public UserData registerUser(string username, string password)
{
// PBKDF2
string pwsalt = "";
string pwhash = "";
// password hash
using (var db = new Rfc2898DeriveBytes(password, SALT_SIZE, ITERATIONS))
{
pwsalt = Convert.ToBase64String(db.Salt);
pwhash = Convert.ToBase64String(db.GetBytes(KEY_SIZE));
}
// KEK
string keksalt = "";
string kek = "";
// kek generation
using (var db = new Rfc2898DeriveBytes(password, SALT_SIZE, ITERATIONS))
{
keksalt = Convert.ToBase64String(db.Salt);
kek = Convert.ToBase64String(db.GetBytes(KEY_SIZE));
}
// RSA
string publickey;
string privatekey;
string privateiv;
string encryptedprivatekey;
// Generate RSA key pair
using (var rsa = new RSACryptoServiceProvider(RSA_SIZE))
{
try
{
privatekey = rsa.ToXmlString(true);
publickey = rsa.ToXmlString(false);
}
finally
{
// IMPORTANT, avoid storing key in windows store
rsa.PersistKeyInCsp = false;
}
}
byte[] privatekeyb = Encoding.UTF8.GetBytes(privatekey);
/*
logF("register user {0} , password {1}", username, password);
log("");
logF("kek {0}", kek);
log("");
logF("privatekey {0}", privatekey);
log("");
*/
using (var cipher = new AesManaged())
{
cipher.Mode = CipherMode.CBC;
cipher.KeySize = 128;
cipher.BlockSize = 128;
cipher.Padding = PaddingMode.PKCS7;
//
cipher.GenerateIV();
privateiv = Convert.ToBase64String(cipher.IV);
cipher.Key = Convert.FromBase64String(kek);
cipher.IV = Convert.FromBase64String(privateiv);
using (ICryptoTransform encryptor = cipher.CreateEncryptor(cipher.Key,cipher.IV))
{
using (MemoryStream to = new MemoryStream())
{
using (CryptoStream writer = new CryptoStream(to, encryptor, CryptoStreamMode.Write))
{
writer.Write(privatekeyb, 0, privatekeyb.Length);
writer.FlushFinalBlock();
encryptedprivatekey = Convert.ToBase64String(to.ToArray());
}
}
}
cipher.Clear();
}
UserData ud = new UserData()
{
username = username,
passwordSalt = pwsalt,
passwordHash = pwhash,
KEKSalt = keksalt,
privateIV = privateiv,
publicKey = publickey,
encryptedPrivateKey = encryptedprivatekey
};
return ud;
}
/*
private void writeObject(SslStream sslStream, object obj)
{
byte[] userDataBytes;
MemoryStream ms = new MemoryStream();
BinaryFormatter bf1 = new BinaryFormatter();
bf1.Serialize(ms, obj);
userDataBytes = ms.ToArray();
byte[] userDataLen = BitConverter.GetBytes((Int32)userDataBytes.Length);
sslStream.Write(userDataLen, 0, 4);
sslStream.Write(userDataBytes, 0, userDataBytes.Length);
logF("Sent an object of type {0} length {1}:", obj.GetType(), userDataBytes.Length);
log(Util.XmlSerializeToString(obj));
}
private object readObject(SslStream sslStream)
{
byte[] readMsgLen = new byte[4];
int dataRead = 0;
do
{
dataRead += sslStream.Read(readMsgLen, 0, 4 - dataRead);
} while (dataRead < 4);
int dataLen = BitConverter.ToInt32(readMsgLen,0);
logF("header: message length {0}", dataLen);
if(dataLen == 0)
{
return null;
}
byte[] readMsgData = new byte[dataLen];
int len = dataLen;
dataRead = 0;
do
{
dataRead += sslStream.Read(readMsgData, dataRead, len - dataRead);
} while (dataRead < len);
logF("received {0} bytes", len) ;
//deserialize
MemoryStream ms = new MemoryStream(readMsgData);
BinaryFormatter bf1 = new BinaryFormatter();
ms.Position = 0;
object rawObj = bf1.Deserialize(ms);
log(Util.XmlSerializeToString(rawObj));
return rawObj;
}*/
public SecureCalendar registerCalendar(string username, string password, UserData userdata)
{
SecureCalendar sc = new SecureCalendar() { };
// KEK
string FEK = "";
string events = "10:00 Dev team meeting. 20:00 Son birthday party";
// kek generation
using (var db = new Rfc2898DeriveBytes(password, SALT_SIZE, ITERATIONS))
{
db.Salt = Convert.FromBase64String(userdata.KEKSalt);
FEK = Convert.ToBase64String(db.GetBytes(KEY_SIZE));
}
// generate KEK
using (var cipher = new AesManaged())
{
cipher.Mode = CipherMode.CBC;
cipher.KeySize = KEY_SIZE * 8;
cipher.GenerateKey();
cipher.GenerateIV();
FEK = Convert.ToBase64String(cipher.Key);
sc.IV = Convert.ToBase64String(cipher.IV);
using (ICryptoTransform encryptor = cipher.CreateEncryptor(
cipher.Key,
cipher.IV))
{
using (MemoryStream to = new MemoryStream())
{
using (CryptoStream writer = new CryptoStream(to, encryptor, CryptoStreamMode.Write))
{
byte[] x = Encoding.UTF8.GetBytes(Util.XmlSerializeToString(events));
writer.Write(x, 0, x.Length);
writer.FlushFinalBlock();
sc.encryptedEvents = Convert.ToBase64String(to.ToArray());
}
}
}
cipher.Clear();
}
//Encode FEK with public key
RSACryptoServiceProvider rsaPublic = new RSACryptoServiceProvider();
rsaPublic.FromXmlString(userdata.publicKey);
byte[] eFEKb = rsaPublic.Encrypt(Convert.FromBase64String(FEK), false);
string eFEK = Convert.ToBase64String(eFEKb);
sc.keys.Add(new EncryptedFileEncryptionKey() {
username = username,
eFEK = eFEK
});
return sc;
}
