rsa加密工具

package com.datbc.pig360.db.util;
import javax.crypto.Cipher;
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.Base64;
import java.util.HashMap;
import java.util.Map;
/** */

/**
 * <p>
 * RSA公钥/私钥/签名工具包
 * </p>
 * <p>
 * 罗纳德·李维斯特（Ron [R]ivest）、阿迪·萨莫尔（Adi [S]hamir）和伦纳德·阿德曼（Leonard [A]dleman）
 * </p>
 * <p>
 * 字符串格式的密钥在未在特殊说明情况下都为BASE64编码格式<br/>
 * 由于非对称加密速度极其缓慢，一般文件不使用它来加密而是使用对称加密，<br/>
 * 非对称加密算法可以用来对对称加密的密钥加密，这样保证密钥的安全也就保证了数据的安全
 * </p>
 *
 * @author IceWee
 * @version 1.0
 * @date 2012-4-26
 */
public class RSAUtils {
    /** */
    /**
     * 加密算法RSA
     */
    public static final String KEY_ALGORITHM = "RSA";

    /**
     * 加密算法对接go语言
     */
    public static final String KEY_ALGORITHM_GO = "RSA/ECB/PKCS1Padding";

    /** */
    /**
     * 签名算法
     */
    public static final String SIGNATURE_ALGORITHM = "MD5withRSA";

    /** */
    /**
     * 获取公钥的key
     */
    private static final String PUBLIC_KEY = "RSAPublicKey";

    /** */
    /**
     * 获取私钥的key
     */
    private static final String PRIVATE_KEY = "RSAPrivateKey";

    /** */
    /**
     * RSA最大加密明文大小
     */
    private static final int MAX_ENCRYPT_BLOCK = 117;

    /** */
    /**
     * RSA最大解密密文大小
     */
    private static final int MAX_DECRYPT_BLOCK = 128;

    /** */
    /**
     * <p>
     * 生成密钥对(公钥和私钥)
     * </p>
     *
     * @return
     * @throws Exception
     */
    public static Map<String, Object> genKeyPair() throws Exception {
        KeyPairGenerator keyPairGen = KeyPairGenerator.getInstance(KEY_ALGORITHM);
        keyPairGen.initialize(1024);
        KeyPair keyPair = keyPairGen.generateKeyPair();
        RSAPublicKey publicKey = (RSAPublicKey) keyPair.getPublic();
        RSAPrivateKey privateKey = (RSAPrivateKey) keyPair.getPrivate();
        Map<String, Object> keyMap = new HashMap<String, Object>(2);
        keyMap.put(PUBLIC_KEY, publicKey);
        keyMap.put(PRIVATE_KEY, privateKey);
        return keyMap;
    }

    /** */
    /**
     * <p>
     * 用私钥对信息生成数字签名
     * </p>
     *
     * @param data       已加密数据
     * @param privateKey 私钥(BASE64编码)
     * @return
     * @throws Exception
     */
    public static String sign(byte[] data, String privateKey) throws Exception {
        byte[] keyBytes = Base64Utils.decode(privateKey);
        PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes);
        KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
        PrivateKey privateK = keyFactory.generatePrivate(pkcs8KeySpec);
        Signature signature = Signature.getInstance(SIGNATURE_ALGORITHM);
        signature.initSign(privateK);
        signature.update(data);
        return Base64Utils.encode(signature.sign());
    }

    /** */
    /**
     * <p>
     * 校验数字签名
     * </p>
     *
     * @param data      已加密数据
     * @param publicKey 公钥(BASE64编码)
     * @param sign      数字签名
     * @return
     * @throws Exception
     */
    public static boolean verify(byte[] data, String publicKey, String sign)
            throws Exception {
        byte[] keyBytes = Base64Utils.decode(publicKey);
        X509EncodedKeySpec keySpec = new X509EncodedKeySpec(keyBytes);
        KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
        PublicKey publicK = keyFactory.generatePublic(keySpec);
        Signature signature = Signature.getInstance(SIGNATURE_ALGORITHM);
        signature.initVerify(publicK);
        signature.update(data);
        return signature.verify(Base64Utils.decode(sign));
    }

