/// <summary>
/// Constructor of Session class for a new User
/// </summary>
/// <param name="username">Username of the user</param>
/// <param name="password">Password of the user</param>
/// <param name="localObjectStorage">LocalObjectStorage</param>
internal Session(string username, string password, LocalObjectStorage localObjectStorage)
{
LocalObjectStorage = localObjectStorage;
rsaKeyPair = Crypto.DeriveRsaKey(Encoding.UTF8.GetBytes(username), Encoding.UTF8.GetBytes(password));
KademliaId id = Crypto.Hash(rsaKeyPair.Public);
Username = username;
User = localObjectStorage.GetObject(id) as User;
if (User == null)
{
User = new User(rsaKeyPair.Public) {ObjectId = id};
localObjectStorage.StoreObject(User, true);
}
onUserUpdated = UpdateUser;
localObjectStorage.OnUserUpdated += onUserUpdated;
}
/// <summary>
/// Generates a signature for the data
/// </summary>
/// <param name="data">Data to sign</param>
/// <returns>The signature of the hashed data</returns>
internal static byte[] Sign(byte[] data, RsaKeyPair keyPair)
{
return DecryptRsa(Hash(data), keyPair);
}
/// <summary>
/// Decrypts data with an RSA key pair
/// </summary>
/// <param name="data">Data to decrypt</param>
/// <param name="keyPair">RSA Key pair to use for decryption</param>
/// <returns>The decrypted data</returns>
internal static byte[] DecryptRsa(byte[] data, RsaKeyPair keyPair)
{
var c = new BigInt(data);
var d = new BigInt(keyPair.Private);
var n = new BigInt(keyPair.Public);
return c.PowerMod(d, n).ToByteArray();
}