/// <summary>Performs a Cryptography operation on a given ERA file</summary>
/// <param name="path">Path to the input ERA file</param>
/// <param name="eraName">The naked ERA file, void of directory or extension data</param>
/// <param name="outputPath">Path to </param>
/// <param name="transformType">Type of Cryptography operation to perform</param>
/// <param name="verboseOutput">(Optional) the object to write verbose operation output to</param>
/// <returns>The output file's full path</returns>
/// <exception cref="FileNotFoundException">Input ERA file does not exist</exception>
public static string Crypt(string path, string eraName, string outputPath, CryptographyTransformType transformType,
TextWriter verboseOutput = null)
{
if (string.IsNullOrWhiteSpace(outputPath))
{
outputPath = path;
}
string input_file = Path.Combine(path, eraName) + EraFile.kExtensionEncrypted;
string output_file = Path.Combine(outputPath, eraName) + EraFile.kExtensionEncrypted;
// If we're encrypting, the input file will be a .bin, else the output file will be a .bin
switch (transformType)
{
case CryptographyTransformType.Decrypt:
output_file += EraFile.kExtensionDecrypted;
break;
case CryptographyTransformType.Encrypt:
input_file += EraFile.kExtensionDecrypted;
break;
default:
throw new KSoft.Debug.UnreachableException(transformType.ToString());
}
if (!File.Exists(input_file))
{
throw new FileNotFoundException("ERA file for cryptography operation does not exist", input_file);
}
if (verboseOutput != null)
{
verboseOutput.WriteLine("Input: {0}", input_file);
verboseOutput.WriteLine("Output: {0}", output_file);
}
using (var er_fs = File.OpenRead(input_file))
using (var er = new IO.EndianReader(er_fs, Shell.EndianFormat.Big))
using (var ew_fs = new FileStream(output_file, FileMode.Create, FileAccess.Write))
using (var ew = new IO.EndianWriter(ew_fs, Shell.EndianFormat.Big))
{
CryptStream(er, ew, transformType);
}
return(output_file);
}
public static void CryptStream(IO.EndianReader input, IO.EndianWriter output, CryptographyTransformType transformType)
{
Contract.Requires(input != null);
Contract.Requires(output != null);
// This should be OK because PhxTEA is buffered
//Contract.Requires(input.BaseStream != output.BaseStream);
var tea = new Security.Cryptography.PhxTEA(input, output);
tea.InitializeKey(Security.Cryptography.PhxTEA.kKeyEra);
switch (transformType)
{
case CryptographyTransformType.Decrypt:
tea.Decrypt();
break;
case CryptographyTransformType.Encrypt:
tea.Encrypt();
break;
}
}