/*
* Adito
*
* Copyright (C) 2003-2006 3SP LTD. All Rights Reserved
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2 of
* the License, or (at your option) any later version.
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public
* License along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
package com.maverick.crypto.publickey;
import java.io.IOException;
import com.maverick.crypto.digests.SHA1Digest;
import java.math.BigInteger;
import com.maverick.crypto.security.SecureRandom;
public class RsaPrivateKey
extends RsaKey {
protected BigInteger privateExponent;
protected final static byte[] ASN_SHA1 = {
0x30, 0x21, 0x30, 0x09, 0x06, 0x05, 0x2b, 0x0e,
0x03, 0x02, 0x1a, 0x05, 0x00, 0x04, 0x14
};
public RsaPrivateKey(BigInteger modulus, BigInteger privateExponent) {
super(modulus);
this.privateExponent = privateExponent;
}
/* (non-Javadoc)
* @see com.maverick.crypto.publickey.RsaPrivateKeyInterface#getPrivateExponent()
*/
public BigInteger getPrivateExponent() {
return privateExponent;
}
/* (non-Javadoc)
* @see com.maverick.crypto.publickey.RsaPrivateKeyInterface#sign(byte[])
*/
public byte[] sign(byte[] msg) throws IOException {
SHA1Digest hash = new SHA1Digest();
hash.update(msg, 0, msg.length);
byte[] data = new byte[hash.getDigestSize()];
hash.doFinal(data, 0);
byte[] tmp = new byte[data.length + ASN_SHA1.length];
System.arraycopy(ASN_SHA1, 0, tmp, 0, ASN_SHA1.length);
System.arraycopy(data, 0, tmp, ASN_SHA1.length, data.length);
data = tmp;
BigInteger dataInt = new BigInteger(1, data);
int mLen = (getModulus().bitLength() + 7) / 8;
dataInt = Rsa.padPKCS1(dataInt, 1, mLen);
BigInteger signatureInt = null;
BigInteger privateExponent = getPrivateExponent();
BigInteger modulus = getModulus();
signatureInt = Rsa.doPrivate(dataInt,
modulus, privateExponent);
byte[] sig = unsignedBigIntToBytes(signatureInt, mLen);
return sig;
}
protected static byte[] unsignedBigIntToBytes(BigInteger bi, int size) {
byte[] tmp = bi.toByteArray();
byte[] tmp2 = null;
if (tmp.length > size) {
tmp2 = new byte[size];
System.arraycopy(tmp, tmp.length - size, tmp2, 0, size);
}
else if (tmp.length < size) {
tmp2 = new byte[size];
System.arraycopy(tmp, 0, tmp2, size - tmp.length, tmp.length);
}
else {
tmp2 = tmp;
}
return tmp2;
}
public boolean equals(Object obj) {
if (obj instanceof RsaPrivateKey) {
RsaPrivateKey key = (RsaPrivateKey) obj;
return key.getBitLength() == getBitLength()
&& key.getModulus().compareTo(getModulus()) == 0
&& key.getPrivateExponent().compareTo(getPrivateExponent()) == 0;
}
return false;
}
}