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VeraCrypt/src/Core/Unix/Linux/CoreLinux.cpp

507 lines
13 KiB
C++

/*
Derived from source code of TrueCrypt 7.1a, which is
Copyright (c) 2008-2012 TrueCrypt Developers Association and which is governed
by the TrueCrypt License 3.0.
Modifications and additions to the original source code (contained in this file)
and all other portions of this file are Copyright (c) 2013-2025 AM Crypto
and are governed by the Apache License 2.0 the full text of which is
contained in the file License.txt included in VeraCrypt binary and source
code distribution packages.
*/
#include <fstream>
#include <iomanip>
#include <mntent.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/mount.h>
#include <sys/wait.h>
#include "CoreLinux.h"
#include "Platform/SystemInfo.h"
#include "Platform/TextReader.h"
#include "Volume/EncryptionModeXTS.h"
#ifdef WOLFCRYPT_BACKEND
#include "Volume/EncryptionModeWolfCryptXTS.h"
#endif
#include "Driver/Fuse/FuseService.h"
#include "Core/Unix/CoreServiceProxy.h"
namespace VeraCrypt
{
CoreLinux::CoreLinux ()
{
}
CoreLinux::~CoreLinux ()
{
}
DevicePath CoreLinux::AttachFileToLoopDevice (const FilePath &filePath, bool readOnly) const
{
list <string> loopPaths;
loopPaths.push_back ("/dev/loop");
loopPaths.push_back ("/dev/loop/");
loopPaths.push_back ("/dev/.static/dev/loop");
// On Fedora 23,"losetup -f" must be called first to create a default loop device
list <string> args;
args.push_back ("-f");
try
{
Process::Execute ("losetup", args);
}
catch (...) { }
for (int devIndex = 0; devIndex < 256; devIndex++)
{
string loopDev;
foreach (const string &loopPath, loopPaths)
{
loopDev = loopPath + StringConverter::ToSingle (devIndex);
if (FilesystemPath (loopDev).IsBlockDevice())
break;
}
if (loopDev.empty())
continue;
list <string> args;
list <string>::iterator readOnlyArg;
if (readOnly)
{
args.push_back ("-r");
readOnlyArg = --args.end();
}
args.push_back ("--");
args.push_back (loopDev);
args.push_back (filePath);
try
{
Process::Execute ("losetup", args);
return loopDev;
}
catch (ExecutedProcessFailed&)
{
if (readOnly)
{
try
{
args.erase (readOnlyArg);
Process::Execute ("losetup", args);
return loopDev;
}
catch (ExecutedProcessFailed&) { }
}
}
}
throw LoopDeviceSetupFailed (SRC_POS, wstring (filePath));
}
void CoreLinux::DetachLoopDevice (const DevicePath &devicePath) const
{
list <string> args;
args.push_back ("-d");
args.push_back (devicePath);
for (int t = 0; true; t++)
{
try
{
Process::Execute ("losetup", args);
break;
}
catch (ExecutedProcessFailed&)
{
if (t > 5)
throw;
Thread::Sleep (200);
}
}
}
void CoreLinux::DismountNativeVolume (shared_ptr <VolumeInfo> mountedVolume) const
{
string devPath = mountedVolume->VirtualDevice;
if (devPath.find ("/dev/mapper/veracrypt") != 0)
throw NotApplicable (SRC_POS);
size_t devCount = 0;
while (FilesystemPath (devPath).IsBlockDevice())
{
list <string> dmsetupArgs;
dmsetupArgs.push_back ("remove");
dmsetupArgs.push_back (StringConverter::Split (devPath, "/").back());
for (int t = 0; true; t++)
{
try
{
Process::Execute ("dmsetup", dmsetupArgs);
break;
}
catch (...)
