http://files.cnblogs.com/files/liuJava/rsa.zip、
直接上工具类 JAR 和前台JS 都在上面的链接里
package my.tools.security;import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.math.BigInteger;
import java.security.KeyPair;
import java.security.KeyFactory;
import java.security.KeyPairGenerator;
import java.security.Provider;
import java.security.PublicKey;
import java.security.PrivateKey;
import java.security.SecureRandom;
import java.security.NoSuchAlgorithmException;
import java.security.InvalidParameterException;
import java.security.interfaces.RSAPublicKey;
import java.security.interfaces.RSAPrivateKey;
import java.security.spec.RSAPublicKeySpec;
import java.security.spec.RSAPrivateKeySpec;
import java.security.spec.InvalidKeySpecException;import javax.crypto.Cipher;import org.apache.commons.io.IOUtils;
import org.apache.commons.io.FileUtils;
import org.apache.commons.codec.DecoderException;
import org.apache.commons.codec.binary.Hex;
import org.bouncycastle.jce.provider.BouncyCastleProvider;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;import org.apache.commons.lang.StringUtils;
import org.apache.commons.lang.time.DateFormatUtils;/*** RSA算法加密/解密工具类。* * @author fuchun* @version 1.0.0, 2010-05-05*/
public abstract class RSAUtils {private static final Logger LOGGER = LoggerFactory.getLogger(RSAUtils.class);/** 算法名称 */private static final String ALGORITHOM = "RSA";/**保存生成的密钥对的文件名称。 */private static final String RSA_PAIR_FILENAME = "/__RSA_PAIR.txt";/** 密钥大小 */private static final int KEY_SIZE = 1024;/** 默认的安全服务提供者 */private static final Provider DEFAULT_PROVIDER = new BouncyCastleProvider();private static KeyPairGenerator keyPairGen = null;private static KeyFactory keyFactory = null;/** 缓存的密钥对。 */private static KeyPair oneKeyPair = null;private static File rsaPairFile = null;static {try {keyPairGen = KeyPairGenerator.getInstance(ALGORITHOM, DEFAULT_PROVIDER);keyFactory = KeyFactory.getInstance(ALGORITHOM, DEFAULT_PROVIDER);} catch (NoSuchAlgorithmException ex) {LOGGER.error(ex.getMessage());}rsaPairFile = new File(getRSAPairFilePath());}private RSAUtils() {}/*** 生成并返回RSA密钥对。*/private static synchronized KeyPair generateKeyPair() {try {keyPairGen.initialize(KEY_SIZE, new SecureRandom(DateFormatUtils.format("yyyyMMdd").getBytes()));oneKeyPair = keyPairGen.generateKeyPair();saveKeyPair(oneKeyPair);return oneKeyPair;} catch (InvalidParameterException ex) {LOGGER.error("KeyPairGenerator does not support a key length of " + KEY_SIZE + ".", ex);} catch (NullPointerException ex) {LOGGER.error("RSAUtils#KEY_PAIR_GEN is null, can not generate KeyPairGenerator instance.",ex);}return null;}/*** 返回生成/读取的密钥对文件的路径。*/private static String getRSAPairFilePath() {String urlPath = RSAUtils.class.getResource("/").getPath();return (new File(urlPath).getParent() + RSA_PAIR_FILENAME);}/*** 若需要创建新的密钥对文件，则返回 {@code true}，否则 {@code false}。*/private static boolean isCreateKeyPairFile() {// 是否创建新的密钥对文件boolean createNewKeyPair = false;if (!rsaPairFile.exists() || rsaPairFile.isDirectory()) {createNewKeyPair = true;}return createNewKeyPair;}/*** 将指定的RSA密钥对以文件形式保存。* * @param keyPair 要保存的密钥对。*/private static void saveKeyPair(KeyPair keyPair) {FileOutputStream fos = null;ObjectOutputStream oos = null;try {fos = FileUtils.openOutputStream(rsaPairFile);oos = new ObjectOutputStream(fos);oos.writeObject(keyPair);} catch (Exception ex) {ex.printStackTrace();} finally {IOUtils.closeQuietly(oos);IOUtils.closeQuietly(fos);}}/*** 返回RSA密钥对。*/public static KeyPair getKeyPair() {// 首先判断是否需要重新生成新的密钥对文件if (isCreateKeyPairFile()) {// 直接强制生成密钥对文件，并存入缓存。return generateKeyPair();}if (oneKeyPair != null) {return oneKeyPair;}return readKeyPair();}// 同步读出保存的密钥对private static KeyPair readKeyPair() {FileInputStream fis = null;ObjectInputStream ois = null;try {fis = FileUtils.openInputStream(rsaPairFile);ois = new ObjectInputStream(fis);oneKeyPair = (KeyPair) ois.readObject();return oneKeyPair;} catch (Exception ex) {ex.printStackTrace();} finally {IOUtils.closeQuietly(ois);IOUtils.closeQuietly(fis);}return null;}/*** 根据给定的系数和专用指数构造一个RSA专用的公钥对象。