VeraCrypt
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authorMounir IDRASSI <mounir.idrassi@idrix.fr>2019-03-02 13:43:39 (GMT)
committerMounir IDRASSI <mounir.idrassi@idrix.fr>2019-03-02 13:45:38 (GMT)
commitf7bc58b38f3e61a387849ff1d840bb32a7b9b4c4 (patch)
treed278554b377c267de68d9c885aad2754e3577dc8 /src/Common
parent321715202aed04dd9892d1c0686d080763ab212d (diff)
downloadVeraCrypt-f7bc58b38f3e61a387849ff1d840bb32a7b9b4c4.zip
VeraCrypt-f7bc58b38f3e61a387849ff1d840bb32a7b9b4c4.tar.gz
Windows: mitigate some memory attacks by making VeraCrypt applications memory inaccessible by non-admin users. Implementation borrowed from KeePassXC source code (https://github.com/keepassxreboot/keepassxc/blob/release/2.4.0/src/core/Bootstrap.cpp#L150)
Diffstat (limited to 'src/Common')
-rw-r--r--src/Common/Dlgcode.c90
-rw-r--r--src/Common/Dlgcode.h1
2 files changed, 91 insertions, 0 deletions
diff --git a/src/Common/Dlgcode.c b/src/Common/Dlgcode.c
index 6d6ed69..2bc0f7e 100644
--- a/src/Common/Dlgcode.c
+++ b/src/Common/Dlgcode.c
@@ -17,6 +17,7 @@
#include <dbghelp.h>
#include <dbt.h>
#include <Setupapi.h>
+#include <aclapi.h>
#include <fcntl.h>
#include <io.h>
#include <math.h>
@@ -2892,6 +2893,9 @@ void InitApp (HINSTANCE hInstance, wchar_t *lpszCommandLine)
char langId[6];
InitCommonControlsPtr InitCommonControlsFn = NULL;
wchar_t modPath[MAX_PATH];
+
+ /* Protect this process memory from being accessed by non-admin users */
+ EnableProcessProtection ();
GetModuleFileNameW (NULL, modPath, ARRAYSIZE (modPath));
@@ -13908,6 +13912,92 @@ BOOL BufferHasPattern (const unsigned char* buffer, size_t bufferLen, const void
return bRet;
}
+/* Implementation borrowed from KeePassXC source code (https://github.com/keepassxreboot/keepassxc/blob/release/2.4.0/src/core/Bootstrap.cpp#L150)
+ *
+ * Reduce current user acess rights for this process to the minimum in order to forbid non-admin users from reading the process memory.
+ */
+BOOL EnableProcessProtection()
+{
+ BOOL bSuccess = FALSE;
+
+ // Process token and user
+ HANDLE hToken = NULL;
+ PTOKEN_USER pTokenUser = NULL;
+ DWORD cbBufferSize = 0;
+
+ // Access control list
+ PACL pACL = NULL;
+ DWORD cbACL = 0;
+
+ // Open the access token associated with the calling process
+ if (!OpenProcessToken(GetCurrentProcess(), TOKEN_QUERY, &hToken)) {
+ goto Cleanup;
+ }
+
+ // Retrieve the token information in a TOKEN_USER structure
+ GetTokenInformation(hToken, TokenUser, NULL, 0, &cbBufferSize);
+
+ pTokenUser = (PTOKEN_USER) HeapAlloc(GetProcessHeap(), 0, cbBufferSize;
+ if (pTokenUser == NULL) {
+ goto Cleanup;
+ }
+
+ if (!GetTokenInformation(hToken, TokenUser, pTokenUser, cbBufferSize, &cbBufferSize)) {
+ goto Cleanup;
+ }
+
+ if (!IsValidSid(pTokenUser->User.Sid)) {
+ goto Cleanup;
+ }
+
+ // Calculate the amount of memory that must be allocated for the DACL
+ cbACL = sizeof(ACL) + sizeof(ACCESS_ALLOWED_ACE) + GetLengthSid(pTokenUser->User.Sid);
+
+ // Create and initialize an ACL
+ pACL = (PACL) HeapAlloc(GetProcessHeap(), 0, cbACL);
+ if (pACL == NULL) {
+ goto Cleanup;
+ }
+
+ if (!InitializeAcl(pACL, cbACL, ACL_REVISION)) {
+ goto Cleanup;
+ }
+
+ // Add allowed access control entries, everything else is denied
+ if (!AddAccessAllowedAce(
+ pACL,
+ ACL_REVISION,
+ SYNCHRONIZE | PROCESS_QUERY_LIMITED_INFORMATION | PROCESS_TERMINATE, // same as protected process
+ pTokenUser->User.Sid // pointer to the trustee's SID
+ )) {
+ goto Cleanup;
+ }
+
+ // Set discretionary access control list
+ bSuccess = (ERROR_SUCCESS == SetSecurityInfo(GetCurrentProcess(), // object handle
+ SE_KERNEL_OBJECT, // type of object
+ DACL_SECURITY_INFORMATION, // change only the objects DACL
+ NULL,
+ NULL, // do not change owner or group
+ pACL, // DACL specified
+ NULL // do not change SACL
+ ))? TRUE: FALSE;
+
+Cleanup:
+
+ if (pACL != NULL) {
+ HeapFree(GetProcessHeap(), 0, pACL);
+ }
+ if (pTokenUser != NULL) {
+ HeapFree(GetProcessHeap(), 0, pTokenUser);
+ }
+ if (hToken != NULL) {
+ CloseHandle(hToken);
+ }
+
+ return bSuccess;
+}
+
#if !defined(SETUP) && defined(_WIN64)
#define RtlGenRandom SystemFunction036
diff --git a/src/Common/Dlgcode.h b/src/Common/Dlgcode.h
index 8a75f26..eccb8e8 100644
--- a/src/Common/Dlgcode.h
+++ b/src/Common/Dlgcode.h
@@ -537,6 +537,7 @@ BOOL VerifyModuleSignature (const wchar_t* path);
void GetInstallationPath (HWND hwndDlg, wchar_t* szInstallPath, DWORD cchSize, BOOL* pbInstallPathDetermined);
BOOL GetSetupconfigLocation (wchar_t* path, DWORD cchSize);
BOOL BufferHasPattern (const unsigned char* buffer, size_t bufferLen, const void* pattern, size_t patternLen);
+BOOL EnableProcessProtection();
#ifdef _WIN64
void GetAppRandomSeed (unsigned char* pbRandSeed, size_t cbRandSeed);
#endif