生成 公钥 和私钥 对
public class KeyGenerater { private byte[] priKey; private byte[] pubKey; public void generater() { try { java.security.KeyPairGenerator keygen = java.security.KeyPairGenerator .getInstance("RSA"); SecureRandom secrand = new SecureRandom(); secrand.setSeed("syj".getBytes()); // 初始化随机产生器 keygen.initialize(1024, secrand); KeyPair keys = keygen.genKeyPair(); PublicKey pubkey = keys.getPublic(); PrivateKey prikey = keys.getPrivate(); pubKey = Base64.encodeToByte(pubkey.getEncoded()); priKey = Base64.encodeToByte(prikey.getEncoded()); System.out.println("pubKey = " + new String(pubKey)); System.out.println("priKey = " + new String(priKey)); } catch (java.lang.Exception e) { System.out.println("生成密钥对失败"); e.printStackTrace(); } } public byte[] getPriKey() { return priKey; } public byte[] getPubKey() { return pubKey; }} 2. 加密过程（数字签名）:利用私钥对传输数据进行数据加密
public class Signaturer { /** * * Description:数字签名 * * @param priKeyText * @param plainText * @return */ public static byte[] sign(byte[] priKeyText, String plainText) { try { PKCS8EncodedKeySpec priPKCS8 = new PKCS8EncodedKeySpec(Base64 .decode(priKeyText)); KeyFactory keyf = KeyFactory.getInstance("RSA"); PrivateKey prikey = keyf.generatePrivate(priPKCS8); // 用私钥对信息生成数字签名 java.security.Signature signet = java.security.Signature .getInstance("MD5withRSA"); signet.initSign(prikey); signet.update(plainText.getBytes()); byte[] signed = Base64.encodeToByte(signet.sign()); return signed; } catch (java.lang.Exception e) { System.out.println("签名失败"); e.printStackTrace(); } return null; }} 3. 校验数字签名, 利用公钥和数据明文进行编码校验 ”数据字签名“的数据 Check。
public class SignProvider { private SignProvider() { } /** * * Description:校验数字签名,此方法不会抛出任务异常,成功返回true,失败返回false,要求全部参数不能为空 * * @param pubKeyText * 公钥,base64编码 * @param plainText * 明文 * @param signTest * 数字签名的密文,base64编码 * @return 校验成功返回true 失败返回false */ public static boolean verify(byte[] pubKeyText, String plainText, byte[] signText) { try { // 解密由base64编码的公钥,并构造X509EncodedKeySpec对象 java.security.spec.X509EncodedKeySpec bobPubKeySpec = new java.security.spec.X509EncodedKeySpec( Base64.decode(pubKeyText)); // RSA对称加密算法 java.security.KeyFactory keyFactory = java.security.KeyFactory .getInstance("RSA"); // 取公钥匙对象 java.security.PublicKey pubKey = keyFactory .generatePublic(bobPubKeySpec); // 解密由base64编码的数字签名 byte[] signed = Base64.decode(signText); java.security.Signature signatureChecker = java.security.Signature .getInstance("MD5withRSA"); signatureChecker.initVerify(pubKey); signatureChecker.update(plainText.getBytes()); // 验证签名是否正常 if (signatureChecker.verify(signed)) return true; else return false; } catch (Throwable e) { System.out.println("校验签名失败"); e.printStackTrace(); return false; } }}