mainform.cpp

著名的SecureBlackBox控件完整源码

//---------------------------------------------------------------------------

#include <vcl.h>
#pragma hdrstop

#include "MainForm.h"
//---------------------------------------------------------------------------
#pragma package(smart_init)
#pragma link "SBCustomCertStorage"
#pragma link "SBPDF"
#pragma link "SBX509"
#pragma resource "*.dfm"
TfrmMain *frmMain;
//---------------------------------------------------------------------------
__fastcall TfrmMain::TfrmMain(TComponent* Owner)
        : TForm(Owner)
{
  SetLicenseKey((AnsiString)
  "ADDCD14AD06709806817E0B3D7BFD0A2222D536FE156466C5D5FE65DB5DEAE76" + 
  "FFDEBC07E915A5751C12C01C783958872A38E4A5EDA140E7247E0F2E56442A3C" + 
  "F3E9347AD8FDE52083A0DFC86BC00ECB0FD0CF1B51159A2BCB84F6EA6349EF47" + 
  "5C15A59AFCC55F7C3AAD26C279628B5D91B1DC94BD2385354A70CCA3B76101D9" + 
  "F41C84A639FC3CCE4BA8F0CC4A66DCD150114A3F58C1AD46B7B94643741BC20A" + 
  "8DCA83AB921480951B423CAA19EF1863A47CA2C3422E7E5634BED98939A5AE43" + 
  "DE1E4BAD79E66D8A5C973B3455656C8C9B6FF024FADD6CDA02D0F506D98493C8" + 
  "BD1ED7B237DB75FA31F2C82654490CDDDEE24E19939137B9E1DB05508733B22F");
}
//---------------------------------------------------------------------------
void __fastcall TfrmMain::btnBrowseSourceClick(TObject *Sender)
{
    if (OpenDialogPDF->Execute())
        editSource->Text = OpenDialogPDF->FileName;
}
//---------------------------------------------------------------------------
void __fastcall TfrmMain::btnCancelClick(TObject *Sender)
{
    Close();
}
//---------------------------------------------------------------------------
void __fastcall TfrmMain::btnOKClick(TObject *Sender)
{
    // creating a temporary file copy
    AnsiString TempPath = GenerateTempFilename();
    if (!CopyFile(editSource->Text.c_str(), TempPath.c_str(), false))
    {
        MessageDlg("Failed to create a temporary file", mtError, TMsgDlgButtons()<<mbOK, 0);
        return;
    }
    // opening the temporary file
    bool DocumentChanged = false;
    TFileStream* F = new TFileStream(TempPath, fmOpenReadWrite | fmShareDenyWrite);
    try
    {
        try
        {
            // opening the document
            Document->Open(F);
            try
            {
                // checking if the document is secured
                if ((!Document->Encrypted) && (!Document->Signed))
                {
                    MessageDlg("The document is neither encrypted nor signed", mtInformation, TMsgDlgButtons()<<mbOK, 0);
                    return;
                }
                // checking if the document is encrypted
                if (Document->Encrypted)
                {
                    // showing encryption information to user
                    if (DisplayEncryptionInfo())
                    {
                        // decrypting the document
                        if (AnsiString(Document->EncryptionHandler->ClassName()) == "TElPDFPasswordSecurityHandler")
                        {
                            AnsiString Pass = RequestPassword("Please supply a password to decrypt the document:");
                            // trying the supplied password
                            bool PV = false;
                            ((TElPDFPasswordSecurityHandler*)(Document->EncryptionHandler))->OwnerPassword = Pass;
                            if (((TElPDFPasswordSecurityHandler*)(Document->EncryptionHandler))->IsOwnerPasswordValid())
                                PV = true;
                            else
                            {
                                ((TElPDFPasswordSecurityHandler*)(Document->EncryptionHandler))->UserPassword = Pass;
                                if (((TElPDFPasswordSecurityHandler*)(Document->EncryptionHandler))->IsUserPasswordValid())
                                    PV = true;
                            }
                            if (PV)
                            {
                                // password is OK
                                Document->Decrypt();
                                DocumentChanged = true;
                                MessageDlg("Document was successfully decrypted", mtInformation, TMsgDlgButtons()<<mbOK, 0);
                            }
                            else
                                MessageDlg("Invalid password", mtError, TMsgDlgButtons()<<mbOK, 0);
                        }
                        else if (AnsiString(Document->EncryptionHandler->ClassName()) == "TElPDFPublicKeySecurityHandler")
                        {
                            // requesting certificate from user
                            if (RequestCertificate())
                            {
                                CertStorage->Clear();
                                CertStorage->Add(Cert, true);
                                ((TElPDFPublicKeySecurityHandler*)(Document->EncryptionHandler))->CertStorage = CertStorage;
                                Document->Decrypt();
                                DocumentChanged = true;
                                MessageDlg("Document was successfully decrypted", mtInformation, TMsgDlgButtons()<<mbOK, 0);
                            }
                            else
                                MessageDlg("No certificate for decryption found", mtError, TMsgDlgButtons()<<mbOK, 0);
                        }
                        else
                            MessageDlg("The document is encrypted with unsupported security handler", mtError, TMsgDlgButtons()<<mbOK, 0);
                    }
                }
                // displaying signatures info for signed documents
                if (Document->Signed)
                    DisplaySignaturesInfo();
            }
            __finally
            {
                // closing the document
                Document->Close(DocumentChanged);
            }
        }
        __finally
        {
            delete F;
        }
    }
    catch(Exception &e)
    {
        MessageDlg((AnsiString)"Error: " + e.Message, mtError, TMsgDlgButtons()<<mbOK, 0);
        DocumentChanged = false;
    }

