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core/ASCOfficePDFReader/SecurityHandler.cpp

306 lines
7.6 KiB
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#include "stdafx.h"
#include "StringExt.h"
#include "PDFDoc.h"
#include "Decrypt.h"
#include "GlobalParams.h"
#include "SecurityHandler.h"
//-------------------------------------------------------------------------------------------------------------------------------
// SecurityHandler
//-------------------------------------------------------------------------------------------------------------------------------
SecurityHandler *SecurityHandler::Make(PDFDoc *pDocument, Object *pEncryptDict)
{
SecurityHandler *pSecurityHandler = NULL;
Object oFilter;
pEncryptDict->DictLookup("Filter", &oFilter);
if ( oFilter.IsName("Standard") )
{
pSecurityHandler = new StandardSecurityHandler( pDocument, pEncryptDict );
}
else if ( oFilter.IsName() )
{
// TO DO: Error "Couldn't find the security handler"
pSecurityHandler = NULL;
}
else
{
// TO DO: Error "Missing or invalid 'Filter' entry in encryption dictionary"
pSecurityHandler = NULL;
}
oFilter.Free();
return pSecurityHandler;
}
SecurityHandler::SecurityHandler(PDFDoc *pDocument)
{
m_pDocument = pDocument;
}
SecurityHandler::~SecurityHandler()
{
}
BOOL SecurityHandler::CheckEncryption(StringExt *seOwnerPassword, StringExt *seUserPassword)
{
void *pAuthData = NULL;
if ( seOwnerPassword || seUserPassword )
{
pAuthData = MakeAuthData( seOwnerPassword, seUserPassword );
}
else
{
pAuthData = NULL;
}
BOOL bResult = Authorize( pAuthData );
if ( pAuthData )
{
FreeAuthData( pAuthData );
}
for (int nIndex = 0; !bResult && nIndex < 3; ++nIndex )
{
if ( !( pAuthData = GetAuthData() ) )
{
break;
}
bResult = Authorize( pAuthData );
if ( pAuthData )
{
FreeAuthData( pAuthData );
}
}
if ( !bResult )
{
// TO DO: Error "Incorrect password"
}
return bResult;
}
//-------------------------------------------------------------------------------------------------------------------------------
// StandardSecurityHandler
//-------------------------------------------------------------------------------------------------------------------------------
class StandardAuthData
{
public:
StandardAuthData(StringExt *seOwnerPassword, StringExt *seUserPassword)
{
m_seOwnerPassword = seOwnerPassword;
m_seUserPassword = seUserPassword;
}
~StandardAuthData()
{
if ( m_seOwnerPassword )
{
delete m_seOwnerPassword;
}
if ( m_seUserPassword )
{
delete m_seUserPassword;
}
}
public:
StringExt *m_seOwnerPassword;
StringExt *m_seUserPassword;
};
StandardSecurityHandler::StandardSecurityHandler(PDFDoc *pDocument, Object *pEncryptDict):
SecurityHandler(pDocument)
{
m_bValid = FALSE;
m_seFileID = NULL;
m_seOwnerKey = NULL;
m_seUserKey = NULL;
Object oVersion, oRevision, oLength, oOwnerKey, oUserKey, oPermission;
pEncryptDict->DictLookup("V", &oVersion);
pEncryptDict->DictLookup("R", &oRevision);
pEncryptDict->DictLookup("Length", &oLength);
pEncryptDict->DictLookup("O", &oOwnerKey);
pEncryptDict->DictLookup("U", &oUserKey);
pEncryptDict->DictLookup("P", &oPermission);
Object oFileID;
m_pDocument->GetXRef()->GetTrailerDict()->DictLookup("ID", &oFileID);
if ( oVersion.IsInt() && oRevision.IsInt() && oOwnerKey.IsString() && oOwnerKey.GetString()->GetLength() == 32 && oUserKey.IsString() && oUserKey.GetString()->GetLength() == 32 && oPermission.IsInt() )
{
m_nEncryptVersion = oVersion.GetInt();
m_nEncryptRevision = oRevision.GetInt();
m_eCryptType = cryptRC4;
// <20> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD> Revision = 2, <20><><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD> 40-<2D><><EFBFBD> - <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> PDF-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> Length
if ( m_nEncryptRevision == 2 || !oLength.IsInt() )
{
