Java使用RSA加密解密签名及校验

我就是我 2022-04-06 14:42 1999阅读 0赞

项目要用到非对称加密解密签名校验什么的，于是从网上参考写一个RSA进行加密解密签名及校验的实例，听说是来源于《Java加密解密的艺术》。

RSA加密解密类RSAEncrypt.java：

package com.bijian.study;
    
    import java.io.BufferedReader;
    import java.io.BufferedWriter;
    import java.io.FileReader;
    import java.io.FileWriter;
    import java.io.IOException;
    import java.security.InvalidKeyException;
    import java.security.KeyFactory;
    import java.security.KeyPair;
    import java.security.KeyPairGenerator;
    import java.security.NoSuchAlgorithmException;
    import java.security.SecureRandom;
    import java.security.interfaces.RSAPrivateKey;
    import java.security.interfaces.RSAPublicKey;
    import java.security.spec.InvalidKeySpecException;
    import java.security.spec.PKCS8EncodedKeySpec;
    import java.security.spec.X509EncodedKeySpec;
    
    import javax.crypto.BadPaddingException;
    import javax.crypto.Cipher;
    import javax.crypto.IllegalBlockSizeException;
    import javax.crypto.NoSuchPaddingException;
    
    import org.apache.commons.codec.binary.Base64;
    
    public class RSAEncrypt {
    	
    	/**
    	 * 字节数据转字符串专用集合
    	 */
    	private static final char[] HEX_CHAR = { '0', '1', '2', '3', '4', '5', '6',
    			'7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f' };
    
    	/**
    	 * 随机生成密钥对
    	 */
    	public static void genKeyPair(String filePath) {
    		// KeyPairGenerator类用于生成公钥和私钥对，基于RSA算法生成对象
    		KeyPairGenerator keyPairGen = null;
    		try {
    			keyPairGen = KeyPairGenerator.getInstance("RSA");
    		} catch (NoSuchAlgorithmException e) {
    			// TODO Auto-generated catch block
    			e.printStackTrace();
    		}
    		// 初始化密钥对生成器，密钥大小为96-1024位
    		keyPairGen.initialize(1024, new SecureRandom());
    		// 生成一个密钥对，保存在keyPair中
    		KeyPair keyPair = keyPairGen.generateKeyPair();
    		// 得到私钥
    		RSAPrivateKey privateKey = (RSAPrivateKey) keyPair.getPrivate();
    		// 得到公钥
    		RSAPublicKey publicKey = (RSAPublicKey) keyPair.getPublic();
    		try {
    			// 得到公钥字符串
    			String publicKeyString = Base64.encodeBase64String(publicKey.getEncoded());
    			// 得到私钥字符串
    			String privateKeyString = Base64.encodeBase64String(privateKey.getEncoded());
    			// 将密钥对写入到文件
    			FileWriter pubfw = new FileWriter(filePath + "/publicKey.keystore");
    			FileWriter prifw = new FileWriter(filePath + "/privateKey.keystore");
    			BufferedWriter pubbw = new BufferedWriter(pubfw);
    			BufferedWriter pribw = new BufferedWriter(prifw);
    			pubbw.write(publicKeyString);
    			pribw.write(privateKeyString);
    			pubbw.flush();
    			pubbw.close();
    			pubfw.close();
    			pribw.flush();
    			pribw.close();
    			prifw.close();
    		} catch (Exception e) {
    			e.printStackTrace();
    		}
    	}
    
    	/**
    	 * 从文件中输入流中加载公钥
    	 * 
    	 * @param in
    	 *            公钥输入流
    	 * @throws Exception
    	 *             加载公钥时产生的异常
    	 */
    	public static String loadPublicKeyByFile(String path) throws Exception {
    		try {
    			BufferedReader br = new BufferedReader(new FileReader(path
    					+ "/publicKey.keystore"));
    			String readLine = null;
    			StringBuilder sb = new StringBuilder();
    			while ((readLine = br.readLine()) != null) {
    				sb.append(readLine);
    			}
    			br.close();
    			return sb.toString();
    		} catch (IOException e) {
    			throw new Exception("公钥数据流读取错误");
    		} catch (NullPointerException e) {
    			throw new Exception("公钥输入流为空");
    		}
    	}
    
