一.项目结构
二.代码具体实现
1.密钥对生成的两种方式：一种生成公钥私文件，一种生成公钥私串
KeyPairGenUtil.java
package com.wangjinxiang.genkey.util;
import java.io.FileOutputStream;
import java.io.ObjectOutputStream;
import java.security.Key;
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.NoSuchAlgorithmException;
import java.security.SecureRandom;
import sun.misc.BASE64Encoder;
public class KeyPairGenUtil {
/** 指定加密算法为RSA */
private static final String ALGORITHM = "RSA";
/** 密钥长度，用来初始化 */
private static final int KEYSIZE = 1024;
/** 指定公钥存放文件 */
private static String PUBLIC_KEY_FILE = "PublicKey";
/** 指定私钥存放文件 */
private static String PRIVATE_KEY_FILE = "PrivateKey";
public static void main(String[] args) throws Exception {
//generateKeyPair();
genKeyPair();
}
/**
* 生成密钥对文件
* @throws Exception
*/
private static void generateKeyPair() throws Exception {
// /** RSA算法要求有一个可信任的随机数源 */
// SecureRandom secureRandom = new SecureRandom();
/** 为RSA算法创建一个KeyPairGenerator对象 */
KeyPairGenerator keyPairGenerator = KeyPairGenerator.getInstance(ALGORITHM);
/** 利用上面的随机数据源初始化这个KeyPairGenerator对象 */
// keyPairGenerator.initialize(KEYSIZE, secureRandom);
keyPairGenerator.initialize(KEYSIZE);
/** 生成密匙对 */
KeyPair keyPair = keyPairGenerator.generateKeyPair();
/** 得到公钥 */
Key publicKey = keyPair.getPublic();
/** 得到私钥 */
Key privateKey = keyPair.getPrivate();
ObjectOutputStream oos1 = null;
ObjectOutputStream oos2 = null;
try {
/** 用对象流将生成的密钥写入文件 */
oos1 = new ObjectOutputStream(new FileOutputStream(PUBLIC_KEY_FILE));
oos2 = new ObjectOutputStream(new FileOutputStream(PRIVATE_KEY_FILE));
oos1.writeObject(publicKey);
oos2.writeObject(privateKey);
} catch (Exception e) {
throw e;
} finally {
/** 清空缓存，关闭文件输出流 */
oos1.close();
oos2.close();
}
}
/**
* 生成密钥对
* @throws NoSuchAlgorithmException
*/
private static void genKeyPair() throws NoSuchAlgorithmException {
/** RSA算法要求有一个可信任的随机数源 */
SecureRandom secureRandom = new SecureRandom();
/** 为RSA算法创建一个KeyPairGenerator对象 */
KeyPairGenerator keyPairGenerator = KeyPairGenerator.getInstance(ALGORITHM);
/** 利用上面的随机数据源初始化这个KeyPairGenerator对象 */
keyPairGenerator.initialize(KEYSIZE, secureRandom);
//keyPairGenerator.initialize(KEYSIZE);
/** 生成密匙对 */
KeyPair keyPair = keyPairGenerator.generateKeyPair();
/** 得到公钥 */
Key publicKey = keyPair.getPublic();
/** 得到私钥 */
Key privateKey = keyPair.getPrivate();
byte[] publicKeyBytes = publicKey.getEncoded();
byte[] privateKeyBytes = privateKey.getEncoded();
String publicKeyBase64 = new BASE64Encoder().encode(publicKeyBytes);
String privateKeyBase64 = new BASE64Encoder().encode(privateKeyBytes);
System.out.println("publicKeyBase64.length():" + publicKeyBase64.length());
System.out.println("publicKeyBase64:" + publicKeyBase64);
System.out.println("privateKeyBase64.length():" + privateKeyBase64.length());
System.out.println("privateKeyBase64:" + privateKeyBase64);
}
}2.将密钥串生成方式的密钥对在常量类里定义，以便后面的应用使用
Constants.java
package com.wangjinxiang.constant;
public class Constants {
//#priKeyText
public final static String priKeyText = "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";
//#pubKeyText
public final static String pubKeyText = "MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQCYO23qMcvv0gpGs97rfmxITjjz5m/sjZ4JgYvPBs+JHwD/SCv7TJCEKVm4aXTEPTXRkN7LgUjQTnEGGS1JBY4zyqpnmJcfpNxWpdgAyE/4poMJ8rcZvqm14DOjNH+69mwpIdJkySHuzUCzQtMJ8GG2owNc9frTOpZozlcUWbGWfQIDAQAB";
