SUPR3HardenedVerify.cpp revision 2a076b740155a538ded6407c44aae5eff986a42f
/* $Id$ */
/** @file
* VirtualBox Support Library - Verification of Hardened Installation.
*/
/*
* Copyright (C) 2006-2013 Oracle Corporation
*
* This file is part of VirtualBox Open Source Edition (OSE), as
* available from http://www.virtualbox.org. This file is free software;
* you can redistribute it and/or modify it under the terms of the GNU
* General Public License (GPL) as published by the Free Software
* Foundation, in version 2 as it comes in the "COPYING" file of the
* VirtualBox OSE distribution. VirtualBox OSE is distributed in the
* hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
*
* The contents of this file may alternatively be used under the terms
* of the Common Development and Distribution License Version 1.0
* (CDDL) only, as it comes in the "COPYING.CDDL" file of the
* VirtualBox OSE distribution, in which case the provisions of the
* CDDL are applicable instead of those of the GPL.
*
* You may elect to license modified versions of this file under the
* terms and conditions of either the GPL or the CDDL or both.
*/
/*******************************************************************************
* Header Files *
*******************************************************************************/
#if defined(RT_OS_OS2)
# define INCL_BASE
# define INCL_ERRORS
# include <os2.h>
# include <stdio.h>
# include <stdlib.h>
# include <unistd.h>
# include <sys/fcntl.h>
# include <sys/errno.h>
# include <sys/syslimits.h>
#elif defined(RT_OS_WINDOWS)
# include <Windows.h>
# ifndef IN_SUP_HARDENED_R3
# include <stdio.h>
# endif
#else /* UNIXes */
# include <sys/types.h>
# include <stdio.h>
# include <stdlib.h>
# include <dirent.h>
# include <dlfcn.h>
# include <fcntl.h>
# include <limits.h>
# include <errno.h>
# include <unistd.h>
# include <sys/stat.h>
# include <sys/time.h>
# include <sys/fcntl.h>
# include <pwd.h>
# ifdef RT_OS_DARWIN
# include <mach-o/dyld.h>
# endif
#endif
#include <VBox/sup.h>
#include <VBox/err.h>
#include <iprt/asm.h>
#include <iprt/ctype.h>
#include <iprt/param.h>
#include <iprt/path.h>
#include <iprt/string.h>
#include "SUPLibInternal.h"
#if defined(RT_OS_WINDOWS) && defined(VBOX_WITH_HARDENING)
# define SUPHNTVI_NO_NT_STUFF
# include "win/SUPHardenedVerify-win.h"
#endif
/*******************************************************************************
* Defined Constants And Macros *
*******************************************************************************/
/** The max path length acceptable for a trusted path. */
#define SUPR3HARDENED_MAX_PATH 260U
#ifdef RT_OS_SOLARIS
# define dirfd(d) ((d)->d_fd)
#endif
/** Compare table file names with externally supplied names. */
#if defined(RT_OS_WINDOWS) || defined(RT_OS_OS2)
# define SUP_COMP_FILENAME suplibHardenedStrICmp
#else
# define SUP_COMP_FILENAME suplibHardenedStrCmp
#endif
/*******************************************************************************
* Global Variables *
*******************************************************************************/
/**
* The files that gets verified.
*
* @todo This needs reviewing against the linux packages.
* @todo The excessive use of kSupID_SharedLib needs to be reviewed at some point. For
* the time being we're building the linux packages with SharedLib pointing to
* AppPrivArch (lazy bird).
*/
static SUPINSTFILE const g_aSupInstallFiles[] =
{
/* type, dir, fOpt, "pszFile" */
/* ---------------------------------------------------------------------- */
{ kSupIFT_Dll, kSupID_AppPrivArch, false, "VMMR0.r0" },
{ kSupIFT_Dll, kSupID_AppPrivArch, false, "VBoxDDR0.r0" },
{ kSupIFT_Dll, kSupID_AppPrivArch, false, "VBoxDD2R0.r0" },
#ifdef VBOX_WITH_RAW_MODE
{ kSupIFT_Rc, kSupID_AppPrivArch, false, "VMMGC.gc" },
{ kSupIFT_Rc, kSupID_AppPrivArch, false, "VBoxDDGC.gc" },
{ kSupIFT_Rc, kSupID_AppPrivArch, false, "VBoxDD2GC.gc" },
#endif
{ kSupIFT_Dll, kSupID_SharedLib, false, "VBoxRT" SUPLIB_DLL_SUFF },
{ kSupIFT_Dll, kSupID_SharedLib, false, "VBoxVMM" SUPLIB_DLL_SUFF },
{ kSupIFT_Dll, kSupID_SharedLib, false, "VBoxREM" SUPLIB_DLL_SUFF },
#if HC_ARCH_BITS == 32
{ kSupIFT_Dll, kSupID_SharedLib, true, "VBoxREM32" SUPLIB_DLL_SUFF },
{ kSupIFT_Dll, kSupID_SharedLib, true, "VBoxREM64" SUPLIB_DLL_SUFF },
#endif
{ kSupIFT_Dll, kSupID_SharedLib, false, "VBoxDD" SUPLIB_DLL_SUFF },
{ kSupIFT_Dll, kSupID_SharedLib, false, "VBoxDD2" SUPLIB_DLL_SUFF },
{ kSupIFT_Dll, kSupID_SharedLib, false, "VBoxDDU" SUPLIB_DLL_SUFF },
//#ifdef VBOX_WITH_DEBUGGER_GUI
{ kSupIFT_Dll, kSupID_SharedLib, true, "VBoxDbg" SUPLIB_DLL_SUFF },
{ kSupIFT_Dll, kSupID_SharedLib, true, "VBoxDbg3" SUPLIB_DLL_SUFF },
//#endif
//#ifdef VBOX_WITH_SHARED_CLIPBOARD
{ kSupIFT_Dll, kSupID_AppPrivArch, true, "VBoxSharedClipboard" SUPLIB_DLL_SUFF },
//#endif
//#ifdef VBOX_WITH_SHARED_FOLDERS
{ kSupIFT_Dll, kSupID_AppPrivArch, true, "VBoxSharedFolders" SUPLIB_DLL_SUFF },
//#endif
//#ifdef VBOX_WITH_DRAG_AND_DROP
{ kSupIFT_Dll, kSupID_AppPrivArch, true, "VBoxDragAndDropSvc" SUPLIB_DLL_SUFF },
//#endif
//#ifdef VBOX_WITH_GUEST_PROPS
{ kSupIFT_Dll, kSupID_AppPrivArch, true, "VBoxGuestPropSvc" SUPLIB_DLL_SUFF },
//#endif
//#ifdef VBOX_WITH_GUEST_CONTROL
{ kSupIFT_Dll, kSupID_AppPrivArch, true, "VBoxGuestControlSvc" SUPLIB_DLL_SUFF },
//#endif
{ kSupIFT_Dll, kSupID_AppPrivArch, true, "VBoxHostChannel" SUPLIB_DLL_SUFF },
{ kSupIFT_Dll, kSupID_AppPrivArch, true, "VBoxSharedCrOpenGL" SUPLIB_DLL_SUFF },
{ kSupIFT_Dll, kSupID_AppPrivArch, true, "VBoxOGLhostcrutil" SUPLIB_DLL_SUFF },
{ kSupIFT_Dll, kSupID_AppPrivArch, true, "VBoxOGLhosterrorspu" SUPLIB_DLL_SUFF },
{ kSupIFT_Dll, kSupID_AppPrivArch, true, "VBoxOGLrenderspu" SUPLIB_DLL_SUFF },
{ kSupIFT_Exe, kSupID_AppBin, true, "VBoxManage" SUPLIB_EXE_SUFF },
#ifdef VBOX_WITH_MAIN
{ kSupIFT_Exe, kSupID_AppBin, false, "VBoxSVC" SUPLIB_EXE_SUFF },
#ifdef RT_OS_WINDOWS
{ kSupIFT_Dll, kSupID_SharedLib, false, "VBoxC" SUPLIB_DLL_SUFF },
#else
{ kSupIFT_Exe, kSupID_AppPrivArch, false, "VBoxXPCOMIPCD" SUPLIB_EXE_SUFF },
{ kSupIFT_Dll, kSupID_SharedLib, false, "VBoxXPCOM" SUPLIB_DLL_SUFF },
{ kSupIFT_Dll, kSupID_AppPrivArchComp, false, "VBoxXPCOMIPCC" SUPLIB_DLL_SUFF },
{ kSupIFT_Dll, kSupID_AppPrivArchComp, false, "VBoxC" SUPLIB_DLL_SUFF },
{ kSupIFT_Dll, kSupID_AppPrivArchComp, false, "VBoxSVCM" SUPLIB_DLL_SUFF },
{ kSupIFT_Data, kSupID_AppPrivArchComp, false, "VBoxXPCOMBase.xpt" },
#endif
#endif
