这篇文章主要介绍了Java加密算法RSA代码实例,文中通过示例代码介绍的非常详细，对大家的学习或者工作具有一定的参考学习价值,需要的朋友可以参考下

代码如下

import javax.crypto.BadPaddingException;import javax.crypto.Cipher;import javax.crypto.IllegalBlockSizeException;import javax.crypto.NoSuchPaddingException;import java.security.*;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 java.util.HashMap;import java.util.Map; public class RSADecrypt { public static Map<String, String> createKeyPair() throws NoSuchAlgorithmException { //创建秘钥对生成器 KeyPairGenerator generator = KeyPairGenerator.getInstance("rsa"); //初始化密钥对生成器 generator.initialize(1024); //生成密钥对 KeyPair keyPair = generator.generateKeyPair(); //获取公钥私钥 RSAPrivateKey privateKey = (RSAPrivateKey) keyPair.getPrivate(); RSAPublicKey publicKey = (RSAPublicKey) keyPair.getPublic(); String publicKeyStr = new String(publicKey.getEncoded()); String privateKeyStr = new String(privateKey.getEncoded()); //公钥私钥存放map Map<String, String> keyMap = new HashMap<>(); keyMap.put("publicKey", publicKeyStr); keyMap.put("privateKey", privateKeyStr); return keyMap; } /** * 获取公钥 * @param publicKey * @return */ public static RSAPublicKey getPublicKey(String publicKey) throws NoSuchAlgorithmException, InvalidKeySpecException { KeyFactory keyFactory = KeyFactory.getInstance("rsa"); //X509编码 X509EncodedKeySpec x509EncodedKeySpec = new X509EncodedKeySpec(publicKey.getBytes()); RSAPublicKey rsaPublicKey = (RSAPublicKey) keyFactory.generatePublic(x509EncodedKeySpec); return rsaPublicKey; } /** * 获取私钥 * @param privateKey * @return */ public static RSAPrivateKey getPrivateKey(String privateKey) throws NoSuchAlgorithmException, InvalidKeySpecException { KeyFactory keyFactory = KeyFactory.getInstance("rsa"); //PKCS#8编码 PKCS8EncodedKeySpec pkcs8EncodedKeySpec = new PKCS8EncodedKeySpec(privateKey.getBytes()); RSAPrivateKey rsaPrivateKey = (RSAPrivateKey) keyFactory.generatePrivate(pkcs8EncodedKeySpec); return rsaPrivateKey; } /** * 公钥加密 * @param src * @param publicKey * @return */ public static byte[] publicEncrypt(String src, RSAPublicKey publicKey) throws NoSuchPaddingException, NoSuchAlgorithmException, InvalidKeyException, BadPaddingException, IllegalBlockSizeException { Cipher cipher = Cipher.getInstance("rsa"); cipher.init(Cipher.ENCRYPT_MODE,publicKey); byte[] encryptedData = cipher.doFinal(src.getBytes()); return encryptedData; } /** * 私钥解密 * @param data * @param privateKey * @return * @throws NoSuchPaddingException * @throws NoSuchAlgorithmException * @throws InvalidKeyException * @throws BadPaddingException * @throws IllegalBlockSizeException */ public static String privateDecrypt(byte[] data, RSAPrivateKey privateKey) throws NoSuchPaddingException, NoSuchAlgorithmException, InvalidKeyException, BadPaddingException, IllegalBlockSizeException { Cipher cipher = Cipher.getInstance("rsa"); cipher.init(Cipher.DECRYPT_MODE,privateKey); byte[] result = cipher.doFinal(data); return new String(result); } public static void main(String[] args) throws NoSuchAlgorithmException, InvalidKeySpecException, IllegalBlockSizeException, InvalidKeyException, BadPaddingException, NoSuchPaddingException { Map<String,String> keyPair = createKeyPair(); RSAPublicKey publicKey = getPublicKey(keyPair.get("publicKey")); RSAPrivateKey privateKey = getPrivateKey(keyPair.get("privateKey")); String str = "hello world"; /** * 公钥加密，私钥解密 */ byte[] encryptedData = publicEncrypt(str,publicKey); String result = privateDecrypt(encryptedData, privateKey); /** * 私钥加密，公钥解密 */ byte[] encrypted = privateEncrypt(str, privateKey); String source = publicDecrypt(encrypted, publicKey); } /** * 私钥加密 * @param src * @param privateKey * @return * @throws NoSuchPaddingException * @throws NoSuchAlgorithmException * @throws InvalidKeyException * @throws BadPaddingException * @throws IllegalBlockSizeException */ public static byte[] privateEncrypt(String src, RSAPrivateKey privateKey) throws NoSuchPaddingException, NoSuchAlgorithmException, InvalidKeyException, BadPaddingException, IllegalBlockSizeException { Cipher cipher = Cipher.getInstance("rsa"); cipher.init(Cipher.DECRYPT_MODE,privateKey); byte[] result = cipher.doFinal(src.getBytes()); return result; } /** * 公钥解密 * @param data * @param publicKey * @return * @throws NoSuchPaddingException * @throws NoSuchAlgorithmException * @throws InvalidKeyException * @throws BadPaddingException * @throws IllegalBlockSizeException */ public static String publicDecrypt(byte[] data, RSAPublicKey publicKey) throws NoSuchPaddingException, NoSuchAlgorithmException, InvalidKeyException, BadPaddingException, IllegalBlockSizeException { Cipher cipher = Cipher.getInstance("rsa"); cipher.init(Cipher.DECRYPT_MODE,publicKey); byte[] result = cipher.doFinal(data); return new String(result); }}

上面例子使用密钥长度1024，如果想使用2048密钥，只需要在初始化密钥对生成器做一些变动，其他部分可以复用。

generator.initialize(2048);

这个例子只是基本常用的RSA加解密，也可加入base64，签名。

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持。