测试：
public static void main(String[] args) {try {//生成公钥私钥Map<String, Object> map = RSAUtil.initKey(2048);String PrivateKey = RSAUtil.getPrivateKey(map);String PublicKey = RSAUtil.getPublicKey(map);System.out.println("PrivateKey:" + PrivateKey);System.out.println("PublicKey:" + PublicKey);//明文String data = "hello rsa!";//公钥加密私钥解密byte[] encData = RSAUtil.encryptByPublicKey(data.getBytes(), PublicKey);byte[] decData = RSAUtil.decryptByPrivateKey(encData, PrivateKey);System.out.println(new String(decData));//私钥加密公钥解密byte[] encData1 = RSAUtil.encryptByPrivateKey(data.getBytes(), PrivateKey);byte[] decData1 = RSAUtil.decryptByPublicKey(encData1, PublicKey);System.out.println(new String(decData1));//私钥签名公钥验签String signStr = RSAUtil.sign(data.getBytes(), PrivateKey);boolean verify = RSAUtil.verify(data.getBytes(), PublicKey, signStr);System.out.println(signStr + verify);} catch (Exception e) {//密钥不对等情况e.printStackTrace();}}
输出
"C:\Program Files\Java\jdk1.8.0_221\bin\java.exe" "-javaagent:D:\Program Files\JetBrains\IntelliJ IDEA .2\lib\idea_rt.jar=52263:D:\Program Files\JetBrains\IntelliJ IDEA .2\bin" -Dfile.encoding=UTF-8 -classpath "E:\javaproj\rsa-demo\bin;C:\Program Files\Java\jdk1.8.0_221\jre\lib\charsets.jar;C:\Program Files\Java\jdk1.8.0_221\jre\lib\deploy.jar;C:\Program Files\Java\jdk1.8.0_221\jre\lib\ext\access-bridge-64.jar;C:\Program Files\Java\jdk1.8.0_221\jre\lib\ext\cldrdata.jar;C:\Program Files\Java\jdk1.8.0_221\jre\lib\ext\dnsns.jar;C:\Program Files\Java\jdk1.8.0_221\jre\lib\ext\jaccess.jar;C:\Program Files\Java\jdk1.8.0_221\jre\lib\ext\jfxrt.jar;C:\Program Files\Java\jdk1.8.0_221\jre\lib\ext\localedata.jar;C:\Program Files\Java\jdk1.8.0_221\jre\lib\ext\nashorn.jar;C:\Program Files\Java\jdk1.8.0_221\jre\lib\ext\sunec.jar;C:\Program Files\Java\jdk1.8.0_221\jre\lib\ext\sunjce_provider.jar;C:\Program Files\Java\jdk1.8.0_221\jre\lib\ext\sunmscapi.jar;C:\Program Files\Java\jdk1.8.0_221\jre\lib\ext\sunpkcs11.jar;C:\Program Files\Java\jdk1.8.0_221\jre\lib\ext\zipfs.jar;C:\Program Files\Java\jdk1.8.0_221\jre\lib\javaws.jar;C:\Program Files\Java\jdk1.8.0_221\jre\lib\jce.jar;C:\Program Files\Java\jdk1.8.0_221\jre\lib\jfr.jar;C:\Program Files\Java\jdk1.8.0_221\jre\lib\jfxswt.jar;C:\Program Files\Java\jdk1.8.0_221\jre\lib\jsse.jar;C:\Program Files\Java\jdk1.8.0_221\jre\lib\management-agent.jar;C:\Program Files\Java\jdk1.8.0_221\jre\lib\plugin.jar;C:\Program Files\Java\jdk1.8.0_221\jre\lib\resources.jar;C:\Program Files\Java\jdk1.8.0_221\jre\lib\rt.jar;E:\javaproj\rsa-demo\lib\commons-codec-1.10.jar" com.wjs.rsaDemo.RSAUtilPrivateKey: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:MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAuEcxdJFTCLQlMtm60T6ZfbL9c3c2tF5+f5AFKhO2JJt81PdrRWaQl/WK7CqeHMRAvLsKLRImxN6m4fJRjfhtaWuebe2Jl9JTlui+8ec+XjEsdifKEO6qQAN6T0armYPOZHvLYSSSaZwi4GCQGYZU0oCrwc8BAsvffEaVfHqkQ5a+tAR/hnIAmuci8juzv5fYc04IqZApHVyseF++C4pXwAxT4VYAucv9N0UJxV3Jq342zpS8SMnn+Geelnl6O8wLsUhtmEdccrd67qcRdbiAZ/F27i+43beMIEBdCVcZhgdUljMxu69y8sTyG5xDAIgP/4jUlHygjUbmTiMmpcjmkQIDAQABhello rsa!hello rsa!CCnsnslB08p1E4aMdK5BNi9ZwRkGPj1bvnMrIn0LNsiTmc4r06rE5lbB9Tz3C9W50jnQBHyMI6TBFkU6cyUeDAAFzHI/PLgKw2hCd76DX0o7BuknNTUZ6yuHmQQEyFp0CMrb1sUkKtUv0aq+4nqJwGbZ9v3LLoPmKl/oD/LYD0tciWBkskoGOKxF2izosY71lWyFZV6OtQYQbdo39TcHJh9eeqM1/4JeLFm2+wnnOF+1j2AR+Ki1WNeAtXcDAQHqz1GmKgg46FlycD/xlxzoWgega6BpjyiHIh1vIMK24PztP9PwibmsZliBUB3V4+iyaTTVXTUkatFo0RALNs902A==trueProcess finished with exit code 0