{ kSupIFT_Dll, kSupID_SharedLib, true, "VRDPAuth" SUPLIB_DLL_SUFF },
{ kSupIFT_Dll, kSupID_SharedLib, true, "VBoxAuth" SUPLIB_DLL_SUFF },
{ kSupIFT_Dll, kSupID_SharedLib, true, "VBoxVRDP" SUPLIB_DLL_SUFF },
//#ifdef VBOX_WITH_HEADLESS
{ kSupIFT_Exe, kSupID_AppBin, true, "VBoxHeadless" SUPLIB_EXE_SUFF },
{ kSupIFT_Dll, kSupID_AppPrivArch, true, "VBoxHeadless" SUPLIB_DLL_SUFF },
{ kSupIFT_Dll, kSupID_AppPrivArch, true, "VBoxVideoRecFB" SUPLIB_DLL_SUFF },
//#endif
//#ifdef VBOX_WITH_QTGUI
{ kSupIFT_Exe, kSupID_AppBin, true, "VirtualBox" SUPLIB_EXE_SUFF },
{ kSupIFT_Dll, kSupID_AppPrivArch, true, "VirtualBox" SUPLIB_DLL_SUFF },
# if !defined(RT_OS_DARWIN) && !defined(RT_OS_WINDOWS) && !defined(RT_OS_OS2)
{ kSupIFT_Dll, kSupID_SharedLib, true, "VBoxKeyboard" SUPLIB_DLL_SUFF },
# endif
//#endif
//#ifdef VBOX_WITH_VBOXSDL
{ kSupIFT_Exe, kSupID_AppBin, true, "VBoxSDL" SUPLIB_EXE_SUFF },
{ kSupIFT_Dll, kSupID_AppPrivArch, true, "VBoxSDL" SUPLIB_DLL_SUFF },
//#endif
//#ifdef VBOX_WITH_WEBSERVICES
{ kSupIFT_Exe, kSupID_AppBin, true, "vboxwebsrv" SUPLIB_EXE_SUFF },
//#endif
#ifdef RT_OS_LINUX
{ kSupIFT_Exe, kSupID_AppBin, true, "VBoxTunctl" SUPLIB_EXE_SUFF },
#endif
//#ifdef VBOX_WITH_NETFLT
{ kSupIFT_Exe, kSupID_AppBin, true, "VBoxNetDHCP" SUPLIB_EXE_SUFF },
{ kSupIFT_Dll, kSupID_AppPrivArch, true, "VBoxNetDHCP" SUPLIB_DLL_SUFF },
//#endif
//#ifdef VBOX_WITH_LWIP_NAT
{ kSupIFT_Exe, kSupID_AppBin, true, "VBoxNetNAT" SUPLIB_EXE_SUFF },
{ kSupIFT_Dll, kSupID_AppPrivArch, true, "VBoxNetNAT" SUPLIB_DLL_SUFF },
//#endif
#if defined(VBOX_WITH_HARDENING) && defined(RT_OS_WINDOWS)
# define HARDENED_TESTCASE_BIN_ENTRY(a_szName) \
{ kSupIFT_TestExe, kSupID_AppBin, true, a_szName SUPLIB_EXE_SUFF }, \
{ kSupIFT_TestDll, kSupID_AppBin, true, a_szName SUPLIB_DLL_SUFF }
HARDENED_TESTCASE_BIN_ENTRY("tstMicro"),
HARDENED_TESTCASE_BIN_ENTRY("tstPDMAsyncCompletion"),
HARDENED_TESTCASE_BIN_ENTRY("tstPDMAsyncCompletionStress"),
HARDENED_TESTCASE_BIN_ENTRY("tstVMM"),
HARDENED_TESTCASE_BIN_ENTRY("tstVMREQ"),
# define HARDENED_TESTCASE_ENTRY(a_szName) \
{ kSupIFT_TestExe, kSupID_Testcase, true, a_szName SUPLIB_EXE_SUFF }, \
{ kSupIFT_TestDll, kSupID_Testcase, true, a_szName SUPLIB_DLL_SUFF }
HARDENED_TESTCASE_ENTRY("tstCFGM"),
HARDENED_TESTCASE_ENTRY("tstIntNet-1"),
HARDENED_TESTCASE_ENTRY("tstMMHyperHeap"),
HARDENED_TESTCASE_ENTRY("tstR0ThreadPreemptionDriver"),
HARDENED_TESTCASE_ENTRY("tstRTR0MemUserKernelDriver"),
HARDENED_TESTCASE_ENTRY("tstRTR0SemMutexDriver"),
HARDENED_TESTCASE_ENTRY("tstRTR0TimerDriver"),
HARDENED_TESTCASE_ENTRY("tstSSM"),
#endif
};
/** Array parallel to g_aSupInstallFiles containing per-file status info. */
static SUPVERIFIEDFILE g_aSupVerifiedFiles[RT_ELEMENTS(g_aSupInstallFiles)];
/** Array index by install directory specifier containing info about verified directories. */
static SUPVERIFIEDDIR g_aSupVerifiedDirs[kSupID_End];
/**
* Assembles the path to a directory.
*
* @returns VINF_SUCCESS on success, some error code on failure (fFatal
* decides whether it returns or not).
*
* @param enmDir The directory.
* @param pszDst Where to assemble the path.
* @param cchDst The size of the buffer.
* @param fFatal Whether failures should be treated as fatal (true) or not (false).
*/
static int supR3HardenedMakePath(SUPINSTDIR enmDir, char *pszDst, size_t cchDst, bool fFatal)
{
int rc;
switch (enmDir)
{
case kSupID_AppBin: /** @todo fix this AppBin crap (uncertain wtf some binaries actually are installed). */
case kSupID_Bin:
rc = supR3HardenedPathExecDir(pszDst, cchDst);
break;
case kSupID_SharedLib:
rc = supR3HardenedPathSharedLibs(pszDst, cchDst);
break;
case kSupID_AppPrivArch:
rc = supR3HardenedPathAppPrivateArch(pszDst, cchDst);
break;
case kSupID_AppPrivArchComp:
rc = supR3HardenedPathAppPrivateArch(pszDst, cchDst);
if (RT_SUCCESS(rc))
{
size_t off = suplibHardenedStrLen(pszDst);
if (cchDst - off >= sizeof("/components"))
suplibHardenedMemCopy(&pszDst[off], "/components", sizeof("/components"));
else
rc = VERR_BUFFER_OVERFLOW;
}
break;
case kSupID_AppPrivNoArch:
rc = supR3HardenedPathAppPrivateNoArch(pszDst, cchDst);
break;
case kSupID_Testcase:
rc = supR3HardenedPathExecDir(pszDst, cchDst);
if (RT_SUCCESS(rc))
{
size_t off = suplibHardenedStrLen(pszDst);
if (cchDst - off >= sizeof("/testcase"))
suplibHardenedMemCopy(&pszDst[off], "/testcase", sizeof("/testcase"));
else
rc = VERR_BUFFER_OVERFLOW;
}
break;
default:
return supR3HardenedError(VERR_INTERNAL_ERROR, fFatal,
"supR3HardenedMakePath: enmDir=%d\n", enmDir);
}
if (RT_FAILURE(rc))
supR3HardenedError(rc, fFatal,
"supR3HardenedMakePath: enmDir=%d rc=%d\n", enmDir, rc);
return rc;
}
/**
* Assembles the path to a file table entry, with or without the actual filename.
*
* @returns VINF_SUCCESS on success, some error code on failure (fFatal
* decides whether it returns or not).
*
* @param pFile The file table entry.
* @param pszDst Where to assemble the path.
* @param cchDst The size of the buffer.
* @param fWithFilename If set, the filename is included, otherwise it is omitted (no trailing slash).
* @param fFatal Whether failures should be treated as fatal (true) or not (false).
*/
static int supR3HardenedMakeFilePath(PCSUPINSTFILE pFile, char *pszDst, size_t cchDst, bool fWithFilename, bool fFatal)
{
/*
* Combine supR3HardenedMakePath and the filename.
*/
int rc = supR3HardenedMakePath(pFile->enmDir, pszDst, cchDst, fFatal);
if (RT_SUCCESS(rc) && fWithFilename)
{
size_t cchFile = suplibHardenedStrLen(pFile->pszFile);
size_t off = suplibHardenedStrLen(pszDst);
if (cchDst - off >= cchFile + 2)
{
pszDst[off++] = '/';
suplibHardenedMemCopy(&pszDst[off], pFile->pszFile, cchFile + 1);
}
else
rc = supR3HardenedError(VERR_BUFFER_OVERFLOW, fFatal,
"supR3HardenedMakeFilePath: pszFile=%s off=%lu\n",
pFile->pszFile, (long)off);
}
return rc;
}
/**
* Verifies a directory.
*
* @returns VINF_SUCCESS on success. On failure, an error code is returned if
* fFatal is clear and if it's set the function wont return.
* @param enmDir The directory specifier.
* @param fFatal Whether validation failures should be treated as
* fatal (true) or not (false).
*/
DECLHIDDEN(int) supR3HardenedVerifyFixedDir(SUPINSTDIR enmDir, bool fFatal)
{
/*
* Validate the index just to be on the safe side...
*/
if (enmDir <= kSupID_Invalid || enmDir >= kSupID_End)
return supR3HardenedError(VERR_INTERNAL_ERROR, fFatal,
"supR3HardenedVerifyDir: enmDir=%d\n", enmDir);
/*
* Already validated?
