public byte[] createPinAuthforChangePin(byte[] sharedSecret, string newpin, string currentpin)
{
// new pin
byte[] newPinEnc = null;
{
var newpin64 = this.paddingPin64(newpin);
newPinEnc = AES256CBC.Encrypt(sharedSecret, newpin64);
}
// current pin
var currentPinHashEnc = createPinHashEnc(currentpin, sharedSecret);
// source data
var data = new List <byte>();
data.AddRange(newPinEnc.ToArray());
data.AddRange(currentPinHashEnc.ToArray());
// HMAC-SHA-256(sharedSecret, newPinEnc)
byte[] pinAuth;
using (var hmacsha256 = new HMACSHA256(sharedSecret)) {
var dgst = hmacsha256.ComputeHash(data.ToArray());
pinAuth = dgst.ToList().Take(16).ToArray();
}
return(pinAuth);
}
public byte[] createPinAuthforSetPin(byte[] sharedSecret, string newpin)
{
var newpin64 = this.paddingPin64(newpin);
var newPinEnc = AES256CBC.Encrypt(sharedSecret, newpin64);
// HMAC-SHA-256(sharedSecret, newPinEnc)
byte[] pinAuth;
using (var hmacsha256 = new HMACSHA256(sharedSecret)) {
var dgst = hmacsha256.ComputeHash(newPinEnc);
pinAuth = dgst.ToList().Take(16).ToArray();
}
return(pinAuth);
}
public byte[] createPinHashEnc(string pin, byte[] sharedSecret)
{
// AES256-CBC(sharedSecret, IV=0, LEFT(SHA-256(PIN), 16))
// pinsha = SHA-256(PIN) ->32byte
byte[] pinbyte = Encoding.ASCII.GetBytes(pin);
SHA256 sha = new SHA256CryptoServiceProvider();
byte[] pinsha = sha.ComputeHash(pinbyte);
// pinsha16 = LEFT 16(pinsha)
byte[] pinsha16 = pinsha.ToList().Skip(0).Take(16).ToArray();
// pinHashEnc = AES256-CBC(sharedSecret, IV=0, pinsha16)
string key = Common.BytesToHexString(sharedSecret);
string data = Common.BytesToHexString(pinsha16);
var pinHashEnc = AES256CBC.Encrypt(sharedSecret, pinsha16);
return(pinHashEnc);
}
// newPinEnc: AES256-CBC(sharedSecret, IV = 0, newPin)
public byte[] createNewPinEnc(byte[] sharedSecret, byte[] newpin64)
{
byte[] newPinEnc = AES256CBC.Encrypt(sharedSecret, newpin64);
return(newPinEnc);
}