工具类RSAUtil
import java.io.ByteArrayOutputStream;import java.security.*;import java.security.interfaces.RSAPrivateKey;import java.security.interfaces.RSAPublicKey;import java.security.spec.*;import java.util.Base64;import java.util.HashMap;import java.util.Map;import javax.crypto.Cipher;/*** RSA 加密 工具类*/public abstract class RSAUtil {public static final String KEY_ALGORITHM = "RSA";public static final String SIGNATURE_ALGORITHM = "SHA1WithRSA";public static final String PUBLIC_KEY = "RSAPublicKey";public static final String PRIVATE_KEY = "RSAPrivateKey";public static String sign(byte[] data, String privateKey) throws NoSuchAlgorithmException, InvalidKeySpecException, SignatureException, InvalidKeyException {// 解密由base64编码的私钥byte[] keyBytes = Base64.getDecoder().decode(privateKey);// 构造PKCS8EncodedKeySpec对象PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes);// KEY_ALGORITHM 指定的加密算法KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);// 取私钥匙对象PrivateKey priKey = keyFactory.generatePrivate(pkcs8KeySpec);// 用私钥对信息生成数字签名Signature signature = Signature.getInstance(SIGNATURE_ALGORITHM);signature.initSign(priKey);signature.update(data);return Base64.getEncoder().encodeToString(signature.sign());}/*** 校验数字签名*/public static boolean verify(byte[] data, String publicKey, String sign)throws Exception {// 解密由base64编码的公钥byte[] keyBytes = Base64.getDecoder().decode(publicKey);// 构造X509EncodedKeySpec对象X509EncodedKeySpec keySpec = new X509EncodedKeySpec(keyBytes);// KEY_ALGORITHM 指定的加密算法KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);// 取公钥匙对象PublicKey pubKey = keyFactory.generatePublic(keySpec);Signature signature = Signature.getInstance(SIGNATURE_ALGORITHM);signature.initVerify(pubKey);signature.update(data);// 验证签名是否正常return signature.verify(Base64.getDecoder().decode(sign));}/*** 解密<br>* 用私钥解密*/public static byte[] decryptByPrivateKey(byte[] data, String key)throws Exception {byte[] decryptedData = null;// 对密钥解密byte[] keyBytes = Base64.getDecoder().decode(key);// 取得私钥PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes);KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);Key privateKey = keyFactory.generatePrivate(pkcs8KeySpec);// 对数据解密Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());cipher.init(Cipher.DECRYPT_MODE, privateKey);int maxDecryptBlockSize = getMaxDencryptBytesByPrivate(keyFactory, privateKey);ByteArrayOutputStream bout = new ByteArrayOutputStream();try {int dataLength = data.length;for (int i = 0; i < dataLength; i += maxDecryptBlockSize) {int decryptLength = Math.min(dataLength - i, maxDecryptBlockSize);byte[] doFinal = cipher.doFinal(data, i, decryptLength);bout.write(doFinal);}decryptedData = bout.toByteArray();} finally {bout.close();}return decryptedData;}/*** 将Base64编码的密文解密为字符串*/public static String