*/
if (g_aSupVerifiedDirs[enmDir].fValidated)
return VINF_SUCCESS; /** @todo revalidate? */
/* initialize the entry. */
if (g_aSupVerifiedDirs[enmDir].hDir != 0)
supR3HardenedError(VERR_INTERNAL_ERROR, fFatal,
"supR3HardenedVerifyDir: hDir=%p enmDir=%d\n",
(void *)g_aSupVerifiedDirs[enmDir].hDir, enmDir);
g_aSupVerifiedDirs[enmDir].hDir = -1;
g_aSupVerifiedDirs[enmDir].fValidated = false;
/*
* Make the path and open the directory.
*/
char szPath[RTPATH_MAX];
int rc = supR3HardenedMakePath(enmDir, szPath, sizeof(szPath), fFatal);
if (RT_SUCCESS(rc))
{
#if defined(RT_OS_WINDOWS)
PRTUTF16 pwszPath;
rc = RTStrToUtf16(szPath, &pwszPath);
if (RT_SUCCESS(rc))
{
HANDLE hDir = CreateFileW(pwszPath,
GENERIC_READ,
FILE_SHARE_READ | FILE_SHARE_DELETE | FILE_SHARE_WRITE,
NULL,
OPEN_EXISTING,
FILE_ATTRIBUTE_NORMAL | FILE_FLAG_BACKUP_SEMANTICS,
NULL);
if (hDir != INVALID_HANDLE_VALUE)
{
/** @todo check the type */
/* That's all on windows, for now at least... */
g_aSupVerifiedDirs[enmDir].hDir = (intptr_t)hDir;
g_aSupVerifiedDirs[enmDir].fValidated = true;
}
else if (enmDir == kSupID_Testcase)
{
g_aSupVerifiedDirs[enmDir].fValidated = true;
rc = VINF_SUCCESS; /* Optional directory, ignore if missing. */
}
else
{
int err = GetLastError();
rc = supR3HardenedError(VERR_PATH_NOT_FOUND, fFatal,
"supR3HardenedVerifyDir: Failed to open \"%s\": err=%d\n",
szPath, err);
}
RTUtf16Free(pwszPath);
}
else
rc = supR3HardenedError(rc, fFatal,
"supR3HardenedVerifyDir: Failed to convert \"%s\" to UTF-16: err=%d\n", szPath, rc);
#else /* UNIXY */
int fd = open(szPath, O_RDONLY, 0);
if (fd >= 0)
{
/*
* On unixy systems we'll make sure the directory is owned by root
* and not writable by the group and user.
*/
struct stat st;
if (!fstat(fd, &st))
{
if ( st.st_uid == 0
&& !(st.st_mode & (S_IWGRP | S_IWOTH))
&& S_ISDIR(st.st_mode))
{
g_aSupVerifiedDirs[enmDir].hDir = fd;
g_aSupVerifiedDirs[enmDir].fValidated = true;
}
else
{
if (!S_ISDIR(st.st_mode))
rc = supR3HardenedError(VERR_NOT_A_DIRECTORY, fFatal,
"supR3HardenedVerifyDir: \"%s\" is not a directory\n",
szPath, (long)st.st_uid);
else if (st.st_uid)
rc = supR3HardenedError(VERR_ACCESS_DENIED, fFatal,
"supR3HardenedVerifyDir: Cannot trust the directory \"%s\": not owned by root (st_uid=%ld)\n",
szPath, (long)st.st_uid);
else
rc = supR3HardenedError(VERR_ACCESS_DENIED, fFatal,
"supR3HardenedVerifyDir: Cannot trust the directory \"%s\": group and/or other writable (st_mode=0%lo)\n",
szPath, (long)st.st_mode);
close(fd);
}
}
else
{
int err = errno;
rc = supR3HardenedError(VERR_ACCESS_DENIED, fFatal,
"supR3HardenedVerifyDir: Failed to fstat \"%s\": %s (%d)\n",
szPath, strerror(err), err);
close(fd);
}
}
else if (enmDir == kSupID_Testcase)
{
g_aSupVerifiedDirs[enmDir].fValidated = true;
rc = VINF_SUCCESS; /* Optional directory, ignore if missing. */
}
else
{
int err = errno;
rc = supR3HardenedError(VERR_PATH_NOT_FOUND, fFatal,
"supR3HardenedVerifyDir: Failed to open \"%s\": %s (%d)\n",
szPath, strerror(err), err);
}
#endif /* UNIXY */
}
return rc;
}
#ifdef RT_OS_WINDOWS
/**
* Opens the file for verification.
*
* @returns VINF_SUCCESS on success. On failure, an error code is returned if
* fFatal is clear and if it's set the function wont return.
* @param pFile The file entry.
* @param fFatal Whether validation failures should be treated as
* kl fatal (true) or not (false).
* @param phFile The file handle, set to -1 if we failed to open
* the file. The function may return VINF_SUCCESS
* and a -1 handle if the file is optional.
*/
static int supR3HardenedVerifyFileOpen(PCSUPINSTFILE pFile, bool fFatal, intptr_t *phFile)
{
*phFile = -1;
char szPath[RTPATH_MAX];
int rc = supR3HardenedMakeFilePath(pFile, szPath, sizeof(szPath), true /*fWithFilename*/, fFatal);
if (RT_SUCCESS(rc))
{
PRTUTF16 pwszPath;
rc = RTStrToUtf16(szPath, &pwszPath);
if (RT_SUCCESS(rc))
{
HANDLE hFile = CreateFileW(pwszPath,
GENERIC_READ,
FILE_SHARE_READ,
NULL,
OPEN_EXISTING,
FILE_ATTRIBUTE_NORMAL,
NULL);
if (hFile)
{
*phFile = (intptr_t)hFile;
rc = VINF_SUCCESS;
}
else
{
int err = GetLastError();
if ( !pFile->fOptional
|| ( err != ERROR_FILE_NOT_FOUND
&& (err != ERROR_PATH_NOT_FOUND || pFile->enmDir != kSupID_Testcase) ) )
rc = supR3HardenedError(VERR_PATH_NOT_FOUND, fFatal,
"supR3HardenedVerifyFileInternal: Failed to open '%s': err=%d\n", szPath, err);
}
RTUtf16Free(pwszPath);
}
else
rc = supR3HardenedError(rc, fFatal, "supR3HardenedVerifyFileInternal: Failed to convert '%s' to UTF-16: %Rrc\n",
szPath, rc);
}
return rc;
}
/**
* Worker for supR3HardenedVerifyFileInternal.
*
* @returns VINF_SUCCESS on success. On failure, an error code is returned if
* fFatal is clear and if it's set the function wont return.
* @param pFile The file entry.
* @param pVerified The verification record.
* @param fFatal Whether validation failures should be treated as
* fatal (true) or not (false).
* @param fLeaveFileOpen Whether the file should be left open.
*/
static int supR3HardenedVerifyFileSignature(PCSUPINSTFILE pFile, PSUPVERIFIEDFILE pVerified, bool fFatal, bool fLeaveFileOpen)
{
# if defined(VBOX_WITH_HARDENING) && !defined(IN_SUP_R3_STATIC) /* Latter: Not in VBoxCpuReport and friends. */
/*
* Open the file if we have to.
*/
int rc;
intptr_t hFileOpened;
intptr_t hFile = pVerified->hFile;
if (hFile != -1)
hFileOpened = -1;
else
{
rc = supR3HardenedVerifyFileOpen(pFile, fFatal, &hFileOpened);
if (RT_FAILURE(rc))
return rc;
hFile = hFileOpened;
}
/*
* Verify the signature.
*/
char szErr[1024];
RTERRINFO ErrInfo;
RTErrInfoInit(&ErrInfo, szErr, sizeof(szErr));
uint32_t fFlags = SUPHNTVI_F_REQUIRE_BUILD_CERT;
if (pFile->enmType == kSupIFT_Rc)
fFlags |= SUPHNTVI_F_RC_IMAGE;
rc = supHardenedWinVerifyImageByHandleNoName((HANDLE)hFile, fFlags, &ErrInfo);
if (RT_SUCCESS(rc))
pVerified->fCheckedSignature = true;
else
{
pVerified->fCheckedSignature = false;
rc = supR3HardenedError(rc, fFatal, "supR3HardenedVerifyFileInternal: '%s': Image verify error rc=%Rrc: %s\n",
pFile->pszFile, rc, szErr);
}
/*
* Close the handle if we opened the file and we should close it.
*/
if (hFileOpened != -1)
{
if (fLeaveFileOpen && RT_SUCCESS(rc))
pVerified->hFile = hFileOpened;
else
CloseHandle((HANDLE)hFileOpened);
}
return rc;
# else /* Not checking signatures. */
return VINF_SUCCESS;
# endif /* Not checking signatures. */
}
#endif
/**
* Verifies a file entry.
*
* @returns VINF_SUCCESS on success. On failure, an error code is returned if
* fFatal is clear and if it's set the function wont return.
*
* @param iFile The file table index of the file to be verified.
* @param fFatal Whether validation failures should be treated as
* fatal (true) or not (false).
* @param fLeaveFileOpen Whether the file should be left open.
* @param fVerifyAll Set if this is an verify all call and we will
* postpone signature checking.
