DACLWRAP.CXX

//+------------------------------------------------------------------- 
//
// Copyright (C) 1995, Microsoft Corporation.
//
// File: daclwrap.cxx
//
// Contents: class encapsulating file security.
//
// Classes: CDaclWrap
//
// History: Nov-93 Created DaveMont
//
//--------------------------------------------------------------------
#include <t2.hxx>
#include <daclwrap.hxx>

#if DBG
extern ULONG Debug;
#endif
//+---------------------------------------------------------------------------
//
// Member: CDaclWrap::CDaclWrap, public
//
// Synopsis: initialize data members, constructor will not throw
//
// Arguments: none
//
//----------------------------------------------------------------------------
CDaclWrap::CDaclWrap()
: _ccaa(0)
{
}
//+---------------------------------------------------------------------------
//
// Member: Dtor, public
//
// Synopsis: cleanup allocated data
//
// Arguments: none
//
//----------------------------------------------------------------------------
CDaclWrap::~CDaclWrap()
{
for (ULONG j = 0; j < _ccaa; j++)
delete _aaa[j].pcaa;
}
//+---------------------------------------------------------------------------
//
// Member: CDaclWrap::SetAccess, public
//
// Synopsis: caches data for a new ACE
//
// Arguments: IN [option] - rePlace, Revoke, Grant, Deny
// IN [Name] - principal (username)
// IN [System] - server/machine where Name is defined
// IN [access] - access mode (Read Change None All)
//
//----------------------------------------------------------------------------
ULONG CDaclWrap::SetAccess(ULONG option, WCHAR *Name, WCHAR *System, ULONG access)
{
ULONG ret;

// sorry, static number of ACCESSes can be set at one time

if (_ccaa >= CMAXACES)
return(ERROR_BUFFER_OVERFLOW);

// allocate a new account access class

if (NULL == (_aaa[_ccaa].pcaa = new CAccountAccess(Name, System)))
{
return(ERROR_NOT_ENOUGH_MEMORY);
}

// to fix the bug where someone asks to both grant and deny under
// the /p option (the deny is thru access = N)

if ((GENERIC_NONE == access) && (OPTION_REPLACE == option))
{
_aaa[_ccaa].option = OPTION_DENY;
} else
{
_aaa[_ccaa].option = option;
}

SID *psid;

if (ERROR_SUCCESS == ( ret = _aaa[_ccaa].pcaa->Init(access)))
{
// get the sid to make sure the username is valid

if (ERROR_SUCCESS == ( ret =_aaa[_ccaa].pcaa->Sid(&psid)))
{
// loop thru the existing sids, making sure the new one is not a duplicate

SID *poldsid;
for (ULONG check = 0;check < _ccaa ; check++)
{
if (ERROR_SUCCESS == ( ret =_aaa[check].pcaa->Sid(&poldsid)))
{
if (EqualSid(psid,poldsid))
{
VERBOSE((stderr, "SetAccess found matching new sids\n"))
return(ERROR_BAD_ARGUMENTS);
}
}
}
_ccaa++;
}
}
return(ret);
}

//+---------------------------------------------------------------------------
//
// Member: CDaclWrap:BuildAcl, public
//
// Synopsis: merges cached new aces with the input ACL
//
// Arguments: OUT [pnewdacl] - Address of new ACL to build
// IN [poldacl] - (OPTIONAL) old ACL that is to be merged
// IN [revision] - ACL revision
// IN [fdir] - True = directory
//
//----------------------------------------------------------------------------
ULONG CDaclWrap::BuildAcl(ACL **pnewdacl, ACL *poldacl, UCHAR revision, BOOL fdir)
{
ULONG ret, caclsize;

