bool SetKeyPermissions(IntPtr hKey, ACCOUNT_PERM Account)
{
// apply key permissions
int iLength = 0;
int iReturn = 0;
IntPtr pOldSD = IntPtr.Zero;
IntPtr pSec = IntPtr.Zero;
MEM_DATA tMem = new MEM_DATA();
try
{
tMem.pAcl = IntPtr.Zero;
tMem.pSd = IntPtr.Zero;
// allocate space
iReturn = RegGetKeySecurity(hKey, DACL_SECURITY_INFORMATION, pOldSD, ref iLength);
if (iLength > 0)
{
pOldSD = (LocalAlloc(LMEM_INITIALIZED, iLength));
if (pOldSD != IntPtr.Zero)
{
// load structure
if ((RegGetKeySecurity(hKey, DACL_SECURITY_INFORMATION, pOldSD, ref iLength) == 0))
{
// create dacl
if (CreateKeyDescriptor(pOldSD, Account, ref tMem))
{
// set descriptor
return (RegSetKeySecurity(hKey, DACL_SECURITY_INFORMATION, tMem.pSd) == ERROR_SUCCESS);
}
}
}
}
return false;
}
finally
{
// cleanup
if (pOldSD != IntPtr.Zero)
{
LocalFree(pOldSD);
pOldSD = IntPtr.Zero;
}
if (tMem.pSd != IntPtr.Zero)
{
LocalFree(tMem.pSd);
tMem.pSd = IntPtr.Zero;
}
if (tMem.pAcl != IntPtr.Zero)
{
LocalFree(tMem.pAcl);
tMem.pAcl = IntPtr.Zero;
}
}
}
bool CreateKeyDescriptor(IntPtr pOldSD, ACCOUNT_PERM Account, ref MEM_DATA MemData)
{
// reconstruct security descriptor
bool bDefault = false;
bool bPresent = false;
int iControlBits = 0;
int iControlSet = 0;
int iDomain = 0;
int iFlag = 0;
int iLength = 0;
int iRevision = 0;
int iSidLen = 0;
int iTotal = 0;
int iUse = 0;
StringBuilder sDomain = new StringBuilder(256);
IntPtr pNewACL = IntPtr.Zero;
IntPtr pAcl = IntPtr.Zero;
IntPtr pSid = IntPtr.Zero;
IntPtr pPnt = IntPtr.Zero;
ACL_SIZE_INFORMATION tAclSize = new ACL_SIZE_INFORMATION();
ACL tTempACL = new ACL();
ACE tTempAce = new ACE();
try
{
MemData.pAcl = IntPtr.Zero;
MemData.pSd = IntPtr.Zero;
// get size
pSid = LocalAlloc(LMEM_INITIALIZED, SECURITY_DESCRIPTOR_MIN_LENGTH);
if (pSid == IntPtr.Zero)
{
return false;
}
// store pointer
MemData.pSd = pSid;
// init descriptor
if (InitializeSecurityDescriptor(pSid, SECURITY_DESCRIPTOR_REVISION) == 0)
{
return false;
}
// check for existing sd
if (pOldSD != IntPtr.Zero)
{
if (GetSecurityDescriptorDacl(pOldSD, out bPresent, ref pAcl, out bDefault) == true)
{
// extract dacl
if ((bPresent == true) && (pAcl != IntPtr.Zero))
{
if (GetAclInformation(pAcl, ref tAclSize, Marshal.SizeOf(tAclSize), ACL_INFORMATION_CLASS.AclSizeInformation) == false)
{
return false;
}
else
{
iTotal = tAclSize.AclBytesInUse;
}
}
else
{
iTotal = Marshal.SizeOf(tTempACL);
}
}
else
{
return false;
}
}
// allocate sid //
// get callers sid
if (Account.pSid == IntPtr.Zero)
{
iDomain = 256;
// get size
LookupAccountName(null, Account.AccountName, IntPtr.Zero, ref iSidLen, sDomain, ref iDomain, out iUse);
