public byte[] Encrypt (byte[] value, byte[] randomK)
#endif
{
int domainLen = (int)((_domain.Bits >> 3) + ((_domain.Bits & 7) == 0 ? 0 : 1));
int encBlockBytes = (_symmetricAlgo == null ? 0 : _symmetricAlgo.BlockSize >> 3);
int encKeyLen = (_symmetricAlgo == null ? value.Length : _symmetricAlgo.KeySize >> 3);
int encPaddingLen = 0;
int encTotalBytes = value.Length;
int macKeyLen = _mac.HashSize >> 3;
byte[] result;
int ridx = 0;
if (_params.D == null)
_params.CreateNewPrivateKey ();
if (_params.Q == null)
_params.CreatePublicKeyFromPrivateKey ();
if (_symmetricAlgo != null) {
int mod = value.Length % encBlockBytes;
int rmod = encBlockBytes - mod;
if (mod == 0) {
if (!(_symmetricAlgo.Padding == PaddingMode.None || _symmetricAlgo.Padding == PaddingMode.Zeros))
encPaddingLen = _symmetricAlgo.BlockSize >> 3;
} else {
encPaddingLen = rmod;
}
encTotalBytes += encPaddingLen;
}
// Step.1
#if !TEST
ECKeyPair pair = new ECKeyPair (null, null, _domain);
#else
ECKeyPair pair = new ECKeyPair (new Number (randomK, false), null, _domain);
#endif
// Step.2
// TODO: 点圧縮を利用しないオプションを追加する
byte[] R = pair.ExportPublicKey (true);
result = new byte[R.Length + encTotalBytes + macKeyLen];
for (int i = 0; i < R.Length; i ++) result[ridx ++] = R[i];
// Step.3 & 4
// TODO: Cofactor Diffie-Hellmanプリミティブを利用するオプションを追加する
byte[] z = _params.Q.Multiply (pair.D).Export ().X.ToByteArray (domainLen, false);
// Step.5
byte[] K = _kdf.Calculate (z, encKeyLen + macKeyLen);
// Step.6
byte[] MK = new byte[macKeyLen];
for (int i = 0; i < MK.Length; i++)
MK[i] = K[K.Length - MK.Length + i];
// Step.7
if (_symmetricAlgo == null) {
for (int i = 0; i < value.Length; i++)
result[ridx++] = (byte)(value[i] ^ K[i]);
} else {
byte[] EK = new byte[encKeyLen];
for (int i = 0; i < EK.Length; i ++)
EK[i] = K[i];
using (ICryptoTransform transform = _symmetricAlgo.CreateEncryptor (EK, new byte[encBlockBytes])) {
int i = 0;
for (; i < value.Length - encBlockBytes; i += encBlockBytes)
transform.TransformBlock (value, i, encBlockBytes, result, ridx + i);
byte[] padding = transform.TransformFinalBlock (value, i, value.Length - i);
Buffer.BlockCopy (padding, 0, result, ridx + i, padding.Length);
ridx += i + padding.Length;
}
}
// Step.8
// TODO: HMAC-SHA1-80への対応
_mac.Key = MK;
_mac.Initialize ();
_mac.TransformBlock (result, R.Length, encTotalBytes, null, 0);
if (_sharedInfo == null)
_mac.TransformFinalBlock (result, 0, 0);
else
_mac.TransformFinalBlock (_sharedInfo, 0, _sharedInfo.Length);
_mac.Hash.CopyTo (result, ridx);
return result;
}
public byte[] Encrypt(byte[] value, byte[] randomK)
#endif
{
int domainLen = (int)((_domain.Bits >> 3) + ((_domain.Bits & 7) == 0 ? 0 : 1));
int encBlockBytes = (_symmetricAlgo == null ? 0 : _symmetricAlgo.BlockSize >> 3);
int encKeyLen = (_symmetricAlgo == null ? value.Length : _symmetricAlgo.KeySize >> 3);
int encPaddingLen = 0;
int encTotalBytes = value.Length;
int macKeyLen = _mac.HashSize >> 3;
byte[] result;
int ridx = 0;
if (_params.D == null)
{
_params.CreateNewPrivateKey();
}
if (_params.Q == null)
{
_params.CreatePublicKeyFromPrivateKey();
}
if (_symmetricAlgo != null)
{
int mod = value.Length % encBlockBytes;
int rmod = encBlockBytes - mod;
if (mod == 0)
{
if (!(_symmetricAlgo.Padding == PaddingMode.None || _symmetricAlgo.Padding == PaddingMode.Zeros))
{
encPaddingLen = _symmetricAlgo.BlockSize >> 3;
}
}
else
{
encPaddingLen = rmod;
}
encTotalBytes += encPaddingLen;
}
// Step.1
#if !TEST
ECKeyPair pair = new ECKeyPair(null, null, _domain);
#else
ECKeyPair pair = new ECKeyPair(new Number(randomK, false), null, _domain);
#endif
// Step.2
// TODO: 点圧縮を利用しないオプションを追加する
byte[] R = pair.ExportPublicKey(true);
result = new byte[R.Length + encTotalBytes + macKeyLen];
for (int i = 0; i < R.Length; i++)
{
result[ridx++] = R[i];
}
// Step.3 & 4
// TODO: Cofactor Diffie-Hellmanプリミティブを利用するオプションを追加する
byte[] z = _params.Q.Multiply(pair.D).Export().X.ToByteArray(domainLen, false);
// Step.5
byte[] K = _kdf.Calculate(z, encKeyLen + macKeyLen);
// Step.6
byte[] MK = new byte[macKeyLen];
for (int i = 0; i < MK.Length; i++)
{
MK[i] = K[K.Length - MK.Length + i];
}
// Step.7
if (_symmetricAlgo == null)
{
for (int i = 0; i < value.Length; i++)
{
result[ridx++] = (byte)(value[i] ^ K[i]);
}
}
else
{
byte[] EK = new byte[encKeyLen];
for (int i = 0; i < EK.Length; i++)
{
EK[i] = K[i];
}
using (ICryptoTransform transform = _symmetricAlgo.CreateEncryptor(EK, new byte[encBlockBytes])) {
int i = 0;
for (; i < value.Length - encBlockBytes; i += encBlockBytes)
{
transform.TransformBlock(value, i, encBlockBytes, result, ridx + i);
}
byte[] padding = transform.TransformFinalBlock(value, i, value.Length - i);
Buffer.BlockCopy(padding, 0, result, ridx + i, padding.Length);
ridx += i + padding.Length;
}
}
// Step.8
// TODO: HMAC-SHA1-80への対応
_mac.Key = MK;
_mac.Initialize();
_mac.TransformBlock(result, R.Length, encTotalBytes, null, 0);
if (_sharedInfo == null)
{
_mac.TransformFinalBlock(result, 0, 0);
}
else
{
_mac.TransformFinalBlock(_sharedInfo, 0, _sharedInfo.Length);
}
_mac.Hash.CopyTo(result, ridx);
return(result);
}