    // if the document was changed (e.g., decrypted), moving the temporary file to the place
    // of destination file
    if (DocumentChanged)
    {
        if (SaveDialogPDF->Execute())
        {
            if (!CopyFile(TempPath.c_str(), SaveDialogPDF->FileName.c_str(), false))
                MessageDlg("Failed to save the decrypted file", mtError, TMsgDlgButtons()<<mbOK, 0);
            else
                MessageDlg("The decrypted file was successfully saved", mtInformation, TMsgDlgButtons()<<mbOK, 0);
        }
    }

    // deleting the temporary file
    DeleteFile(TempPath);
    Close();
}
//---------------------------------------------------------------------------
AnsiString TfrmMain::GenerateTempFilename(void)
{
    const char* szSBB = "sbb";
    DWORD dwNeeded = GetTempPathA(0, NULL);
    char* szPath = new char[dwNeeded+1];
    dwNeeded = GetTempPathA(dwNeeded, szPath);
    if (dwNeeded == 0)
    {
        delete[] szPath;
        throw(Exception("Failed to get temporary path"));
    }
    char* szResult = new char[MAX_PATH];
    if (GetTempFileNameA(szPath, szSBB, 0, szResult) == 0)
    {
        delete[] szPath;
        delete[] szResult;
        throw(Exception("Failed to generate a temporary file name"));
    }

    AnsiString sResult = AnsiString(szResult);
    delete[] szPath;
    delete[] szResult;
    return sResult;
}
//---------------------------------------------------------------------------
bool TfrmMain::DisplayEncryptionInfo(void)
{
    frmEncryptionProps->Initialize(Document);
    return (frmEncryptionProps->ShowModal() == mrOk);
}
//---------------------------------------------------------------------------
AnsiString TfrmMain::RequestPassword(const AnsiString Prompt)
{
    frmRequestPassword->lPrompt->Caption = Prompt;
    frmRequestPassword->editPassword->Text = "";
    if (frmRequestPassword->ShowModal() == mrOk)
        return frmRequestPassword->editPassword->Text;
    else
        return "";
}
//---------------------------------------------------------------------------
bool TfrmMain::RequestCertificate(void)
{
    bool Result = false;
    if (OpenDialogCert->Execute())
    {
        try
        {
            int R;
            TFileStream* F = new TFileStream(OpenDialogCert->FileName, fmOpenRead | fmShareDenyWrite);
            try
            {
                AnsiString Pass = RequestPassword("Password is needed to decrypt the certificate:");
                R = Cert->LoadFromStreamPFX(F, Pass, F->Size);
            }
            __finally
            {
                delete F;
            }
            if (R != 0)
                MessageDlg((AnsiString)"Failed to load certificate, error " + R, mtError, TMsgDlgButtons()<<mbOK, 0);
            else
                Result = true;
        }
        catch(Exception &e)
        {
            MessageDlg((AnsiString)"Failed to open certificate file: " + e.Message, mtError, TMsgDlgButtons()<<mbOK, 0);
        }
    }
    return Result;
}
//---------------------------------------------------------------------------
void TfrmMain::DisplaySignaturesInfo(void)
{
    frmSignaturesProps->Initialize(Document);
    frmSignaturesProps->ShowModal();
}
//---------------------------------------------------------------------------