{
if (t > 20)
throw;
Thread::Sleep (100);
}
}
for (int t = 0; FilesystemPath (devPath).IsBlockDevice() && t < 20; t++)
{
Thread::Sleep (100);
}
devPath = string (mountedVolume->VirtualDevice) + "_" + StringConverter::ToSingle (devCount++);
}
}
HostDeviceList CoreLinux::GetHostDevices (bool pathListOnly) const
{
HostDeviceList devices;
TextReader tr ("/proc/partitions");
string line;
while (tr.ReadLine (line))
{
vector <string> fields = StringConverter::Split (line);
if (fields.size() != 4
|| fields[3].find ("loop") == 0 // skip loop devices
|| fields[3].find ("cloop") == 0
|| fields[3].find ("ram") == 0 // skip RAM devices
|| fields[3].find ("dm-") == 0 // skip device mapper devices
|| fields[2] == "1" // skip extended partitions
)
continue;
try
{
StringConverter::ToUInt32 (fields[0]);
}
catch (...)
{
continue;
}
try
{
make_shared_auto (HostDevice, hostDevice);
hostDevice->Path = string (fields[3].find ("/dev/") == string::npos ? "/dev/" : "") + fields[3];
if (!pathListOnly)
{
hostDevice->Size = StringConverter::ToUInt64 (fields[2]) * 1024;
hostDevice->MountPoint = GetDeviceMountPoint (hostDevice->Path);
hostDevice->SystemNumber = 0;
}
try
{
StringConverter::GetTrailingNumber (fields[3]);
if (devices.size() > 0)
{
HostDevice &prevDev = **--devices.end();
if (string (hostDevice->Path).find (prevDev.Path) == 0)
{
prevDev.Partitions.push_back (hostDevice);
continue;
}
}
}
catch (...) { }
devices.push_back (hostDevice);
continue;
}
catch (...)
{
continue;
}
}
return devices;
}
MountedFilesystemList CoreLinux::GetMountedFilesystems (const DevicePath &devicePath, const DirectoryPath &mountPoint) const
{
MountedFilesystemList mountedFilesystems;
DevicePath realDevicePath = devicePath;
if (!devicePath.IsEmpty())
{
char *resolvedPath = realpath (string (devicePath).c_str(), NULL);
if (resolvedPath)
{
realDevicePath = resolvedPath;
free (resolvedPath);
}
}
FILE *mtab = fopen ("/etc/mtab", "r");
if (!mtab)
mtab = fopen ("/proc/mounts", "r");
throw_sys_sub_if (!mtab, "/proc/mounts");
finally_do_arg (FILE *, mtab, { fclose (finally_arg); });
static Mutex mutex;
ScopeLock sl (mutex);
struct mntent *entry;
while ((entry = getmntent (mtab)) != nullptr)
{
make_shared_auto (MountedFilesystem, mf);
if (entry->mnt_fsname)
mf->Device = DevicePath (entry->mnt_fsname);
else
continue;
if (entry->mnt_dir)
mf->MountPoint = DirectoryPath (entry->mnt_dir);
if (entry->mnt_type)
mf->Type = entry->mnt_type;
if ((devicePath.IsEmpty() || devicePath == mf->Device || realDevicePath == mf->Device) && (mountPoint.IsEmpty() || mountPoint == mf->MountPoint))
mountedFilesystems.push_back (mf);
}
return mountedFilesystems;
}
void CoreLinux::MountFilesystem (const DevicePath &devicePath, const DirectoryPath &mountPoint, const string &filesystemType, bool readOnly, const string &systemMountOptions) const
{
bool fsMounted = false;
try
{
if (!FilesystemSupportsUnixPermissions (devicePath))
{
stringstream userMountOptions;
userMountOptions << "uid=" << GetRealUserId() << ",gid=" << GetRealGroupId() << ",umask=077" << (!systemMountOptions.empty() ? "," : "");
