/// <summary>
/// Creates a verifier that the server can later use to authenticate users later on (v)
/// </summary>
public static byte[] ComputeServerVerifier(byte[] privateKey)
{
NetBigInteger x = new NetBigInteger(NetUtility.ToHexString(privateKey), 16);
// Verifier (v) = g^x (mod N)
var serverVerifier = g.ModPow(x, N);
return(serverVerifier.ToByteArrayUnsigned());
}
/// <summary>
/// Calculates server's S.
/// </summary>
/// <param name="N"></param>
/// <param name="A"></param>
/// <param name="v"></param>
/// <param name="u"></param>
/// <param name="b"></param>
/// <returns></returns>
public static NetBigInteger CalcSServer(NetBigInteger N, NetBigInteger A, NetBigInteger v, NetBigInteger u, NetBigInteger b)
{
// Host: S = (Av^u) ^ b (computes session key)
NetBigInteger S = (A.Multiply(v.ModPow(u, N))).ModPow(b, N);
return(S);
}
//public byte[] GenerateObfuscationCallback()
//{
// var _loc5_ = 0;
// var _loc6_ = "";
// var _loc1_ = "";
// var _loc2_ = 0;
// while (_loc2_ < 128)
// {
// _loc5_ = (int)(MathF.random() * 256);
// _loc6_ = Convert.ToString(_loc5_, 16);
// if (_loc6_.Length == 1)
// {
// _loc6_ = "0" + _loc6_;
// }
// _loc1_ = _loc1_ + _loc6_;
// _loc2_++;
// }
// this.privateKey = new NetBigInteger(_loc1_, 16);
// var _loc3_ = ENC_BASE_GENERATOR.ModPow(privateKey, ENC_PRIME_MODULUS);
// var loc3Bytes = _loc3_.ToByteArray();
// Console.WriteLine("Generated key, L:" + loc3Bytes.Length);
// return loc3Bytes;
//}
public byte[] GenerateObfuscationCallback()
{
var finalizedString = "";
for (int i = 0; i < 128; i++)
{
var randomNum = Convert.ToInt32(MathF.random() * 256);
var randomizedString = Convert.ToString(randomNum, 16);
if (randomizedString.Length == 1)
{
randomizedString = "0" + randomizedString;
}
finalizedString = finalizedString + randomizedString;
}
Console.WriteLine(finalizedString);
// Output 0: a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1
// Output 1: b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7b7
// Output 2: dededededededededededededededededededededededededededededededededededededededededededededededededededededededededededededededededede3a3a3a3a3a3a3a3a3a3a3a3a3a3a3a3a3a3a3a3a3a3a3a3a3a3a3a3a3a3a3a3a3a3a3a3a3a3a3a3a3a3a3a3a3a3a3a3a3a3a3a3a3a3a3a3a3a3a3a3a3a3a
privateKey = new NetBigInteger(finalizedString, 16);
var generatedKey = ENC_BASE_GENERATOR.ModPow(privateKey, ENC_PRIME_MODULUS);
var bytes = generatedKey.ToByteArray();
Console.WriteLine("Generated key, L:" + bytes.Length);
return(bytes);
}
/// <summary>
/// Calculates B.
/// </summary>
/// <param name="N"></param>
/// <param name="g"></param>
/// <param name="b"></param>
/// <param name="v"></param>
/// <returns></returns>
public static NetBigInteger CalcB(NetBigInteger N, NetBigInteger g, NetBigInteger b, NetBigInteger v)
{
//B = k*v + g^b % N
NetBigInteger k = Calck(N, g);
return((k.Multiply(v).Add(g.ModPow(b, N))).Mod(N));
}
/// <summary>
/// Calculates client's S.
/// </summary>
/// <param name="N"></param>
/// <param name="g"></param>
/// <param name="B"></param>
/// <param name="k"></param>
/// <param name="x"></param>
/// <param name="a"></param>
/// <param name="u"></param>
/// <returns></returns>
public static NetBigInteger CalcSClient(NetBigInteger N, NetBigInteger g, NetBigInteger B, NetBigInteger k, NetBigInteger x, NetBigInteger a, NetBigInteger u)
{
// <premaster secret> = (B - (k * g^x)) ^ (a + (u * x)) % N
// (B + (N - ((k*g.ModExp(x,N))%N))) - Do it this way. Thanks Valery.
NetBigInteger S = (B.Add(N.Subtract((k.Multiply(g.ModPow(x, N))).Mod(N)))).ModPow(a.Add(u.Multiply(x)), N);
return(S);
}
public static byte[] ComputeServerSessionValue(byte[] clientPublicEphemeral, byte[] verifier, byte[] udata, byte[] serverPrivateEphemeral)
{
// S = (Av^u) ^ b (mod N)
var A = new NetBigInteger(NetUtility.ToHexString(clientPublicEphemeral), 16);
var v = new NetBigInteger(NetUtility.ToHexString(verifier), 16);
var u = new NetBigInteger(NetUtility.ToHexString(udata), 16);
var b = new NetBigInteger(NetUtility.ToHexString(serverPrivateEphemeral), 16);
NetBigInteger retval = v.ModPow(u, N).Multiply(A).Mod(N).ModPow(b, N).Mod(N);
return(retval.ToByteArrayUnsigned());
}
/// <summary>
/// Returns A.