}DigestUtil.java
package com.wangjinxiang.util;
public class DigestUtil {
/**
* 字节转为十六进制字符串
* @param字节
* @return 十六进制字符串
*/
public static String byte2hex(byte[] b) {
String hs = "";
String stmp = "";
for (int n = 0; b != null && n < b.length; n++) {
stmp = (java.lang.Integer.toHexString(b[n] & 0XFF));
if (stmp.length() == 1)
hs = hs + "0" + stmp;
else
hs = hs + stmp;
}
return hs;
}
/**
* 十六进制字符转为字节
* @param 十六进制字符
* @return 字节
*/
public static byte[] hex2byte(byte[] b) {
if ((b.length % 2) != 0)
throw new IllegalArgumentException("byte length is not correct");
byte[] b2 = new byte[b.length / 2];
for (int n = 0; n < b.length; n += 2) {
String item = new String(b, n, 2);
b2[n / 2] = (byte) Integer.parseInt(item, 16);
}
return b2;
}
/**
* 字符串转换成十六进制值
* @param bin String 我们看到的要转换成十六进制的字符串
* @return
*/
public static String bin2hex(String bin) {
char[] digital = "0123456789ABCDEF".toCharArray();
StringBuffer sb = new StringBuffer("");
byte[] bs = bin.getBytes();
int bit;
for (int i = 0; i < bs.length; i++) {
bit = (bs[i] & 0x0f0) >> 4;
sb.append(digital[bit]);
bit = bs[i] & 0x0f;
sb.append(digital[bit]);
}
return sb.toString();
}
}3.加解密应用实例RSAUtil.java
说明：加解密是用公钥加密，用私钥解密
package com.wangjinxiang.util;
import java.security.KeyFactory;
import java.security.PrivateKey;
import java.security.spec.PKCS8EncodedKeySpec;
import javax.crypto.Cipher;
import org.apache.commons.codec.binary.Base64;
import com.wangjinxiang.constant.Constants;
import sun.misc.BASE64Decoder;
import sun.misc.BASE64Encoder;
public class RSAUtil {
/** 指定加密算法为RSA */
private static final String ALGORITHM = "RSA";
public static void main(String[] args) throws Exception {
String source = "深圳,您好!";// 要加密的字符串
System.out.println("准备用公钥加密的字符串为：" + source);
String cryptograph = encrypt(source);// 生成的密文
System.out.print("用公钥加密后的结果为:" + cryptograph);
System.out.println();
String target = decrypt(cryptograph);// 解密密文
System.out.println("用私钥解密后的字符串为：" + target);
System.out.println();
}
/**
* 加密方法
* @param source 源数据
* @return
* @throws Exception
*/
public static String encrypt(String source) throws Exception {
java.security.spec.X509EncodedKeySpec x509KeySpec = new java.security.spec.X509EncodedKeySpec(Base64.decodeBase64(Constants.pubKeyText));
// RSA算法
java.security.KeyFactory keyFactory = java.security.KeyFactory.getInstance("RSA");
// 取公钥匙对象
java.security.PublicKey publicKey = keyFactory.generatePublic(x509KeySpec);
// 得到Cipher对象来实现对源数据的RSA加密
Cipher cipher = Cipher.getInstance(ALGORITHM);
cipher.init(Cipher.ENCRYPT_MODE, publicKey);
byte[] b = source.getBytes();
/** 执行加密操作 */
byte[] b1 = cipher.doFinal(b);
BASE64Encoder encoder = new BASE64Encoder();
return encoder.encode(b1);
}
/**
* 解密算法
* @param cryptograph 密文
* @return
* @throws Exception
*/
public static String decrypt(String cryptograph) throws Exception {
PKCS8EncodedKeySpec priPKCS8 = new PKCS8EncodedKeySpec(Base64.decodeBase64(Constants.priKeyText));
KeyFactory keyf = KeyFactory.getInstance("RSA");
PrivateKey privateKey = keyf.generatePrivate(priPKCS8);
/** 得到Cipher对象对已用公钥加密的数据进行RSA解密 */
Cipher cipher = Cipher.getInstance(ALGORITHM);
cipher.init(Cipher.DECRYPT_MODE, privateKey);
BASE64Decoder decoder = new BASE64Decoder();
byte[] b1 = decoder.decodeBuffer(cryptograph);
/** 执行解密操作 */
byte[] b = cipher.doFinal(b1);
return new String(b);
}
}运行结果：
准备用公钥加密的字符串为：深圳,您好!