    /** */
    /**
     * <P>
     * 私钥解密
     * </p>
     *
     * @param encryptedData 已加密数据
     * @param privateKey    私钥(BASE64编码)
     * @return
     * @throws Exception
     */
    public static byte[] decryptByPrivateKey(byte[] encryptedData, String privateKey)
            throws Exception {
        byte[] keyBytes = Base64Utils.decode(privateKey);
        PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes);
        KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
        Key privateK = keyFactory.generatePrivate(pkcs8KeySpec);
        Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());
        cipher.init(Cipher.DECRYPT_MODE, privateK);
        int inputLen = encryptedData.length;
        ByteArrayOutputStream out = new ByteArrayOutputStream();
        int offSet = 0;
        byte[] cache;
        int i = 0;
        // 对数据分段解密
        while (inputLen - offSet > 0) {
            if (inputLen - offSet > MAX_DECRYPT_BLOCK) {
                cache = cipher.doFinal(encryptedData, offSet, MAX_DECRYPT_BLOCK);
            } else {
                cache = cipher.doFinal(encryptedData, offSet, inputLen - offSet);
            }
            out.write(cache, 0, cache.length);
            i++;
            offSet = i * MAX_DECRYPT_BLOCK;
        }
        byte[] decryptedData = out.toByteArray();
        out.close();
        return decryptedData;
    }

    /** */
    /**
     * <p>
     * 公钥解密
     * </p>
     *
     * @param encryptedData 已加密数据
     * @param publicKey     公钥(BASE64编码)
     * @return
     * @throws Exception
     */
    public static byte[] decryptByPublicKey(byte[] encryptedData, String publicKey)
            throws Exception {
        byte[] keyBytes = Base64Utils.decode(publicKey);
        X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(keyBytes);
        KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
        Key publicK = keyFactory.generatePublic(x509KeySpec);
        Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());
        cipher.init(Cipher.DECRYPT_MODE, publicK);
        int inputLen = encryptedData.length;
        ByteArrayOutputStream out = new ByteArrayOutputStream();
        int offSet = 0;
        byte[] cache;
        int i = 0;
        // 对数据分段解密
        while (inputLen - offSet > 0) {
            if (inputLen - offSet > MAX_DECRYPT_BLOCK) {
                cache = cipher.doFinal(encryptedData, offSet, MAX_DECRYPT_BLOCK);
            } else {
                cache = cipher.doFinal(encryptedData, offSet, inputLen - offSet);
            }
            out.write(cache, 0, cache.length);
            i++;
            offSet = i * MAX_DECRYPT_BLOCK;
        }
        byte[] decryptedData = out.toByteArray();
        out.close();
        return decryptedData;
    }

    /** */
    /**
     * <p>
     * 公钥加密
     * </p>
     *
     * @param data      源数据
     * @param publicKey 公钥(BASE64编码)
     * @return
     * @throws Exception
     */
    public static byte[] encryptByPublicKey(byte[] data, String publicKey)
            throws Exception {
        byte[] keyBytes = Base64Utils.decode(publicKey);
        X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(keyBytes);
        KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
        Key publicK = keyFactory.generatePublic(x509KeySpec);
        // 对数据加密
        Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());
        cipher.init(Cipher.ENCRYPT_MODE, publicK);
        int inputLen = data.length;
        ByteArrayOutputStream out = new ByteArrayOutputStream();
        int offSet = 0;
        byte[] cache;
        int i = 0;
        // 对数据分段加密
        while (inputLen - offSet > 0) {
            if (inputLen - offSet > MAX_ENCRYPT_BLOCK) {
                cache = cipher.doFinal(data, offSet, MAX_ENCRYPT_BLOCK);
            } else {
                cache = cipher.doFinal(data, offSet, inputLen - offSet);
            }
            out.write(cache, 0, cache.length);
            i++;
            offSet = i * MAX_ENCRYPT_BLOCK;
        }
        byte[] encryptedData = out.toByteArray();
        out.close();
        return encryptedData;
    }
    /**
     * 得到公钥
     * @param key 密钥字符串（经过base64编码）
     * @throws Exception
     */
    public static PublicKey getPublicKey(String key) throws Exception {
        byte[] keyBytes;
        keyBytes = Base64Utils.decode(key);

