nextcloud-desktop/src/libsync/clientsideencryptiontokenselector.cpp
Matthieu Gallien 2a52ec33b0 add support to use PKCS#11 harware token to store certifice for e2ee
Close #5685

Signed-off-by: Matthieu Gallien <matthieu.gallien@nextcloud.com>
2025-02-07 09:12:29 +01:00

286 lines
12 KiB
C++

/*
* Copyright © 2023, Matthieu Gallien <matthieu.gallien@nextcloud.com>
* Copyright (C) 2017 The Qt Company Ltd.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* for more details.
*
* 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.
*/
#include "clientsideencryptiontokenselector.h"
#include "clientsideencryptionprimitives.h"
#include "account.h"
#include <QLoggingCategory>
#include <QtConcurrentRun>
#include <QSslCertificateExtension>
#if defined(Q_OS_WIN)
#include <wincrypt.h>
#endif
#include <libp11.h>
#include <openssl/pem.h>
namespace {
static unsigned char* unsignedData(QByteArray& array)
{
return (unsigned char*)array.data();
}
static QByteArray BIO2ByteArray(OCC::Bio &b) {
auto pending = static_cast<int>(BIO_ctrl_pending(b));
QByteArray res(pending, '\0');
BIO_read(b, unsignedData(res), pending);
return res;
}
}
namespace OCC
{
Q_LOGGING_CATEGORY(lcCseSelector, "nextcloud.sync.clientsideencryption.selector", QtInfoMsg)
ClientSideEncryptionTokenSelector::ClientSideEncryptionTokenSelector(QObject *parent)
: QObject{parent}
{
}
bool ClientSideEncryptionTokenSelector::isSetup() const
{
return !_sha256Fingerprint.isEmpty();
}
QVariantList ClientSideEncryptionTokenSelector::discoveredCertificates() const
{
return _discoveredCertificates;
}
QByteArray ClientSideEncryptionTokenSelector::sha256Fingerprint() const
{
return _sha256Fingerprint;
}
void ClientSideEncryptionTokenSelector::clear()
{
_discoveredCertificates.clear();
_sha256Fingerprint.clear();
}
QFuture<void> ClientSideEncryptionTokenSelector::searchForCertificates(const AccountPtr &account)
{
return QtConcurrent::run([this, account] () -> void {
discoverCertificates(account);
});
}
void ClientSideEncryptionTokenSelector::setSha256Fingerprint(const QByteArray &sha256Fingerprint)
{
if (_sha256Fingerprint == sha256Fingerprint) {
return;
}
_sha256Fingerprint = sha256Fingerprint;
Q_EMIT sha256FingerprintChanged();
}
void ClientSideEncryptionTokenSelector::discoverCertificates(const AccountPtr &account)
{
auto ctx = Pkcs11Context{Pkcs11Context::State::CreateContext};
auto rc = PKCS11_CTX_load(ctx, account->encryptionHardwareTokenDriverPath().toLatin1().constData());
if (rc) {
qCWarning(lcCseSelector()) << "loading pkcs11 engine failed:" << ERR_reason_error_string(ERR_get_error()) << account->encryptionHardwareTokenDriverPath();
Q_EMIT failedToInitialize(account);
return;
}
auto tokensCount = 0u;
PKCS11_SLOT *tempTokenSlots = nullptr;
/* get information on all slots */
if (PKCS11_enumerate_slots(ctx, &tempTokenSlots, &tokensCount) < 0) {
qCWarning(lcCseSelector()) << "no slots available" << ERR_reason_error_string(ERR_get_error());
Q_EMIT failedToInitialize(account);
return;
}
auto deleter = [&ctx, tokensCount] (PKCS11_SLOT* pointer) noexcept -> void {
PKCS11_release_all_slots(ctx, pointer, tokensCount);
};
auto tokenSlots = std::unique_ptr<PKCS11_SLOT[], decltype(deleter)>{tempTokenSlots, deleter};
if (!tokensCount) {
qCWarning(lcCseSelector()) << "no tokens found";
Q_EMIT failedToInitialize(account);
return;
}
_discoveredCertificates.clear();
auto currentSlot = static_cast<PKCS11_SLOT*>(nullptr);
for(auto tokenIndex = 0u; tokenIndex < tokensCount; ++tokenIndex) {
currentSlot = PKCS11_find_next_token(ctx, tokenSlots.get(), tokensCount, currentSlot);
if (currentSlot == nullptr || currentSlot->token == nullptr) {
break;
}
qCDebug(lcCseSelector()) << "Slot manufacturer......:" << currentSlot->manufacturer;
qCDebug(lcCseSelector()) << "Slot description.......:" << currentSlot->description;
qCDebug(lcCseSelector()) << "Slot token label.......:" << currentSlot->token->label;
qCDebug(lcCseSelector()) << "Slot token manufacturer:" << currentSlot->token->manufacturer;
qCDebug(lcCseSelector()) << "Slot token model.......:" << currentSlot->token->model;
qCDebug(lcCseSelector()) << "Slot token serialnr....:" << currentSlot->token->serialnr;
auto keysCount = 0u;
auto certificatesFromToken = static_cast<PKCS11_CERT*>(nullptr);
if (PKCS11_enumerate_certs(currentSlot->token, &certificatesFromToken, &keysCount)) {