CoreUnix::MountFilesystem (devicePath, mountPoint, filesystemType, readOnly, userMountOptions.str() + systemMountOptions);
fsMounted = true;
}
}
catch (...) { }
if (!fsMounted)
CoreUnix::MountFilesystem (devicePath, mountPoint, filesystemType, readOnly, systemMountOptions);
}
void CoreLinux::MountVolumeNative (shared_ptr <Volume> volume, MountOptions &options, const DirectoryPath &auxMountPoint) const
{
bool xts = (typeid (*volume->GetEncryptionMode()) ==
#ifdef WOLFCRYPT_BACKEND
typeid (EncryptionModeWolfCryptXTS));
#else
typeid (EncryptionModeXTS));
#endif
bool algoNotSupported = (typeid (*volume->GetEncryptionAlgorithm()) == typeid (Kuznyechik))
|| (typeid (*volume->GetEncryptionAlgorithm()) == typeid (SM4))
|| (typeid (*volume->GetEncryptionAlgorithm()) == typeid (CamelliaKuznyechik))
|| (typeid (*volume->GetEncryptionAlgorithm()) == typeid (KuznyechikTwofish))
|| (typeid (*volume->GetEncryptionAlgorithm()) == typeid (KuznyechikAES))
|| (typeid (*volume->GetEncryptionAlgorithm()) == typeid (KuznyechikSM4))
|| (typeid (*volume->GetEncryptionAlgorithm()) == typeid (SerpentSM4))
|| (typeid (*volume->GetEncryptionAlgorithm()) == typeid (SM4Twofish))
|| (typeid (*volume->GetEncryptionAlgorithm()) == typeid (TwofishSerpentSM4))
|| (typeid (*volume->GetEncryptionAlgorithm()) == typeid (KuznyechikSerpentCamellia));
if (options.NoKernelCrypto
|| !xts
|| algoNotSupported
|| volume->IsEncryptionNotCompleted ()
|| volume->GetProtectionType() == VolumeProtection::HiddenVolumeReadOnly)
{
throw NotApplicable (SRC_POS);
}
if (!SystemInfo::IsVersionAtLeast (2, 6, xts ? 24 : 20))
throw NotApplicable (SRC_POS);
// Load device mapper kernel module
list <string> execArgs;
foreach (const string &dmModule, StringConverter::Split ("dm_mod dm-mod dm"))
{
execArgs.clear();
execArgs.push_back (dmModule);
try
{
Process::Execute ("modprobe", execArgs);
break;
}
catch (...) { }
}
bool loopDevAttached = false;
bool nativeDevCreated = false;
bool filesystemMounted = false;
// Attach volume to loopback device if required
VolumePath volumePath = volume->GetPath();
if (!volumePath.IsDevice())
{
volumePath = AttachFileToLoopDevice (volumePath, options.Protection == VolumeProtection::ReadOnly);
loopDevAttached = true;
}
string nativeDevPath;
try
{
// Create virtual device using device mapper
size_t nativeDevCount = 0;
size_t secondaryKeyOffset = volume->GetEncryptionMode()->GetKey().Size();
size_t cipherCount = volume->GetEncryptionAlgorithm()->GetCiphers().size();
foreach_reverse_ref (const Cipher &cipher, volume->GetEncryptionAlgorithm()->GetCiphers())
{
stringstream dmCreateArgs;
dmCreateArgs << "0 " << volume->GetSize() / ENCRYPTION_DATA_UNIT_SIZE << " crypt ";
// Mode
dmCreateArgs << StringConverter::ToLower (StringConverter::ToSingle (cipher.GetName())) << (xts ? (SystemInfo::IsVersionAtLeast (2, 6, 33) ? "-xts-plain64 " : "-xts-plain ") : "-lrw-benbi ");
size_t keyArgOffset = dmCreateArgs.str().size();
dmCreateArgs << setw (cipher.GetKeySize() * (xts ? 4 : 2) + (xts ? 0 : 16 * 2)) << 0 << setw (0);
// Sector and data unit offset
uint64 startSector = volume->GetLayout()->GetDataOffset (volume->GetHostSize()) / ENCRYPTION_DATA_UNIT_SIZE;
