RSA加密java工具 java

import javax.crypto.Cipher; import java.io.File; import java.io.IOException; import java.nio.file.Files; import java.security.*; import java.security.interfaces.RSAPrivateKey; import java.security.interfaces.RSAPublicKey; import java.security.spec.PKCS8EncodedKeySpec; import java.security.spec.X509EncodedKeySpec; public class RSAUtils {private static String ALGORITHM = "RSA"; private static int KEY_SIZE = 1024; private static String SEED = "msat"; /** * 生成公钥、私钥 * @return 公钥私钥 */ public static String[] generateKeys() throws NoSuchAlgorithmException { //1.初始化密钥对生成器 KeyPairGenerator keyPairGenerator = KeyPairGenerator.getInstance(ALGORITHM); keyPairGenerator.initialize(KEY_SIZE,new SecureRandom(Base64Utils.encrypt(SEED.getBytes()).getBytes())); //2.生成密钥对 KeyPair keyPair = keyPairGenerator.generateKeyPair(); //3.base64编码公钥、私钥返回 PublicKey publicKey = keyPair.getPublic(); PrivateKey privateKey = keyPair.getPrivate(); String[] result = new String[2]; result[0] = Base64Utils.encrypt(publicKey.getEncoded()); //公钥 result[1] = Base64Utils.encrypt(privateKey.getEncoded()); return result; }/** * 私钥加密 * @param content 被加密内容 * @param keyPrivateBase64 私钥(base64加密) */ public static String encryptByPrivate(String content,String keyPrivateBase64) throws Exception { RSAPrivateKey privateKey = obtainPrivateKey(keyPrivateBase64); Cipher cipher = Cipher.getInstance(ALGORITHM); cipher.init(Cipher.ENCRYPT_MODE,privateKey); byte[] encoded = cipher.doFinal(content.getBytes("UTF-8")); return Base64Utils.encrypt(encoded); }/** * 私钥解密 * @param encodedContent * @param keyPrivateBase64 * @return */ public static String decryptByPrivate(String encodedContent,String keyPrivateBase64) throws Exception { RSAPrivateKey privateKey = obtainPrivateKey(keyPrivateBase64); Cipher cipher = Cipher.getInstance(ALGORITHM); cipher.init(Cipher.DECRYPT_MODE,privateKey); byte[] bytes = cipher.doFinal(Base64Utils.decrypt(encodedContent)); return new String(bytes); }private static RSAPrivateKey obtainPrivateKey(String keyPrivateBase64) throws Exception { byte[] keyBytes = Base64Utils.decrypt(keyPrivateBase64); return (RSAPrivateKey) KeyFactory.getInstance(ALGORITHM) .generatePrivate(new PKCS8EncodedKeySpec(keyBytes)); }/** * 公钥加密 * @param content 被加密内容 * @param keyPublicBase64 公钥(base64加密) * @return */ public static String encryptByPublic(String content,String keyPublicBase64) throws Exception { RSAPublicKey publicKey = obtainPublicKey(keyPublicBase64); Cipher cipher = Cipher.getInstance(ALGORITHM); cipher.init(Cipher.ENCRYPT_MODE,publicKey); byte[] encoded = cipher.doFinal(content.getBytes("utf-8")); return Base64Utils.encrypt(encoded); }/** * 公钥解密 * @param encodedContent * @param keyPublicBase64 * @return */ public static String decryptByPublic(String encodedContent,String keyPublicBase64) throws Exception { RSAPublicKey publicKey = obtainPublicKey(keyPublicBase64); Cipher cipher = Cipher.getInstance(ALGORITHM); cipher.init(Cipher.DECRYPT_MODE,publicKey); return new String(cipher.doFinal(Base64Utils.decrypt(encodedContent))); }private static RSAPublicKey obtainPublicKey(String keyPublicBase64) throws Exception { byte[] keyBytes = Base64Utils.decrypt(keyPublicBase64); return (RSAPublicKey) KeyFactory.getInstance(ALGORITHM) .generatePublic(new X509EncodedKeySpec(keyBytes)); }/** * 存储key到文件 * @param filePath 文件路径 * @param keyBase64base64编码的key * @return true */ public static boolean storeKey(String filePath,String keyBase64) throws IOException { File target = new File(filePath); if (target.isDirectory()) throw new RuntimeException("filePath should not be a dir path"); if (!target.exists()) target.createNewFile(); Files.write(target.toPath(),keyBase64.getBytes()); return true; }/** * 从文件读取key * @param filePath * @return * @throws IOException */ public static String readKey(String filePath) throws IOException { return new String(Files.readAllBytes(new File(filePath).toPath())); } }

测试:

@Test public void test() throws Exception { String content = "aaabbbccc"; String[] generateKeys = RSAUtils.generateKeys(); String publicKey = generateKeys[0]; String privateKey = generateKeys[1]; System.out.println("原始内容:" + content); System.out.println("pubicKey:" + publicKey); System.out.println("privateKey:" + privateKey); //私钥加密 String encoded = RSAUtils.encryptByPrivate(content, privateKey); System.out.println("私钥加密后:" + encoded); System.out.println("公钥解密后:" + RSAUtils.decryptByPublic(encoded,publicKey)); //公钥加密 String pubEncoded = RSAUtils.encryptByPublic(content,publicKey); System.out.println("公钥加密后:" + pubEncoded); System.out.println("私钥解密后:" + RSAUtils.decryptByPrivate(pubEncoded,privateKey)); //将key写入文件 RSAUtils.storeKey("id_rsa",privateKey); //私钥 RSAUtils.storeKey("id_rsa.pub",publicKey); //公钥 System.out.println("读取到公钥:" + RSAUtils.readKey("id_rsa.pub")); System.out.println("读取到私钥:" + RSAUtils.readKey("id_rsa")); }

【RSA加密java工具】