* * @param modulus 系数。* @param publicExponent 专用指数。* @return RSA专用公钥对象。*/public static RSAPublicKey generateRSAPublicKey(byte[] modulus, byte[] publicExponent) {RSAPublicKeySpec publicKeySpec = new RSAPublicKeySpec(new BigInteger(modulus),new BigInteger(publicExponent));try {return (RSAPublicKey) keyFactory.generatePublic(publicKeySpec);} catch (InvalidKeySpecException ex) {LOGGER.error("RSAPublicKeySpec is unavailable.", ex);} catch (NullPointerException ex) {LOGGER.error("RSAUtils#KEY_FACTORY is null, can not generate KeyFactory instance.", ex);}return null;}/*** 根据给定的系数和专用指数构造一个RSA专用的私钥对象。* * @param modulus 系数。* @param privateExponent 专用指数。* @return RSA专用私钥对象。*/public static RSAPrivateKey generateRSAPrivateKey(byte[] modulus, byte[] privateExponent) {RSAPrivateKeySpec privateKeySpec = new RSAPrivateKeySpec(new BigInteger(modulus),new BigInteger(privateExponent));try {return (RSAPrivateKey) keyFactory.generatePrivate(privateKeySpec);} catch (InvalidKeySpecException ex) {LOGGER.error("RSAPrivateKeySpec is unavailable.", ex);} catch (NullPointerException ex) {LOGGER.error("RSAUtils#KEY_FACTORY is null, can not generate KeyFactory instance.", ex);}return null;}/*** 根据给定的16进制系数和专用指数字符串构造一个RSA专用的私钥对象。* * @param modulus 系数。* @param privateExponent 专用指数。* @return RSA专用私钥对象。*/public static RSAPrivateKey getRSAPrivateKey(String hexModulus, String hexPrivateExponent) {if(StringUtils.isBlank(hexModulus) || StringUtils.isBlank(hexPrivateExponent)) {if(LOGGER.isDebugEnabled()) {LOGGER.debug("hexModulus and hexPrivateExponent cannot be empty. RSAPrivateKey value is null to return.");}return null;}byte[] modulus = null;byte[] privateExponent = null;try {modulus = Hex.decodeHex(hexModulus.toCharArray());privateExponent = Hex.decodeHex(hexPrivateExponent.toCharArray());} catch(DecoderException ex) {LOGGER.error("hexModulus or hexPrivateExponent value is invalid. return null(RSAPrivateKey).");}if(modulus != null && privateExponent != null) {return generateRSAPrivateKey(modulus, privateExponent);}return null;}/*** 根据给定的16进制系数和专用指数字符串构造一个RSA专用的公钥对象。* * @param modulus 系数。* @param publicExponent 专用指数。* @return RSA专用公钥对象。*/public static RSAPublicKey getRSAPublidKey(String hexModulus, String hexPublicExponent) {if(StringUtils.isBlank(hexModulus) || StringUtils.isBlank(hexPublicExponent)) {if(LOGGER.isDebugEnabled()) {LOGGER.debug("hexModulus and hexPublicExponent cannot be empty. return null(RSAPublicKey).");}return null;}byte[] modulus = null;byte[] publicExponent = null;try {modulus = Hex.decodeHex(hexModulus.toCharArray());publicExponent = Hex.decodeHex(hexPublicExponent.toCharArray());} catch(DecoderException ex) {LOGGER.error("hexModulus or hexPublicExponent value is invalid. return null(RSAPublicKey).");}if(modulus != null && publicExponent != null) {return generateRSAPublicKey(modulus, publicExponent);}return null;}/*** 使用指定的公钥加密数据。* * @param publicKey 给定的公钥。* @param data 要加密的数据。* @return 加密后的数据。*/public static byte[] encrypt(PublicKey publicKey, byte[] data) throws Exception {Cipher ci = Cipher.getInstance(ALGORITHOM, DEFAULT_PROVIDER);ci.init(Cipher.ENCRYPT_MODE, publicKey);return ci.doFinal(data);}/*** 使用指定的私钥解密数据。* * @param privateKey 给定的私钥。* @param data 要解密的数据。* @return 原数据。*/public static byte[] decrypt(PrivateKey privateKey, byte[] data) throws Exception {Cipher ci = Cipher.getInstance(ALGORITHOM, DEFAULT_PROVIDER);ci.init(Cipher.DECRYPT_MODE, privateKey);return ci.doFinal(data);}/*** 使用给定的公钥加密给定的字符串。* <p />* 若 {@code publicKey} 为 {@code null}，或者 {@code plaintext} 为 {@code null} 则返回 {@code* null}。* * @param publicKey 给定的公钥。* @param plaintext 字符串。* @return 给定字符串的密文。*/public static String encryptString(PublicKey publicKey, String plaintext) {if (publicKey == null || plaintext == null) {return null;}byte[] data = plaintext.getBytes();try {byte[] en_data = encrypt(publicKey, data);return new String(Hex.encodeHex(en_data));} catch (Exception ex) {LOGGER.error(ex.getCause().getMessage());}return null;}/*** 使用默认的公钥加密给定的字符串。