用公钥加密后的结果为:Q5bZjBlIIPII04NOCIwYDPYBGNSC5Hv7XKc8TlkCRbZyAK4M4nm9uYcEded0Nbj7HeLXNZY8XrQD
l2+FsYjfL0DlioCoJQm7bnwlVwYmdNMXOB3bfepywpeFRDSNswJxueLqVtmIKcbuCuXBvdIqrfDq
PVbCVfI59/GhqAcqM6U=
用私钥解密后的字符串为：深圳,您好!4.加签验签实例SignUtil.java
说明：加签是用私钥，验签是用公钥
package com.wangjinxiang.util;
import java.security.KeyFactory;
import java.security.PrivateKey;
import java.security.spec.PKCS8EncodedKeySpec;
import org.apache.commons.codec.binary.Base64;
import com.wangjinxiang.constant.Constants;
public class SignUtil {
private final static String CHARACTER_ENCODING_UTF_8 = "UTF-8";
public static void main(String[] args) {
String signString = "深圳,您好!";
try {
// 加签
String localSignature = SignUtil.sign(Constants.priKeyText.getBytes(CHARACTER_ENCODING_UTF_8), signString);
System.out.println(localSignature);
//验签
boolean verifyResult = SignUtil.verify(Constants.pubKeyText.getBytes(CHARACTER_ENCODING_UTF_8), signString, localSignature);
System.out.println("verifyResult:" + verifyResult);
} catch (Exception e) {
e.printStackTrace();
}
}
/**
* RSA私钥加签
* @param priKeyText经过base64处理后的私钥
* @param plainText明文内容
* @return 十六进制的签名字符串
* @throws Exception
*/
public static String sign(byte[] priKeyText, String plainText) throws Exception {
try {
PKCS8EncodedKeySpec priPKCS8 = new PKCS8EncodedKeySpec(Base64.decodeBase64(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("SHA256withRSA");
signet.initSign(prikey);
signet.update(plainText.getBytes("UTF-8"));
return DigestUtil.byte2hex(signet.sign());
} catch (Exception e) {
throw e;
}
}
/**
* 公钥验签
* @param pubKeyText经过base64处理后的公钥
* @param plainText明文内容
* @param signText十六进制的签名字符串
* @return 验签结果 true验证一致 false验证不一致
*/
public static boolean verify(byte[] pubKeyText, String plainText, String 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.decodeBase64(pubKeyText));
// RSA算法
java.security.KeyFactory keyFactory = java.security.KeyFactory.getInstance("RSA");
// 取公钥匙对象
java.security.PublicKey pubKey = keyFactory.generatePublic(bobPubKeySpec);
// 十六进制数字签名转为字节
byte[] signed = DigestUtil.hex2byte(signText.getBytes("UTF-8"));
java.security.Signature signatureChecker = java.security.Signature.getInstance("SHA256withRSA");
signatureChecker.initVerify(pubKey);
signatureChecker.update(plainText.getBytes("UTF-8"));
// 验证签名是否正常
return signatureChecker.verify(signed);
} catch (Throwable e) {
return false;
}
}
}运行结果：
