public CaptchaContainer(EndPoint ep, int id, Key pubKey, object payload)
{
_ep = ep;
_id = id;
using (SymmetricAlgorithm algo = new CamelliaManaged ())
using (ECIES ecies = new ECIES (DefaultAlgorithm.ECDomainName, algo)) {
ecies.Parameters.PublicKey = pubKey.GetByteArray ();
_encrypted = ecies.Encrypt (Serializer.Instance.Serialize (payload));
}
}
public static object Decrypt(ECKeyPair privateKey, byte[] encrypted)
{
using (SymmetricAlgorithm algo = new CamelliaManaged ())
using (ECIES ecies = new ECIES (DefaultAlgorithm.ECDomainName, algo)) {
ecies.Parameters.PrivateKey = privateKey.PrivateKey;
try {
return Serializer.Instance.Deserialize (ecies.Decrypt (encrypted));
} catch {
return null;
}
}
}
static byte[] ParsePrivateKey (string str_key, string str_passwd, out ECDomainNames domain)
{
try {
string str_domain = null;
byte[] key = null;
if (!char.IsDigit (str_key[0])) {
if (str_passwd.Length == 0)
throw new CryptographicException ("秘密鍵は暗号化されています。パスフレーズを入力してください。");
byte[] pass = ComputeHash (new SHA256Managed (), Encoding.UTF8.GetBytes (str_passwd), true);
byte[] iv = ComputeHash (new SHA1Managed (), Encoding.UTF8.GetBytes (str_passwd), true);
Array.Resize<byte> (ref iv, 128 >> 3);
string encType = str_key.Substring (0, str_key.IndexOf ('='));
str_key = str_key.Substring (str_key.IndexOf ('=') + 1);
str_domain = str_key.Substring (0, str_key.IndexOf ('='));
str_key = str_key.Substring (str_key.IndexOf ('=') + 1);
byte[] encrypted = Convert.FromBase64String (str_key);
try {
SymmetricAlgorithm algo = null;
switch (encType) {
case "camellia256":
algo = new CamelliaManaged ();
break;
case "rijndael256":
algo = new openCrypto.RijndaelManaged ();
break;
default:
throw new CryptographicException ("秘密鍵の暗号化タイプを認識できません");
}
key = Decrypt (algo, CipherMode.CBC, pass, iv, encrypted);
} catch {
throw new CryptographicException ("パスフレーズが違います");
}
} else {
str_domain = str_key.Substring (0, str_key.IndexOf ('='));
str_key = str_key.Substring (str_key.IndexOf ('=') + 1);
key = Convert.FromBase64String (str_key);
}
str_domain = "secp" + str_domain;
domain = (ECDomainNames)Enum.Parse (typeof (ECDomainNames), str_domain);
return key;
} catch (CryptographicException) {
throw;
} catch {
throw new CryptographicException ("秘密鍵として認識することができません");
}
}
private void btnEncryptText_Click (object sender, EventArgs e)
{
if (txtEncryptPlain.Text.Length == 0)
return;
try {
KeyEntry publicKeyEntry = cbPublicKeys2.SelectedItem as KeyEntry;
if (publicKeyEntry == null)
throw new Exception ("暗号化に利用する公開鍵を選択してください");
ECDomainNames domain;
byte[] publicKey = ParsePublicKey (publicKeyEntry.Key, out domain);
string encryptType = null;
SymmetricAlgorithm algo = null;
switch (cbEncryptCrypto.SelectedIndex) {
case 0:
encryptType = "ecies+xor";
algo = null;
break;
case 1:
case 2:
encryptType = "ecies+camellia";
algo = new CamelliaManaged ();
algo.BlockSize = 128;
if (cbEncryptCrypto.SelectedIndex == 1) {
encryptType += "128";
algo.KeySize = 128;
} else {
encryptType += "256";
algo.KeySize = 256;
}
break;
case 3:
case 4:
encryptType = "ecies+rijndael";
algo = new openCrypto.RijndaelManaged ();
algo.BlockSize = 128;
if (cbEncryptCrypto.SelectedIndex == 3) {
encryptType += "128";
algo.KeySize = 128;
} else {
encryptType += "256";
algo.KeySize = 256;
}
break;
default:
throw new CryptographicException ("Unknown");
}
if (algo != null) {
algo.Mode = CipherMode.CBC;
algo.Padding = PaddingMode.PKCS7;
}
ECIES ecies = new ECIES (domain, algo);
ecies.Parameters.PublicKey = publicKey;
string encrypted = Convert.ToBase64String (ecies.Encrypt (Encoding.UTF8.GetBytes (txtEncryptPlain.Text)));
txtEncryptCipher.Text = encryptType + "=" + encrypted;
} catch (Exception ex) {
MessageBox.Show (ex.Message);
}
}
string ToPrivateKeyString (byte[] privateKey, string passphrase, ECDomainNames domain)
{
string domainName = domain.ToString ().Substring (4);
if (passphrase.Length > 0) {
byte[] pass = ComputeHash (new SHA256Managed (), Encoding.UTF8.GetBytes (txtGeneratedKeyPass.Text), true);
byte[] iv = ComputeHash (new SHA1Managed (), Encoding.UTF8.GetBytes (txtGeneratedKeyPass.Text), true);
Array.Resize<byte> (ref iv, 128 >> 3);
string encType = null;
SymmetricAlgorithm algo = null;
switch (cbPassEncryptType.SelectedIndex) {
case 0:
encType = "camellia256";
algo = new CamelliaManaged ();
break;
case 1:
encType = "rijndael256";
algo = new openCrypto.RijndaelManaged ();
break;
default:
throw new CryptographicException ("暗号化の種類を認識できません");
}
byte[] encrypted = Encrypt (algo, CipherMode.CBC, pass, iv, privateKey);
string privateKeyText = Convert.ToBase64String (encrypted);
return encType + "=" + domainName + "=" + privateKeyText;
} else {
string privateKeyText = Convert.ToBase64String (privateKey);
return domainName + "=" + privateKeyText;
}
}