* <p />* 若{@code plaintext} 为 {@code null} 则返回 {@code null}。* * @param plaintext 字符串。* @return 给定字符串的密文。*/public static String encryptString(String plaintext) {if(plaintext == null) {return null;}byte[] data = plaintext.getBytes();KeyPair keyPair = getKeyPair();try {byte[] en_data = encrypt((RSAPublicKey)keyPair.getPublic(), data);return new String(Hex.encodeHex(en_data));} catch(NullPointerException ex) {LOGGER.error("keyPair cannot be null.");} catch(Exception ex) {LOGGER.error(ex.getCause().getMessage());}return null;}/*** 使用给定的私钥解密给定的字符串。* <p />* 若私钥为 {@code null}，或者 {@code encrypttext} 为 {@code null}或空字符串则返回 {@code null}。* 私钥不匹配时，返回 {@code null}。* * @param privateKey 给定的私钥。* @param encrypttext 密文。* @return 原文字符串。*/public static String decryptString(PrivateKey privateKey, String encrypttext) {if (privateKey == null || StringUtils.isBlank(encrypttext)) {return null;}try {byte[] en_data = Hex.decodeHex(encrypttext.toCharArray());byte[] data = decrypt(privateKey, en_data);return new String(data);} catch (Exception ex) {LOGGER.error(String.format("\"%s\" Decryption failed. Cause: %s", encrypttext, ex.getCause().getMessage()));}return null;}/*** 使用默认的私钥解密给定的字符串。* <p />* 若{@code encrypttext} 为 {@code null}或空字符串则返回 {@code null}。* 私钥不匹配时，返回 {@code null}。* * @param encrypttext 密文。* @return 原文字符串。*/public static String decryptString(String encrypttext) {if(StringUtils.isBlank(encrypttext)) {return null;}KeyPair keyPair = getKeyPair();try {byte[] en_data = Hex.decodeHex(encrypttext.toCharArray());byte[] data = decrypt((RSAPrivateKey)keyPair.getPrivate(), en_data);return new String(data);} catch(NullPointerException ex) {LOGGER.error("keyPair cannot be null.");} catch (Exception ex) {LOGGER.error(String.format("\"%s\" Decryption failed. Cause: %s", encrypttext, ex.getMessage()));}return null;}/*** 使用默认的私钥解密由JS加密（使用此类提供的公钥加密）的字符串。* * @param encrypttext 密文。* @return {@code encrypttext} 的原文字符串。*/public static String decryptStringByJs(String encrypttext) {String text = decryptString(encrypttext);if(text == null) {return null;}return StringUtils.reverse(text);}/** 返回已初始化的默认的公钥。*/public static RSAPublicKey getDefaultPublicKey() {KeyPair keyPair = getKeyPair();if(keyPair != null) {return (RSAPublicKey)keyPair.getPublic();}return null;}/** 返回已初始化的默认的私钥。*/public static RSAPrivateKey getDefaultPrivateKey() {KeyPair keyPair = getKeyPair();if(keyPair != null) {return (RSAPrivateKey)keyPair.getPrivate();}return null;}
}
用法说下：还是直接上个JAVA里面的测试：
public static void main(String[] args) {RSAPublicKey publicKey = RSAUtils.getDefaultPublicKey();char[] encodeHex = Hex.encodeHex(publicKey.getPublicExponent().toByteArray());String exponent = new String (encodeHex);char[] encodeHex2 = Hex.encodeHex(publicKey.getModulus().toByteArray());String modulus=new String (encodeHex2);String encryptString = RSAUtils.encryptString(publicKey, "你好啊啊啊啊");System.out.println(encryptString);String decryptStringByJs = RSAUtils.decryptStringByJs(encryptString);char[] charArray = decryptStringByJs.toCharArray();String resultString = ""; for (int i=charArray.length-1; i>=0; i--){ resultString += charArray[i]; } System.out.println(resultString);}
在WEB项目中 给一些需要加密的数据加密的时候
后台分发秘钥
RSAPublicKey publicKey = RSAUtils.getDefaultPublicKey();char[] encodeHex = Hex.encodeHex(publicKey.getPublicExponent().toByteArray());String exponent = new String (encodeHex);ActionContext.getContext().put("exponent", exponent); ActionContext.getContext().put("modulus", new String(Hex.encodeHex(publicKey.getModulus().toByteArray())));
演示下JS请求 后台秘钥的过程
function dls(){// 这2个 就是请求来的 var modulus = $("#modulus").val(), exponent = $("#exponentid").val();var key = RSAUtils.getKeyPair(exponent, "", modulus);pwd2 = RSAUtils.encryptedString(key, $("#passwordid").val());$("#passwordid").val(pwd2)document.getElementById("formid").submit();}
后台解密的过程
解密：
password = RSAUtils.decryptStringByJs(password);
)
