com.itextpdf.signatures.PrivateKeySignature Maven / Gradle / Ivy
/*
*
* This file is part of the iText (R) project.
Copyright (c) 1998-2020 iText Group NV
* Authors: Bruno Lowagie, Paulo Soares, et al.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License version 3
* as published by the Free Software Foundation with the addition of the
* following permission added to Section 15 as permitted in Section 7(a):
* FOR ANY PART OF THE COVERED WORK IN WHICH THE COPYRIGHT IS OWNED BY
* ITEXT GROUP. ITEXT GROUP DISCLAIMS THE WARRANTY OF NON INFRINGEMENT
* OF THIRD PARTY RIGHTS
*
* 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 Affero General Public License for more details.
* You should have received a copy of the GNU Affero General Public License
* along with this program; if not, see http://www.gnu.org/licenses or write to
* the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
* Boston, MA, 02110-1301 USA, or download the license from the following URL:
* http://itextpdf.com/terms-of-use/
*
* The interactive user interfaces in modified source and object code versions
* of this program must display Appropriate Legal Notices, as required under
* Section 5 of the GNU Affero General Public License.
*
* In accordance with Section 7(b) of the GNU Affero General Public License,
* a covered work must retain the producer line in every PDF that is created
* or manipulated using iText.
*
* You can be released from the requirements of the license by purchasing
* a commercial license. Buying such a license is mandatory as soon as you
* develop commercial activities involving the iText software without
* disclosing the source code of your own applications.
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*/
package com.itextpdf.signatures;
import java.security.GeneralSecurityException;
import java.security.PrivateKey;
import java.security.Signature;
/**
* Implementation of the {@link IExternalSignature} interface that
* can be used when you have a {@link PrivateKey} object.
*
* @author Paulo Soares
*/
public class PrivateKeySignature implements IExternalSignature {
/**
* The private key object.
*/
private PrivateKey pk;
/**
* The hash algorithm.
*/
private String hashAlgorithm;
/**
* The encryption algorithm (obtained from the private key)
*/
private String encryptionAlgorithm;
/**
* The security provider
*/
private String provider;
/**
* Creates a {@link PrivateKeySignature} instance.
*
* @param pk A {@link PrivateKey} object.
* @param hashAlgorithm A hash algorithm (e.g. "SHA-1", "SHA-256",...).
* @param provider A security provider (e.g. "BC").
*/
public PrivateKeySignature(PrivateKey pk, String hashAlgorithm, String provider) {
this.pk = pk;
this.provider = provider;
this.hashAlgorithm = DigestAlgorithms.getDigest(DigestAlgorithms.getAllowedDigest(hashAlgorithm));
this.encryptionAlgorithm = SignUtils.getPrivateKeyAlgorithm(pk);
}
/**
* {@inheritDoc}
*/
@Override
public String getHashAlgorithm() {
return hashAlgorithm;
}
/**
* {@inheritDoc}
*/
@Override
public String getEncryptionAlgorithm() {
return encryptionAlgorithm;
}
/**
* {@inheritDoc}
*/
@Override
public byte[] sign(byte[] message) throws GeneralSecurityException {
String algorithm = hashAlgorithm + "with" + encryptionAlgorithm;
Signature sig = SignUtils.getSignatureHelper(algorithm, provider);
sig.initSign(pk);
sig.update(message);
return sig.sign();
}
}