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LFileSettings::SetDecryptOptions

Summary

Sets the file options used by LEADTOOLS when loading encrypted files.

Syntax

#include "ltwrappr.h"

static L_INT LFileSettings::SetDecryptOptions(pOptions)

Parameters

pFILEDECRYPTOPTIONS pOptions

Pointer to a structure that contains the options used when loading encrypted files.

Returns

Value	Meaning
SUCCESS	The function was successful.
< 1	An error occurred. Refer to Return Codes.

Comments

The values set by this function are valid only for the current thread. To change the values used by the current thread, this function must be called again from that thread.

These settings are used for loading all encrypted files (DOC, DOCX, PDF, PPT, PPTX, XLS, XLSX, XLSB, etc). An additional password can be provided for loading encrypted PDF files using LFileSettings::SetPDFOptions.

The following scenarios are possible when loading encrypted files:

To load encrypted DOC, DOCX, or any other document file, use LFileSettings::SetDecryptOptions.
To load encrypted PDF files, use LFileSettings::SetDecryptOptions or LFileSettings::SetPDFOptions. Both can also be used.

To get the current options used when loading encrypted files, call LFileSettings::GetDecryptOptions.

Required DLLs and Libraries

LTFIL
File format DLLs
For a listing of the exact DLLs and Libraries needed, based on the toolkit version, refer to Files To Be Included With Your Application.

Platforms

Win32, x64.

Example

static L_INT EXT_CALLBACK GetPasswordProc(const L_TCHAR* pszFileName, L_TCHAR** ppszPassword, L_VOID* pUserData) 
{ 
   UNREFERENCED_PARAMETER(pUserData); 
   /* A proper implementation would bring up a message box asking the user "please provide a password for the file 'pszFileName'" */ 
   /* We will keep it simple and hardcode a password, but we will need to prevent an infinite loop. So we will not provide the same password more than once for the same file */ 
   static L_TCHAR szOldFileName[L_MAXPATH]; 
   if (!_tcscmp(pszFileName, szOldFileName)) 
      return ERROR_INV_PASSWORD; /* I already tried this password for this file */ 
   L_TCHAR* pszMyPassword = L_TEXT("Excel"); 
   L_INT nRet = LBase::AllocBuffer((_tcslen(pszMyPassword) + 1) * sizeof(L_TCHAR), (L_VOID**)ppszPassword); 
   if (nRet == SUCCESS) 
   { 
      memcpy(*ppszPassword, pszMyPassword, (_tcslen(pszMyPassword) + 1) * sizeof(L_TCHAR)); 
      _tcscpy_s(szOldFileName, _countof(szOldFileName), pszFileName); /* store the filename to indicate that we already provided the password for this filename */ 
   } 
   return nRet; 
} 
 
L_INT TestLoadEncrypted(LBitmapBase* pLBitmap) 
{ 
   /* This is an encrypted Excel file which requires the password 'Excel' to load properly */ 
   L_TCHAR* pszFileName = L_TEXT("Encrypted - Encrypted Excel.xlsx"); 
 
   /* Provide a default password 'DefaultPassword'. If this is not valid, call the GetPasswordProc function */ 
   FILEDECRYPTOPTIONS options; 
   LFileSettings::GetDecryptOptions(&options, sizeof(FILEDECRYPTOPTIONS)); 
   options.pszPassword = L_TEXT("DefaultPassword"); 
   options.pfnCallback = GetPasswordProc; 
   options.pUserData = NULL; 
 
   LFileSettings::SetDecryptOptions(&options); 
 
   LFile file(pLBitmap, pszFileName); 
 
   FILEINFO fileInfo = { sizeof(FILEINFO) }; 
   L_INT nRet; 
   if ((nRet = file.GetInfo(&fileInfo, sizeof(FILEINFO), 0, NULL)) != SUCCESS) 
      return nRet; 
 
   return file.Load(0, ORDER_BGRORGRAY, NULL, &fileInfo); 
}