com.itextpdf.text.pdf.security.PrivateKeySignature Maven / Gradle / Ivy
/*
*
* This file is part of the iText (R) project.
Copyright (c) 1998-2017 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
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*
* 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.
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* 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/
*
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* 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
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package com.itextpdf.text.pdf.security;
import java.security.GeneralSecurityException;
import java.security.PrivateKey;
import java.security.Signature;
/**
* Implementation of the ExternalSignature interface that can be used
* when you have a PrivateKey object.
* @author Paulo Soares
*/
public class PrivateKeySignature implements ExternalSignature {
/** 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 an ExternalSignature instance
* @param pk a PrivateKey object
* @param hashAlgorithm the hash algorithm (e.g. "SHA-1", "SHA-256",...)
* @param provider the security provider (e.g. "BC")
*/
public PrivateKeySignature(PrivateKey pk, String hashAlgorithm, String provider) {
this.pk = pk;
this.provider = provider;
this.hashAlgorithm = DigestAlgorithms.getDigest(DigestAlgorithms.getAllowedDigests(hashAlgorithm));
encryptionAlgorithm = pk.getAlgorithm();
if (encryptionAlgorithm.startsWith("EC")) {
encryptionAlgorithm = "ECDSA";
}
}
/**
* Returns the hash algorithm.
* @return the hash algorithm (e.g. "SHA-1", "SHA-256,...")
* @see com.itextpdf.text.pdf.security.ExternalSignature#getHashAlgorithm()
*/
public String getHashAlgorithm() {
return hashAlgorithm;
}
/**
* Returns the encryption algorithm used for signing.
* @return the encryption algorithm ("RSA" or "DSA")
* @see com.itextpdf.text.pdf.security.ExternalSignature#getEncryptionAlgorithm()
*/
public String getEncryptionAlgorithm() {
return encryptionAlgorithm;
}
/**
* Signs it using the encryption algorithm in combination with
* the digest algorithm.
* @param message the message you want to be hashed and signed
* @return a signed message digest
* @throws GeneralSecurityException
*/
public byte[] sign(byte[] b) throws GeneralSecurityException {
String signMode = hashAlgorithm + "with" + encryptionAlgorithm;
Signature sig;
if (provider == null)
sig = Signature.getInstance(signMode);
else
sig = Signature.getInstance(signMode, provider);
sig.initSign(pk);
sig.update(b);
return sig.sign();
}
}