decryptByPrivateKeyToString(String base64Str, String key) throws Exception {byte[] data = Base64.getDecoder().decode(base64Str);byte[] oriData = decryptByPrivateKey(data, key);return new String(oriData);}/*** 获取公钥加密可加密的最大数据字节长度*/private static int getMaxEncryptBytesByPublicKey(KeyFactory keyFactory, Key key) throws InvalidKeySpecException {return getPublicKeyBitLength(keyFactory, key) / 8 - 11;}/*** 获取公钥解密每块的字节长度*/private static int getMaxDencryptBytesByPrivate(KeyFactory keyFactory, Key key) throws InvalidKeySpecException {return getPrivateKeyBitLength(keyFactory, key) / 8;}/*** 获取公钥加密可加密的最大数据字节长度*/private static int getMaxEncryptBytesByPrivate(KeyFactory keyFactory, Key key) throws InvalidKeySpecException {return getPrivateKeyBitLength(keyFactory, key) / 8 - 11;}/*** 获取公钥解密每块的字节长度*/private static int getMaxDencryptBytesByPublicKey(KeyFactory keyFactory, Key key) throws InvalidKeySpecException {return getPublicKeyBitLength(keyFactory, key) / 8;}/*** 获取公钥的字节长度*/private static int getPublicKeyBitLength(KeyFactory keyFactory, Key key) throws InvalidKeySpecException {RSAPublicKeySpec publicKeySpec = keyFactory.getKeySpec(key, RSAPublicKeySpec.class);return publicKeySpec.getModulus().bitLength();}/*** 获取私钥的字节长度*/private static int getPrivateKeyBitLength(KeyFactory keyFactory, Key key) throws InvalidKeySpecException {RSAPrivateKeySpec publicKeySpec = keyFactory.getKeySpec(key, RSAPrivateKeySpec.class);return publicKeySpec.getModulus().bitLength();}/*** 解密<br>* 用公钥解密*/public static byte[] decryptByPublicKey(byte[] data, String key)throws Exception {byte[] decryptedData = null;// 对密钥解密byte[] keyBytes = Base64.getDecoder().decode(key);// 取得公钥X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(keyBytes);KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);Key publicKey = keyFactory.generatePublic(x509KeySpec);// 对数据解密Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());cipher.init(Cipher.DECRYPT_MODE, publicKey);int maxDecryptBlockSize = getMaxDencryptBytesByPublicKey(keyFactory, publicKey);ByteArrayOutputStream bout = new ByteArrayOutputStream();try {int dataLength = data.length;for (int i = 0; i < dataLength; i += maxDecryptBlockSize) {int decryptLength = Math.min(dataLength - i, maxDecryptBlockSize);byte[] doFinal = cipher.doFinal(data, i, decryptLength);bout.write(doFinal);}decryptedData = bout.toByteArray();} finally {bout.close();}return decryptedData;}/*** 加密<br>* 用公钥加密*/public static byte[] encryptByPublicKey(byte[] data, String key)throws Exception {byte[] encryptedData = null;// 对公钥解密byte[] keyBytes = Base64.getDecoder().decode(key);// 取得公钥X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(keyBytes);KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);Key publicKey = keyFactory.generatePublic(x509KeySpec);// 对数据加密Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());cipher.init(Cipher.ENCRYPT_MODE, publicKey);int maxEncryptBlockSize = getMaxEncryptBytesByPublicKey(keyFactory, publicKey);ByteArrayOutputStream bout = new ByteArrayOutputStream();try {int dataLength = data.length;for (int i = 0; i < data.length; i += maxEncryptBlockSize) {int