private byte[] encryptBlock(
byte[] inBytes,
int inOff,
int inLen,
byte[] z)
//throws InvalidCipherTextException
{
byte[] C = null;
KeyParameter macKey = null;
KDFParameters kParam = new KDFParameters(z, param.getDerivationV());
int c_text_length = 0;
int macKeySize = param.getMacKeySize();
kdf.init(kParam);
if (cipher == null) // stream mode
{
byte[] buf = new byte[inLen + (macKeySize / 8)];
C = new byte[inLen + mac.getMacSize()];
c_text_length = inLen;
kdf.generateBytes(buf, 0, buf.Length);
for (int i = 0; i != inLen; i++)
{
C[i] = (byte)(inBytes[inOff + i] ^ buf[i]);
}
macKey = new KeyParameter(buf, inLen, (macKeySize / 8));
}
else
{
int cipherKeySize = ((IESWithCipherParameters)param).getCipherKeySize();
byte[] buf = new byte[(cipherKeySize / 8) + (macKeySize / 8)];
cipher.init(true, new KeyParameter(buf, 0, (cipherKeySize / 8)));
c_text_length = cipher.getOutputSize(inLen);
C = new byte[c_text_length + mac.getMacSize()];
int off = cipher.processBytes(inBytes, inOff, inLen, C, 0);
cipher.doFinal(C, off);
macKey = new KeyParameter(buf, (cipherKeySize / 8), (macKeySize / 8));
}
byte[] macIV = param.getEncodingV();
mac.init(macKey);
mac.update(C, 0, c_text_length);
mac.update(macIV, 0, macIV.Length);
//
// return the message and it's MAC
//
mac.doFinal(C, c_text_length);
return(C);
}
public void init(
DerivationParameters param)
{
if (!(typeof(KDFParameters).IsInstanceOfType(param)))
{
throw new ArgumentException("KDF parameters required for KDF2Generator");
}
KDFParameters p = (KDFParameters)param;
shared = p.getSharedSecret();
iv = p.getIV();
}
private byte[] decryptBlock(
byte[] in_enc,
int inOff,
int inLen,
byte[] z)
//throws InvalidCipherTextException
{
byte[] M = null;
KeyParameter macKey = null;
KDFParameters kParam = new KDFParameters(z, param.getDerivationV());
int macKeySize = param.getMacKeySize();
kdf.init(kParam);
inLen -= mac.getMacSize();
if (cipher == null) // stream mode
{
byte[] buf = new byte[inLen + (macKeySize / 8)];
M = new byte[inLen];
kdf.generateBytes(buf, 0, buf.Length);
for (int i = 0; i != inLen; i++)
{
M[i] = (byte)(in_enc[inOff + i] ^ buf[i]);
}
macKey = new KeyParameter(buf, inLen, (macKeySize / 8));
}
else
{
int cipherKeySize = ((IESWithCipherParameters)param).getCipherKeySize();
byte[] buf = new byte[(cipherKeySize / 8) + (macKeySize / 8)];
cipher.init(false, new KeyParameter(buf, 0, (cipherKeySize / 8)));
byte[] tmp = new byte[cipher.getOutputSize(inLen)];
int off = cipher.processBytes(in_enc, inOff, inLen, tmp, 0);
off += cipher.doFinal(tmp, off);
M = new byte[off];
Array.Copy(tmp, 0, M, 0, off);
macKey = new KeyParameter(buf, (cipherKeySize / 8), (macKeySize / 8));
}
byte[] macIV = param.getEncodingV();
mac.init(macKey);
mac.update(in_enc, inOff, inLen);
mac.update(macIV, 0, macIV.Length);
mac.doFinal(macBuf, 0);
inOff += inLen;
for (int t = 0; t < macBuf.Length; t++)
{
if (macBuf[t] != in_enc[inOff + t])
{
throw (new InvalidCipherTextException("Mac codes failed to equal."));
}
}
return(M);
}