dmCreateArgs << ' ' << (xts ? startSector + volume->GetEncryptionMode()->GetSectorOffset() : 0) << ' ';
if (nativeDevCount == 0)
dmCreateArgs << string (volumePath) << ' ' << startSector;
else
dmCreateArgs << nativeDevPath << " 0";
SecureBuffer dmCreateArgsBuf (dmCreateArgs.str().size());
dmCreateArgsBuf.CopyFrom (ConstBufferPtr ((uint8 *) dmCreateArgs.str().c_str(), dmCreateArgs.str().size()));
// Keys
const SecureBuffer &cipherKey = cipher.GetKey();
secondaryKeyOffset -= cipherKey.Size();
ConstBufferPtr secondaryKey = volume->GetEncryptionMode()->GetKey().GetRange (xts ? secondaryKeyOffset : 0, xts ? cipherKey.Size() : 16);
SecureBuffer hexStr (3);
for (size_t i = 0; i < cipherKey.Size(); ++i)
{
sprintf ((char *) hexStr.Ptr(), "%02x", (int) cipherKey[i]);
dmCreateArgsBuf.GetRange (keyArgOffset + i * 2, 2).CopyFrom (hexStr.GetRange (0, 2));
sprintf ((char *) hexStr.Ptr(), "%02x", (int) secondaryKey[i]);
dmCreateArgsBuf.GetRange (keyArgOffset + cipherKey.Size() * 2 + i * 2, 2).CopyFrom (hexStr.GetRange (0, 2));
}
stringstream nativeDevName;
nativeDevName << "veracrypt" << options.SlotNumber;
if (nativeDevCount != cipherCount - 1)
nativeDevName << "_" << cipherCount - nativeDevCount - 2;
nativeDevPath = "/dev/mapper/" + nativeDevName.str();
execArgs.clear();
execArgs.push_back ("create");
execArgs.push_back (nativeDevName.str());
Process::Execute ("dmsetup", execArgs, -1, nullptr, &dmCreateArgsBuf);
// Wait for the device to be created
for (int t = 0; true; t++)
{
try
{
FilesystemPath (nativeDevPath).GetType();
break;
}
catch (...)
{
if (t > 20)
throw;
Thread::Sleep (100);
}
}
nativeDevCreated = true;
++nativeDevCount;
}
// Test whether the device mapper is able to read and decrypt the last sector
SecureBuffer lastSectorBuf (volume->GetSectorSize());
uint64 lastSectorOffset = volume->GetSize() - volume->GetSectorSize();
File nativeDev;
nativeDev.Open (nativeDevPath);
nativeDev.ReadAt (lastSectorBuf, lastSectorOffset);
SecureBuffer lastSectorBuf2 (volume->GetSectorSize());
volume->ReadSectors (lastSectorBuf2, lastSectorOffset);
if (memcmp (lastSectorBuf.Ptr(), lastSectorBuf2.Ptr(), volume->GetSectorSize()) != 0)
throw KernelCryptoServiceTestFailed (SRC_POS);
// Mount filesystem
if (!options.NoFilesystem && options.MountPoint && !options.MountPoint->IsEmpty())
{
MountFilesystem (nativeDevPath, *options.MountPoint,
StringConverter::ToSingle (options.FilesystemType),
options.Protection == VolumeProtection::ReadOnly,
StringConverter::ToSingle (options.FilesystemOptions));
filesystemMounted = true;
}
FuseService::SendAuxDeviceInfo (auxMountPoint, nativeDevPath, volumePath);
}
catch (...)
{
try
{
if (filesystemMounted)
DismountFilesystem (*options.MountPoint, true);
}
catch (...) { }
try
{
if (nativeDevCreated)
{
make_shared_auto (VolumeInfo, vol);
vol->VirtualDevice = nativeDevPath;
DismountNativeVolume (vol);
}
}
catch (...) { }
try
{
if (loopDevAttached)
DetachLoopDevice (volumePath);
}
catch (...) { }
throw;
}
}
unique_ptr <CoreBase> Core (new CoreServiceProxy <CoreLinux>);
unique_ptr <CoreBase> CoreDirect (new CoreLinux);
}