*/
static int supR3HardenedVerifyFileInternal(int iFile, bool fFatal, bool fLeaveFileOpen, bool fVerifyAll)
{
PCSUPINSTFILE pFile = &g_aSupInstallFiles[iFile];
PSUPVERIFIEDFILE pVerified = &g_aSupVerifiedFiles[iFile];
/*
* Already done validation? Do signature validation if we haven't yet.
*/
if (pVerified->fValidated)
{
/** @todo revalidate? Check that the file hasn't been replace or similar. */
#ifdef RT_OS_WINDOWS
if (!pVerified->fCheckedSignature && !fVerifyAll)
return supR3HardenedVerifyFileSignature(pFile, pVerified, fFatal, fLeaveFileOpen);
#endif
return VINF_SUCCESS;
}
/* initialize the entry. */
if (pVerified->hFile != 0)
supR3HardenedError(VERR_INTERNAL_ERROR, fFatal,
"supR3HardenedVerifyFileInternal: hFile=%p (%s)\n",
(void *)pVerified->hFile, pFile->pszFile);
pVerified->hFile = -1;
pVerified->fValidated = false;
pVerified->fCheckedSignature = false;
/*
* Verify the directory then proceed to open it.
* (This'll make sure the directory is opened and that we can (later)
* use openat if we wish.)
*/
int rc = supR3HardenedVerifyFixedDir(pFile->enmDir, fFatal);
if (RT_SUCCESS(rc))
{
#if defined(RT_OS_WINDOWS)
rc = supR3HardenedVerifyFileOpen(pFile, fFatal, &pVerified->hFile);
if (RT_SUCCESS(rc))
{
if (!fVerifyAll)
rc = supR3HardenedVerifyFileSignature(pFile, pVerified, fFatal, fLeaveFileOpen);
if (RT_SUCCESS(rc))
{
pVerified->fValidated = true;
if (!fLeaveFileOpen)
{
CloseHandle((HANDLE)pVerified->hFile);
pVerified->hFile = -1;
}
}
}
#else /* !RT_OS_WINDOWS */
char szPath[RTPATH_MAX];
rc = supR3HardenedMakeFilePath(pFile, szPath, sizeof(szPath), true /*fWithFilename*/, fFatal);
if (RT_SUCCESS(rc))
{
int fd = open(szPath, O_RDONLY, 0);
if (fd >= 0)
{
/*
* On unixy systems we'll make sure the file is owned by root
* and not writable by the group and user.
*/
struct stat st;
if (!fstat(fd, &st))
{
if ( st.st_uid == 0
&& !(st.st_mode & (S_IWGRP | S_IWOTH))
&& S_ISREG(st.st_mode))
{
/* it's valid. */
if (fLeaveFileOpen)
pVerified->hFile = fd;
else
close(fd);
pVerified->fValidated = true;
}
else
{
if (!S_ISREG(st.st_mode))
rc = supR3HardenedError(VERR_IS_A_DIRECTORY, fFatal,
"supR3HardenedVerifyFileInternal: \"%s\" is not a regular file\n",
szPath, (long)st.st_uid);
else if (st.st_uid)
rc = supR3HardenedError(VERR_ACCESS_DENIED, fFatal,
"supR3HardenedVerifyFileInternal: Cannot trust the file \"%s\": not owned by root (st_uid=%ld)\n",
szPath, (long)st.st_uid);
else
rc = supR3HardenedError(VERR_ACCESS_DENIED, fFatal,
"supR3HardenedVerifyFileInternal: Cannot trust the file \"%s\": group and/or other writable (st_mode=0%lo)\n",
szPath, (long)st.st_mode);
close(fd);
}
}
else
{
int err = errno;
rc = supR3HardenedError(VERR_ACCESS_DENIED, fFatal,
"supR3HardenedVerifyFileInternal: Failed to fstat \"%s\": %s (%d)\n",
szPath, strerror(err), err);
close(fd);
}
}
else
{
int err = errno;
if (!pFile->fOptional || err != ENOENT)
rc = supR3HardenedError(VERR_PATH_NOT_FOUND, fFatal,
"supR3HardenedVerifyFileInternal: Failed to open \"%s\": %s (%d)\n",
szPath, strerror(err), err);
}
}
#endif /* !RT_OS_WINDOWS */
}
return rc;
}
/**
* Verifies that the specified table entry matches the given filename.
*
* @returns VINF_SUCCESS if matching. On mismatch fFatal indicates whether an
* error is returned or we terminate the application.
*
* @param iFile The file table index.
* @param pszFilename The filename.
* @param fFatal Whether validation failures should be treated as
* fatal (true) or not (false).
*/
static int supR3HardenedVerifySameFile(int iFile, const char *pszFilename, bool fFatal)
{
PCSUPINSTFILE pFile = &g_aSupInstallFiles[iFile];
/*
* Construct the full path for the file table entry
* and compare it with the specified file.
*/
char szName[RTPATH_MAX];
int rc = supR3HardenedMakeFilePath(pFile, szName, sizeof(szName), true /*fWithFilename*/, fFatal);
if (RT_FAILURE(rc))
return rc;
if (SUP_COMP_FILENAME(szName, pszFilename))
{
/*
* Normalize the two paths and compare again.
*/
rc = VERR_NOT_SAME_DEVICE;
#if defined(RT_OS_WINDOWS)
LPSTR pszIgnored;
char szName2[RTPATH_MAX];
if ( GetFullPathName(szName, RT_ELEMENTS(szName2), &szName2[0], &pszIgnored)
&& GetFullPathName(pszFilename, RT_ELEMENTS(szName), &szName[0], &pszIgnored))
if (!SUP_COMP_FILENAME(szName2, szName))
rc = VINF_SUCCESS;
#else
AssertCompile(RTPATH_MAX >= PATH_MAX);
char szName2[RTPATH_MAX];
if ( realpath(szName, szName2) != NULL
&& realpath(pszFilename, szName) != NULL)
if (!SUP_COMP_FILENAME(szName2, szName))
rc = VINF_SUCCESS;
#endif
if (RT_FAILURE(rc))
{
supR3HardenedMakeFilePath(pFile, szName, sizeof(szName), true /*fWithFilename*/, fFatal);
return supR3HardenedError(rc, fFatal,
"supR3HardenedVerifySameFile: \"%s\" isn't the same as \"%s\"\n",
pszFilename, szName);
}
}
/*
* Check more stuff like the stat info if it's an already open file?
*/
return VINF_SUCCESS;
}
/**
* Verifies a file.
*
* @returns VINF_SUCCESS on success.
* VERR_NOT_FOUND if the file isn't in the table, this isn't ever a fatal error.
* On verification failure, an error code will be returned when fFatal is clear,
* otherwise the program will be terminated.
*
* @param pszFilename The filename.
* @param fFatal Whether validation failures should be treated as
* fatal (true) or not (false).
*/
DECLHIDDEN(int) supR3HardenedVerifyFixedFile(const char *pszFilename, bool fFatal)
{
/*
* Lookup the file and check if it's the same file.
*/
const char *pszName = supR3HardenedPathFilename(pszFilename);
for (unsigned iFile = 0; iFile < RT_ELEMENTS(g_aSupInstallFiles); iFile++)
if (!SUP_COMP_FILENAME(pszName, g_aSupInstallFiles[iFile].pszFile))
{
int rc = supR3HardenedVerifySameFile(iFile, pszFilename, fFatal);
if (RT_SUCCESS(rc))
rc = supR3HardenedVerifyFileInternal(iFile, fFatal, false /* fLeaveFileOpen */, false /* fVerifyAll */);
return rc;
}
return VERR_NOT_FOUND;
}
/**
* Verifies a program, worker for supR3HardenedVerifyAll.
*
* @returns See supR3HardenedVerifyAll.
* @param pszProgName See supR3HardenedVerifyAll.
* @param fFatal See supR3HardenedVerifyAll.
* @param fLeaveOpen The leave open setting used by
* supR3HardenedVerifyAll.
*/
static int supR3HardenedVerifyProgram(const char *pszProgName, bool fFatal, bool fLeaveOpen)
{
/*
* Search the table looking for the executable and the DLL/DYLIB/SO.
