How to Encrypt PDF files using Foxit PDF SDK (C++)

Foxit PDF SDK provides a range of encryption and decryption functions to meet different levels of document security protection. Users can use regular password encryption and certificate-driven encryption, or use their own security handler for custom security implementation. It also provides APIs to integrate with the third-party security mechanism (Microsoft RMS). These APIs allow developers to work with the Microsoft RMS SDK to both encrypt (protect) and decrypt (unprotect) PDF documents.

Note: For more detailed information about the RMS encryption and decryption, please refer to the simple demo “security” in the “examples\simple_demo” folder of the download package.

Example:

How to encrypt a PDF file with a Certificate

#include "include/pdf/fs_pdfdoc.h"
#include "include/pdf/fs_security.h"
using namespace foxit;
using namespace foxit::common;
using foxit::common::Library;
using namespace pdf;
...
PDFDoc doc(input_file);
ErrorCode error_code = doc.Load();
 if (error_code != foxit::e_ErrSuccess) {
 return false;
 }
// Do encryption.
StringArray envelopes;
String initial_key;
WString cert_file_path = input_path + L"foxit.cer";
if (!GetCertificateInfo((const char*)String::FromUnicode(cert_file_path), envelopes, initial_key, true, 16)) {
 return false;
}
CertificateSecurityHandler handler;
CertificateEncryptData encrypt_data(true, SecurityHandler::e_CipherAES, envelopes);
handler.Initialize(encrypt_data, initial_key);
doc.SetSecurityHandler(handler);
WString output_file = output_directory + L"certificate_encrypt.pdf";
doc.SaveAs(output_file, PDFDoc::e_SaveFlagNoOriginal);
...

How to encrypt a PDF file with Foxit DRM

#include "include/pdf/fs_pdfdoc.h"
#include "include/pdf/fs_security.h"
using namespace foxit;
using namespace foxit::common;
using foxit::common::Library;
using namespace pdf;
...
PDFDoc doc(input_file);
ErrorCode error_code = doc.Load();
if (error_code != foxit::e_ErrSuccess) {
 return false;
}
// Do encryption.
DRMSecurityHandler handler = DRMSecurityHandler();
const char* file_id = "Simple-DRM-file-ID";
String initialize_key = "Simple-DRM-initialize-key";
DRMEncryptData encrypt_data(true, "Simple-DRM-filter", SecurityHandler::e_CipherAES, 16, true, 0xfffffffc);
handler.Initialize(encrypt_data, file_id, initialize_key);
doc.SetSecurityHandler(handler);
WString output_file = output_directory + L"foxit_drm_encrypt.pdf";
doc.SaveAs(output_file, PDFDoc::e_SaveFlagNoOriginal);
...