package com.geostar.gfstack.cas.util; import org.apache.commons.codec.binary.Base64; import javax.crypto.Cipher; import java.security.*; import java.security.interfaces.RSAPrivateKey; import java.security.interfaces.RSAPublicKey; import java.security.spec.PKCS8EncodedKeySpec; import java.security.spec.X509EncodedKeySpec; /** * RSA加解密工具类，实现公钥加密私钥解密和私钥解密公钥解密 */ public class RSAUtils { private static final String src = "abcdefghijklmnopqrstuvwxyz"; public static void main(String[] args) throws Exception { System.out.println("\n"); RSAKeyPair keyPair = generateKeyPair(); System.out.println("公钥：" + keyPair.getPublicKey()); System.out.println("私钥：" + keyPair.getPrivateKey()); System.out.println("\n"); test1(keyPair, src); System.out.println("\n"); test2(keyPair, src); System.out.println("\n"); } /** * 公钥加密私钥解密 */ private static void test1(RSAKeyPair keyPair, String source) throws Exception { System.out.println("***************** 公钥加密私钥解密开始 *****************"); String text1 = encryptByPublicKey(keyPair.getPublicKey(), source); String text2 = decryptByPrivateKey(keyPair.getPrivateKey(), text1); System.out.println("加密前：" + source); System.out.println("加密后：" + text1); System.out.println("解密后：" + text2); if (source.equals(text2)) { System.out.println("解密字符串和原始字符串一致，解密成功"); } else { System.out.println("解密字符串和原始字符串不一致，解密失败"); } System.out.println("***************** 公钥加密私钥解密结束 *****************"); } /** * 私钥加密公钥解密 * * @throws Exception */ private static void test2(RSAKeyPair keyPair, String source) throws Exception { System.out.println("***************** 私钥加密公钥解密开始 *****************"); String text1 = encryptByPrivateKey(keyPair.getPrivateKey(), source); String text2 = decryptByPublicKey(keyPair.getPublicKey(), text1); System.out.println("加密前：" + source); System.out.println("加密后：" + text1); System.out.println("解密后：" + text2); if (source.equals(text2)) { System.out.println("解密字符串和原始字符串一致，解密成功"); } else { System.out.println("解密字符串和原始字符串不一致，解密失败"); } System.out.println("***************** 私钥加密公钥解密结束 *****************"); } /** * 公钥解密 * * @param publicKeyText * @param text * @return * @throws Exception */ public static String decryptByPublicKey(String publicKeyText, String text) throws Exception { X509EncodedKeySpec x509EncodedKeySpec = new X509EncodedKeySpec(Base64.decodeBase64(publicKeyText)); KeyFactory keyFactory = KeyFactory.getInstance("RSA"); PublicKey publicKey = keyFactory.generatePublic(x509EncodedKeySpec); Cipher cipher = Cipher.getInstance("RSA"); cipher.init(Cipher.DECRYPT_MODE, publicKey); byte[] result = cipher.doFinal(Base64.decodeBase64(text)); return new String(result); } /** * 私钥加密 * * @param privateKeyText * @param text * @return * @throws Exception */ public static String encryptByPrivateKey(String privateKeyText, String text) throws Exception { PKCS8EncodedKeySpec pkcs8EncodedKeySpec = new PKCS8EncodedKeySpec(Base64.decodeBase64(privateKeyText)); KeyFactory keyFactory = KeyFactory.getInstance("RSA"); PrivateKey privateKey = keyFactory.generatePrivate(pkcs8EncodedKeySpec); Cipher cipher = Cipher.getInstance("RSA"); cipher.init(Cipher.ENCRYPT_MODE, privateKey); byte[] result = cipher.doFinal(text.getBytes()); return Base64.encodeBase64String(result); } /** * 私钥解密 * * @param privateKeyText * @param text * @return * @throws Exception */ public static String decryptByPrivateKey(String privateKeyText, String text) throws Exception { PKCS8EncodedKeySpec pkcs8EncodedKeySpec5 = new PKCS8EncodedKeySpec(Base64.decodeBase64(privateKeyText)); KeyFactory keyFactory = KeyFactory.getInstance("RSA"); PrivateKey privateKey = keyFactory.generatePrivate(pkcs8EncodedKeySpec5); Cipher cipher = Cipher.getInstance("RSA"); cipher.init(Cipher.DECRYPT_MODE, privateKey); byte[] result = cipher.doFinal(Base64.decodeBase64(text)); return new String(result); } /** * 公钥加密 * * @param publicKeyText * @param text * @return */ public static String encryptByPublicKey(String publicKeyText, String text) throws Exception { X509EncodedKeySpec x509EncodedKeySpec2 = new X509EncodedKeySpec(Base64.decodeBase64(publicKeyText)); KeyFactory keyFactory = KeyFactory.getInstance("RSA"); PublicKey publicKey = keyFactory.generatePublic(x509EncodedKeySpec2); Cipher cipher = Cipher.getInstance("RSA"); cipher.init(Cipher.ENCRYPT_MODE, publicKey); byte[] result = cipher.doFinal(text.getBytes()); return Base64.encodeBase64String(result); } /** * 构建RSA密钥对 * * @return * @throws NoSuchAlgorithmException */ public static RSAKeyPair generateKeyPair() throws NoSuchAlgorithmException { KeyPairGenerator keyPairGenerator = KeyPairGenerator.getInstance("RSA"); keyPairGenerator.initialize(1024); KeyPair keyPair = keyPairGenerator.generateKeyPair(); RSAPublicKey rsaPublicKey = (RSAPublicKey) keyPair.getPublic(); RSAPrivateKey rsaPrivateKey = (RSAPrivateKey) keyPair.getPrivate(); String publicKeyString = Base64.encodeBase64String(rsaPublicKey.getEncoded()); String privateKeyString = Base64.encodeBase64String(rsaPrivateKey.getEncoded()); RSAKeyPair rsaKeyPair = new RSAKeyPair(publicKeyString, privateKeyString); return rsaKeyPair; } /** * RSA密钥对对象 */ public static class RSAKeyPair { private String publicKey; private String privateKey; public RSAKeyPair(String publicKey, String privateKey) { this.publicKey = publicKey; this.privateKey = privateKey; } public String getPublicKey() { return publicKey; } public String getPrivateKey() { return privateKey; } } }
参考：https://www.jianshu.com/p/048be4864559