*/
int rc = VINF_SUCCESS;
bool fExe = false;
bool fDll = false;
size_t const cchProgName = suplibHardenedStrLen(pszProgName);
for (unsigned iFile = 0; iFile < RT_ELEMENTS(g_aSupInstallFiles); iFile++)
if (!suplibHardenedStrNCmp(pszProgName, g_aSupInstallFiles[iFile].pszFile, cchProgName))
{
if ( ( g_aSupInstallFiles[iFile].enmType == kSupIFT_Dll
|| g_aSupInstallFiles[iFile].enmType == kSupIFT_TestDll)
&& !suplibHardenedStrCmp(&g_aSupInstallFiles[iFile].pszFile[cchProgName], SUPLIB_DLL_SUFF))
{
/* This only has to be found (once). */
if (fDll)
rc = supR3HardenedError(VERR_INTERNAL_ERROR, fFatal,
"supR3HardenedVerifyProgram: duplicate DLL entry for \"%s\"\n", pszProgName);
else
rc = supR3HardenedVerifyFileInternal(iFile, fFatal, fLeaveOpen, false /* fVerifyAll */);
fDll = true;
}
else if ( ( g_aSupInstallFiles[iFile].enmType == kSupIFT_Exe
|| g_aSupInstallFiles[iFile].enmType == kSupIFT_TestExe)
&& !suplibHardenedStrCmp(&g_aSupInstallFiles[iFile].pszFile[cchProgName], SUPLIB_EXE_SUFF))
{
/* Here we'll have to check that the specific program is the same as the entry. */
if (fExe)
rc = supR3HardenedError(VERR_INTERNAL_ERROR, fFatal,
"supR3HardenedVerifyProgram: duplicate EXE entry for \"%s\"\n", pszProgName);
else
rc = supR3HardenedVerifyFileInternal(iFile, fFatal, fLeaveOpen, false /* fVerifyAll */);
fExe = true;
char szFilename[RTPATH_MAX];
int rc2 = supR3HardenedPathExecDir(szFilename, sizeof(szFilename) - cchProgName - sizeof(SUPLIB_EXE_SUFF));
if (RT_SUCCESS(rc2))
{
suplibHardenedStrCat(szFilename, "/");
suplibHardenedStrCat(szFilename, g_aSupInstallFiles[iFile].pszFile);
supR3HardenedVerifySameFile(iFile, szFilename, fFatal);
}
else
rc = supR3HardenedError(rc2, fFatal,
"supR3HardenedVerifyProgram: failed to query program path: rc=%d\n", rc2);
}
}
/*
* Check the findings.
*/
if (RT_SUCCESS(rc))
{
if (!fDll && !fExe)
rc = supR3HardenedError(VERR_NOT_FOUND, fFatal,
"supR3HardenedVerifyProgram: Couldn't find the program \"%s\"\n", pszProgName);
else if (!fExe)
rc = supR3HardenedError(VERR_NOT_FOUND, fFatal,
"supR3HardenedVerifyProgram: Couldn't find the EXE entry for \"%s\"\n", pszProgName);
else if (!fDll)
rc = supR3HardenedError(VERR_NOT_FOUND, fFatal,
"supR3HardenedVerifyProgram: Couldn't find the DLL entry for \"%s\"\n", pszProgName);
}
return rc;
}
/**
* Verifies all the known files (called from SUPR3HardenedMain).
*
* @returns VINF_SUCCESS on success.
* On verification failure, an error code will be returned when fFatal is clear,
* otherwise the program will be terminated.
*
* @param fFatal Whether validation failures should be treated as
* fatal (true) or not (false).
* @param pszProgName The program name. This is used to verify that
* both the executable and corresponding
* DLL/DYLIB/SO are valid.
*/
DECLHIDDEN(int) supR3HardenedVerifyAll(bool fFatal, const char *pszProgName)
{
/*
* On windows
*/
#if defined(RT_OS_WINDOWS)
bool fLeaveOpen = true;
#else
bool fLeaveOpen = false;
#endif
/*
* The verify all the files.
*/
int rc = VINF_SUCCESS;
for (unsigned iFile = 0; iFile < RT_ELEMENTS(g_aSupInstallFiles); iFile++)
{
int rc2 = supR3HardenedVerifyFileInternal(iFile, fFatal, fLeaveOpen, true /* fVerifyAll */);
if (RT_FAILURE(rc2) && RT_SUCCESS(rc))
rc = rc2;
}
/*
* Verify the program name, that is to say, check that it's in the table
* (thus verified above) and verify the signature on platforms where we
* sign things.
*/
int rc2 = supR3HardenedVerifyProgram(pszProgName, fFatal, fLeaveOpen);
if (RT_FAILURE(rc2) && RT_SUCCESS(rc))
rc2 = rc;
return rc;
}
/**
* Copies the N messages into the error buffer and returns @a rc.
*
* @returns Returns @a rc
* @param rc The return code.
* @param pErrInfo The error info structure.
* @param cMsgs The number of messages in the ellipsis.
* @param ... Message parts.
*/
static int supR3HardenedSetErrorN(int rc, PRTERRINFO pErrInfo, unsigned cMsgs, ...)
{
if (pErrInfo)
{
size_t cbErr = pErrInfo->cbMsg;
char *pszErr = pErrInfo->pszMsg;
va_list va;
va_start(va, cMsgs);
while (cMsgs-- > 0 && cbErr > 0)
{
const char *pszMsg = va_arg(va, const char *);
size_t cchMsg = VALID_PTR(pszMsg) ? suplibHardenedStrLen(pszMsg) : 0;
if (cchMsg >= cbErr)
cchMsg = cbErr - 1;
suplibHardenedMemCopy(pszErr, pszMsg, cchMsg);
pszErr[cchMsg] = '\0';
pszErr += cchMsg;
cbErr -= cchMsg;
}
va_end(va);
pErrInfo->rc = rc;
pErrInfo->fFlags |= RTERRINFO_FLAGS_SET;
}
return rc;
}
/**
* Copies the three messages into the error buffer and returns @a rc.
*
* @returns Returns @a rc
* @param rc The return code.
* @param pErrInfo The error info structure.
* @param pszMsg1 The first message part.
* @param pszMsg2 The second message part.
* @param pszMsg3 The third message part.
*/
static int supR3HardenedSetError3(int rc, PRTERRINFO pErrInfo, const char *pszMsg1,
const char *pszMsg2, const char *pszMsg3)
{
return supR3HardenedSetErrorN(rc, pErrInfo, 3, pszMsg1, pszMsg2, pszMsg3);
}
#ifdef SOME_UNUSED_FUNCTION
/**
* Copies the two messages into the error buffer and returns @a rc.
*
* @returns Returns @a rc
* @param rc The return code.
* @param pErrInfo The error info structure.
* @param pszMsg1 The first message part.
* @param pszMsg2 The second message part.
*/
static int supR3HardenedSetError2(int rc, PRTERRINFO pErrInfo, const char *pszMsg1,
const char *pszMsg2)
{
return supR3HardenedSetErrorN(rc, pErrInfo, 2, pszMsg1, pszMsg2);
}
/**
* Copies the error message to the error buffer and returns @a rc.
*
* @returns Returns @a rc
* @param rc The return code.
* @param pErrInfo The error info structure.
* @param pszMsg The message.
*/
static int supR3HardenedSetError(int rc, PRTERRINFO pErrInfo, const char *pszMsg)
{
return supR3HardenedSetErrorN(rc, pErrInfo, 1, pszMsg);
}
#endif /* SOME_UNUSED_FUNCTION */
/**
* Output from a successfull supR3HardenedVerifyPathSanity call.
*/
typedef struct SUPR3HARDENEDPATHINFO
{
/** The length of the path in szCopy. */
uint16_t cch;
/** The number of path components. */
uint16_t cComponents;
/** Set if the path ends with slash, indicating that it's a directory
* reference and not a file reference. The slash has been removed from
* the copy. */
bool fDirSlash;
/** The offset where each path component starts, i.e. the char after the
* slash. The array has cComponents + 1 entries, where the final one is
* cch + 1 so that one can always terminate the current component by
* szPath[aoffComponent[i] - 1] = '\0'. */
uint16_t aoffComponents[32+1];
/** A normalized copy of the path.
* Reserve some extra space so we can be more relaxed about overflow
* checks and terminator paddings, especially when recursing. */
char szPath[SUPR3HARDENED_MAX_PATH * 2];
} SUPR3HARDENEDPATHINFO;
/** Pointer to a parsed path. */
typedef SUPR3HARDENEDPATHINFO *PSUPR3HARDENEDPATHINFO;
/**
* Verifies that the path is absolutely sane, it also parses the path.
*
* A sane path starts at the root (w/ drive letter on DOS derived systems) and
* does not have any relative bits (/../) or unnecessary slashes (/bin//ls).
* Sane paths are less or equal to SUPR3HARDENED_MAX_PATH bytes in length. UNC
* paths are not supported.
*
* @returns VBox status code.
* @param pszPath The path to check.
* @param pErrInfo The error info structure.
* @param pInfo Where to return a copy of the path along with
* parsing information.
*/
static int supR3HardenedVerifyPathSanity(const char *pszPath, PRTERRINFO pErrInfo, PSUPR3HARDENEDPATHINFO pInfo)
{
const char *pszSrc = pszPath;
char *pszDst = pInfo->szPath;
/*
* Check that it's an absolute path and copy the volume/root specifier.
*/
#if defined(RT_OS_WINDOWS) || defined(RT_OS_OS2)
if ( !RT_C_IS_ALPHA(pszSrc[0])
|| pszSrc[1] != ':'
|| !RTPATH_IS_SLASH(pszSrc[2]))
return supR3HardenedSetError3(VERR_SUPLIB_PATH_NOT_ABSOLUTE, pErrInfo, "The path is not absolute: '", pszPath, "'");
*pszDst++ = RT_C_TO_UPPER(pszSrc[0]);
*pszDst++ = ':';
*pszDst++ = RTPATH_SLASH;
pszSrc += 3;
#else
if (!RTPATH_IS_SLASH(pszSrc[0]))
return supR3HardenedSetError3(VERR_SUPLIB_PATH_NOT_ABSOLUTE, pErrInfo, "The path is not absolute: '", pszPath, "'");
*pszDst++ = RTPATH_SLASH;
pszSrc += 1;
#endif
/*
* No path specifying the root or something very shortly thereafter will
* be approved of.
