org.shredzone.acme4j.util.KeyPairUtils Maven / Gradle / Ivy
/*
* acme4j - Java ACME client
*
* Copyright (C) 2015 Richard "Shred" Körber
* http://acme4j.shredzone.org
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
*
* 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.
*/
package org.shredzone.acme4j.util;
import java.io.IOException;
import java.io.Reader;
import java.io.Writer;
import java.security.InvalidAlgorithmParameterException;
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.NoSuchAlgorithmException;
import java.security.NoSuchProviderException;
import java.security.SecureRandom;
import org.bouncycastle.jce.ECNamedCurveTable;
import org.bouncycastle.jce.spec.ECParameterSpec;
import org.bouncycastle.openssl.PEMException;
import org.bouncycastle.openssl.PEMKeyPair;
import org.bouncycastle.openssl.PEMParser;
import org.bouncycastle.openssl.jcajce.JcaPEMKeyConverter;
import org.bouncycastle.openssl.jcajce.JcaPEMWriter;
/**
* Utility class offering convenience methods for {@link KeyPair}.
*
* Requires {@code Bouncy Castle}. This class is part of the {@code acme4j-utils} module.
*/
public class KeyPairUtils {
private KeyPairUtils() {
// utility class without constructor
}
/**
* Creates a new standard {@link KeyPair}.
*
* This method can be used if no specific key type is required. It returns a
* "secp384r1" ECDSA key pair.
*
* @return Generated {@link KeyPair}
* @since 2.8
*/
public static KeyPair createKeyPair() {
return createECKeyPair("secp384r1");
}
/**
* Creates a new RSA {@link KeyPair}.
*
* @param keysize
* Key size
* @return Generated {@link KeyPair}
*/
public static KeyPair createKeyPair(int keysize) {
try {
KeyPairGenerator keyGen = KeyPairGenerator.getInstance("RSA");
keyGen.initialize(keysize);
return keyGen.generateKeyPair();
} catch (NoSuchAlgorithmException ex) {
throw new IllegalStateException(ex);
}
}
/**
* Creates a new elliptic curve {@link KeyPair}.
*
* @param name
* ECDSA curve name (e.g. "secp256r1")
* @return Generated {@link KeyPair}
*/
public static KeyPair createECKeyPair(String name) {
try {
ECParameterSpec ecSpec = ECNamedCurveTable.getParameterSpec(name);
KeyPairGenerator g = KeyPairGenerator.getInstance("ECDSA", "BC");
g.initialize(ecSpec, new SecureRandom());
return g.generateKeyPair();
} catch (NoSuchAlgorithmException | InvalidAlgorithmParameterException ex) {
throw new IllegalArgumentException("Invalid curve name " + name, ex);
} catch (NoSuchProviderException ex) {
throw new IllegalStateException(ex);
}
}
/**
* Reads a {@link KeyPair} from a PEM file.
*
* @param r
* {@link Reader} to read the PEM file from. The {@link Reader} is closed
* after use.
* @return {@link KeyPair} read
*/
public static KeyPair readKeyPair(Reader r) throws IOException {
try (PEMParser parser = new PEMParser(r)) {
PEMKeyPair keyPair = (PEMKeyPair) parser.readObject();
return new JcaPEMKeyConverter().getKeyPair(keyPair);
} catch (PEMException ex) {
throw new IOException("Invalid PEM file", ex);
}
}
/**
* Writes a {@link KeyPair} PEM file.
*
* @param keypair
* {@link KeyPair} to write
* @param w
* {@link Writer} to write the PEM file to. The {@link Writer} is closed
* after use.
*/
public static void writeKeyPair(KeyPair keypair, Writer w) throws IOException {
try (JcaPEMWriter jw = new JcaPEMWriter(w)) {
jw.writeObject(keypair);
}
}
}