internal void closeDecMpeFile()
{
if (_decMpeFileInfo != null)
{
DecryptBtn.IsEnabled = false;
DecQuestionListPanel.Children.RemoveRange(1, DecQuestionListPanel.Children.Count - 1);
_decMpeFileInfo._encryptedFS.Close();
_decMpeFileInfo = null;
}
}
internal void openDecMpeFile(bool isShowMessage)
{
if (File.Exists(DecEncryptedFileTxt.Text) == false)
{
return;
}
var currentCursor = this.Cursor;
this.Cursor = Cursors.Wait;
string message;
var decMPEfileInfo = MPECore.readHeader(DecEncryptedFileTxt.Text);
if (decMPEfileInfo._errorDetailMessage != "")
{
if (isShowMessage)
{
message = ResourceService.Current.getMessage("MsgETargetNotMPE") + decMPEfileInfo._errorDetailMessage; // The specified file is not a Multiple Passwords Encrypted file.\r\n\r\nDetailed information:
MessageBox.Show(message, "Error", MessageBoxButton.OK, MessageBoxImage.Error, MessageBoxResult.OK);
}
goto EXIT;
}
int nQuestions = decMPEfileInfo._nQuestions;
int nRequiredPasswords = decMPEfileInfo._nRequiredPasswords;
// create UI
_decPasswordTxts = new TextBox[nQuestions];
setFlag(decMPEfileInfo._flag);
DecryptBtn.IsEnabled = true;
DecNumRequiredPasswordsCmb.Items.Clear();
DecNumRequiredPasswordsCmb.Items.Add(nRequiredPasswords);
DecNumRequiredPasswordsCmb.SelectedIndex = 0;
for (int i = 0; i < nQuestions; ++i)
{
var question = decMPEfileInfo._decQuestions[i];
var border = new Border();
border.BorderThickness = TH_BOADER;
border.BorderBrush = Brushes.Gray;
border.Margin = TH_MARGIN_T5_R5;
var scrollViewer = new ScrollViewer();
scrollViewer.HorizontalScrollBarVisibility = ScrollBarVisibility.Auto;
scrollViewer.VerticalScrollBarVisibility = ScrollBarVisibility.Disabled;
scrollViewer.Padding = TH_PADDING_5;
border.Child = scrollViewer;
var questionStackPanel = new StackPanel();
questionStackPanel.Orientation = Orientation.Vertical;
scrollViewer.Content = questionStackPanel;
var hintStackPanel = new StackPanel();
hintStackPanel.Orientation = Orientation.Horizontal;
questionStackPanel.Children.Add(hintStackPanel);
var hintLabel = new Label();
hintLabel.Content = "Hint" + (i + 1) + ":";
hintLabel.Width = HEADER_WIDTH;
hintStackPanel.Children.Add(hintLabel);
var hintTextBox = new TextBox();
hintTextBox.MinWidth = HINT_WIDTH;
hintTextBox.IsEnabled = false;
hintStackPanel.Children.Add(hintTextBox);
hintTextBox.Text = question.hint;
var questionRemoveButton = new Button();
questionRemoveButton.Content = "X";
questionRemoveButton.Width = HINT_REMOVE_BUTTON_WIDTH;
questionRemoveButton.Margin = TH_MARGIN_L10;
questionRemoveButton.IsEnabled = false;
hintStackPanel.Children.Add(questionRemoveButton);
var passwordStackPanel = new StackPanel();
passwordStackPanel.Orientation = Orientation.Horizontal;
passwordStackPanel.Margin = TH_MARGIN_T5;
questionStackPanel.Children.Add(passwordStackPanel);
var passwordLabel = new Label();
passwordLabel.Content = "Password:"******"" && isShowMessage)
{
message = ResourceService.Current.getMessage("MsgWMPEInvalidFormat") + decMPEfileInfo._warningDetailMessage; // The specified file may not be decrypted properly.\r\n\r\nDetailed information:
