RSAUtils非對稱加密

import org.bouncycastle.jce.provider.BouncyCastleProvider;
import org.bouncycastle.util.encoders.Base64;
import org.springframework.util.Base64Utils;
import javax.crypto.BadPaddingException;
import javax.crypto.Cipher;
import javax.crypto.IllegalBlockSizeException;
import javax.crypto.ShortBufferException;
import java.io.ByteArrayOutputStream;
import java.security.*;
import java.security.interfaces.RSAPrivateKey;
import java.security.interfaces.RSAPublicKey;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;
import java.util.HashMap;
import java.util.Map;
import java.util.UUID;
import java.util.regex.Pattern;


/**
 * RSA安全編碼組件
 *
 * @author wbw
 * @version 1.0
 */
public class RSAUtils {
    /**
     * 非對稱加密密鑰算法
     */
    public static final String KEY_ALGORITHM_RSA = "RSA";

    private static String RSA_JAVA = "RSA/None/PKCS1Padding";

    /**
     * 公鑰
     */
    private static final String RSA_PUBLIC_KEY = "RSAPublicKey";

    /**
     * 私鑰
     */
    private static final String RSA_PRIVATE_KEY = "RSAPrivateKey";

    /**
     * RSA密鑰長度
     * 默認1024位，
     * 密鑰長度必須是64的倍數，
     * 范圍在512至65536位之間。
     */
    private static final int KEY_SIZE = 1024;

    static{
        Security.insertProviderAt(new BouncyCastleProvider(), 1);
    }
    /**
     * 私鑰解密
     *
     * @param data
     *            待解密數據
     * @param key
     *            私鑰
     * @return byte[] 解密數據
     * @throws Exception
     */
    public static byte[] decryptByPrivateKey(byte[] data, byte[] key)
            throws Exception {

        // 取得私鑰
        PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(key);

        KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM_RSA);

        // 生成私鑰
        PrivateKey privateKey = keyFactory.generatePrivate(pkcs8KeySpec);

        // 對數據解密
        Cipher cipher = Cipher.getInstance(RSA_JAVA);

        cipher.init(Cipher.DECRYPT_MODE, privateKey);

        int blockSize = cipher.getBlockSize();
        if(blockSize>0){
            ByteArrayOutputStream bout = new ByteArrayOutputStream(64);
            int j = 0;
            while (data.length - j * blockSize > 0) {
                bout.write(cipher.doFinal(data, j * blockSize, blockSize));
                j++;
            }
            return bout.toByteArray();
        }
        return cipher.doFinal(data);
    }

    /**
     * 公鑰解密
     *
     * @param data
     *            待解密數據
     * @param key
     *            公鑰
     * @return byte[] 解密數據
     * @throws Exception
     */
    public static byte[] decryptByPublicKey(byte[] data, byte[] key)
            throws Exception {

        // 取得公鑰
        X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(key);

        KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM_RSA);

        // 生成公鑰
        PublicKey publicKey = keyFactory.generatePublic(x509KeySpec);

        // 對數據解密
        Cipher cipher = Cipher.getInstance(RSA_JAVA);

        cipher.init(Cipher.DECRYPT_MODE, publicKey);

        return cipher.doFinal(data);
    }

    /**
     * 公鑰加密
     *
     * @param data
     *            待加密數據
     * @param key
     *            公鑰
     * @return byte[] 加密數據
     * @throws Exception
     */
    public static byte[] encryptByPublicKey(byte[] data, byte[] key)
            throws Exception {

        // 取得公鑰
        X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(key);

        KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM_RSA);

        PublicKey publicKey = keyFactory.generatePublic(x509KeySpec);

        // 對數據加密
        Cipher cipher = Cipher.getInstance(RSA_JAVA);

        cipher.init(Cipher.ENCRYPT_MODE, publicKey);

        int blockSize = cipher.getBlockSize();
        byte[] raw = getBytes(data, cipher, blockSize);
        if (raw != null) {
            return raw;
        }
        return cipher.doFinal(data);
    }

    private static byte[] getBytes(byte[] data, Cipher cipher, int blockSize) throws ShortBufferException, IllegalBlockSizeException, BadPaddingException {
        if(blockSize>0){
            int outputSize = cipher.getOutputSize(data.length);
            int leavedSize = data.length % blockSize;
            int blocksSize = leavedSize != 0 ? data.length / blockSize + 1
                    : data.length / blockSize;
            byte[] raw = new byte[outputSize * blocksSize];
            int i = 0,remainSize=0;
            while ((remainSize = data.length - i * blockSize) > 0) {
                int inputLen = remainSize > blockSize?blockSize:remainSize;
                cipher.doFinal(data, i * blockSize, inputLen, raw, i * outputSize);
                i++;
            }
            return raw;
        }
        return null;
    }

    /**
     * 私鑰加密
     *
     * @param data
     *            待加密數據
     * @param key
     *            私鑰
     * @return byte[] 加密數據
     * @throws Exception
     */
    public static byte[] encryptByPrivateKey(byte[] data, byte[] key)
            throws Exception {

        // 取得私鑰
        PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(key);

        KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM_RSA);

        // 生成私鑰
        PrivateKey privateKey = keyFactory.generatePrivate(pkcs8KeySpec);

        // 對數據加密
        Cipher cipher = Cipher.getInstance(RSA_JAVA);

        cipher.init(Cipher.ENCRYPT_MODE, privateKey);

        int blockSize = cipher.getBlockSize();
        byte[] raw = getBytes(data, cipher, blockSize);
        return cipher.doFinal(data);
    }

