io.gravitee.am.certificate.api.KeyUtils Maven / Gradle / Ivy

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/**
 * Copyright (C) 2015 The Gravitee team (http://gravitee.io)
 *
 * 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 io.gravitee.am.certificate.api;

import lombok.experimental.UtilityClass;

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.math.BigInteger;
import java.security.KeyFactory;
import java.security.NoSuchAlgorithmException;
import java.security.interfaces.ECPublicKey;
import java.security.interfaces.RSAPublicKey;
import java.security.spec.InvalidKeySpecException;
import java.security.spec.X509EncodedKeySpec;
import java.util.Base64;

/**
 * @author Titouan COMPIEGNE (titouan.compiegne at graviteesource.com)
 * @author GraviteeSource Team
 */
@UtilityClass
public final class KeyUtils {

    public static String toSSHRSAString(RSAPublicKey publicKey) throws IOException {
        ByteArrayOutputStream out = new ByteArrayOutputStream();
        /* encode the "ssh-rsa" string */
        byte[] sshrsa = new byte[]{0, 0, 0, 7, 's', 's', 'h', '-', 'r', 's', 'a'};
        out.write(sshrsa);
        /* Encode the public exponent */
        BigInteger e = publicKey.getPublicExponent();
        byte[] data = e.toByteArray();
        encodeUInt32(data.length, out);
        out.write(data);
        /* Encode the modulus */
        BigInteger m = publicKey.getModulus();
        data = m.toByteArray();
        encodeUInt32(data.length, out);
        out.write(data);
        return Base64.getEncoder().encodeToString(out.toByteArray());
    }

    private static void encodeUInt32(int value, OutputStream out) throws IOException {
        byte[] tmp = new byte[4];
        tmp[0] = (byte)((value >>> 24) & 0xff);
        tmp[1] = (byte)((value >>> 16) & 0xff);
        tmp[2] = (byte)((value >>> 8) & 0xff);
        tmp[3] = (byte)(value & 0xff);
        out.write(tmp);
    }

    public static String toEcdsaString(ECPublicKey publicKey) throws NoSuchAlgorithmException, InvalidKeySpecException {
        KeyFactory keyFactory = KeyFactory.getInstance("EC");
        X509EncodedKeySpec keySpec = keyFactory.getKeySpec(publicKey, X509EncodedKeySpec.class);
        return new String(java.util.Base64.getEncoder().encode(keySpec.getEncoded()));
    }
}