m_nFileKeyLength = 5; // 5 <20><><EFBFBD><EFBFBD> = 40-<2D><><EFBFBD>
}
else
{
m_nFileKeyLength = oLength.GetInt() / 8;
}
m_bEncryptMetadata = TRUE;
if ( m_nEncryptVersion == 4 && m_nEncryptRevision == 4 )
{
Object oCryptFilters, oStreamFilter, oStringFilter;
pEncryptDict->DictLookup("CF", &oCryptFilters);
pEncryptDict->DictLookup("StmF", &oStreamFilter);
pEncryptDict->DictLookup("StrF", &oStringFilter);
if ( oCryptFilters.IsDict() && oStreamFilter.IsName() && oStringFilter.IsName() && !strcmp( oStreamFilter.GetName(), oStringFilter.GetName() ) )
{
Object oCryptCurFilter;
if ( oCryptFilters.DictLookup( oStreamFilter.GetName(), &oCryptCurFilter )->IsDict() )
{
Object oCFM;
oCryptCurFilter.DictLookup("CFM", &oCFM);
if ( oCFM.IsName("V2") )
{
m_nEncryptVersion = 2;
m_nEncryptRevision = 3;
Object oCFLength;
if ( oCryptCurFilter.DictLookup("Length", &oCFLength)->IsInt() )
{
// <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>, <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD> oCFLength / 8
m_nFileKeyLength = oCFLength.GetInt();
}
oCFLength.Free();
}
else if ( oCFM.IsName("AESV2") )
{
m_nEncryptVersion = 2;
m_nEncryptRevision = 3;
m_eCryptType = cryptAES;
Object oCFLength;
if ( oCryptCurFilter.DictLookup("Length", &oCFLength)->IsInt() )
{
// <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>, <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD> oCFLength / 8
m_nFileKeyLength = oCFLength.GetInt();
}
oCFLength.Free();
}
oCFM.Free();
}
oCryptCurFilter.Free();
}
oStringFilter.Free();
oStreamFilter.Free();
oCryptFilters.Free();
Object oEncryptMetadata;
if ( pEncryptDict->DictLookup("EncryptMetadata", &oEncryptMetadata)->IsBool() )
{
m_bEncryptMetadata = oEncryptMetadata.GetBool();
}
oEncryptMetadata.Free();
}
m_nPermissionFlags = oPermission.GetInt();
m_seOwnerKey = oOwnerKey.GetString()->Copy();
m_seUserKey = oUserKey.GetString()->Copy();
if ( m_nEncryptVersion >= 1 && m_nEncryptVersion <= 2 && m_nEncryptRevision >= 2 && m_nEncryptRevision <= 3 )
{
if ( oFileID.IsArray() )
{
Object oFileIDString;
if ( oFileID.ArrayGet(0, &oFileIDString)->IsString() )
{
m_seFileID = oFileIDString.GetString()->Copy();
}
else
{
m_seFileID = new StringExt();
}
oFileIDString.Free();
}
else
{
m_seFileID = new StringExt();
}
m_bValid = TRUE;
}
else
{
// TO DO: Error "Unsupported version/revision of Standard security handler"
}
}
else
{
// TO DO: Error "Weird encryption info"
}
if ( m_nFileKeyLength > 16 )
{
m_nFileKeyLength = 16;
}
oFileID.Free();
oPermission.Free();
oUserKey.Free();
oOwnerKey.Free();
oLength.Free();
oRevision.Free();
oVersion.Free();
}
StandardSecurityHandler::~StandardSecurityHandler()
{
if ( m_seFileID )
{
delete m_seFileID;
}
if ( m_seOwnerKey )
{
delete m_seOwnerKey;
}
if ( m_seUserKey )
{
delete m_seUserKey;
}
}
void *StandardSecurityHandler::MakeAuthData(StringExt *seOwnerPassword, StringExt *seUserPassword)
{
return new StandardAuthData( seOwnerPassword ? seOwnerPassword->Copy() : (StringExt *)NULL, seUserPassword ? seUserPassword->Copy(): (StringExt *)NULL );
}
void *StandardSecurityHandler::GetAuthData()
{
return NULL;
}
void StandardSecurityHandler::FreeAuthData(void *pAuthData)
{
if ( pAuthData )
delete (StandardAuthData *)pAuthData;
}
BOOL StandardSecurityHandler::Authorize(void *pAuthData)
{
StringExt *seOwnerPassword, *seUserPassword;
if ( !m_bValid )
{
return FALSE;
}
if ( pAuthData )
{
seOwnerPassword = ((StandardAuthData *)pAuthData)->m_seOwnerPassword;
seUserPassword = ((StandardAuthData *)pAuthData)->m_seUserPassword;
}
else
{
seOwnerPassword = NULL;
seUserPassword = NULL;
}
if ( !Decrypt::MakeFileKey( m_nEncryptVersion, m_nEncryptRevision, m_nFileKeyLength, m_seOwnerKey, m_seUserKey, m_nPermissionFlags, m_seFileID, seOwnerPassword, seUserPassword, m_sFileKey, m_bEncryptMetadata, &m_bOwnerPasswordValid ) )
{
return FALSE;
}
return TRUE;
}