// get the size of the new ACL we are going to create

if (ERROR_SUCCESS == (ret = _GetNewAclSize(&caclsize, poldacl, fdir)))
{
// allocate the new ACL

if (ERROR_SUCCESS == (ret = _AllocateNewAcl(pnewdacl, caclsize, revision)))
{
// and fill it up

if (ERROR_SUCCESS != (ret = _FillNewAcl(*pnewdacl, poldacl, fdir)))
{
// free the buffer if we failed

LocalFree(*pnewdacl);
}

}
}
return(ret);
}

//+---------------------------------------------------------------------------
//
// Member: CDaclWrap:_GetNewAclSize, private
//
// Synopsis: returns the size need to merge the new ACEs with the old ACL,
// this is an ugly algorithm:
//
//if (old aces exist)
// for (new aces)
// if (new ace option == GRANT)
// for (old aces)
// if (new ace SID == old ace SID)
// do inheritance check
// found = true
// if (old ace type == ALLOWED)
// old ace mask |= new ace mask
// else
// old ace mask &= ~new ace mask
// if (!found)
// add size of new ace
// else
// new ace mask = 0
// else
// add size of new ace
//
// for (old aces)
// for (new aces)
// if (new ace option == DENY, REPLACE, REVOKE)
// if (new ace SID == old ace SID)
// found = true
// break
// if (!found)
// add size of old ace
// else
// old ace mask = 0
//else
// for (new aces)
// add size of new ace
//
//
// Arguments: OUT [caclsize] - returns size
// IN [poldacl] - (OPTIONAL) old ACL that is to be merged
// IN [fdir] - True = directory
//
//----------------------------------------------------------------------------
ULONG CDaclWrap::_GetNewAclSize(ULONG *caclsize, ACL *poldacl, BOOL fdir)
{
ULONG ret;

// the size for the ACL header

*caclsize = sizeof(ACL);

// initialize the access requests
for (ULONG j = 0; j < _ccaa; j++)
_aaa[j].pcaa->ReInit();

// if we are merging, calculate the merge size

if (poldacl)
{
// first the grant options

for (j = 0; j < _ccaa; j++)
{
SID *psid;
if (OPTION_GRANT == _aaa[j].option)
{
BOOL ffound = FALSE;
ACE_HEADER *pah = (ACE_HEADER *)Add2Ptr(poldacl, sizeof(ACL));

for (ULONG cace = 0; cace < poldacl->AceCount;
cace++, pah = (ACE_HEADER *)Add2Ptr(pah, pah->AceSize))
{
if (ERROR_SUCCESS == (ret = _aaa[j].pcaa->Sid(&psid)))
{
if (EqualSid(psid,
(SID *)&((ACCESS_ALLOWED_ACE *)
pah)->SidStart) )
{
// if old and new types are the same, just and with the old

if (fdir && (pah->AceType == _aaa[j].pcaa->AceType()))
{
// make sure that we can handle the inheritance
_aaa[j].pcaa->AddInheritance(pah->AceFlags);

ffound = TRUE;
} else if (pah->AceType == _aaa[j].pcaa->AceType())
{
ffound = TRUE;
}

if (ACCESS_ALLOWED_ACE_TYPE == pah->AceType)
{
(ACCESS_MASK) ((ACCESS_ALLOWED_ACE *)
pah)->Mask |= _aaa[j].pcaa->AccessMask();
} else if (ACCESS_DENIED_ACE_TYPE == pah->AceType)
{
(ACCESS_MASK) ((ACCESS_ALLOWED_ACE *)
pah)->Mask &= ~_aaa[j].pcaa->AccessMask();
} else
{
VERBOSE((stderr, "_GetNewAclSize found an ace that was not allowed or denied\n"))
return(ERROR_INVALID_DATA);
}
}
} else
{
return(ret);
}
}
if (!ffound)
{
// bugbug allowed/denied sizes currently the same

*caclsize += sizeof(ACCESS_ALLOWED_ACE) -
sizeof(DWORD) +
GetLengthSid(psid);

