rsa 加密聊天程序

package com.banko.rsachat; import java.io.UnsupportedEncodingException; import java.math.BigInteger; import java.net.URLDecoder; import java.net.URLEncoder; import java.security.KeyPair; import java.security.KeyPairGenerator; import java.security.NoSuchAlgorithmException; import java.security.interfaces.RSAPrivateCrtKey; import java.security.interfaces.RSAPublicKey; import java.util.logging.Level; import java.util.logging.Logger; public class RSAChinese { public static final String E = "65537"; public static final String N = "6843313101291659592693028390370620217135751844805285054508177640036800872121365560329363814663088712048917867411880982302294734169414491505385852183253477"; public static final String D = "1094625192499511230453042046725593355451639327236428326386762076392050041082846439448470498560895703615113748666115507592108308465632534638114424404205633"; public static final String P = "100709084290345694865330116906846965717425950527844819314656941768325736751797"; public static final String Q = "67951299026434323043402172046339884185876196849192897542415639826146862563441"; public static String[] key = {E, N, D, P, Q}; /** * 创建密钥对生成器，指定加密和解密算法为RSA * @param keylen * @return */ public static String[] createKey(int keylen) {// 输入密钥长度 String[] output = new String[5]; // 用来存储密钥的e n d p q try { KeyPairGenerator kpg = KeyPairGenerator.getInstance("RSA"); kpg.initialize(keylen); // 指定密钥的长度，初始化密钥对生成器 KeyPair kp = kpg.generateKeyPair(); // 生成密钥对 RSAPublicKey puk = (RSAPublicKey) kp.getPublic(); RSAPrivateCrtKey prk = (RSAPrivateCrtKey) kp.getPrivate(); BigInteger e = puk.getPublicExponent(); BigInteger n = puk.getModulus(); BigInteger d = prk.getPrivateExponent(); BigInteger p = prk.getPrimeP(); BigInteger q = prk.getPrimeQ(); output[0] = e.toString(); output[1] = n.toString(); output[2] = d.toString(); output[3] = p.toString(); output[4] = q.toString(); } catch (NoSuchAlgorithmException ex) { Logger.getLogger(RSAChinese.class.getName()).log(Level.SEVERE, null, ex); } return output; } /** * 加密在RSA公钥中包含有两个整数信息：e和n。对于明文数字m,计算密文的公式是m的e次方再与n求模。 * @param clearText 明文 * @param eStr 公钥 * @param nStr * @return */ public static String encrypt(String clearText, String eStr, String nStr) { String secretText = new String(); try { clearText = URLEncoder.encode(clearText,"GB18030"); byte text[]=clearText.getBytes("GB18030");//将字符串转换成byte类型数组，实质是各个字符的二进制形式 BigInteger mm=new BigInteger(text);//二进制串转换为一个大整数 clearText = mm.toString(); BigInteger e = new BigInteger(eStr); BigInteger n = new BigInteger(nStr); byte[] ptext = clearText.getBytes("GB18030"); // 获取明文的大整数 BigInteger m = new BigInteger(ptext); BigInteger c = m.modPow(e, n); secretText = c.toString(); } catch (UnsupportedEncodingException ex) { Logger.getLogger(RSAChinese.class.getName()).log(Level.SEVERE, null, ex); } return secretText; } /** * 解密 * @param secretText 密文 * @param dStr 私钥 * @param nStr * @return */ public static String decrypt(String secretText, String dStr, String nStr) { StringBuffer clearTextBuffer = new StringBuffer(); BigInteger d = new BigInteger(dStr);// 获取私钥的参数d,n BigInteger n = new BigInteger(nStr); BigInteger c = new BigInteger(secretText); BigInteger m = c.modPow(d, n);// 解密明文 byte[] mt = m.toByteArray();// 计算明文对应的字符串并输出 for (int i = 0; i < mt.length; i++) { clearTextBuffer.append((char) mt[i]); } String temp = clearTextBuffer.toString();//temp为明文的字符串形式 BigInteger b = new BigInteger(temp);//b为明文的BigInteger类型 byte[] mt1=b.toByteArray(); try { String clearText = (new String(mt1,"GB18030")); clearText=URLDecoder.decode(clearText,"GB18030"); return clearText; } catch (UnsupportedEncodingException e) { // TODO Auto-generated catch block e.printStackTrace(); } return null; } public static void main(String[] args) { RSAChinese rsa = new RSAChinese(); String[] str = rsa.createKey(512); String clearText = "123abc测试"; String secretText = RSAChinese.encrypt(clearText, key[0], key[1]); System.out.println("明文是：" + clearText); System.out.println("密文是：" + secretText); System.out.println("解密后的明文是：" + RSAChinese.decrypt(secretText, key[2], key[1])); } }