MessageBox.Show(message, "Warning", MessageBoxButton.OK, MessageBoxImage.Warning, MessageBoxResult.OK);
}
_decMpeFileInfo = decMPEfileInfo;
EXIT:
this.Cursor = currentCursor;
}
internal static bool Decrypt(
DecMPEFileInfo decMpeFileInfo,
string[] passwords,
string outputDir,
IProgress <string> progress = null)
{
int nQuestions = decMpeFileInfo._nQuestions;
int nRequiredPasswords = decMpeFileInfo._nRequiredPasswords;
int nDecryptedQuestionKeys = 0; // Number of QuestionKeys that could be decoded. (J)複号できたQuestionKeyの数
int[] questionKeyIndexes = new int[nRequiredPasswords]; // Index of QuestionKeys that could be decoded. (J)複号できたQuestionKeyのIndex
byte[] questionKeys = new byte[nRequiredPasswords * Crypto.AES_KEY_SIZE_BYTE]; // Combined Question Key (for decrypt dataKey)
// check password
for (int i = 0; i < nQuestions && nDecryptedQuestionKeys < nRequiredPasswords; ++i)
{
var passwordTxt = passwords[i];
if (passwordTxt == "")
{
continue;
}
var question = decMpeFileInfo._decQuestions[i];
byte[] password = Encoding.UTF8.GetBytes(passwordTxt);
for (int j = 0; j < question.nPasswords; ++j)
{
var result = Crypto.decryptByte(question.encryptedQuestionKeys, j * Crypto.AES_KEY_SIZE_BYTE_WITH_PADDING, Crypto.AES_KEY_SIZE_BYTE_WITH_PADDING, password, Crypto.createSalt(i, j));
if (result != null)
{
if (result.Length != Crypto.AES_KEY_SIZE_BYTE)
{ // assertion
throw new Exception("broken file");
}
// store question key
Buffer.BlockCopy(result, 0, questionKeys, nDecryptedQuestionKeys * Crypto.AES_KEY_SIZE_BYTE, Crypto.AES_KEY_SIZE_BYTE);
questionKeyIndexes[nDecryptedQuestionKeys] = i;
nDecryptedQuestionKeys += 1;
break;
}
}
}
if (nDecryptedQuestionKeys < nRequiredPasswords)
{
return(false); // fail. number of passwords is not enough.
}
// decrypt data
byte[] dataKey = null;
int[][] combinaitons = Combination.enumerateCombination(nQuestions, nRequiredPasswords);
for (int i = 0; i < combinaitons.Length; ++i)
{
if (combinaitons[i].SequenceEqual(questionKeyIndexes))
{
dataKey = Crypto.decryptByte(decMpeFileInfo._encryptedDataKeys, i * Crypto.AES_KEY_SIZE_BYTE_WITH_PADDING, Crypto.AES_KEY_SIZE_BYTE_WITH_PADDING, questionKeys);
break;
}
}
if (dataKey == null)
{
throw new Exception("broken file");
}
progress?.Report("(1/3) decripting archive.");
// OK
var tmpFileCompress = System.IO.Path.GetRandomFileName();
try
{
using (FileStream zipFS = new FileStream(tmpFileCompress, FileMode.Create))
{
decMpeFileInfo._encryptedFS.Position = decMpeFileInfo._dataStartPosition;
Crypto.decryptStream(decMpeFileInfo._encryptedFS, zipFS, dataKey);
}
// ZipFile.ExtractToDirectory can not read files unless Close() is done on zipFS
//(J) zipFS を Close() しないと ZipFile.ExtractToDirectory はファイルを読み込めない
try
{
progress?.Report("(2/3) creating output file(s).");
System.IO.Compression.ZipFile.ExtractToDirectory(tmpFileCompress, outputDir);
}
catch (Exception ex)
{
throw ex;
}
}
finally
{
File.Delete(tmpFileCompress);
}
progress?.Report("(3/3) finished.");
return(true); // succeed
}
internal static DecMPEFileInfo readHeader(string encryptedFileName)
{
// Anaryze MPE File.