SIZE((stderr, "adding on size of an new ACE (to the new ACL) = %d\n",*caclsize))
} else
{
if (fdir && (ERROR_SUCCESS != (ret = _aaa[j].pcaa->TestInheritance())))
return(ret);
_aaa[j].pcaa->ClearAccessMask();
}
} else if ( (OPTION_REPLACE == _aaa[j].option) ||
(OPTION_DENY == _aaa[j].option) )
{
if (ERROR_SUCCESS == (ret = _aaa[j].pcaa->Sid(&psid)))
{
// bugbug allowed/denied sizes currently the same

*caclsize += sizeof(ACCESS_ALLOWED_ACE) -
sizeof(DWORD) +
GetLengthSid(psid);

SIZE((stderr, "adding on size of an new ACE (to the new ACL) = %d\n",*caclsize))
} else
return(ret);
}
}
// now for the deny, replace & revoke options

ACE_HEADER *pah = (ACE_HEADER *)Add2Ptr(poldacl, sizeof(ACL));
SID *psid;

// loop thru the old ACL

for (ULONG cace = 0; cace < poldacl->AceCount;
cace++, pah = (ACE_HEADER *)Add2Ptr(pah, pah->AceSize))
{
BOOL ffound = FALSE;

// and thru the new ACEs looking for matching SIDs

for (ULONG j = 0; j < _ccaa; j++)
{
if ( (_aaa[j].option & OPTION_DENY ) ||
(_aaa[j].option & OPTION_REPLACE ) ||
(_aaa[j].option & OPTION_REVOKE ) )
{
if (ERROR_SUCCESS == (ret = _aaa[j].pcaa->Sid(&psid)))
{
if (EqualSid(psid,
(SID *)&((ACCESS_ALLOWED_ACE *)
pah)->SidStart) )
{
ffound = TRUE;
}
} else
return(ret);
}
}
if (!ffound)
{
// if we did not find a match, add the size of the old ACE

*caclsize += ((ACE_HEADER *)pah)->AceSize;

SIZE((stderr, "adding on size of an old ACE (to the new ACL) = %d\n",*caclsize))
} else
{
(ACCESS_MASK) ((ACCESS_ALLOWED_ACE *)pah)->Mask = 0;
}
}
SIZE((stderr, "final size for new ACL = %d\n",*caclsize))
} else
{
// no old ACL, just add up the sizes of the new aces

for (j = 0; j < _ccaa; j++)
{
// need to know the size of the sid

SID *psid;
if (ERROR_SUCCESS == (ret = _aaa[j].pcaa->Sid(&psid)))
{
// bugbug allowed/denied sizes currently the same

*caclsize += sizeof(ACCESS_ALLOWED_ACE) -
sizeof(DWORD) +
GetLengthSid(psid);

SIZE((stderr, "adding on size of an new ACE (to the new ACL) = %d\n",*caclsize))
} else
{
return(ret);
}
}
SIZE((stderr, "final size for new ACL = %d\n",*caclsize))
}
return(ERROR_SUCCESS);
}
//+---------------------------------------------------------------------------
//
// Member: CDaclWrap:_AllocateNewAcl, private
//
// Synopsis: allocates and initializes the new ACL
//
// Arguments: OUT [pnewdacl] - address of new ACL to allocate
// IN [caclsize] - size to allocate for the new ACL
// IN [revision] - revision of the new ACL
//
//----------------------------------------------------------------------------
ULONG CDaclWrap::_AllocateNewAcl(ACL **pnewdacl, ULONG caclsize, ULONG revision)
{
if (NULL == (*pnewdacl = (ACL *) LocalAlloc(LMEM_FIXED, caclsize)))
{
return(ERROR_NOT_ENOUGH_MEMORY);
}

if (!InitializeAcl(*pnewdacl,caclsize, revision))
{
ULONG ret = GetLastError();
LocalFree(*pnewdacl);
return(ret);

