public void TestDiffuser()
{
const string helloWorld = "Hello World!";
var helloWorldBytes = Encoding.UTF8.GetBytes(helloWorld);
BigInteger b = helloWorldBytes.ToBigIntegerFromBigEndianUnsignedBytes();
Diffuser d = new XteaDiffuser();
var scrambled = d.Scramble(b, helloWorldBytes.Length);
var unscrambed = d.Unscramble(scrambled, helloWorldBytes.Length);
var unscrambledBytes = unscrambed.ToUnsignedBigEndianBytes();
string recovered = Encoding.UTF8.GetString(unscrambledBytes);
Assert.AreEqual(helloWorld, recovered);
}
private static void Split()
{
int degree = Arguments.HasSpecifiedSecurityLevel
? Arguments.SecurityLevel
: IrreduciblePolynomial.MaxDegree;
if (!Arguments.QuietMode)
{
Console.Write("Generating shares using a ({0},{1}) scheme with ", Arguments.Threshold, Arguments.Shares);
if (Arguments.HasSpecifiedSecurityLevel)
{
Console.Write("a {0} bit", Arguments.SecurityLevel);
}
else
{
Console.Write("dynamic");
}
Console.WriteLine(" security level.");
Console.Error.Write("Enter the secret, ");
if (Arguments.HexMode)
{
Console.Error.Write("at most {0} hex digits: ", degree / 4);
}
else
{
Console.Error.Write("at most {0} ASCII characters: ", degree / 8);
}
}
var secret = String.Empty;
try {
secret = ReadLineHidden();
}
catch {
Fatal("I/O error while reading secret");
}
int securitySize = Arguments.SecurityLevel;
if (!Arguments.HasSpecifiedSecurityLevel)
{
securitySize = Arguments.HexMode
? 4 * (((secret.Length + 1) & ~1))
: 8 * secret.Length;
if (!IrreduciblePolynomial.IsValidDegree(securitySize))
{
Fatal("security level invalid (secret too long?)");
}
if (!Arguments.QuietMode)
{
Console.Error.WriteLine("Using a {0} bit security level.", securitySize);
}
}
Diffuser diffuser = new NullDiffuser();
if (Arguments.EnableDiffusion)
{
if (securitySize >= 64)
{
diffuser = new XteaDiffuser();
}
else
{
Warning("security level too small for the diffusion layer");
}
}
var secretBytes = MakeSecretBytes(secret, Arguments.HexMode, degree);
foreach (var share in SecretSplitter.Split(SecretShareType.Message, secretBytes, Arguments.Threshold, diffuser).GetShares(Arguments.Shares))
{
Console.WriteLine(share.ToString(SecretShareFormattingOptions.None));
}
}
private static void Combine()
{
if (!Arguments.QuietMode)
{
Console.WriteLine("Enter {0} shares separated by newlines:", Arguments.Threshold);
}
int polynomialDegree = -1;
var totalShares = new List <string>();
for (int i = 0; i < Arguments.Threshold; i++)
{
if (!Arguments.QuietMode)
{
Console.Write("Share [{0}/{1}]: ", i + 1, Arguments.Threshold);
}
string currentShare = String.Empty;
try {
currentShare = Console.ReadLine();
}
catch {
Fatal("I/O error while reading shares");
}
SecretShare share;
if (!SecretShare.TryParse(currentShare, out share))
{
Fatal("invalid syntax");
}
if (polynomialDegree < 0)
{
polynomialDegree = share.Point.Y.PrimePolynomial.Degree;
if (!IrreduciblePolynomial.IsValidDegree(polynomialDegree))
{
Fatal("share has illegal length");
}
}
else if (polynomialDegree != share.Point.Y.PrimePolynomial.Degree)
{
Fatal("shares have different security levels");
}
totalShares.Add(currentShare);
}
Diffuser diffuser = new NullDiffuser();
if (Arguments.EnableDiffusion)
{
if (polynomialDegree >= 64)
{
diffuser = new XteaDiffuser();
}
else
{
Warning("security level too small for the diffusion layer");
}
}
var recoveredSecret = SecretCombiner.Combine(totalShares, diffuser);
if (!Arguments.QuietMode)
{
Console.Error.Write("Resulting secret: ");
}
Console.Error.WriteLine(Arguments.HexMode ? recoveredSecret.RecoveredHexString : recoveredSecret.RecoveredTextString);
}
