private void DecryptWorkerDoWork(object sender, DoWorkEventArgs e)
{
TimeSpan ts;
const int timeSlice = 50;
const int nrOfSpeedMeasurements = 50;
ulong passwordCount = 0, prevPasswordCount = 0;
object[] args = (object[])e.Argument;
IDecryptor decryptor = DecryptorFactory.Get((EncryptionRecord)args[0]);
IPasswordIterator passwordIterator = (IPasswordIterator)args[1];
ValidationMode validationMode = (ValidationMode)args[2];
IMovingAverage avg = new SimpleMovingAverage(nrOfSpeedMeasurements);
PasswordValidity passwordValidity = PasswordValidity.Invalid;
Stopwatch stopWatch = new Stopwatch();
stopWatch.Start();
string currentPassword = passwordIterator.GetNextPassword();
while (!string.IsNullOrEmpty(currentPassword) &&
validationMode != ValidationMode.None &&
!decryptBackgroundWorker.CancellationPending)
{
passwordValidity = decryptor.ValidatePassword(currentPassword, validationMode);
passwordCount++;
ts = stopWatch.Elapsed;
if (ts.Milliseconds > timeSlice || passwordValidity != PasswordValidity.Invalid)
{
avg.AddSample((60000 * (passwordCount - prevPasswordCount)) / ((ulong)ts.Milliseconds + 1)); //Avoid div by zero
decryptBackgroundWorker.ReportProgress(0, new object[]
{ passwordValidity, currentPassword, (ulong)avg.Average, passwordCount });
prevPasswordCount = passwordCount;
stopWatch.Restart();
if ((passwordValidity & PasswordValidity.OwnerPasswordIsValid) == PasswordValidity.OwnerPasswordIsValid)
{
validationMode &= ~ValidationMode.ValidateOwnerPassword;
}
if ((passwordValidity & PasswordValidity.UserPasswordIsValid) == PasswordValidity.UserPasswordIsValid)
{
validationMode &= ~ValidationMode.ValidateUserPassword;
}
}
currentPassword = passwordIterator.GetNextPassword();
}
if (decryptBackgroundWorker.CancellationPending)
{
e.Cancel = true;
}
else
{
e.Result = passwordCount;
}
}
private void OnDecryptCmdExecute()
{
Status = string.Empty;
ClearAllErrors();
if (SelectedFile == null)
{
Status = "Please select a PDF file to decrypt.";
SetErrors("SelectedFile", new List <ValidationResult>()
{
new ValidationResult(false, Status)
});
}
else if (!SelectedFile.EncryptionRecordInfo.isEncrypted)
{
Status = "No encryption dictionary found in PDF.";
}
else if (!SelectedFile.OwnerPasswordIsSet && !SelectedFile.UserPasswordIsSet)
{
Status = "Both the User password and the Owner password are empty.";
}
else if (ValidationModeRequested == ValidationMode.None)
{
Status = "Please select the password you want to recover.";
SetErrors("ValidationModeRequested", new List <ValidationResult>()
{
new ValidationResult(false, Status)
});
}
else if ((ValidationModeRequested & ValidationMode.ValidateOwnerPassword) == ValidationMode.ValidateOwnerPassword &&
(ValidationModeRequested & ValidationMode.ValidateUserPassword) == ValidationMode.ValidateUserPassword &&
!string.IsNullOrEmpty(SelectedFile.RecoveredOwnerPassword) &&
!string.IsNullOrEmpty(SelectedFile.RecoveredUserPassword))
{
Status = "The requested passwords are already recovered.";
}
else if ((ValidationModeRequested == ValidationMode.ValidateOwnerPassword &&
!string.IsNullOrEmpty(SelectedFile.RecoveredOwnerPassword)) ||
((ValidationModeRequested == ValidationMode.ValidateUserPassword &&
!string.IsNullOrEmpty(SelectedFile.RecoveredUserPassword))))
{
Status = "The requested password is already recovered.";
}
else if (SelectedTabItem is ITabViewModel)
{
string errormsg = string.Empty;
IPasswordIterator passwordIterator = SelectedTabItem.PasswordIterator;
if (passwordIterator.Initialize(SelectedFile.EncryptionRecordInfo.PasswordCharset,
SelectedFile.EncryptionRecordInfo.MaxPasswordSize,
ref errormsg) == Constants.Success)
{
IsBusy = true;
CurrentPassword = string.Empty;
passwordIterator.PasswordCasing = PasswordCasing;
passwordIterator.RemoveWhitespace = RemoveWhitespace;
decryptBackgroundWorker.RunWorkerAsync(new object[]
{ SelectedFile.EncryptionRecordInfo, passwordIterator, ValidationModeRequested });
}
else
{
SetErrors("SelectedTabItem", new List <ValidationResult>()
{
new ValidationResult(false, errormsg)
});
Status = errormsg;
}
}
}