}

return(ERROR_SUCCESS);
}
//+---------------------------------------------------------------------------
//
// Member: CDaclWrap:_SetAllowedAce, private
//
// Synopsis: appends an allowed ACE to the input ACL
//
// Arguments: IN [dacl] - ACL to add the ACE to
// IN [mask] - access mask to add
// IN [psid] - SID to add
// IN [fdir] - if a Dir add inherit ACE as well
//
//----------------------------------------------------------------------------
ULONG CDaclWrap::_SetAllowedAce(ACL *dacl, ACCESS_MASK mask, SID *psid, BOOL fdir)
{
ULONG ret = ERROR_SUCCESS;

// compute the size of the ACE we are making

USHORT acesize = sizeof(ACCESS_ALLOWED_ACE) - sizeof(DWORD) + GetLengthSid(psid);

SIZE((stderr, "adding allowed ace, size = %d\n",fdir ? acesize*2 : acesize))

// static buffer in the hopes we won't have to allocate memory

BYTE buf[1024];

// allocator either uses buf or allocates a new buffer if size is not enough

FastAllocator fa(buf, 1024);

// get the buffer for the ACE

ACCESS_ALLOWED_ACE *paaa = (ACCESS_ALLOWED_ACE *)fa.GetBuf(acesize);

// fill in the ACE

memcpy(&paaa->SidStart,psid,GetLengthSid(psid));
paaa->Mask = mask;

paaa->Header.AceType = ACCESS_ALLOWED_ACE_TYPE;
paaa->Header.AceFlags = fdir ? CONTAINER_INHERIT_ACE | OBJECT_INHERIT_ACE : 0;
paaa->Header.AceSize = acesize;

// put the ACE into the ACL

if (!AddAce(dacl,
dacl->AclRevision,
0xffffffff,
paaa,
paaa->Header.AceSize))
ret = GetLastError();
return(ret);
}
//+---------------------------------------------------------------------------
//
// Member: CDaclWrap:_SetDeniedAce, private
//
// Synopsis: appends a denied ACE to the input ACL
//
// Arguments: IN [dacl] - ACL to add the ACE to
// IN [mask] - access mask to add
// IN [psid] - SID to add
// IN [fdir] - if a Dir add inherit ACE as well
//
//----------------------------------------------------------------------------
ULONG CDaclWrap::_SetDeniedAce(ACL *dacl, ACCESS_MASK mask, SID *psid, BOOL fdir)
{
ULONG ret = ERROR_SUCCESS;

// compute the size of the ACE we are making

USHORT acesize = sizeof(ACCESS_DENIED_ACE) -
sizeof(DWORD) +
GetLengthSid(psid);

SIZE((stderr, "adding denied ace, size = %d\n",acesize))

// static buffer in the hopes we won't have to allocate memory

BYTE buf[1024];

// allocator either uses buf or allocates a new buffer if size is not enough

FastAllocator fa(buf, 1024);

// get the buffer for the ACE

ACCESS_DENIED_ACE *paaa = (ACCESS_DENIED_ACE *)fa.GetBuf(acesize);

// fill in the ACE

memcpy(&paaa->SidStart,psid,GetLengthSid(psid));
paaa->Mask = mask;

paaa->Header.AceType = ACCESS_DENIED_ACE_TYPE;
paaa->Header.AceFlags = fdir ? CONTAINER_INHERIT_ACE | OBJECT_INHERIT_ACE : 0;
paaa->Header.AceSize = acesize;