//(J) MPEファイル解析
string errorDetailMessage = "";
string warningDetailMessage = "";
var encryptedFS = new FileStream(encryptedFileName, FileMode.Open);
byte[] buf = new byte[AppConst.MPE_HEADER_SIZE];
int readByte = encryptedFS.Read(buf, 0, AppConst.MPE_HEADER_SIZE);
if (readByte < AppConst.MPE_HEADER_SIZE)
{
errorDetailMessage = "File size is too small.";
goto ERROR;
}
var reader = new MPEHeaderReader(buf);
string headerConst = reader.ReadString(3);
if (headerConst != AppConst.MPE_HEADER_CONST)
{
errorDetailMessage = "MPE Header constant is incorrect.";
goto ERROR;
}
string warningDetail = "";
string archiveVersion = reader.ReadString(3);
if (archiveVersion != AppConst.MPE_FORMAT_VERSION)
{
warningDetail += "archive format version:" + archiveVersion + " preferred:000\r\n";
}
string encoderVersion = reader.ReadString(3);
if (encoderVersion != AppConst.MPE_ENCODER_VERSION)
{
warningDetail += "encoder version:" + encoderVersion + " preferred:000\r\n";
}
int questionHeaderLen = reader.ReadInt();
byte[] questionHeaderCRC = reader.ReadBytes(4);
long dataLen = reader.ReadLong();
byte[] dataCRC = reader.ReadBytes(4);
if (AppConst.MPE_HEADER_SIZE + questionHeaderLen + dataLen != encryptedFS.Length)
{
errorDetailMessage = "File size is incorrect.";
goto ERROR;
}
// question header
byte[] questionHeaderBuf = new byte[questionHeaderLen];
encryptedFS.Read(questionHeaderBuf, 0, questionHeaderLen);
byte[] questionHeaderCRCVerify;
using (CRC crcProvider = new CRC(CRCpolynomial.CRC32_C))
{
questionHeaderCRCVerify = crcProvider.ComputeHash(questionHeaderBuf);
}
if (questionHeaderCRC.SequenceEqual(questionHeaderCRCVerify) == false)
{
warningDetail += "question header CRC32 unmatched.\r\n";
}
// TODO:別スレッドで検算
long dataStartPosition = encryptedFS.Position;
byte[] dataCRCVerify;
using (CRC crcProvider = new CRC(CRCpolynomial.CRC32_C))
{
dataCRCVerify = crcProvider.ComputeHash(encryptedFS);
}
if (dataCRC.SequenceEqual(dataCRCVerify) == false)
{
warningDetail += "data CRC32 unmatched.\r\n";
}
byte flag;
int nQuestions;
int nRequiredPasswords;
int nPasswordCombinations;
byte[] encryptedDataKeys;
DecQuestion[] questions;
try
{
// parse question header
reader = new MPEHeaderReader(questionHeaderBuf);
flag = reader.ReadByte();
nQuestions = reader.ReadInt();
nRequiredPasswords = reader.ReadInt();
nPasswordCombinations = reader.ReadInt();
// assertion: nQuestions C nRequiredPasswords == nPasswordCombinations
encryptedDataKeys = reader.ReadBytes(nPasswordCombinations * Crypto.AES_KEY_SIZE_BYTE_WITH_PADDING);
questions = new DecQuestion[nQuestions];
for (int i = 0; i < nQuestions; ++i)
{
var question = new DecQuestion();
int hintLen = reader.ReadInt();
question.hint = reader.ReadString(hintLen);
question.nPasswords = reader.ReadInt();
question.encryptedQuestionKeys = reader.ReadBytes(question.nPasswords * Crypto.AES_KEY_SIZE_BYTE_WITH_PADDING);
questions[i] = question;
}
if (reader.Position != questionHeaderBuf.Length)
{
errorDetailMessage = "MPE Header is incorrect.";
goto ERROR;
}
}
catch (IndexOutOfRangeException)
{
errorDetailMessage = "MPE Header is incorrect.";
goto ERROR;
}
var decMpeFileInfo = new DecMPEFileInfo();
decMpeFileInfo._encryptedFS = encryptedFS;
decMpeFileInfo._dataStartPosition = dataStartPosition;
decMpeFileInfo._flag = flag;
decMpeFileInfo._nQuestions = nQuestions;
decMpeFileInfo._nRequiredPasswords = nRequiredPasswords;
decMpeFileInfo._encryptedDataKeys = encryptedDataKeys;
decMpeFileInfo._decQuestions = questions;
decMpeFileInfo._errorDetailMessage = errorDetailMessage;
decMpeFileInfo._warningDetailMessage = warningDetailMessage;
return(decMpeFileInfo);
ERROR:
encryptedFS.Close();
decMpeFileInfo = new DecMPEFileInfo();
decMpeFileInfo._warningDetailMessage = warningDetailMessage;
decMpeFileInfo._errorDetailMessage = errorDetailMessage;
return(decMpeFileInfo);
}