*/
if (pszSrc[0] == '\0')
return supR3HardenedSetError3(VERR_SUPLIB_PATH_IS_ROOT, pErrInfo, "The path is root: '", pszPath, "'");
if ( pszSrc[1] == '\0'
|| pszSrc[2] == '\0')
return supR3HardenedSetError3(VERR_SUPLIB_PATH_TOO_SHORT, pErrInfo, "The path is too short: '", pszPath, "'");
/*
* Check each component. No parent references or double slashes.
*/
pInfo->cComponents = 0;
pInfo->fDirSlash = false;
while (pszSrc[0])
{
/* Sanity checks. */
if (RTPATH_IS_SLASH(pszSrc[0])) /* can be relaxed if we care. */
return supR3HardenedSetError3(VERR_SUPLIB_PATH_NOT_CLEAN, pErrInfo,
"The path is not clean of double slashes: '", pszPath, "'");
if ( pszSrc[0] == '.'
&& pszSrc[1] == '.'
&& RTPATH_IS_SLASH(pszSrc[2]))
return supR3HardenedSetError3(VERR_SUPLIB_PATH_NOT_ABSOLUTE, pErrInfo,
"The path is not absolute: '", pszPath, "'");
/* Record the start of the component. */
if (pInfo->cComponents >= RT_ELEMENTS(pInfo->aoffComponents) - 1)
return supR3HardenedSetError3(VERR_SUPLIB_PATH_TOO_MANY_COMPONENTS, pErrInfo,
"The path has too many components: '", pszPath, "'");
pInfo->aoffComponents[pInfo->cComponents++] = pszDst - &pInfo->szPath[0];
/* Traverse to the end of the component, copying it as we go along. */
while (pszSrc[0])
{
if (RTPATH_IS_SLASH(pszSrc[0]))
{
pszSrc++;
if (*pszSrc)
*pszDst++ = RTPATH_SLASH;
else
pInfo->fDirSlash = true;
break;
}
*pszDst++ = *pszSrc++;
if ((uintptr_t)(pszDst - &pInfo->szPath[0]) >= SUPR3HARDENED_MAX_PATH)
return supR3HardenedSetError3(VERR_SUPLIB_PATH_TOO_LONG, pErrInfo,
"The path is too long: '", pszPath, "'");
}
}
/* Terminate the string and enter its length. */
pszDst[0] = '\0';
pszDst[1] = '\0'; /* for aoffComponents */
pInfo->cch = (uint16_t)(pszDst - &pInfo->szPath[0]);
pInfo->aoffComponents[pInfo->cComponents] = pInfo->cch + 1;
return VINF_SUCCESS;
}
/**
* The state information collected by supR3HardenedVerifyFsObject.
*
* This can be used to verify that a directory we've opened for enumeration is
* the same as the one that supR3HardenedVerifyFsObject just verified. It can
* equally be used to verify a native specfied by the user.
*/
typedef struct SUPR3HARDENEDFSOBJSTATE
{
#ifdef RT_OS_WINDOWS
/** Not implemented for windows yet. */
char chTodo;
#else
/** The stat output. */
struct stat Stat;
#endif
} SUPR3HARDENEDFSOBJSTATE;
/** Pointer to a file system object state. */
typedef SUPR3HARDENEDFSOBJSTATE *PSUPR3HARDENEDFSOBJSTATE;
/** Pointer to a const file system object state. */
typedef SUPR3HARDENEDFSOBJSTATE const *PCSUPR3HARDENEDFSOBJSTATE;
/**
* Query information about a file system object by path.
*
* @returns VBox status code, error buffer filled on failure.
* @param pszPath The path to the object.
* @param pFsObjState Where to return the state information.
* @param pErrInfo The error info structure.
*/
static int supR3HardenedQueryFsObjectByPath(char const *pszPath, PSUPR3HARDENEDFSOBJSTATE pFsObjState, PRTERRINFO pErrInfo)
{
#if defined(RT_OS_WINDOWS)
/** @todo Windows hardening. */
pFsObjState->chTodo = 0;
return VINF_SUCCESS;
#else
/*
* Stat the object, do not follow links.
*/
if (lstat(pszPath, &pFsObjState->Stat) != 0)
{
/* Ignore access errors */
if (errno != EACCES)
return supR3HardenedSetErrorN(VERR_SUPLIB_STAT_FAILED, pErrInfo,
5, "stat failed with ", strerror(errno), " on: '", pszPath, "'");
}
/*
* Read ACLs.
*/
/** @todo */
return VINF_SUCCESS;
#endif
}
/**
* Query information about a file system object by native handle.
*
* @returns VBox status code, error buffer filled on failure.
* @param hNative The native handle to the object @a pszPath
* specifies and this should be verified to be the
* same file system object.
* @param pFsObjState Where to return the state information.
* @param pszPath The path to the object. (For the error message
* only.)
* @param pErrInfo The error info structure.
*/
static int supR3HardenedQueryFsObjectByHandle(RTHCUINTPTR hNative, PSUPR3HARDENEDFSOBJSTATE pFsObjState,
char const *pszPath, PRTERRINFO pErrInfo)
{
#if defined(RT_OS_WINDOWS)
/** @todo Windows hardening. */
pFsObjState->chTodo = 0;
return VINF_SUCCESS;
#else
/*
* Stat the object, do not follow links.
*/
if (fstat((int)hNative, &pFsObjState->Stat) != 0)
return supR3HardenedSetErrorN(VERR_SUPLIB_STAT_FAILED, pErrInfo,
5, "fstat failed with ", strerror(errno), " on '", pszPath, "'");
/*
* Read ACLs.
*/
/** @todo */
return VINF_SUCCESS;
#endif
}
/**
* Verifies that the file system object indicated by the native handle is the
* same as the one @a pFsObjState indicates.
*
* @returns VBox status code, error buffer filled on failure.
* @param pFsObjState1 File system object information/state by path.
* @param pFsObjState2 File system object information/state by handle.
* @param pszPath The path to the object @a pFsObjState
* describes. (For the error message.)
* @param pErrInfo The error info structure.
*/
static int supR3HardenedIsSameFsObject(PCSUPR3HARDENEDFSOBJSTATE pFsObjState1, PCSUPR3HARDENEDFSOBJSTATE pFsObjState2,
const char *pszPath, PRTERRINFO pErrInfo)
{
#if defined(RT_OS_WINDOWS)
/** @todo Windows hardening. */
return VINF_SUCCESS;
#elif defined(RT_OS_OS2)
return VINF_SUCCESS;
#else
/*
* Compare the ino+dev, then the uid+gid and finally the important mode
* bits. Technically the first one should be enough, but we're paranoid.
*/
if ( pFsObjState1->Stat.st_ino != pFsObjState2->Stat.st_ino
|| pFsObjState1->Stat.st_dev != pFsObjState2->Stat.st_dev)
return supR3HardenedSetError3(VERR_SUPLIB_NOT_SAME_OBJECT, pErrInfo,
"The native handle is not the same as '", pszPath, "' (ino/dev)");
if ( pFsObjState1->Stat.st_uid != pFsObjState2->Stat.st_uid
|| pFsObjState1->Stat.st_gid != pFsObjState2->Stat.st_gid)
return supR3HardenedSetError3(VERR_SUPLIB_NOT_SAME_OBJECT, pErrInfo,
"The native handle is not the same as '", pszPath, "' (uid/gid)");
if ( (pFsObjState1->Stat.st_mode & (S_IFMT | S_IWUSR | S_IWGRP | S_IWOTH))
!= (pFsObjState2->Stat.st_mode & (S_IFMT | S_IWUSR | S_IWGRP | S_IWOTH)))
return supR3HardenedSetError3(VERR_SUPLIB_NOT_SAME_OBJECT, pErrInfo,
"The native handle is not the same as '", pszPath, "' (mode)");
return VINF_SUCCESS;
#endif
}
/**
* Verifies a file system object (file or directory).
*
* @returns VBox status code, error buffer filled on failure.
* @param pFsObjState The file system object information/state to be
* verified.
* @param fDir Whether this is a directory or a file.
* @param fRelaxed Whether we can be more relaxed about this
* directory (only used for grand parent
* directories).
* @param pszPath The path to the object. For error messages and
* securing a couple of hacks.
* @param pErrInfo The error info structure.
*/
static int supR3HardenedVerifyFsObject(PCSUPR3HARDENEDFSOBJSTATE pFsObjState, bool fDir, bool fRelaxed,
const char *pszPath, PRTERRINFO pErrInfo)
{
#if defined(RT_OS_WINDOWS)
/** @todo Windows hardening. */
NOREF(pFsObjState); NOREF(fDir); NOREF(fRelaxed); NOREF(pszPath); NOREF(pErrInfo);
return VINF_SUCCESS;
#elif defined(RT_OS_OS2)
/* No hardening here - it's a single user system. */
NOREF(pFsObjState); NOREF(fDir); NOREF(fRelaxed); NOREF(pszPath); NOREF(pErrInfo);
return VINF_SUCCESS;
#else
/*
* The owner must be root.
*
* This can be extended to include predefined system users if necessary.
*/
if (pFsObjState->Stat.st_uid != 0)
return supR3HardenedSetError3(VERR_SUPLIB_OWNER_NOT_ROOT, pErrInfo, "The owner is not root: '", pszPath, "'");
/*
* The object type must be directory or file, no symbolic links or other
* risky stuff (sorry dude, but we're paranoid on purpose here).
