/// <summary>
/// The command method to decrypt the given data
/// </summary>
private void Decrypt()
{
byte[] encrypted;
byte[] decrypted;
//Decryption sequence differs according to the selected data format
switch (DataInput.DataFormatSelected)
{
//Decrypt file
case Format.File:
//Get the encrypted file bytes
encrypted = ByteConvert.FileToBytes(EncryptedFilePath);
//Decrypt
decrypted = KeyPairSetup.Decrypt(encrypted);
//true if decrypted not null
if (decrypted != null)
{
//Create an encrypted file path
DecryptedFilePath = DataInput.GetDecryptedFilePath(EncryptedFilePath);
//Write decrypted bytes to file
File.WriteAllBytes(DecryptedFilePath, decrypted);
}
break;
//Decrypt a text
case Format.Text:
//Convert the encrypted hex string to bytes
encrypted = ByteConvert.HexStringToBytes(EncryptedText);
//Decrypt as text
DecryptedText = KeyPairSetup.DecryptToText(encrypted);
break;
//Decrypt a hex value
case Format.Hex:
//Convert the encrypted hex string to bytes
encrypted = ByteConvert.HexStringToBytes(EncryptedText);
//Decrypt
decrypted = KeyPairSetup.Decrypt(encrypted);
//true if decrypted not null
if (decrypted != null)
{
//Convert decrypted bytes to hex string
DecryptedText = ByteConvert.BytesToHexString(decrypted);
}
break;
}
}
/// <summary>
/// transforms the data to bytes according to the selected format option
/// </summary>
/// <param name="format">The format option to use for byte extraction</param>
/// <param name="data">The data to extract the bytes from</param>
/// <returns>the extracted bytes</returns>
private byte[] GetBytesAccordingToFormatSelected(Format format, string data)
{
byte[] bytes = null;
switch (format)
{
case Format.File:
bytes = ByteConvert.FileToBytes(data);
break;
case Format.Text:
bytes = ByteConvert.StringToAsciiBytes(data);
break;
case Format.Hex:
bytes = ByteConvert.HexStringToBytes(data);
break;
default:
Debugger.Break();
break;
}
return(bytes);
}
/// <summary>
/// The command method to decrypt the given data
/// </summary>
private void Decrypt()
{
//field for saving the encrypted and decrypted byte arrays
byte[] encrypted;
byte[] decryptedBytes;
//Convert the secret key and iv to byte arrays
var secretKey = ByteConvert.HexStringToBytes(SecretKey);
var iv = ByteConvert.HexStringToBytes(IV);
try
{
//Decrypt the data according to the selected file format
switch (DataInput.DataFormatSelected)
{
//Decrypt to a regular string
case Format.Text:
//Convert the text string to a byte array
encrypted = ByteConvert.HexStringToBytes(EncryptedText);
//Decrypt the byte array to a text string
DecryptedText = SelectedCipherApi.DecryptToText(SelectedAlgorithim, SelectedKeySize, secretKey, iv, encrypted);
break;
case Format.Hex:
//Convert the hex string to a byte array
encrypted = ByteConvert.HexStringToBytes(EncryptedText);
//Decrypt the byte array to a decrypted byte array
decryptedBytes = SelectedCipherApi.DecryptToBytes(SelectedAlgorithim, SelectedKeySize, secretKey, iv, encrypted);
//Convert the decrypted byte array to a hex string
DecryptedText = ByteConvert.BytesToHexString(decryptedBytes);
break;
case Format.File:
//Get the encrypted file as a byte array
encrypted = ByteConvert.FileToBytes(EncryptedFilePath);
//Decrypt the byte array to a decrypted byte array
decryptedBytes = SelectedCipherApi.DecryptToBytes(SelectedAlgorithim, SelectedKeySize, secretKey, iv, encrypted);
//Create a new file name with the encrypted file path and the "Decrypted" text
DecryptedFilePath = Path.Combine(Directory.GetParent(EncryptedFilePath).ToString(), Path.GetFileName(EncryptedFilePath).Replace("Encrypted", "Decrypted"));
//Write all byte to the decrypted file
File.WriteAllBytes(DecryptedFilePath, decryptedBytes);
break;
}
}
//catches msdn exceptions
catch (CryptographicException msdnException)
{
//Open a error message box
Dialog.OpenErrorMessageBoxAsync(msdnException, "Decryption Failure", WindowDialogType.Error);
}
//catches bouncy castle exceptions
catch (CryptoException bouncyException)
{
//Open a error message box
Dialog.OpenErrorMessageBoxAsync(bouncyException, "Decryption Failure", WindowDialogType.Error);
}
//Catch any other errors
catch (Exception exception)
{
//Open a error message box
Dialog.OpenErrorMessageBoxAsync(exception, "Unknown Error, Contact Developer", WindowDialogType.Error);
}
}