    	/**
    	 * 从字符串中加载公钥
    	 * 
    	 * @param publicKeyStr
    	 *            公钥数据字符串
    	 * @throws Exception
    	 *             加载公钥时产生的异常
    	 */
    	public static RSAPublicKey loadPublicKeyByStr(String publicKeyStr)
    			throws Exception {
    		try {
    			byte[] buffer = Base64.decodeBase64(publicKeyStr);
    			KeyFactory keyFactory = KeyFactory.getInstance("RSA");
    			X509EncodedKeySpec keySpec = new X509EncodedKeySpec(buffer);
    			return (RSAPublicKey) keyFactory.generatePublic(keySpec);
    		} catch (NoSuchAlgorithmException e) {
    			throw new Exception("无此算法");
    		} catch (InvalidKeySpecException e) {
    			throw new Exception("公钥非法");
    		} catch (NullPointerException e) {
    			throw new Exception("公钥数据为空");
    		}
    	}
    
    	/**
    	 * 从文件中加载私钥
    	 * 
    	 * @param keyFileName
    	 *            私钥文件名
    	 * @return 是否成功
    	 * @throws Exception
    	 */
    	public static String loadPrivateKeyByFile(String path) throws Exception {
    		try {
    			BufferedReader br = new BufferedReader(new FileReader(path
    					+ "/privateKey.keystore"));
    			String readLine = null;
    			StringBuilder sb = new StringBuilder();
    			while ((readLine = br.readLine()) != null) {
    				sb.append(readLine);
    			}
    			br.close();
    			return sb.toString();
    		} catch (IOException e) {
    			throw new Exception("私钥数据读取错误");
    		} catch (NullPointerException e) {
    			throw new Exception("私钥输入流为空");
    		}
    	}
    
    	public static RSAPrivateKey loadPrivateKeyByStr(String privateKeyStr)
    			throws Exception {
    		try {
    			byte[] buffer = Base64.decodeBase64(privateKeyStr);
    			PKCS8EncodedKeySpec keySpec = new PKCS8EncodedKeySpec(buffer);
    			KeyFactory keyFactory = KeyFactory.getInstance("RSA");
    			return (RSAPrivateKey) keyFactory.generatePrivate(keySpec);
    		} catch (NoSuchAlgorithmException e) {
    			throw new Exception("无此算法");
    		} catch (InvalidKeySpecException e) {
    			throw new Exception("私钥非法");
    		} catch (NullPointerException e) {
    			throw new Exception("私钥数据为空");
    		}
    	}
    
    	/**
    	 * 公钥加密过程
    	 * 
    	 * @param publicKey
    	 *            公钥
    	 * @param plainTextData
    	 *            明文数据
    	 * @return
    	 * @throws Exception
    	 *             加密过程中的异常信息
    	 */
    	public static byte[] encrypt(RSAPublicKey publicKey, byte[] plainTextData)
    			throws Exception {
    		if (publicKey == null) {
    			throw new Exception("加密公钥为空, 请设置");
    		}
    		Cipher cipher = null;
    		try {
    			// 使用默认RSA
    			cipher = Cipher.getInstance("RSA");
    			// cipher= Cipher.getInstance("RSA", new BouncyCastleProvider());
    			cipher.init(Cipher.ENCRYPT_MODE, publicKey);
    			byte[] output = cipher.doFinal(plainTextData);
    			return output;
    		} catch (NoSuchAlgorithmException e) {
    			throw new Exception("无此加密算法");
    		} catch (NoSuchPaddingException e) {
    			e.printStackTrace();
    			return null;
    		} catch (InvalidKeyException e) {
    			throw new Exception("加密公钥非法,请检查");
    		} catch (IllegalBlockSizeException e) {
    			throw new Exception("明文长度非法");
    		} catch (BadPaddingException e) {
    			throw new Exception("明文数据已损坏");
    		}
    	}
    