*/
if ( !S_ISDIR(pFsObjState->Stat.st_mode)
&& !S_ISREG(pFsObjState->Stat.st_mode))
{
if (S_ISLNK(pFsObjState->Stat.st_mode))
return supR3HardenedSetError3(VERR_SUPLIB_SYMLINKS_ARE_NOT_PERMITTED, pErrInfo,
"Symlinks are not permitted: '", pszPath, "'");
return supR3HardenedSetError3(VERR_SUPLIB_NOT_DIR_NOT_FILE, pErrInfo,
"Not regular file or directory: '", pszPath, "'");
}
if (fDir != !!S_ISDIR(pFsObjState->Stat.st_mode))
{
if (S_ISDIR(pFsObjState->Stat.st_mode))
return supR3HardenedSetError3(VERR_SUPLIB_IS_DIRECTORY, pErrInfo,
"Expected file but found directory: '", pszPath, "'");
return supR3HardenedSetError3(VERR_SUPLIB_IS_FILE, pErrInfo,
"Expected directory but found file: '", pszPath, "'");
}
/*
* The group does not matter if it does not have write access, if it has
* write access it must be group 0 (root/wheel/whatever).
*
* This can be extended to include predefined system groups or groups that
* only root is member of.
*/
if ( (pFsObjState->Stat.st_mode & S_IWGRP)
&& pFsObjState->Stat.st_gid != 0)
{
#ifdef RT_OS_DARWIN
/* HACK ALERT: On Darwin /Applications is root:admin with admin having
full access. So, to work around we relax the hardening a bit and
permit grand parents and beyond to be group writable by admin. */
/** @todo dynamically resolve the admin group? */
bool fBad = !fRelaxed || pFsObjState->Stat.st_gid != 80 /*admin*/ || suplibHardenedStrCmp(pszPath, "/Applications");
#elif defined(RT_OS_FREEBSD)
/* HACK ALERT: PC-BSD 9 has group-writable /usr/pib directory which is
similar to /Applications on OS X (see above).
On FreeBSD root is normally the only member of this group, on
PC-BSD the default user is a member. */
/** @todo dynamically resolve the operator group? */
bool fBad = !fRelaxed || pFsObjState->Stat.st_gid != 5 /*operator*/ || suplibHardenedStrCmp(pszPath, "/usr/pbi");
NOREF(fRelaxed);
#else
NOREF(fRelaxed);
bool fBad = true;
#endif
if (fBad)
return supR3HardenedSetError3(VERR_SUPLIB_WRITE_NON_SYS_GROUP, pErrInfo,
"The group is not a system group and it has write access to '", pszPath, "'");
}
/*
* World must not have write access. There is no relaxing this rule.
*/
if (pFsObjState->Stat.st_mode & S_IWOTH)
return supR3HardenedSetError3(VERR_SUPLIB_WORLD_WRITABLE, pErrInfo,
"World writable: '", pszPath, "'");
/*
* Check the ACLs.
*/
/** @todo */
return VINF_SUCCESS;
#endif
}
/**
* Verifies that the file system object indicated by the native handle is the
* same as the one @a pFsObjState indicates.
*
* @returns VBox status code, error buffer filled on failure.
* @param hNative The native handle to the object @a pszPath
* specifies and this should be verified to be the
* same file system object.
* @param pFsObjState The information/state returned by a previous
* query call.
* @param pszPath The path to the object @a pFsObjState
* describes. (For the error message.)
* @param pErrInfo The error info structure.
*/
static int supR3HardenedVerifySameFsObject(RTHCUINTPTR hNative, PCSUPR3HARDENEDFSOBJSTATE pFsObjState,
const char *pszPath, PRTERRINFO pErrInfo)
{
SUPR3HARDENEDFSOBJSTATE FsObjState2;
int rc = supR3HardenedQueryFsObjectByHandle(hNative, &FsObjState2, pszPath, pErrInfo);
if (RT_SUCCESS(rc))
rc = supR3HardenedIsSameFsObject(pFsObjState, &FsObjState2, pszPath, pErrInfo);
return rc;
}
/**
* Does the recursive directory enumeration.
*
* @returns VBox status code, error buffer filled on failure.
* @param pszDirPath The path buffer containing the subdirectory to
* enumerate followed by a slash (this is never
* the root slash). The buffer is RTPATH_MAX in
* size and anything starting at @a cchDirPath
* - 1 and beyond is scratch space.
* @param cchDirPath The length of the directory path + slash.
* @param pFsObjState Pointer to the file system object state buffer.
* On input this will hold the stats for
* the directory @a pszDirPath indicates and will
* be used to verified that we're opening the same
* thing.
* @param fRecursive Whether to recurse into subdirectories.
* @param pErrInfo The error info structure.
*/
static int supR3HardenedVerifyDirRecursive(char *pszDirPath, size_t cchDirPath, PSUPR3HARDENEDFSOBJSTATE pFsObjState,
bool fRecursive, PRTERRINFO pErrInfo)
{
#if defined(RT_OS_WINDOWS)
/** @todo Windows hardening. */
return VINF_SUCCESS;
#elif defined(RT_OS_OS2)
/* No hardening here - it's a single user system. */
return VINF_SUCCESS;
#else
/*
* Open the directory. Now, we could probably eliminate opendir here
* and go down on kernel API level (open + getdents for instance), however
* that's not very portable and hopefully not necessary.
*/
DIR *pDir = opendir(pszDirPath);
if (!pDir)
{
/* Ignore access errors. */
if (errno == EACCES)
return VINF_SUCCESS;
return supR3HardenedSetErrorN(VERR_SUPLIB_DIR_ENUM_FAILED, pErrInfo,
5, "opendir failed with ", strerror(errno), " on '", pszDirPath, "'");
}
if (dirfd(pDir) != -1)
{
int rc = supR3HardenedVerifySameFsObject(dirfd(pDir), pFsObjState, pszDirPath, pErrInfo);
if (RT_FAILURE(rc))
{
closedir(pDir);
return rc;
}
}
/*
* Enumerate the directory, check all the requested bits.
*/
int rc = VINF_SUCCESS;
for (;;)
{
pszDirPath[cchDirPath] = '\0'; /* for error messages. */
struct dirent Entry;
struct dirent *pEntry;
int iErr = readdir_r(pDir, &Entry, &pEntry);
if (iErr)
{
rc = supR3HardenedSetErrorN(VERR_SUPLIB_DIR_ENUM_FAILED, pErrInfo,
5, "readdir_r failed with ", strerror(iErr), " in '", pszDirPath, "'");
break;
}
if (!pEntry)
break;
/*
* Check the length and copy it into the path buffer so it can be
* stat()'ed.
*/
size_t cchName = suplibHardenedStrLen(pEntry->d_name);
if (cchName + cchDirPath > SUPR3HARDENED_MAX_PATH)
{
rc = supR3HardenedSetErrorN(VERR_SUPLIB_PATH_TOO_LONG, pErrInfo,
4, "Path grew too long during recursion: '", pszDirPath, pEntry->d_name, "'");
break;
}
suplibHardenedMemCopy(&pszDirPath[cchName], pEntry->d_name, cchName + 1);
/*
* Query the information about the entry and verify it.
* (We don't bother skipping '.' and '..' at this point, a little bit
* of extra checks doesn't hurt and neither requires relaxed handling.)
*/
rc = supR3HardenedQueryFsObjectByPath(pszDirPath, pFsObjState, pErrInfo);
if (RT_SUCCESS(rc))
break;
rc = supR3HardenedVerifyFsObject(pFsObjState, S_ISDIR(pFsObjState->Stat.st_mode), false /*fRelaxed*/,
pszDirPath, pErrInfo);
if (RT_FAILURE(rc))
break;
/*
* Recurse into subdirectories if requested.
*/
if ( fRecursive
&& S_ISDIR(pFsObjState->Stat.st_mode)
&& suplibHardenedStrCmp(pEntry->d_name, ".")
&& suplibHardenedStrCmp(pEntry->d_name, ".."))
{
pszDirPath[cchDirPath + cchName] = RTPATH_SLASH;
pszDirPath[cchDirPath + cchName + 1] = '\0';
rc = supR3HardenedVerifyDirRecursive(pszDirPath, cchDirPath + cchName + 1, pFsObjState,
fRecursive, pErrInfo);
if (RT_FAILURE(rc))
break;
}
}
closedir(pDir);
return VINF_SUCCESS;
#endif
}
/**
* Worker for SUPR3HardenedVerifyDir.
*
* @returns See SUPR3HardenedVerifyDir.
* @param pszDirPath See SUPR3HardenedVerifyDir.
* @param fRecursive See SUPR3HardenedVerifyDir.
* @param fCheckFiles See SUPR3HardenedVerifyDir.
* @param pErrInfo See SUPR3HardenedVerifyDir.
*/
DECLHIDDEN(int) supR3HardenedVerifyDir(const char *pszDirPath, bool fRecursive, bool fCheckFiles, PRTERRINFO pErrInfo)
{
/*
* Validate the input path and parse it.