qCWarning(lcCseSelector()) << "PKCS11_enumerate_certs failed" << ERR_reason_error_string(ERR_get_error());
Q_EMIT failedToInitialize(account);
return;
}
for (auto certificateIndex = 0u; certificateIndex < keysCount; ++certificateIndex) {
const auto currentCertificate = &certificatesFromToken[certificateIndex];
qCInfo(lcCseSelector()) << "certificate metadata:"
<< "label:" << currentCertificate->label;
const auto certificateId = QByteArray{reinterpret_cast<char*>(currentCertificate->id), static_cast<int>(currentCertificate->id_len)};
qCInfo(lcCseSelector()) << "new certificate ID:" << certificateId.toBase64();
Bio out;
const auto ret = PEM_write_bio_X509(out, currentCertificate->x509);
if (ret <= 0){
qCWarning(lcCseSelector()) << "PEM_write_bio_X509 failed" << ERR_reason_error_string(ERR_get_error());
Q_EMIT failedToInitialize(account);
return;
}
const auto result = BIO2ByteArray(out);
const auto sslCertificate = QSslCertificate{result, QSsl::Pem};
const auto certificateDigest = sslCertificate.digest(QCryptographicHash::Sha256).toBase64();
qCInfo(lcCseSelector()) << "newly found certificate"
<< "subject:" << sslCertificate.subjectDisplayName()
<< "issuer:" << sslCertificate.issuerDisplayName()
<< "valid since:" << sslCertificate.effectiveDate()
<< "valid until:" << sslCertificate.expiryDate()
<< "serial number:" << sslCertificate.serialNumber()
<< "SHA256 fingerprint:" << certificateDigest;
if (sslCertificate.isSelfSigned()) {
qCDebug(lcCseSelector()) << "newly found certificate is self signed: goint to ignore it";
continue;
}
auto hasNeededExtendedKeyUsageExtension = false;
const auto &allExtensions = sslCertificate.extensions();
for (const auto &oneExtension : allExtensions) {
qCDebug(lcCseSelector()) << "extension:" << (oneExtension.isCritical() ? "is critical" : "") << (oneExtension.isSupported() ? "is supported" : "") << oneExtension.name() << oneExtension.value() << oneExtension.oid();
if (oneExtension.oid() == QStringLiteral("2.5.29.37")) {
const auto extendedKeyUsageList = oneExtension.value().toList();
for (const auto &oneExtendedKeyUsageValue : extendedKeyUsageList) {
qCDebug(lcCseSelector()) << "EKU:" << oneExtendedKeyUsageValue;
if (oneExtendedKeyUsageValue == QStringLiteral("E-mail Protection")) {
hasNeededExtendedKeyUsageExtension = true;
break;
}
}
}
}
if (!hasNeededExtendedKeyUsageExtension) {
qCDebug(lcCseSelector()) << "newly found certificate is missing the required EKU extension: Secure Email (1.3.6.1.5.5.7.3.4)";
continue;
}
_discoveredCertificates.push_back(QVariantMap{
{QStringLiteral("label"), QString::fromLatin1(currentCertificate->label)},
{QStringLiteral("subject"), sslCertificate.subjectDisplayName()},
{QStringLiteral("issuer"), sslCertificate.issuerDisplayName()},
{QStringLiteral("serialNumber"), sslCertificate.serialNumber()},
{QStringLiteral("validSince"), sslCertificate.effectiveDate()},
{QStringLiteral("validUntil"), sslCertificate.expiryDate()},
{QStringLiteral("sha256Fingerprint"), certificateDigest},
{QStringLiteral("certificate"), QVariant::fromValue(sslCertificate)},
});
std::sort(_discoveredCertificates.begin(), _discoveredCertificates.end(), [] (const auto &first, const auto &second) -> bool {
return first.toMap()[QStringLiteral("validSince")].toDateTime() > second.toMap()[QStringLiteral("validSince")].toDateTime();
});
}
}
processDiscoveredCertificates();
}
void ClientSideEncryptionTokenSelector::processDiscoveredCertificates()
{
const auto &allCertificates = discoveredCertificates();
for (const auto &oneCertificate : allCertificates) {
const auto certificateData = oneCertificate.toMap();
const auto sslCertificate = certificateData[QStringLiteral("certificate")].value<QSslCertificate>();
if (sslCertificate.isNull()) {
qCDebug(lcCseSelector()) << "null certificate";
continue;
}
const auto sslErrors = QSslCertificate::verify({sslCertificate});
if (!sslErrors.isEmpty()) {
for (const auto &oneError : sslErrors) {
qCInfo(lcCseSelector()) << oneError;
}
continue;
}
const auto &sha256Fingerprint = sslCertificate.digest(QCryptographicHash::Sha256).toBase64();
qCInfo(lcCseSelector()) << "selected certificate" << certificateData[QStringLiteral("subject")] << "from" << certificateData[QStringLiteral("issuer")] << "fingerprint" << sha256Fingerprint << "serialNumber" << sslCertificate.serialNumber();
setSha256Fingerprint(sha256Fingerprint);
Q_EMIT isSetupChanged();
return;
}
}
}