    	/**
    	 * 私钥加密过程
    	 * 
    	 * @param privateKey
    	 *            私钥
    	 * @param plainTextData
    	 *            明文数据
    	 * @return
    	 * @throws Exception
    	 *             加密过程中的异常信息
    	 */
    	public static byte[] encrypt(RSAPrivateKey privateKey, byte[] plainTextData)
    			throws Exception {
    		if (privateKey == null) {
    			throw new Exception("加密私钥为空, 请设置");
    		}
    		Cipher cipher = null;
    		try {
    			// 使用默认RSA
    			cipher = Cipher.getInstance("RSA");
    			cipher.init(Cipher.ENCRYPT_MODE, privateKey);
    			byte[] output = cipher.doFinal(plainTextData);
    			return output;
    		} catch (NoSuchAlgorithmException e) {
    			throw new Exception("无此加密算法");
    		} catch (NoSuchPaddingException e) {
    			e.printStackTrace();
    			return null;
    		} catch (InvalidKeyException e) {
    			throw new Exception("加密私钥非法,请检查");
    		} catch (IllegalBlockSizeException e) {
    			throw new Exception("明文长度非法");
    		} catch (BadPaddingException e) {
    			throw new Exception("明文数据已损坏");
    		}
    	}
    
    	/**
    	 * 私钥解密过程
    	 * 
    	 * @param privateKey
    	 *            私钥
    	 * @param cipherData
    	 *            密文数据
    	 * @return 明文
    	 * @throws Exception
    	 *             解密过程中的异常信息
    	 */
    	public static byte[] decrypt(RSAPrivateKey privateKey, byte[] cipherData)
    			throws Exception {
    		if (privateKey == null) {
    			throw new Exception("解密私钥为空, 请设置");
    		}
    		Cipher cipher = null;
    		try {
    			// 使用默认RSA
    			cipher = Cipher.getInstance("RSA");
    			// cipher= Cipher.getInstance("RSA", new BouncyCastleProvider());
    			cipher.init(Cipher.DECRYPT_MODE, privateKey);
    			byte[] output = cipher.doFinal(cipherData);
    			return output;
    		} catch (NoSuchAlgorithmException e) {
    			throw new Exception("无此解密算法");
    		} catch (NoSuchPaddingException e) {
    			e.printStackTrace();
    			return null;
    		} catch (InvalidKeyException e) {
    			throw new Exception("解密私钥非法,请检查");
    		} catch (IllegalBlockSizeException e) {
    			throw new Exception("密文长度非法");
    		} catch (BadPaddingException e) {
    			throw new Exception("密文数据已损坏");
    		}
    	}
    
    	/**
    	 * 公钥解密过程
    	 * 
    	 * @param publicKey
    	 *            公钥
    	 * @param cipherData
    	 *            密文数据
    	 * @return 明文
    	 * @throws Exception
    	 *             解密过程中的异常信息
    	 */
    	public static byte[] decrypt(RSAPublicKey publicKey, byte[] cipherData)
    			throws Exception {
    		if (publicKey == null) {
    			throw new Exception("解密公钥为空, 请设置");
    		}
    		Cipher cipher = null;
    		try {
    			// 使用默认RSA
    			cipher = Cipher.getInstance("RSA");
    			// cipher= Cipher.getInstance("RSA", new BouncyCastleProvider());
    			cipher.init(Cipher.DECRYPT_MODE, publicKey);
    			byte[] output = cipher.doFinal(cipherData);
    			return output;
    		} catch (NoSuchAlgorithmException e) {
    			throw new Exception("无此解密算法");
    		} catch (NoSuchPaddingException e) {
    			e.printStackTrace();
    			return null;
    		} catch (InvalidKeyException e) {
    			throw new Exception("解密公钥非法,请检查");
    		} catch (IllegalBlockSizeException e) {
    			throw new Exception("密文长度非法");
    		} catch (BadPaddingException e) {
    			throw new Exception("密文数据已损坏");
    		}
    	}
    