*/
SUPR3HARDENEDPATHINFO Info;
int rc = supR3HardenedVerifyPathSanity(pszDirPath, pErrInfo, &Info);
if (RT_FAILURE(rc))
return rc;
/*
* Verify each component from the root up.
*/
SUPR3HARDENEDFSOBJSTATE FsObjState;
uint32_t const cComponents = Info.cComponents;
for (uint32_t iComponent = 0; iComponent < cComponents; iComponent++)
{
bool fRelaxed = iComponent + 2 < cComponents;
Info.szPath[Info.aoffComponents[iComponent + 1] - 1] = '\0';
rc = supR3HardenedQueryFsObjectByPath(Info.szPath, &FsObjState, pErrInfo);
if (RT_SUCCESS(rc))
rc = supR3HardenedVerifyFsObject(&FsObjState, true /*fDir*/, fRelaxed, Info.szPath, pErrInfo);
if (RT_FAILURE(rc))
return rc;
Info.szPath[Info.aoffComponents[iComponent + 1] - 1] = iComponent + 1 != cComponents ? RTPATH_SLASH : '\0';
}
/*
* Check files and subdirectories if requested.
*/
if (fCheckFiles || fRecursive)
{
Info.szPath[Info.cch] = RTPATH_SLASH;
Info.szPath[Info.cch + 1] = '\0';
return supR3HardenedVerifyDirRecursive(Info.szPath, Info.cch + 1, &FsObjState,
fRecursive, pErrInfo);
}
return VINF_SUCCESS;
}
/**
* Verfies a file.
*
* @returns VBox status code, error buffer filled on failure.
* @param pszFilename The file to verify.
* @param hNativeFile Handle to the file, verify that it's the same
* as we ended up with when verifying the path.
* RTHCUINTPTR_MAX means NIL here.
* @param fMaybe3rdParty Set if the file is could be a supplied by a
* third party. Different validation rules may
* apply to 3rd party code on some platforms.
* @param pErrInfo Where to return extended error information.
* Optional.
*/
DECLHIDDEN(int) supR3HardenedVerifyFile(const char *pszFilename, RTHCUINTPTR hNativeFile,
bool fMaybe3rdParty, PRTERRINFO pErrInfo)
{
/*
* Validate the input path and parse it.
*/
SUPR3HARDENEDPATHINFO Info;
int rc = supR3HardenedVerifyPathSanity(pszFilename, pErrInfo, &Info);
if (RT_FAILURE(rc))
return rc;
if (Info.fDirSlash)
return supR3HardenedSetError3(VERR_SUPLIB_IS_DIRECTORY, pErrInfo,
"The file path specifies a directory: '", pszFilename, "'");
/*
* Verify each component from the root up.
*/
SUPR3HARDENEDFSOBJSTATE FsObjState;
uint32_t const cComponents = Info.cComponents;
for (uint32_t iComponent = 0; iComponent < cComponents; iComponent++)
{
bool fFinal = iComponent + 1 == cComponents;
bool fRelaxed = iComponent + 2 < cComponents;
Info.szPath[Info.aoffComponents[iComponent + 1] - 1] = '\0';
rc = supR3HardenedQueryFsObjectByPath(Info.szPath, &FsObjState, pErrInfo);
if (RT_SUCCESS(rc))
rc = supR3HardenedVerifyFsObject(&FsObjState, !fFinal /*fDir*/, fRelaxed, Info.szPath, pErrInfo);
if (RT_FAILURE(rc))
return rc;
Info.szPath[Info.aoffComponents[iComponent + 1] - 1] = !fFinal ? RTPATH_SLASH : '\0';
}
/*
* Verify the file handle against the last component, if specified.
*/
if (hNativeFile != RTHCUINTPTR_MAX)
{
rc = supR3HardenedVerifySameFsObject(hNativeFile, &FsObjState, Info.szPath, pErrInfo);
if (RT_FAILURE(rc))
return rc;
}
#ifdef RT_OS_WINDOWS
/*
* The files shall be signed on windows, verify that.
*/
rc = VINF_SUCCESS;
HANDLE hVerify;
if (hNativeFile == RTHCUINTPTR_MAX)
{
PRTUTF16 pwszPath;
rc = RTStrToUtf16(pszFilename, &pwszPath);
if (RT_SUCCESS(rc))
{
hVerify = CreateFileW(pwszPath, GENERIC_READ, FILE_SHARE_READ, NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);
RTUtf16Free(pwszPath);
}
else
rc = RTErrInfoSetF(pErrInfo, rc, "Error converting '%s' to UTF-16: %Rrc", pszFilename, rc);
}
else if (!DuplicateHandle(GetCurrentProcess(), (HANDLE)hNativeFile, GetCurrentProcess(), &hVerify,
GENERIC_READ, false /*bInheritHandle*/, 0 /*dwOptions*/))
hVerify = INVALID_HANDLE_VALUE;
if (hVerify != INVALID_HANDLE_VALUE)
{
# ifdef VBOX_WITH_HARDENING
uint32_t fFlags = SUPHNTVI_F_REQUIRE_KERNEL_CODE_SIGNING;
if (!fMaybe3rdParty)
fFlags = SUPHNTVI_F_REQUIRE_BUILD_CERT;
const char *pszSuffix = RTPathSuffix(pszFilename);
if ( pszSuffix
&& pszSuffix[0] == '.'
&& ( RT_C_TO_LOWER(pszSuffix[1]) == 'r'
|| RT_C_TO_LOWER(pszSuffix[1]) == 'g')
&& RT_C_TO_LOWER(pszSuffix[2]) == 'c'
&& pszSuffix[3] == '\0' )
fFlags |= SUPHNTVI_F_RC_IMAGE;
# ifndef IN_SUP_R3_STATIC /* Not in VBoxCpuReport and friends. */
rc = supHardenedWinVerifyImageByHandleNoName(hVerify, fFlags, pErrInfo);
# endif
# endif
CloseHandle(hVerify);
}
else if (RT_SUCCESS(rc))
rc = RTErrInfoSetF(pErrInfo, RTErrConvertFromWin32(GetLastError()),
"Error %u trying to open (or duplicate handle for) '%s'", GetLastError(), pszFilename);
if (RT_FAILURE(rc))
return rc;
#endif
return VINF_SUCCESS;
}
/**
* Gets the pre-init data for the hand-over to the other version
* of this code.
*
* The reason why we pass this information on is that it contains
* open directories and files. Later it may include even more info
* (int the verified arrays mostly).
*
* The receiver is supR3HardenedRecvPreInitData.
*
* @param pPreInitData Where to store it.
*/
DECLHIDDEN(void) supR3HardenedGetPreInitData(PSUPPREINITDATA pPreInitData)
{
pPreInitData->cInstallFiles = RT_ELEMENTS(g_aSupInstallFiles);
pPreInitData->paInstallFiles = &g_aSupInstallFiles[0];
pPreInitData->paVerifiedFiles = &g_aSupVerifiedFiles[0];
pPreInitData->cVerifiedDirs = RT_ELEMENTS(g_aSupVerifiedDirs);
pPreInitData->paVerifiedDirs = &g_aSupVerifiedDirs[0];
}
/**
* Receives the pre-init data from the static executable stub.
*
* @returns VBox status code. Will not bitch on failure since the
* runtime isn't ready for it, so that is left to the exe stub.
*
* @param pPreInitData The hand-over data.
*/
DECLHIDDEN(int) supR3HardenedRecvPreInitData(PCSUPPREINITDATA pPreInitData)
{
/*
* Compare the array lengths and the contents of g_aSupInstallFiles.
*/
if ( pPreInitData->cInstallFiles != RT_ELEMENTS(g_aSupInstallFiles)
|| pPreInitData->cVerifiedDirs != RT_ELEMENTS(g_aSupVerifiedDirs))
return VERR_VERSION_MISMATCH;
SUPINSTFILE const *paInstallFiles = pPreInitData->paInstallFiles;
for (unsigned iFile = 0; iFile < RT_ELEMENTS(g_aSupInstallFiles); iFile++)
if ( g_aSupInstallFiles[iFile].enmDir != paInstallFiles[iFile].enmDir
|| g_aSupInstallFiles[iFile].enmType != paInstallFiles[iFile].enmType
|| g_aSupInstallFiles[iFile].fOptional != paInstallFiles[iFile].fOptional
|| suplibHardenedStrCmp(g_aSupInstallFiles[iFile].pszFile, paInstallFiles[iFile].pszFile))
return VERR_VERSION_MISMATCH;
/*
* Check that we're not called out of order.
* If dynamic linking it screwed up, we may end up here.
*/
if ( ASMMemIsAll8(&g_aSupVerifiedFiles[0], sizeof(g_aSupVerifiedFiles), 0) != NULL
|| ASMMemIsAll8(&g_aSupVerifiedDirs[0], sizeof(g_aSupVerifiedDirs), 0) != NULL)
return VERR_WRONG_ORDER;
/*
* Copy the verification data over.
*/
suplibHardenedMemCopy(&g_aSupVerifiedFiles[0], pPreInitData->paVerifiedFiles, sizeof(g_aSupVerifiedFiles));
suplibHardenedMemCopy(&g_aSupVerifiedDirs[0], pPreInitData->paVerifiedDirs, sizeof(g_aSupVerifiedDirs));
return VINF_SUCCESS;
}