        X509EncodedKeySpec keySpec = new X509EncodedKeySpec(keyBytes);
        KeyFactory keyFactory = KeyFactory.getInstance("RSA");
        PublicKey publicKey = keyFactory.generatePublic(keySpec);
        return publicKey;
    }
    /** */
    /**
     * <p>
     * 公钥加密-go对接
     * </p>
     *
     * @param data      源数据
     * @param publicKey 公钥(BASE64编码)
     * @return
     * @throws Exception
     */
    public static byte[] encryptByPublicKeyGO(byte[] data, String publicKey)
            throws Exception {
        Cipher cipher = Cipher.getInstance(KEY_ALGORITHM_GO);
        //用Go语言产生的公钥加密
        PublicKey pubkey_go=getPublicKey(publicKey);
        cipher.init(Cipher.ENCRYPT_MODE, pubkey_go);
        int inputLen = data.length;
        ByteArrayOutputStream out = new ByteArrayOutputStream();
        int offSet = 0;
        byte[] cache;
        int i = 0;
        // 对数据分段加密
        while (inputLen - offSet > 0) {
            if (inputLen - offSet > MAX_ENCRYPT_BLOCK) {
                cache = cipher.doFinal(data, offSet, MAX_ENCRYPT_BLOCK);
            } else {
                cache = cipher.doFinal(data, offSet, inputLen - offSet);
            }
            out.write(cache, 0, cache.length);
            i++;
            offSet = i * MAX_ENCRYPT_BLOCK;
        }
        byte[] encryptedData = out.toByteArray();
        out.close();
        return encryptedData;
    }

    /** */
    /**
     * <p>
     * 私钥加密
     * </p>
     *
     * @param data       源数据
     * @param privateKey 私钥(BASE64编码)
     * @return
     * @throws Exception
     */
    public static byte[] encryptByPrivateKey(byte[] data, String privateKey)
            throws Exception {
        byte[] keyBytes = Base64Utils.decode(privateKey);
        PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes);
        KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
        Key privateK = keyFactory.generatePrivate(pkcs8KeySpec);
        Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());
        cipher.init(Cipher.ENCRYPT_MODE, privateK);
        int inputLen = data.length;
        ByteArrayOutputStream out = new ByteArrayOutputStream();
        int offSet = 0;
        byte[] cache;
        int i = 0;
        // 对数据分段加密
        while (inputLen - offSet > 0) {
            if (inputLen - offSet > MAX_ENCRYPT_BLOCK) {
                cache = cipher.doFinal(data, offSet, MAX_ENCRYPT_BLOCK);
            } else {
                cache = cipher.doFinal(data, offSet, inputLen - offSet);
            }
            out.write(cache, 0, cache.length);
            i++;
            offSet = i * MAX_ENCRYPT_BLOCK;
        }
        byte[] encryptedData = out.toByteArray();
        out.close();
        return encryptedData;
    }

    /** */
    /**
     * <p>
     * 获取私钥
     * </p>
     *
     * @param keyMap 密钥对
     * @return
     * @throws Exception
     */
    public static String getPrivateKey(Map<String, Object> keyMap)
            throws Exception {
        Key key = (Key) keyMap.get(PRIVATE_KEY);
        return Base64Utils.encode(key.getEncoded());
    }

    /** */
    /**
     * <p>
     * 获取公钥
     * </p>
     *
     * @param keyMap 密钥对 xs
     * @return
     * @throws Exception
     */
    public static String getPublicKey(Map<String, Object> keyMap)
            throws Exception {
        Key key = (Key) keyMap.get(PUBLIC_KEY);
        return Base64Utils.encode(key.getEncoded());
    }

    public static void main(String[] args) throws Exception {

        String publicKey = "MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQDZu0HKiBEaFWu3BafiGveWW/w4fSLBQELtV48Ex6E3v9MX/fLkaW3lx5i4LPwt++UGxAywdge/Dvst59XF71csLA/J8+aJ3E++/LmWSJXwf37L2GTQTyCWso3GStdl71FVRgMQMUuuK4pmbmynu+vRf9hEJE/2pfxSIeS1jyihmwIDAQAB";
        String privateKey = "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";

        String source = "6EPIqjAIQhX9dF56";
        System.out.println("\r加密前文字：\r\n" + source);
        byte[] data = source.getBytes();

        byte[] encodedData = RSAUtils.encryptByPublicKey(data,publicKey);
        System.out.println("加密后文字：\r\n" +Base64.getEncoder().encodeToString(encodedData));
        Base64.getEncoder().encodeToString(encodedData);

        byte[] decodedData = RSAUtils.decryptByPrivateKey(encodedData, privateKey);

        String target = new String(decodedData);
        System.out.println("解密后文字: \r\n" + target);
    }
}