    	/**
    	 * 字节数据转十六进制字符串
    	 * 
    	 * @param data
    	 *            输入数据
    	 * @return 十六进制内容
    	 */
    	public static String byteArrayToString(byte[] data) {
    		StringBuilder stringBuilder = new StringBuilder();
    		for (int i = 0; i < data.length; i++) {
    			// 取出字节的高四位 作为索引得到相应的十六进制标识符 注意无符号右移
    			stringBuilder.append(HEX_CHAR[(data[i] & 0xf0) >>> 4]);
    			// 取出字节的低四位 作为索引得到相应的十六进制标识符
    			stringBuilder.append(HEX_CHAR[(data[i] & 0x0f)]);
    			if (i < data.length - 1) {
    				stringBuilder.append(' ');
    			}
    		}
    		return stringBuilder.toString();
    	}
    }

签名及校验类RSASignature.java：

package com.bijian.study;
    
    import java.security.KeyFactory;
    import java.security.PrivateKey;
    import java.security.PublicKey;
    import java.security.spec.PKCS8EncodedKeySpec;
    import java.security.spec.X509EncodedKeySpec;
    
    import org.apache.commons.codec.binary.Base64;
    
    /**
     * RSA签名验签类
     */
    public class RSASignature {
    
    	/**
    	 * 签名算法
    	 */
    	public static final String SIGN_ALGORITHMS = "SHA1WithRSA";
    
    	/**
    	 * RSA签名
    	 * 
    	 * @param content
    	 *            待签名数据
    	 * @param privateKey
    	 *            商户私钥
    	 * @param encode
    	 *            字符集编码
    	 * @return 签名值
    	 */
    	public static String sign(String content, String privateKey, String encode) {
    		try {
    			PKCS8EncodedKeySpec priPKCS8 = new PKCS8EncodedKeySpec(
    					Base64.decodeBase64(privateKey));
    
    			KeyFactory keyf = KeyFactory.getInstance("RSA");
    			PrivateKey priKey = keyf.generatePrivate(priPKCS8);
    
    			java.security.Signature signature = java.security.Signature
    					.getInstance(SIGN_ALGORITHMS);
    
    			signature.initSign(priKey);
    			signature.update(content.getBytes(encode));
    
    			byte[] signed = signature.sign();
    
    			return Base64.encodeBase64String(signed);
    		} catch (Exception e) {
    			e.printStackTrace();
    		}
    
    		return null;
    	}
    
    	public static String sign(String content, String privateKey) {
    		try {
    			PKCS8EncodedKeySpec priPKCS8 = new PKCS8EncodedKeySpec(
    					Base64.decodeBase64(privateKey));
    			KeyFactory keyf = KeyFactory.getInstance("RSA");
    			PrivateKey priKey = keyf.generatePrivate(priPKCS8);
    			java.security.Signature signature = java.security.Signature
    					.getInstance(SIGN_ALGORITHMS);
    			signature.initSign(priKey);
    			signature.update(content.getBytes());
    			byte[] signed = signature.sign();
    			return Base64.encodeBase64String(signed);
    		} catch (Exception e) {
    			e.printStackTrace();
    		}
    		return null;
    	}
    