encryptLength = Math.min(dataLength - i, maxEncryptBlockSize);byte[] doFinal = cipher.doFinal(data, i, encryptLength);bout.write(doFinal);}encryptedData = bout.toByteArray();} finally {bout.close();}return encryptedData;}/*** 加密<br>* 用私钥加密*/public static byte[] encryptByPrivateKey(byte[] data, String key)throws Exception {byte[] encryptedData = null;// 对密钥解密byte[] keyBytes = Base64.getDecoder().decode(key);// 取得私钥PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes);KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);Key privateKey = keyFactory.generatePrivate(pkcs8KeySpec);// 对数据加密Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());cipher.init(Cipher.ENCRYPT_MODE, privateKey);int maxEncryptBlockSize = getMaxEncryptBytesByPrivate(keyFactory, privateKey);ByteArrayOutputStream bout = new ByteArrayOutputStream();try {int dataLength = data.length;for (int i = 0; i < data.length; i += maxEncryptBlockSize) {int encryptLength = Math.min(dataLength - i, maxEncryptBlockSize);byte[] doFinal = cipher.doFinal(data, i, encryptLength);bout.write(doFinal);}encryptedData = bout.toByteArray();} finally {bout.close();}return encryptedData;}/*** 取得私钥*/public static String getPrivateKey(Map<String, Object> keyMap)throws Exception {Key key = (Key) keyMap.get(PRIVATE_KEY);return Base64.getEncoder().encodeToString(key.getEncoded());}/*** 取得公钥*/public static String getPublicKey(Map<String, Object> keyMap)throws Exception {Key key = (Key) keyMap.get(PUBLIC_KEY);return Base64.getEncoder().encodeToString(key.getEncoded());}/*** 初始化密钥*/public static Map<String, Object> initKey() throws Exception {return initKey(1024);}public static Map<String, Object> initKey(int keySize) throws Exception {KeyPairGenerator keyPairGen = KeyPairGenerator.getInstance(KEY_ALGORITHM);keyPairGen.initialize(keySize);KeyPair keyPair = keyPairGen.generateKeyPair();// 公钥RSAPublicKey publicKey = (RSAPublicKey) keyPair.getPublic();// 私钥RSAPrivateKey privateKey = (RSAPrivateKey) keyPair.getPrivate();Map<String, Object> keyMap = new HashMap<String, Object>(2);keyMap.put(PUBLIC_KEY, publicKey);keyMap.put(PRIVATE_KEY, privateKey);return keyMap;}/*** 测试*/public static void main(String[] args) {try {//生成公钥私钥Map<String, Object> map = RSAUtil.initKey(2048);String PrivateKey = RSAUtil.getPrivateKey(map);String PublicKey = RSAUtil.getPublicKey(map);System.out.println("PrivateKey:" + PrivateKey);System.out.println("PublicKey:" + PublicKey);//明文String data = "hello rsa!";//公钥加密私钥解密byte[] encData = RSAUtil.encryptByPublicKey(data.getBytes(), PublicKey);byte[] decData = RSAUtil.decryptByPrivateKey(encData, PrivateKey);System.out.println(new String(decData));//私钥加密公钥解密byte[] encData1 = RSAUtil.encryptByPrivateKey(data.getBytes(), PrivateKey);byte[] decData1 = RSAUtil.decryptByPublicKey(encData1, PublicKey);System.out.println(new String(decData1));//私钥签名公钥验签String signStr = RSAUtil.sign(data.getBytes(), PrivateKey);boolean verify = RSAUtil.verify(data.getBytes(), PublicKey, signStr);System.out.println(signStr + verify);} catch (Exception e) {//密钥不对等情况e.printStackTrace();}}}
分享一个RSA加解密工具类 公钥加密私钥解密 私钥加密公钥解密 私钥签名公钥验签 生成公钥私钥
