UNUSED(expectedMac); + qCWarning(QT_BT_BLUEZ) << "CMAC verification failed due to missing Linux crypto API."; + return false; +#endif +} + +QT_END_NAMESPACE |