用eclipse做的RSA简单加密小软件

package RSA_Pak; import java.math.BigInteger;//如果为了便于手工验证，可以把s改为1，bit改为8，’标记处’改小 import java.util.Random; import java.util.Scanner; /** * RSA算法简单实现 * @author windy */ public class RSA { /**生成素数的长度 按照bit */ public static int bit = 16; //最好是30以下 /**几个char为一组*/ public static int s = 3; /**将加密完的数据存到code里*/ public String code=""; //大数参数 BigInteger p; BigInteger q; BigInteger n; BigInteger xn; BigInteger e; BigInteger d; /** * 初始化所有参数 */ public RSA() { Random r = new Random(); p = BigInteger.probablePrime(bit, r); q = BigInteger.probablePrime(bit, r); n = p.multiply(q); xn = (p.subtract(BigInteger.ONE)).multiply(q.subtract(BigInteger.ONE)); e = this.getE(); d = this.getMod(); } /**获取E参数*/ public BigInteger getE(){ BigInteger bi = new BigInteger("123"); int k = new Random().nextInt(655) + 200; int count = 1; for (long i = 3; i < xn.longValue(); i++) { k = Math.abs(k); bi = new BigInteger(""+i); if(bi.gcd(xn).equals(BigInteger.ONE)){ if (count > k){ return bi; }else{ count++; } } } return bi; } public void print(char[] c){ System.out.println(); for (int i = 0; i < c.length; i++) { System.out.print(c[i]+", "); } } public void print(byte[] c){ System.out.println(); for (int i = 0; i < c.length; i++) { System.out.print(c[i]+", "); } } /** * 获取加密数据 * @param meg * @return String */ public String getEncryptMeg(String meg){ BigInteger[] bi = this.diliverMeg(meg); BigInteger[] re = new BigInteger[bi.length]; for (int i = 0; i < bi.length; i++) { re[i] = this.getWordsEncrypt(bi[i]); } StringBuilder sb = new StringBuilder(); for (int i = 0; i < re.length; i++) { sb.append(re[i]); } return sb.toString(); } /** * 传入连接分组后的BI数组,进行加密和解密 * (演示用..) * @param bi * @return String */ public String getBigIntegerArrayUnencrypt(BigInteger[] bi){ BigInteger[] re = new BigInteger[bi.length]; BigInteger[] ree = new BigInteger[bi.length]; for (int i = 0; i < bi.length; i++) { re[i] = this.getWordsEncrypt(bi[i]); System.out.println("原始:"+bi[i]); System.out.println("加密:"+re[i]); code+=re[i].toString()+" ";//将分组加密结果存入code，每组结果用空格格开 System.out.println("code:"+code); } for (int i = 0; i < re.length; i++) {//解密，不过只在RSA单类演示下用 ree[i] = this.getWordsUnencrypt(re[i]); //System.out.println("解密:"+ree[i]); } //StringBuilder sb = new StringBuilder(); String s = null;//this.combainateMeg(ree); return s; } /** * 将字符串按照ASCII码分组连接处理 返回一个biginteger数组 * @param meg * @return {@link BigInteger}[] */ public BigInteger[] diliverMeg(String meg){ int len = meg.length()/s; if (meg.length()%s != 0){ for (int i = meg.length()%s; i < s; i++) { meg += ' '; } len++; } BigInteger[] bi = new BigInteger[len]; System.out.println("原始数据的ASCII码为："); for (int i = 0; i < bi.length; i++) { String c = ""; for (int j = 0; j < s; j++) { char a = meg.charAt(i*s+j); System.out.print((int)a+","); int b = Math.abs((int)a); if (b < 100){c += "0"+String.valueOf(b);} //不足百的前补零 else{c += String.valueOf(b);} //产生了一个字符串 } bi[i] = new BigInteger(c); } System.out.println(); return bi; } /** * 把解密完的大数数组按照ASCII码还原为字符内容 * @param bi * @return String */ public String combainateMeg(BigInteger[] bi){ char[] re = new char[bi.length*s]; //解密字符串数组的容器 int index = 0; System.out.println("则解密得到的总数据ASCII码为："); for (int i = 0; i < bi.length; i++) { String a = bi[i].toString(); if (a.length()%3 == 1){ a = "00"+a; }else if(a.length()%3 == 2){ a = "0"+a; } for (int j = 0; j < s; j++) { String b = a.substring(j*3, (j+1)*3); int c = Integer.parseInt(b); System.out.print(c+","); re[index] = (char)c; index++; } } System.out.println(); return String.copyValueOf(re); } public BigInteger getWordsEncrypt(BigInteger bi){ return bi.modPow(e, n); } public BigInteger getWordsUnencrypt(BigInteger bi){ return bi.modPow(d, n); } /** * 计算D的 需要一个好点的算法 * @return {@link BigInteger} */ public BigInteger getMod(){ BigInteger re; BigInteger temp; for (long i = 1; i < 20000; i++) { //基本适合32bit的素数了，‘标记处’ re = xn.multiply(BigInteger.valueOf(i)); re = re.add(BigInteger.ONE); temp = re.mod(this.e); if(temp.equals(BigInteger.ZERO)){ return re.divide(e); } } return null; //时间太长 退出 } /** * 产生一个bit长度的素数 * @return prime */ public BigInteger getPrime(){ Random random = new Random(); BigInteger bi = BigInteger.probablePrime(RSA.bit, random); System.out.println(bi); return bi; } private static String readString(String prompt) {//从控制台读取数据 Scanner scanner = new Scanner(System.in); System.out.println(prompt); return scanner.nextLine(); } public static void main(String[] args) { RSA rsa = new RSA(); System.out.println("q = "+rsa.q); System.out.println("p = "+rsa.p); System.out.println("n = "+rsa.n); System.out.println("xn ="+rsa.xn); System.out.println("e = "+rsa.e); System.out.println("d = "+rsa.d); String meg = readString("请输入您要加密的消息:"); System.out.println("原始信息: "+meg); BigInteger[] re = rsa.diliverMeg(meg); String s = rsa.getBigIntegerArrayUnencrypt(re); System.out.println("还原的信息: "+s); System.out.println(rsa.getEncryptMeg(meg)); } }