RSAsecurity.java
package com.mstf.rsa; import java.security.KeyFactory;import java.security.KeyPair;import java.security.KeyPairGenerator;import java.security.PrivateKey;import java.security.PublicKey;import java.security.interfaces.RSAPrivateKey;import java.security.interfaces.RSAPublicKey;import java.security.spec.PKCS8EncodedKeySpec;import java.security.spec.X509EncodedKeySpec; import javax.crypto.Cipher; import com.sun.org.apache.xerces.internal.impl.dv.util.Base64; /*RSA 工具类。提供加密，解密，生成密钥对等方法。 RSA加密原理概述 RSA的安全性依赖于大数的分解，公钥和私钥都是两个大素数（大于100的十进制位）的函数。据猜测，从一个密钥和密文推断出明文的难度等同于分解两个大素数的积 密钥的产生： 1.选择两个大素数 p,q ,计算 n=p*q; 2.随机选择加密密钥 e ,要求 e 和 (p-1)*(q-1)互质 3.利用 Euclid 算法计算解密密钥 d , 使其满足 e*d = 1(mod(p-1)*(q-1)) (其中 n,d 也要互质) 4:至此得出公钥为 (n,e) 私钥为 (n,d) RSA速度 * 由于进行的都是大数计算，使得RSA最快的情况也比DES慢上100倍，无论 是软件还是硬件实现。 * 速度一直是RSA的缺陷。一般来说只用于少量数据 加密。*/public class RSAsecurity { public static String src = "admin"; public void priENpubDE() { try {// 初始化秘钥KeyPairGenerator keyPairGenerator = KeyPairGenerator.getInstance("RSA");// 秘钥长度keyPairGenerator.initialize(1024);// 初始化秘钥对KeyPair keyPair = keyPairGenerator.generateKeyPair();// 公钥RSAPublicKey rsaPublicKey = (RSAPublicKey) keyPair.getPublic();// 私钥RSAPrivateKey rsaPrivateKey = (RSAPrivateKey) keyPair.getPrivate(); // 2.私钥加密，公钥解密----加密// 生成私钥PKCS8EncodedKeySpec pkcs8EncodedKeySpec = new PKCS8EncodedKeySpec(rsaPrivateKey.getEncoded());KeyFactory keyFactory = KeyFactory.getInstance("RSA");PrivateKey privateKey = keyFactory.generatePrivate(pkcs8EncodedKeySpec);// Cipher类为加密和解密提供密码功能，通过getinstance实例化对象Cipher cipher = Cipher.getInstance("RSA");// 初始化加密cipher.init(Cipher.ENCRYPT_MODE, privateKey);byte[] result = cipher.doFinal(src.getBytes());System.out.println("私钥加密，公钥解密----加密:" + Base64.encode(result)); // 3.私钥加密，公钥解密----解密// 生成公钥X509EncodedKeySpec x509EncodedKeySpec = new X509EncodedKeySpec(rsaPublicKey.getEncoded());keyFactory = KeyFactory.getInstance("RSA");PublicKey publicKey = keyFactory.generatePublic(x509EncodedKeySpec);cipher = Cipher.getInstance("RSA");// 初始化解密cipher.init(Cipher.DECRYPT_MODE, publicKey);result = cipher.doFinal(result);System.out.println("私钥加密，公钥解密----解密:" + new String(result));} catch (Exception e) {// TODO Auto-generated catch blocke.printStackTrace();} } public void pubENpriDE() {try {// 1.初始化秘钥KeyPairGenerator keyPairGenerator = KeyPairGenerator.getInstance("RSA");// 秘钥长度keyPairGenerator.initialize(512);// 初始化秘钥对KeyPair keyPair = keyPairGenerator.generateKeyPair();// 公钥RSAPublicKey rsaPublicKey = (RSAPublicKey) keyPair.getPublic();// 私钥RSAPrivateKey rsaPrivateKey = (RSAPrivateKey) keyPair.getPrivate(); // 2.公钥加密，私钥解密----加密X509EncodedKeySpec x509EncodedKeySpec = new X509EncodedKeySpec(rsaPublicKey.getEncoded());KeyFactory keyFactory = KeyFactory.getInstance("RSA");PublicKey publicKey = keyFactory.generatePublic(x509EncodedKeySpec);// 初始化加密// Cipher类为加密和解密提供密码功能，通过getinstance实例化对象Cipher cipher = Cipher.getInstance("RSA");cipher.init(Cipher.ENCRYPT_MODE, publicKey);// 加密字符串byte[] result = cipher.doFinal(src.getBytes());System.out.println("公钥加密，私钥解密----加密:" + Base64.encode(result)); // 3.公钥加密，私钥解密-----解密PKCS8EncodedKeySpec pkcs8EncodedKeySpec = new PKCS8EncodedKeySpec(rsaPrivateKey.getEncoded());keyFactory = KeyFactory.getInstance("RSA");PrivateKey privateKey = keyFactory.generatePrivate(pkcs8EncodedKeySpec);// 初始化解密cipher.init(Cipher.DECRYPT_MODE, privateKey);// 解密字符串result = cipher.doFinal(result);System.out.println("公钥加密，私钥解密-----解密:" + new String(result)); } catch (Exception e) {// TODO Auto-generated catch blocke.printStackTrace();} }}
RSAtest.java
package com.mstf.rsa; import com.mstf.rsa.RSAsecurity; public class RSAtest {public static void main(String[] args) {RSAsecurity rsAsecurity = new RSAsecurity();System.out.println("私钥加密公钥解密例：");rsAsecurity.priENpubDE();System.out.println("公钥加密私钥解密例：");rsAsecurity.pubENpriDE();}}
以上就是RSA加密和解密的实例介绍的详细内容，更多请关注其它相关文章！
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