    /**
     * 取得私鑰
     *
     * @param keyMap
     *            密鑰Map
     * @return key 私鑰
     * @throws Exception
     */
    public static Key getPrivateKey(Map<String, Key> keyMap)
            throws Exception {
        return keyMap.get(RSA_PRIVATE_KEY);
    }

    /**
     * 取得私鑰
     *
     * @param keyMap
     *            密鑰Map
     * @return byte[] 私鑰
     * @throws Exception
     */
    public static byte[] getPrivateKeyByte(Map<String, Key> keyMap)
            throws Exception {
        return keyMap.get(RSA_PRIVATE_KEY).getEncoded();
    }

    /**
     * 取得公鑰
     *
     * @param keyMap
     *            密鑰Map
     * @return key 公鑰
     * @throws Exception
     */
    public static Key getPublicKey(Map<String, Key> keyMap)
            throws Exception {
        return keyMap.get(RSA_PUBLIC_KEY);
    }

    /**
     * 取得公鑰
     *
     * @param keyMap
     *            密鑰Map
     * @return byte[] 公鑰
     * @throws Exception
     */
    public static byte[] getPublicKeyByte(Map<String, Key> keyMap)
            throws Exception {
        return keyMap.get(RSA_PUBLIC_KEY).getEncoded();
    }

    /**
     * 初始化密鑰
     * @param seed 種子
     * @return Map 密鑰Map
     * @throws Exception
     */
    public static Map<String,Key> initKey(byte[] seed)throws Exception{
        // 實例化密鑰對生成器
        KeyPairGenerator keyPairGen = KeyPairGenerator
                .getInstance(KEY_ALGORITHM_RSA);

        // 初始化密鑰對生成器
        keyPairGen.initialize(KEY_SIZE,    new SecureRandom(seed) );

        // 生成密鑰對
        KeyPair keyPair = keyPairGen.generateKeyPair();

        // 公鑰
        RSAPublicKey publicKey = (RSAPublicKey) keyPair.getPublic();

        // 私鑰
        RSAPrivateKey privateKey = (RSAPrivateKey) keyPair.getPrivate();

        // 封裝密鑰
        Map<String, Key> keyMap = new HashMap<String, Key>(2);

        keyMap.put(RSA_PUBLIC_KEY, publicKey);
        keyMap.put(RSA_PRIVATE_KEY, privateKey);

        return keyMap;
    }

    /**
     * 初始化密鑰
     * @param seed 種子
     * @return Map 密鑰Map
     * @throws Exception
     */
    public static Map<String,Key> initKey(String seed)throws Exception{
        return initKey(seed.getBytes());
    }

    /**
     * 初始化密鑰
     *
     * @return Map 密鑰Map
     * @throws Exception
     */
    public static Map<String, Key> initKey() throws Exception {
        return initKey(UUID.randomUUID().toString().getBytes());
    }

    public static PublicKey getPublicRSAKey(String key) throws Exception {
        X509EncodedKeySpec x509 = new X509EncodedKeySpec(Base64.decode(key));
        KeyFactory kf = KeyFactory.getInstance(KEY_ALGORITHM_RSA);
        return kf.generatePublic(x509);
    }

    public static PrivateKey getPrivateRSAKey(String key) throws Exception {
        PKCS8EncodedKeySpec pkgs8 = new PKCS8EncodedKeySpec(Base64.decode(key));
        KeyFactory kf = KeyFactory.getInstance(KEY_ALGORITHM_RSA);
        return kf.generatePrivate(pkgs8);
    }

}

 

調用

class RSAUtilsTest {
    private static String PUBLIC_KEY = "MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQCAHzDQssuIce0x5thZdTbS1N/iJtkpluE5X3sU0nvRIUAmkqVi9zCuJrRizpOCSGatkX21gQjwJRb7Fz/H38HuyeSv6myLHBbQU866eU3nJPpuQcYiWQMbcWv+y2Y9y0oOqjEZwv+ERj0mLYGO+SHftYwJ3T6yyeHXd3VcMBKkiQIDAQAB";
    private static String  PRIVATE_KEY= "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";

    public static String rsaPublicEncryptAndPrivateKeyDecrypt(String rawText) {

        byte[] privateKey = Base64Utils.decodeFromString(PRIVATE_KEY);
        byte[] publicKey = Base64Utils.decodeFromString(PUBLIC_KEY);
        try {
            System.out.println("原數據為:"+rawText);
            byte[] encryptByPublicKey = RSAUtils.encryptByPublicKey(rawText.getBytes(),
                    publicKey);
            String encryptByPublicKeyString = Base64Utils.encodeToString(encryptByPublicKey);
            System.out.println("公鑰加密后的數據為:"+encryptByPublicKeyString);
            byte[] decryptByPrivateKey = RSAUtils.decryptByPrivateKey(
                    Base64Utils.decodeFromString(encryptByPublicKeyString),
                    privateKey);
            String result=new String(decryptByPrivateKey);
            System.out.println("私鑰解密后的數據為:"+result);
            return result;
        } catch (Exception e) {
            System.out.println(e);
        }

        return null;
    }



    public static void main(String[] args) {
        System.out.println(rsaPublicEncryptAndPrivateKeyDecrypt("Hello world!"));
    }
}

輸出

原數據為:Hello world!
公鑰加密后的數據為:fymr5G4ZWIy3ek9xJ+KAtNAKHVOjX9qPgPDF9wSofGaPsOuRMTz3LvvmpA8CCYJT/Y3TzXEQPWQjUwhcqH/AkDorf78oe1zbXE3m47Unua7yhsGNZdCE14j5JfXB5t6JZ3VOBycLMXgCw6Ol3m3lkaaa6xxAuH5sMN0haseERs8=
私鑰解密后的數據為:Hello world!