7ef0cd04a3dc41ae1396a90a3d8a8b799c68c65202361823dd3a71a05fc2bf57c09ebe2074ba49008cf58288297267d770137ee267c6c296a784c7d50c607c73e1d78799c7de5dadf183f011d604df7270ce5616e465ddc93a95df9095249702fc265e97ed7ab2adf4535d13237040653d7f000a3080a0c4f11f84bbe48849e7
verifyResult:true5.从生成的密钥对文件中读取公私钥加解密实例RSAUtil02.java
package com.wangjinxiang.util2;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.security.Key;
import javax.crypto.Cipher;
import sun.misc.BASE64Decoder;
import sun.misc.BASE64Encoder;
public class RSAUtil02 {
/** 指定加密算法为RSA */
private static final String ALGORITHM = "RSA";
/** 指定公钥存放文件 */
private static String PUBLIC_KEY_FILE = "PublicKey";
/** 指定私钥存放文件 */
private static String PRIVATE_KEY_FILE = "PrivateKey";
public static void main(String[] args) throws Exception {
String source = "深圳,您好!";// 要加密的字符串
System.out.println("准备用公钥加密的字符串为：" + source);
String cryptograph = encrypt(source);// 生成的密文
System.out.print("用公钥加密后的结果为:" + cryptograph);
System.out.println();
String target = decrypt(cryptograph);// 解密密文
System.out.println("用私钥解密后的字符串为：" + target);
System.out.println();
}
/**
* 加密方法
* @param source 源数据
* @return
* @throws Exception
*/
public static String encrypt(String source) throws Exception {
Key publicKey = getKey(PUBLIC_KEY_FILE);
/** 得到Cipher对象来实现对源数据的RSA加密 */
Cipher cipher = Cipher.getInstance(ALGORITHM);
cipher.init(Cipher.ENCRYPT_MODE, publicKey);
byte[] b = source.getBytes();
/** 执行加密操作 */
byte[] b1 = cipher.doFinal(b);
BASE64Encoder encoder = new BASE64Encoder();
return encoder.encode(b1);
}
/**
* 解密算法
* @param cryptograph 密文
* @return
* @throws Exception
*/
public static String decrypt(String cryptograph) throws Exception {
Key privateKey = getKey(PRIVATE_KEY_FILE);
/** 得到Cipher对象对已用公钥加密的数据进行RSA解密 */
Cipher cipher = Cipher.getInstance(ALGORITHM);
cipher.init(Cipher.DECRYPT_MODE, privateKey);
BASE64Decoder decoder = new BASE64Decoder();
byte[] b1 = decoder.decodeBuffer(cryptograph);
/** 执行解密操作 */
byte[] b = cipher.doFinal(b1);
return new String(b);
}
private static Key getKey(String fileName) throws Exception, IOException {
Key key;
ObjectInputStream ois = null;
try {
/** 将文件中的私钥对象读出 */
ois = new ObjectInputStream(new FileInputStream(fileName));
key = (Key) ois.readObject();
} catch (Exception e) {
throw e;
} finally {
ois.close();
}
return key;
}
}运行结果：
准备用公钥加密的字符串为：深圳,您好!
用公钥加密后的结果为:Ep2Y6EstlUWQnmVxsZ0/NIV1NFIPAlg8rJguRdQB+2uBD+/sunrPiVoCm3zbuj317CNG5hwijNBf
qKETmd7HoftpnHxzYwn+lWqlVdUHIO+ZrFn2OB6omlA/aFHCZzIHtKDU72cNuiBiwONxCXyaWq4Z
scDfvzbz3//UYOhlDs4=
用私钥解密后的字符串为：深圳,您好!
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