File indexing completed on 2024-04-14 03:54:58

 /*
     SPDX-FileCopyrightText: 2017 KDE Developers
 
     SPDX-License-Identifier: LGPL-2.0-or-later
 */
 
 #include "katesecuretextbuffer_p.h"
 
 #include "config.h"
 
 #include <KAuth/HelperSupport>
 
 #ifndef Q_OS_WIN
 #include <cerrno>
 #include <unistd.h>
 #endif
 
 #include <QDir>
 #include <QFile>
 #include <QFileInfo>
 #include <QString>
 #include <QTemporaryFile>
 
 KAUTH_HELPER_MAIN("org.kde.ktexteditor6.katetextbuffer", SecureTextBuffer)
 
 ActionReply SecureTextBuffer::savefile(const QVariantMap &args)
 {
     const QString sourceFile = args[QStringLiteral("sourceFile")].toString();
     const QString targetFile = args[QStringLiteral("targetFile")].toString();
     const QByteArray checksum = args[QStringLiteral("checksum")].toByteArray();
     const uint ownerId = (uint)args[QStringLiteral("ownerId")].toInt();
     const uint groupId = (uint)args[QStringLiteral("groupId")].toInt();
 
     if (saveFileInternal(sourceFile, targetFile, checksum, ownerId, groupId)) {
         return ActionReply::SuccessReply();
     }
 
     return ActionReply::HelperErrorReply();
 }
 
 bool SecureTextBuffer::saveFileInternal(const QString &sourceFile,
                                         const QString &targetFile,
                                         const QByteArray &checksum,
                                         const uint ownerId,
                                         const uint groupId)
 {
     // open source file for reading
     // if not possible, signal error
     QFile readFile(sourceFile);
     if (!readFile.open(QIODevice::ReadOnly)) {
         return false;
     }
 
     // construct file info for target file
     // we need to know things like path/exists/permissions
     const QFileInfo targetFileInfo(targetFile);
 
     // create temporary file in current directory to be able to later do an atomic rename
     // we need to pass full path, else QTemporaryFile uses the temporary directory
     // if not possible, signal error, this catches e.g. a non-existing target directory, too
     QTemporaryFile tempFile(targetFileInfo.absolutePath() + QLatin1String("/secureXXXXXX"));
     if (!tempFile.open()) {
         return false;
     }
 
     // copy contents + do checksumming
     // if not possible, signal error
     QCryptographicHash cryptographicHash(checksumAlgorithm);
     const qint64 bufferLength = 4096;
     char buffer[bufferLength];
     qint64 read = -1;
     while ((read = readFile.read(buffer, bufferLength)) > 0) {
         cryptographicHash.addData(QByteArrayView(buffer, read));
         if (tempFile.write(buffer, read) == -1) {
             return false;
         }
     }
 
     // check that copying was successful and checksum matched
     // we need to flush the file, as QTemporaryFile keeps the handle open
     // and we later do things like renaming of the file!
     // if not possible, signal error
     if ((read == -1) || (cryptographicHash.result() != checksum) || !tempFile.flush()) {
         return false;
     }
 
     // try to preserve the permissions
     if (!targetFileInfo.exists()) {
         // ensure new file is readable by anyone
         tempFile.setPermissions(tempFile.permissions() | QFile::Permission::ReadGroup | QFile::Permission::ReadOther);
     } else {
         // ensure the same file permissions
         tempFile.setPermissions(targetFileInfo.permissions());
 
         // ensure file has the same owner and group as before
         setOwner(tempFile.handle(), ownerId, groupId);
     }
 
     // try to (atomic) rename temporary file to the target file
     if (moveFile(tempFile.fileName(), targetFileInfo.filePath())) {
         // temporary file was renamed, there is nothing to remove anymore
         tempFile.setAutoRemove(false);
         return true;
     }
 
     // we failed
     // QTemporaryFile will handle cleanup
     return false;
 }
 
 void SecureTextBuffer::setOwner(const int filedes, const uint ownerId, const uint groupId)
 {
 #ifndef Q_OS_WIN
     if (ownerId != (uint)-2 && groupId != (uint)-2) {
         int result = fchown(filedes, ownerId, groupId);
         // set at least correct group if owner cannot be changed
         if (result != 0 && errno == EPERM) {
             result = fchown(filedes, getuid(), groupId);
             (void)result; // ignore if we can't do a thing
         }
     }
 #else
     // no-op for windows
 #endif
 }
 
 bool SecureTextBuffer::moveFile(const QString &sourceFile, const QString &targetFile)
 {
 #if !defined(Q_OS_WIN) && !defined(Q_OS_ANDROID)
     const int result = std::rename(QFile::encodeName(sourceFile).constData(), QFile::encodeName(targetFile).constData());
     return (result == 0);
 #else
     // use racy fallback for windows
     QFile::remove(targetFile);
     return QFile::rename(sourceFile, targetFile);
 #endif
 }