rsa公钥私钥生成工具-java代码如下：
/*** * @Description: RSA工具类，支持长度为2048的秘钥*/@Slf4jpublic class RSAUtils {/*** 加密算法RSA*/private static final String KEY_ALGORITHM = "RSA";/*** 签名算法*/private static final String SIGNATURE_ALGORITHM = "SHA256withRSA";/*** 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 = 256;/*** @param keySize 生成的秘钥长度 一般为1024或2048* @return* @throws Exception*/public static Map<String, Object> genKeyPair(int keySize){KeyPairGenerator keyPairGen = null;try {keyPairGen = KeyPairGenerator.getInstance(KEY_ALGORITHM);} catch (NoSuchAlgorithmException e) {log.error(String.format("生密钥异常%s", ExceptionUtils.getStackTrace(e)));throw new GlobalException(BasicCodeMsg.SERVER_ERROR);}keyPairGen.initialize(keySize);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);log.info("publicKey：" + Base64.encode(publicKey.getEncoded()));log.info("privateKey：" + Base64.encode(privateKey.getEncoded()));return keyMap;}/*** 对已加密数据进行签名** @param data 已加密的数据* @param privateKey 私钥* @return 对已加密数据生成的签名* @throws Exception*/public static String sign(byte[] data, String privateKey) throws Exception {byte[] keyBytes = Base64.decode(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 Base64.encode(signature.sign());}/*** 验签** @param data签名之前的数据* @param publicKey 公钥* @param sign签名之后的数据* @return 验签是否成功* @throws Exception*/public static boolean verify(byte[] data, String publicKey, String sign) throws Exception {byte[] keyBytes = Base64.decode(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(Base64.decode(sign));}/*** 用私钥对数据进行解密** @param encryptedData 使用公钥加密过的数据* @param privateKey 私钥* @return 解密后的数据* @throws Exception*/public static byte[] decryptByPrivateKey(byte[] encryptedData, String privateKey) throws Exception {byte[] keyBytes = Base64.decode(privateKey);PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes);KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);Key privateK = keyFactory.generatePrivate(pkcs8KeySpec);//Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());Cipher cipher = Cipher.getInstance(KEY_ALGORITHM);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;}/*** 公钥解密** @param encryptedData 使用私钥加密过的数据* @param publicKey公钥* @return 解密后的数据* @throws Exception*/public static byte[] decryptByPublicKey(byte[] encryptedData, String publicKey) throws Exception {byte[] keyBytes = Base64.decode(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;}/*** 公钥加密** @param data需要加密的数据* @param publicKey 公钥* @return 使用公钥加密后的数据* @throws Exception*/public static byte[] encryptByPublicKey(byte[] data, String publicKey) throws Exception {byte[] keyBytes = Base64.decode(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;}/*** 私钥加密** @param data 待加密的数据* @param privateKey 私钥* @return 使用私钥加密后的数据* @throws Exception*/public static byte[] encryptByPrivateKey(byte[] data, String privateKey) throws Exception {byte[] keyBytes = Base64.decode(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;}/*** 获取私钥** @param keyMap 生成的秘钥对* @return* @throws Exception*/public static String getPrivateKey(Map<String, Object> keyMap){Key key = (Key) keyMap.get(PRIVATE_KEY);return Base64.encode(key.getEncoded());}/*** 获取公钥** @param keyMap 生成的秘钥对* @return* @throws Exception*/public static String getPublicKey(Map<String, Object> keyMap) {Key key = (Key) keyMap.get(PUBLIC_KEY);return Base64.encode(key.getEncoded());}}
测试结果：
public static void main(String[] args) {//生成平台密钥Map<String, Object> keyPair = RSAUtils.genKeyPair(2048);}