Account.pSid = LocalAlloc(LMEM_INITIALIZED, iSidLen);
if (Account.pSid == IntPtr.Zero)
{
return false;
}
// get the sid
if (LookupAccountName(null, Account.AccountName, Account.pSid, ref iSidLen, sDomain, ref iDomain, out iUse) == false)
{
return false;
}
}
// ace buffer
iLength = (Marshal.SizeOf(tTempAce) + GetLengthSid(Account.pSid)) - 4;
iTotal += iLength;
pNewACL = LocalAlloc(LMEM_INITIALIZED, iTotal);
if (pNewACL == IntPtr.Zero)
{
return false;
}
// store pointer
MemData.pAcl = pNewACL;
// init acl
if (InitializeAcl(pNewACL, iTotal, ACL_REVISION) == false)
{
return false;
}
// build dacl in sequence
if (Account.AceType == ACCESS_DENIED_ACE_TYPE)
{
if (BuildACE(pNewACL, Account.AceType, Account.AceFlags, Account.AccessMask, Account.pSid) == false)
{
return false;
}
}
// copy non-inherited ace
if ((bPresent == true) && (pAcl != IntPtr.Zero) && (tAclSize.AceCount > 0))
{
// combine old and new ACE entries
for (int count = 0; count < tAclSize.AceCount; count++)
{
// next ace
GetAce(pAcl, count, out pPnt);
if (pPnt == IntPtr.Zero)
{
return false;
}
RtlMoveMemory(ref tTempAce, pPnt, Marshal.SizeOf(tTempAce));
// exit on inherited ace
if (((int)tTempAce.Header.AceFlags & INHERITED_ACE) == INHERITED_ACE)
{
break;
}
int x = (int)pPnt + 8;
IntPtr pPt = new IntPtr(x);
// check ace value
if (!SidIsEqual(Account.pSid, pPt))
{
// add ace
AddAce(pNewACL, ACL_REVISION, MAXDWORD, pPnt, tTempAce.Header.AceSize);
}
}
}
// add explicit permit
if (Account.AceType == ACCESS_ALLOWED_ACE_TYPE)
{
BuildACE(pNewACL, Account.AceType, Account.AceFlags, Account.AccessMask, Account.pSid);
}
// enties with inheritence flag
if ((bPresent == true) && (pAcl != IntPtr.Zero) && (tAclSize.AceCount > 0))
{
for (int count = 0; count < tAclSize.AceCount; count++)
{
GetAce(pAcl, count, out pPnt);
RtlMoveMemory(ref tTempAce, pPnt, Marshal.SizeOf(tTempAce));
AddAce(pNewACL, ACL_REVISION, MAXDWORD, pPnt, tTempAce.Header.AceSize);
}
}
// descriptor flags
if (pOldSD != IntPtr.Zero)
{
if (GetSecurityDescriptorControl(pOldSD, out iFlag, out iRevision) != 0)
{
if ((iFlag & SE_DACL_AUTO_INHERITED) == SE_DACL_AUTO_INHERITED)
{
iControlBits = SE_DACL_AUTO_INHERIT_REQ | SE_DACL_AUTO_INHERITED;
iControlSet = iControlBits;
}
else if ((iFlag & SE_DACL_PROTECTED) == SE_DACL_PROTECTED)
{
iControlBits = SE_DACL_PROTECTED;
iControlSet = iControlBits;
}
if (iControlSet != 0)
{
SetSecurityDescriptorControl(pSid, iControlBits, iControlSet);
}
}
}
// add dacl
return SetSecurityDescriptorDacl(pSid, 1, pNewACL, 0);
}
finally
{
if (Account.pSid != IntPtr.Zero)
{
LocalFree(Account.pSid);
Account.pSid = IntPtr.Zero;
}
}
}
