/*
* Copyright (C)2009 - SSHJ Contributors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package net.schmizz.sshj.signature;
import net.schmizz.sshj.common.SSHRuntimeException;
import net.schmizz.sshj.common.SecurityUtils;
import java.security.GeneralSecurityException;
import java.security.PrivateKey;
import java.security.PublicKey;
import java.security.SignatureException;
/** An abstract class for {@link Signature} that implements common functionality. */
public abstract class AbstractSignature
implements Signature {
protected final String algorithm;
protected java.security.Signature signature;
protected AbstractSignature(String algorithm) {
this.algorithm = algorithm;
}
@Override
public void init(PublicKey publicKey, PrivateKey privateKey) {
try {
signature = SecurityUtils.getSignature(algorithm);
if (publicKey != null)
signature.initVerify(publicKey);
if (privateKey != null)
signature.initSign(privateKey);
} catch (GeneralSecurityException e) {
throw new SSHRuntimeException(e);
}
}
@Override
public void update(byte[] foo) {
update(foo, 0, foo.length);
}
@Override
public void update(byte[] foo, int off, int len) {
try {
signature.update(foo, off, len);
} catch (SignatureException e) {
throw new SSHRuntimeException(e);
}
}
@Override
public byte[] sign() {
try {
return signature.sign();
} catch (SignatureException e) {
throw new SSHRuntimeException(e);
}
}
protected byte[] extractSig(byte[] sig) {
if (sig[0] == 0 && sig[1] == 0 && sig[2] == 0) {
int i = 0;
int j = sig[i++] << 24 & 0xff000000
| sig[i++] << 16 & 0x00ff0000
| sig[i++] << 8 & 0x0000ff00
| sig[i++] & 0x000000ff;
i += j;
j = sig[i++] << 24 & 0xff000000
| sig[i++] << 16 & 0x00ff0000
| sig[i++] << 8 & 0x0000ff00
| sig[i++] & 0x000000ff;
byte[] newSig = new byte[j];
System.arraycopy(sig, i, newSig, 0, j);
return newSig;
}
return sig;
}
}