// put the ACE into the ACL

if (!AddAce(dacl,
dacl->AclRevision,
0xffffffff,
paaa,
paaa->Header.AceSize))
ret = GetLastError();
return(ret);
}
//+---------------------------------------------------------------------------
//
// Member: CDaclWrap:_FillNewAcl, private
//
// Synopsis: The worker routine that actually fills the ACL, it adds the
// new denied ACEs, then if the new ACEs are being merged with
// an existing ACL, the existing ACL's ACE's (that don't
// conflict) are added, finally the new allowed ACEs are added.
// another ugly algorithm:
//
//for (new aces)
// if (new ace option == DENY)
// add new ace
//
//if (old aces)
// for (old aces)
// if (old ace mask != 0)
// add old ace
//
// for (new aces)
// if (new ace option != DENY)
// if ( new ace option != REVOKE)
// if (new ace mask != 0
// add new ace
//
//else
// for (new aces)
// if (new ace option != DENY)
// add new ace
//
// Arguments: IN [pnewdacl] - the new ACL to be filled
// IN [poldacl] - (OPTIONAL) old ACL that is to be merged
// IN [fdir] - TRUE = directory
//
//----------------------------------------------------------------------------
ULONG CDaclWrap::_FillNewAcl(ACL *pnewdacl, ACL *poldacl, BOOL fdir)
{
SID *psid;
ULONG ret;

// set new denied aces

VERBOSE((stderr, "start addr of new ACL %0lx\n",pnewdacl))

for (ULONG j = 0; j < _ccaa; j++)
{
if (_aaa[j].option & OPTION_DENY)
{
if (ERROR_SUCCESS == (ret = _aaa[j].pcaa->Sid(&psid)))
{
if (ERROR_SUCCESS != (ret = _SetDeniedAce(pnewdacl,
_aaa[j].pcaa->AccessMask(),
psid,
fdir )))
return(ret);
} else
return(ret);
}
}

// check and see if the ACL from from the file is in correct format

if (poldacl)
{
SIZE((stderr, "old ACL size = %d, acecount = %d\n",poldacl->AclSize,
poldacl->AceCount))

ACE_HEADER *pah = (ACE_HEADER *)Add2Ptr(poldacl, sizeof(ACL));

// loop thru the old ACL, looking for matches with the new ACEs

BOOL fallowedacefound = FALSE;
for (ULONG cace = 0; cace < poldacl->AceCount;
cace++, pah = (ACE_HEADER *)Add2Ptr(pah, pah->AceSize))
{
// error exit if the old ACL is incorrectly formated

if (pah->AceType == ACCESS_DENIED_ACE_TYPE && fallowedacefound)
{
VERBOSE((stderr, "_FillNewAcl found an denied ACE after an allowed ACE\n"))
return(ERROR_INVALID_DATA);
}
else if (pah->AceType == ACCESS_ALLOWED_ACE_TYPE)
fallowedacefound = TRUE;

// add the old ace to the new ACL if the old ace's mask is not zero

if ( 0 != (ACCESS_MASK)((ACCESS_ALLOWED_ACE *)pah)->Mask)
{
// add the old ace
if (!AddAce(pnewdacl,
pnewdacl->AclRevision,
0xffffffff,
pah,
pah->AceSize))
return(GetLastError());
}
}
// now for the new aces

for (ULONG j = 0; j < _ccaa; j++)
{
if ( (_aaa[j].option != OPTION_DENY) &&
(_aaa[j].option != OPTION_REVOKE) &&
(_aaa[j].pcaa->AccessMask() != 0) )
{
if (ERROR_SUCCESS == (ret = _aaa[j].pcaa->Sid(&psid)))
{
if (ERROR_SUCCESS != (ret = _SetAllowedAce(pnewdacl,
_aaa[j].pcaa->AccessMask(),
psid,
fdir )))
return(ret);
} else
return(ret);
}

}
} else
{
// no old acl, just add the (rest) of the new aces
for (ULONG j = 0; j < _ccaa; j++)
{
if (_aaa[j].option != OPTION_DENY)
{
if (ERROR_SUCCESS == (ret = _aaa[j].pcaa->Sid(&psid)))
{
if (ERROR_SUCCESS != (ret = _SetAllowedAce(pnewdacl,
_aaa[j].pcaa->AccessMask(),
psid,
fdir )))
return(ret);
} else
return(ret);
}
}
}

return(ERROR_SUCCESS);
}