    	/**
    	 * RSA验签名检查
    	 * 
    	 * @param content
    	 *            待签名数据
    	 * @param sign
    	 *            签名值
    	 * @param publicKey
    	 *            分配给开发商公钥
    	 * @param encode
    	 *            字符集编码
    	 * @return 布尔值
    	 */
    	public static boolean doCheck(String content, String sign,
    			String publicKey, String encode) {
    		try {
    			KeyFactory keyFactory = KeyFactory.getInstance("RSA");
    			byte[] encodedKey = Base64.decodeBase64(publicKey);
    			PublicKey pubKey = keyFactory
    					.generatePublic(new X509EncodedKeySpec(encodedKey));
    
    			java.security.Signature signature = java.security.Signature
    					.getInstance(SIGN_ALGORITHMS);
    
    			signature.initVerify(pubKey);
    			signature.update(content.getBytes(encode));
    
    			boolean bverify = signature.verify(Base64.decodeBase64(sign));
    			return bverify;
    
    		} catch (Exception e) {
    			e.printStackTrace();
    		}
    
    		return false;
    	}
    
    	public static boolean doCheck(String content, String sign, String publicKey) {
    		try {
    			KeyFactory keyFactory = KeyFactory.getInstance("RSA");
    			byte[] encodedKey = Base64.decodeBase64(publicKey);
    			PublicKey pubKey = keyFactory
    					.generatePublic(new X509EncodedKeySpec(encodedKey));
    
    			java.security.Signature signature = java.security.Signature
    					.getInstance(SIGN_ALGORITHMS);
    
    			signature.initVerify(pubKey);
    			signature.update(content.getBytes());
    
    			boolean bverify = signature.verify(Base64.decodeBase64(sign));
    			return bverify;
    
    		} catch (Exception e) {
    			e.printStackTrace();
    		}
    
    		return false;
    	}
    }

再来一个Base64的类，当然你也可以用commons-codec-1.10.jar

public class MainTest {
     
    	public static void main(String[] args) throws Exception {
    		String filepath="G:/tmp/";
     
    		//RSAEncrypt.genKeyPair(filepath);
    		
    		
    		System.out.println("--------------公钥加密私钥解密过程-------------------");
    		String plainText="ihep_公钥加密私钥解密";
    		//公钥加密过程
    		byte[] cipherData=RSAEncrypt.encrypt(RSAEncrypt.loadPublicKeyByStr(RSAEncrypt.loadPublicKeyByFile(filepath)),plainText.getBytes());
    		String cipher=Base64.encode(cipherData);
    		//私钥解密过程
    		byte[] res=RSAEncrypt.decrypt(RSAEncrypt.loadPrivateKeyByStr(RSAEncrypt.loadPrivateKeyByFile(filepath)), Base64.decode(cipher));
    		String restr=new String(res);
    		System.out.println("原文："+plainText);
    		System.out.println("加密："+cipher);
    		System.out.println("解密："+restr);
    		System.out.println();
    		
    		System.out.println("--------------私钥加密公钥解密过程-------------------");
    		plainText="ihep_私钥加密公钥解密";
    		//私钥加密过程
    		cipherData=RSAEncrypt.encrypt(RSAEncrypt.loadPrivateKeyByStr(RSAEncrypt.loadPrivateKeyByFile(filepath)),plainText.getBytes());
    		cipher=Base64.encode(cipherData);
    		//公钥解密过程
    		res=RSAEncrypt.decrypt(RSAEncrypt.loadPublicKeyByStr(RSAEncrypt.loadPublicKeyByFile(filepath)), Base64.decode(cipher));
    		restr=new String(res);
    		System.out.println("原文："+plainText);
    		System.out.println("加密："+cipher);
    		System.out.println("解密："+restr);
    		System.out.println();
    		
    		System.out.println("---------------私钥签名过程------------------");
    		String content="ihep_这是用于签名的原始数据";
    		String signstr=RSASignature.sign(content,RSAEncrypt.loadPrivateKeyByFile(filepath));
    		System.out.println("签名原串："+content);
    		System.out.println("签名串："+signstr);
    		System.out.println();
    		