/// </summary>
/// <param name="N"></param>
/// <param name="g"></param>
/// <param name="a"></param>
/// <returns></returns>
public static NetBigInteger CalcA(NetBigInteger N, NetBigInteger g, NetBigInteger a)
{
// A = g^a % N
if (g == null)
{
throw new ArgumentNullException("g");
}
if (N == null)
{
throw new ArgumentNullException("N");
}
return(g.ModPow(a, N));
}
/// <summary>
/// Calculates V. The password verifier.
/// </summary>
/// <param name="N"></param>
/// <param name="g"></param>
/// <param name="x"></param>
/// <returns></returns>
public static NetBigInteger CalcV(NetBigInteger N, NetBigInteger g, NetBigInteger x)
{
// v = g^x % N
return(g.ModPow(x, N));
}
/// <summary>
/// Computes the server session value
/// </summary>
public static byte[] ComputeServerSessionValue(byte[] clientPublicEphemeral, byte[] verifier, byte[] udata, byte[] serverPrivateEphemeral)
{
// S = (Av^u) ^ b (mod N)
var A = new NetBigInteger(NetUtility.ToHexString(clientPublicEphemeral), 16);
var v = new NetBigInteger(NetUtility.ToHexString(verifier), 16);
var u = new NetBigInteger(NetUtility.ToHexString(udata), 16);
var b = new NetBigInteger(NetUtility.ToHexString(serverPrivateEphemeral), 16);
NetBigInteger retval = v.ModPow(u, N).Multiply(A).Mod(N).ModPow(b, N).Mod(N);
return retval.ToByteArrayUnsigned();
}
/// <summary>
/// Calculates V. The password verifier.
/// </summary>
/// <param name="N"></param>
/// <param name="g"></param>
/// <param name="x"></param>
/// <returns></returns>
public static NetBigInteger CalcV(NetBigInteger N, NetBigInteger g, NetBigInteger x)
{
// v = g^x % N
return g.ModPow(x, N);
}
/// <summary>
/// Calculates server's S.
/// </summary>
/// <param name="N"></param>
/// <param name="A"></param>
/// <param name="v"></param>
/// <param name="u"></param>
/// <param name="b"></param>
/// <returns></returns>
public static NetBigInteger CalcSServer(NetBigInteger N, NetBigInteger A, NetBigInteger v, NetBigInteger u, NetBigInteger b)
{
// Host: S = (Av^u) ^ b (computes session key)
NetBigInteger S = (A.Multiply(v.ModPow(u, N))).ModPow(b, N);
return S;
}
/// <summary>
/// Calculates client's S.
/// </summary>
/// <param name="N"></param>
/// <param name="g"></param>
/// <param name="B"></param>
/// <param name="k"></param>
/// <param name="x"></param>
/// <param name="a"></param>
/// <param name="u"></param>
/// <returns></returns>
public static NetBigInteger CalcSClient(NetBigInteger N, NetBigInteger g, NetBigInteger B, NetBigInteger k, NetBigInteger x, NetBigInteger a, NetBigInteger u)
{
// <premaster secret> = (B - (k * g^x)) ^ (a + (u * x)) % N
// (B + (N - ((k*g.ModExp(x,N))%N))) - Do it this way. Thanks Valery.
NetBigInteger S = (B.Add(N.Subtract((k.Multiply(g.ModPow(x, N))).Mod(N)))).ModPow(a.Add(u.Multiply(x)), N);
return S;
}
/// <summary>
/// Calculates B.
/// </summary>
/// <param name="N"></param>
/// <param name="g"></param>
/// <param name="b"></param>
/// <param name="v"></param>
/// <returns></returns>
public static NetBigInteger CalcB(NetBigInteger N, NetBigInteger g, NetBigInteger b, NetBigInteger v)
{
//B = k*v + g^b % N
NetBigInteger k = Calck(N, g);
return (k.Multiply(v).Add(g.ModPow(b, N))).Mod(N);
}
/// <summary>
/// Returns A.
/// </summary>
/// <param name="N"></param>
/// <param name="g"></param>
/// <param name="a"></param>
/// <returns></returns>
public static NetBigInteger CalcA(NetBigInteger N, NetBigInteger g, NetBigInteger a)
{
// A = g^a % N
if (g == null)
throw new ArgumentNullException("g");
if (N == null)
throw new ArgumentNullException("N");
return g.ModPow(a, N);
}
