org.springframework.security.oauth.common.signature.RSAKeySecret.java Source code

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Here is the source code for org.springframework.security.oauth.common.signature.RSAKeySecret.java

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/*
 * Copyright 2008 Web Cohesion
 *
 * 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
 *
 *   https://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 org.springframework.security.oauth.common.signature;

import org.apache.commons.codec.binary.Base64;

import java.security.PrivateKey;
import java.security.PublicKey;
import java.security.KeyFactory;
import java.security.NoSuchAlgorithmException;
import java.security.cert.X509Certificate;
import java.security.spec.EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;
import java.security.spec.InvalidKeySpecException;
import java.security.spec.PKCS8EncodedKeySpec;
import java.io.UnsupportedEncodingException;

/**
 * Signature secret for RSA.
 *
 * @author Ryan Heaton
 */
@SuppressWarnings("serial")
public class RSAKeySecret implements SignatureSecret {

    private final PrivateKey privateKey;
    private final PublicKey publicKey;

    public RSAKeySecret(PrivateKey privateKey, PublicKey publicKey) {
        this.privateKey = privateKey;
        this.publicKey = publicKey;
    }

    /**
     * Create an RSA public key secret with the given private and public key value. The value of the private key is
     * assumed to be the PKCS#8-encoded bytes of the private key. The value of the public key is assumed to be
     * the X509-encoded bytes of the public key.
     *
     * @param privateKey The value of the private key.
     * @param publicKey The value of the public key.
     */
    public RSAKeySecret(byte[] privateKey, byte[] publicKey) {
        this(createPrivateKey(privateKey), createPublicKey(publicKey));
    }

    /**
     * Create an RSA public key secret with the given private and public key.  The values are assumed to be
     * the Base64-encoded values of the bytes of the keys, X509-encoded for the public key and PKCS#8-encoded
     * for the private key.
     *
     * @param privateKey The value of the private key.
     * @param publicKey The value of the public key.
     */
    public RSAKeySecret(String privateKey, String publicKey) {
        this(base64Decode(privateKey), base64Decode(publicKey));
    }

    /**
     * Construct an RSA public key secret with the given public key. The private key will be null.
     *
     * @param publicKey The public key.
     */
    public RSAKeySecret(PublicKey publicKey) {
        this(null, publicKey);
    }

    /**
     * Create an RSA public key secret with the given public key value.  The value is assumed to be
     * the X509-encoded bytes of the public key. The private key will be null.
     *
     * @param publicKey The value of the public key.
     */
    public RSAKeySecret(byte[] publicKey) {
        this(null, createPublicKey(publicKey));
    }

    /**
     * Create an RSA public key secret with the given public key value.  The value is assumed to be
     * the Base64-encoded value of the X509-encoded bytes of the public key. The private key will be null.
     *
     * @param publicKey The value of the public key.
     */
    public RSAKeySecret(String publicKey) {
        this(base64Decode(publicKey));
    }

    /**
     * Create an RSA public key secret with the given X509 certificate. The private key will be null.
     *
     * @param certificate The certificate.
     */
    public RSAKeySecret(X509Certificate certificate) {
        this(certificate.getPublicKey());
    }

    /**
     * Creates a public key from the X509-encoded value of the given bytes.
     *
     * @param publicKey The X509-encoded public key bytes.
     * @return The public key.
     */
    public static PublicKey createPublicKey(byte[] publicKey) {
        if (publicKey == null) {
            return null;
        }

        try {
            KeyFactory fac = KeyFactory.getInstance("RSA");
            EncodedKeySpec spec = new X509EncodedKeySpec(publicKey);
            return fac.generatePublic(spec);
        } catch (NoSuchAlgorithmException e) {
            throw new IllegalStateException(e);
        } catch (InvalidKeySpecException e) {
            throw new IllegalStateException(e);
        }
    }

    /**
     * Creates a private key from the PKCS#8-encoded value of the given bytes.
     *
     * @param privateKey The PKCS#8-encoded private key bytes.
     * @return The private key.
     */
    public static PrivateKey createPrivateKey(byte[] privateKey) {
        if (privateKey == null) {
            return null;
        }

        try {
            KeyFactory fac = KeyFactory.getInstance("RSA");
            EncodedKeySpec spec = new PKCS8EncodedKeySpec(privateKey);
            return fac.generatePrivate(spec);
        } catch (NoSuchAlgorithmException e) {
            throw new IllegalStateException(e);
        } catch (InvalidKeySpecException e) {
            throw new IllegalStateException(e);
        }
    }

    /**
     * Utility method for decoding a base-64-encoded string.
     *
     * @param value The base-64-encoded string.
     * @return The decoded value.
     */
    private static byte[] base64Decode(String value) {
        if (value == null) {
            return null;
        }

        try {
            return Base64.decodeBase64(value.getBytes("UTF-8"));
        } catch (UnsupportedEncodingException e) {
            throw new RuntimeException(e);
        }
    }

    /**
     * The private key.
     *
     * @return The private key.
     */
    public PrivateKey getPrivateKey() {
        return privateKey;
    }

    /**
     * The public key.
     *
     * @return The public key.
     */
    public PublicKey getPublicKey() {
        return publicKey;
    }
}