    		System.out.println("---------------公钥校验签名------------------");
    		System.out.println("签名原串："+content);
    		System.out.println("签名串："+signstr);
    		
    		System.out.println("验签结果："+RSASignature.doCheck(content, signstr, RSAEncrypt.loadPublicKeyByFile(filepath)));
    		System.out.println();
    		
    	}
    }

最后是一个MainTest.java

package com.bijian.study;
    
    import org.apache.commons.codec.binary.Base64;
    
    public class MainTest {
     
    	public static void main(String[] args) throws Exception {
    		
    		String filepath="D:/temp/";
     
    		//RSAEncrypt.genKeyPair(filepath);
    
    		System.out.println("--------------公钥加密私钥解密过程-------------------");
    		String plainText="ihep_公钥加密私钥解密";
    		//公钥加密过程
    		byte[] cipherData=RSAEncrypt.encrypt(RSAEncrypt.loadPublicKeyByStr(RSAEncrypt.loadPublicKeyByFile(filepath)), plainText.getBytes());
    		String cipher=Base64.encodeBase64String(cipherData);
    		//私钥解密过程
    		byte[] res=RSAEncrypt.decrypt(RSAEncrypt.loadPrivateKeyByStr(RSAEncrypt.loadPrivateKeyByFile(filepath)), Base64.decodeBase64(cipher));
    		String restr=new String(res);
    		System.out.println("原文："+plainText);
    		System.out.println("加密："+cipher);
    		System.out.println("解密："+restr);
    		System.out.println();
    		
    		System.out.println("--------------私钥加密公钥解密过程-------------------");
    		plainText="ihep_私钥加密公钥解密";
    		//私钥加密过程
    		cipherData=RSAEncrypt.encrypt(RSAEncrypt.loadPrivateKeyByStr(RSAEncrypt.loadPrivateKeyByFile(filepath)),plainText.getBytes());
    		cipher=Base64.encodeBase64String(cipherData);
    		//公钥解密过程
    		res=RSAEncrypt.decrypt(RSAEncrypt.loadPublicKeyByStr(RSAEncrypt.loadPublicKeyByFile(filepath)), Base64.decodeBase64(cipher));
    		restr=new String(res);
    		System.out.println("原文："+plainText);
    		System.out.println("加密："+cipher);
    		System.out.println("解密："+restr);
    		System.out.println();
    		
    		System.out.println("---------------私钥签名过程------------------");
    		String content="ihep_这是用于签名的原始数据";
    		String signstr=RSASignature.sign(content,RSAEncrypt.loadPrivateKeyByFile(filepath));
    		System.out.println("签名原串："+content);
    		System.out.println("签名串："+signstr);
    		System.out.println();
    		
    		System.out.println("---------------公钥校验签名------------------");
    		System.out.println("签名原串："+content);
    		System.out.println("签名串："+signstr);
    		
    		System.out.println("验签结果："+RSASignature.doCheck(content, signstr, RSAEncrypt.loadPublicKeyByFile(filepath)));
    		System.out.println();
    		
    	}
    }

把生产密钥对的代码注释打开，运行生成密钥对如下：

![fd19329e-cadf-3e86-8778-89a783c819e6.png][]

![8ca4c79b-e669-3fca-8e32-463569858c7f.png][]

文章来源：[https://blog.csdn.net/wangqiuyun/article/details/42143957][https_blog.csdn.net_wangqiuyun_article_details_42143957]

[fd19329e-cadf-3e86-8778-89a783c819e6.png]: /images/20220406/93237e3d09194eca87aadbd87f0620ac.png
[8ca4c79b-e669-3fca-8e32-463569858c7f.png]: /images/20220406/71f00fd1d8754a3c997a99952b9ab2a7.png
[https_blog.csdn.net_wangqiuyun_article_details_42143957]: https://blog.csdn.net/wangqiuyun/article/details/42143957