com.zcj.util.secret.UtilRsa Maven / Gradle / Ivy

Go to download
package com.zcj.util.secret;

import javax.crypto.Cipher;
import java.io.ByteArrayOutputStream;
import java.io.Closeable;
import java.io.FileInputStream;
import java.security.*;
import java.security.cert.Certificate;
import java.security.cert.CertificateFactory;
import java.security.interfaces.RSAPrivateKey;
import java.security.interfaces.RSAPublicKey;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.RSAPrivateKeySpec;
import java.security.spec.RSAPublicKeySpec;
import java.security.spec.X509EncodedKeySpec;

/**
 * RSA 非对称加密算法
 *
 * @author [email protected]
 * @since 2019/11/1
 */
public class UtilRsa {

    private static final String DEFAULT_PRIVATE_KEY_STRING = "MIIBVQIBADANBgkqhkiG9w0BAQEFAASCAT8wggE7AgEAAkEAhObxNn/4Orm4upVrVwjf17RdkS+tZ2hCL7wgTsImfS7N9bPnwjg/76tj9sbdJWxKw2289beCZCps8FT31+iOLwIDAQABAkBglaV/QgkYRJinoKddnSlwDbhiJxASMobHQiUIl7h5CFoHFpsCERPRzDIBXj53Qmc5Y8EX70M6YB0w1s+8KEmBAiEAxgSxv6mMt1JpV7ntZOCyTSebXVmGOGoKD+UPCikghB8CIQCr0S9hmuqVOCTEE09rYcSvLY3Reb9of4mFpv9RysYz8QIhAI5Wr4KLGOhp5+k0cA20ataFIuv+PznsF2GHkMEIASSXAiB9F/E6TBMND3JdO33wPZ94t17wq4Z7a5fRsjNj9pF10QIhAK9bd8H/LlGw9IAWMXtcToa7Hx/7vNxK9mYXYeTe81Cr";
    private static final String DEFAULT_PUBLIC_KEY_STRING = "MFwwDQYJKoZIhvcNAQEBBQADSwAwSAJBAITm8TZ/+Dq5uLqVa1cI39e0XZEvrWdoQi+8IE7CJn0uzfWz58I4P++rY/bG3SVsSsNtvPW3gmQqbPBU99foji8CAwEAAQ==";

    // 公钥（publicKey）对内容（cipherText）解密
    public static String decrypt(String publicKey, String cipherText) throws Exception {
        PublicKey publicKeyObj = getPublicKey(publicKey);
        return decrypt(publicKeyObj, cipherText);
    }

    // 公钥（publicKey）对内容（cipherText）解密
    public static String decrypt(PublicKey publicKey, String cipherText) throws Exception {
        Cipher cipher = Cipher.getInstance("RSA/ECB/PKCS1Padding");
        try {
            cipher.init(Cipher.DECRYPT_MODE, publicKey);
        } catch (InvalidKeyException e) {
            // 因为 IBM JDK 不支持私钥加密, 公钥解密, 所以要反转公私钥
            // 也就是说对于解密, 可以通过公钥的参数伪造一个私钥对象欺骗 IBM JDK
            RSAPublicKey rsaPublicKey = (RSAPublicKey) publicKey;
            RSAPrivateKeySpec spec = new RSAPrivateKeySpec(rsaPublicKey.getModulus(), rsaPublicKey.getPublicExponent());
            Key fakePrivateKey = KeyFactory.getInstance("RSA").generatePrivate(spec);
            cipher = Cipher.getInstance("RSA"); //It is a stateful object. so we need to get new one.
            cipher.init(Cipher.DECRYPT_MODE, fakePrivateKey);
        }

        if (cipherText == null || cipherText.length() == 0) {
            return cipherText;
        }

        byte[] cipherBytes = Base64.base64ToByteArray(cipherText);
        byte[] plainBytes = cipher.doFinal(cipherBytes);

        return new String(plainBytes);
    }

    // 私钥（privateKey）对内容（plainText）加密
    public static String encrypt(String privateKey, String plainText) throws Exception {
        if (privateKey == null) {
            privateKey = DEFAULT_PRIVATE_KEY_STRING;
        }

        byte[] keyBytes = Base64.base64ToByteArray(privateKey);
        return encrypt(keyBytes, plainText);
    }

