RSA加密方法java工具类

package com.qianmi.weidian.common.util;

import java.io.ByteArrayOutputStream;
import java.security.Key;
import java.security.KeyFactory;
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.PrivateKey;
import java.security.PublicKey;
import java.security.Signature;
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 javax.crypto.Cipher;

/** *//**
 * <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
 * @date 2012-4-26
 * @version 1.0
 */
public class RSAUtils {

    /** *//**
     * 加密算法RSA
     */
    public static final String KEY_ALGORITHM = "RSA";

    /** *//**
     * 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 = Base64Util.decodeString(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 Base64Util.encodeByte(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 = Base64Util.decodeString(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(Base64Util.decodeString(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 = Base64Util.decodeString(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 = Base64Util.decodeString(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 = Base64Util.decodeString(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;
    }

    /** *//**
     * <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 = Base64Util.decodeString(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 Base64Util.encodeByte(key.getEncoded());
    }

    /** *//**
     * <p>
     * 获取公钥
     * </p>
     *
     * @param keyMap 密钥对
     * @return
     * @throws Exception
     */
    public static String getPublicKey(Map<String, Object> keyMap)
            throws Exception {
        Key key = (Key) keyMap.get(PUBLIC_KEY);
        return Base64Util.encodeByte(key.getEncoded());
    }

}

package com.qianmi.weidian.common.util;

import sun.misc.BASE64Encoder;

import javax.crypto.Cipher;
import java.io.ByteArrayOutputStream;
import java.security.*;
import java.security.spec.X509EncodedKeySpec;

/** */

/**
 * <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
 * @date 2012-4-26
 * @version 1.0
 */
public class RSAUtils4Client {
    static String privateKey="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";

    /** *//**
     * 加密算法RSA
     */
    public static final String KEY_ALGORITHM = "RSA";

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

    /** *//**
     * <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 = Base64Util.decodeString(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;
    }

    public static void main(String[] args) throws Exception {
        String source = "这是一行测试RSA数字签名的无意义文字";
        System.out.println("原文字：\r\n" + source);
        byte[] data = source.getBytes();
        byte[] encodedData = RSAUtils.encryptByPrivateKey(data, privateKey);
        System.out.println("加密后：\r\n" + new String(encodedData));
        String base64EncodedData = Base64Util.encodeByte(encodedData);
        //System.out.println("加密后BASE64：\r\n" + base64EncodedData);
        System.out.println("加密后BASE64：\r\n" + new BASE64Encoder().encode(encodedData));
    }
}