    // 私钥字节码（privateKeyBytes）对内容（plainText）加密
    public static String encrypt(byte[] privateKeyBytes, String plainText) throws Exception {
        PKCS8EncodedKeySpec spec = new PKCS8EncodedKeySpec(privateKeyBytes);
        KeyFactory factory = KeyFactory.getInstance("RSA", "SunRsaSign");
        PrivateKey privateKey = factory.generatePrivate(spec);
        Cipher cipher = Cipher.getInstance("RSA/ECB/PKCS1Padding");
        try {
            cipher.init(Cipher.ENCRYPT_MODE, privateKey);
        } catch (InvalidKeyException e) {
            //For IBM JDK, 原因请看解密方法中的说明
            RSAPrivateKey rsaPrivateKey = (RSAPrivateKey) privateKey;
            RSAPublicKeySpec publicKeySpec = new RSAPublicKeySpec(rsaPrivateKey.getModulus(), rsaPrivateKey.getPrivateExponent());
            Key fakePublicKey = KeyFactory.getInstance("RSA").generatePublic(publicKeySpec);
            cipher = Cipher.getInstance("RSA");
            cipher.init(Cipher.ENCRYPT_MODE, fakePublicKey);
        }

        byte[] encryptedBytes = cipher.doFinal(plainText.getBytes("UTF-8"));
        String encryptedString = Base64.byteArrayToBase64(encryptedBytes);

        return encryptedString;
    }

    public static PublicKey getPublicKeyByX509(String x509File) {
        if (x509File == null || x509File.length() == 0) {
            return getPublicKey(null);
        }

        FileInputStream in = null;
        try {
            in = new FileInputStream(x509File);

            CertificateFactory factory = CertificateFactory
                    .getInstance("X.509");
            Certificate cer = factory.generateCertificate(in);
            return cer.getPublicKey();
        } catch (Exception e) {
            throw new IllegalArgumentException("Failed to get public key", e);
        } finally {
            close(in);
        }
    }

    public static PublicKey getPublicKey(String publicKeyText) {
        if (publicKeyText == null || publicKeyText.length() == 0) {
            publicKeyText = DEFAULT_PUBLIC_KEY_STRING;
        }
        try {
            byte[] publicKeyBytes = Base64.base64ToByteArray(publicKeyText);
            X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(publicKeyBytes);
            KeyFactory keyFactory = KeyFactory.getInstance("RSA", "SunRsaSign");
            return keyFactory.generatePublic(x509KeySpec);
        } catch (Exception e) {
            throw new IllegalArgumentException("Failed to get public key", e);
        }
    }

    public static PrivateKey getPrivateKey(String privateKeyText) {
        if (privateKeyText == null || privateKeyText.length() == 0) {
            privateKeyText = DEFAULT_PRIVATE_KEY_STRING;
        }
        try {
            byte[] publicKeyBytes = Base64.base64ToByteArray(privateKeyText);
            PKCS8EncodedKeySpec spec = new PKCS8EncodedKeySpec(publicKeyBytes);
            KeyFactory keyFactory = KeyFactory.getInstance("RSA", "SunRsaSign");
            return keyFactory.generatePrivate(spec);
        } catch (Exception e) {
            throw new IllegalArgumentException("Failed to get private key", e);
        }
    }

    public static PublicKey getPublicKeyByPublicKeyFile(String publicKeyFile) {
        if (publicKeyFile == null || publicKeyFile.length() == 0) {
            return getPublicKey(null);
        }

        FileInputStream in = null;
        try {
            in = new FileInputStream(publicKeyFile);
            ByteArrayOutputStream out = new ByteArrayOutputStream();
            int len = 0;
            byte[] b = new byte[512 / 8];
            while ((len = in.read(b)) != -1) {
                out.write(b, 0, len);
            }

            byte[] publicKeyBytes = out.toByteArray();
            X509EncodedKeySpec spec = new X509EncodedKeySpec(publicKeyBytes);
            KeyFactory factory = KeyFactory.getInstance("RSA", "SunRsaSign");
            return factory.generatePublic(spec);
        } catch (Exception e) {
            throw new IllegalArgumentException("Failed to get public key", e);
        } finally {
            close(in);
        }
    }

    public static byte[][] genKeyPairBytes(int keySize)
            throws NoSuchAlgorithmException, NoSuchProviderException {
        byte[][] keyPairBytes = new byte[2][];

        KeyPairGenerator gen = KeyPairGenerator.getInstance("RSA", "SunRsaSign");
        gen.initialize(keySize, new SecureRandom());
        KeyPair pair = gen.generateKeyPair();

        keyPairBytes[0] = pair.getPrivate().getEncoded();
        keyPairBytes[1] = pair.getPublic().getEncoded();

        return keyPairBytes;
    }

    public static String[] genKeyPair(int keySize)
            throws NoSuchAlgorithmException, NoSuchProviderException {
        byte[][] keyPairBytes = genKeyPairBytes(keySize);
        String[] keyPairs = new String[2];

        keyPairs[0] = Base64.byteArrayToBase64(keyPairBytes[0]);
        keyPairs[1] = Base64.byteArrayToBase64(keyPairBytes[1]);

        return keyPairs;
    }

    private static void close(Closeable x) {
        if (x == null) {
            return;
        }
        try {
            x.close();
        } catch (Exception e) {

        }
    }

    @Deprecated
    public static String encrypt(String plainText) throws Exception {
        return encrypt((String) null, plainText);
    }

    @Deprecated
    public static String decrypt(String cipherText) throws Exception {
        return decrypt((String) null, cipherText);
    }

}