RSA公钥加密私钥解密实例
public class RSACrypt {
/**
* 生成RAS公钥与私钥字符串，直接返回
*
* @return
*/
public static HashMap<String, String> getKeys() {
HashMap<String, String> map = new HashMap<String, String>();
KeyPairGenerator keyPairGen = null;
try {
keyPairGen = KeyPairGenerator.getInstance("RSA");
} catch (NoSuchAlgorithmException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
// 初始化密钥对生成器，密钥大小为96-1024位
keyPairGen.initialize(1024, new SecureRandom());
// 生成一个密钥对，保存在keyPair中
KeyPair keyPair = keyPairGen.generateKeyPair();
// 得到公钥字符串
String publicKey = base64ToStr(keyPair.getPublic().getEncoded());
// 得到私钥字符串
String privateKey = base64ToStr(keyPair.getPrivate().getEncoded());
map.put("publicKey", publicKey);
map.put("privateKey", privateKey);
return map;
}
/**
* 根据公钥字符串加载公钥
*
* @param publicKeyStr 公钥字符串
* @return
* @throws Exception
*/
public static RSAPublicKey loadPublicKey(String publicKeyStr) throws Exception {
try {
byte[] buffer = javax.xml.bind.DatatypeConverter.parseBase64Binary(publicKeyStr);
KeyFactory keyFactory = KeyFactory.getInstance("RSA");
X509EncodedKeySpec keySpec = new X509EncodedKeySpec(buffer);
return (RSAPublicKey) keyFactory.generatePublic(keySpec);
} catch (NoSuchAlgorithmException e) {
throw new Exception("无此算法", e);
} catch (InvalidKeySpecException e) {
throw new Exception("公钥非法", e);
} catch (NullPointerException e) {
throw new Exception("公钥数据为空", e);
}
}
/**
* 根据私钥字符串加载私钥
*
* @param privateKeyStr 私钥字符串
* @return
* @throws Exception
*/
public static RSAPrivateKey loadPrivateKey(String privateKeyStr) throws Exception {
try {
byte[] buffer = javax.xml.bind.DatatypeConverter.parseBase64Binary(privateKeyStr);
PKCS8EncodedKeySpec keySpec = new PKCS8EncodedKeySpec(buffer);
KeyFactory keyFactory = KeyFactory.getInstance("RSA");
return (RSAPrivateKey) keyFactory.generatePrivate(keySpec);
} catch (NoSuchAlgorithmException e) {
throw new Exception("无此算法", e);
} catch (InvalidKeySpecException e) {
throw new Exception("私钥非法", e);
} catch (NullPointerException e) {
throw new Exception("私钥数据为空", e);
}
}
/**
* 公钥加密
*
* @param publicKey 公钥
* @param plainTextData 明文数据
* @return
* @throws Exception 加密过程中的异常信息
*/
public static String encrypt(RSAPublicKey publicKey, byte[] plainTextData) throws Exception {
if (publicKey == null) {
throw new Exception("加密公钥为空, 请设置");
}
Cipher cipher = null;
try {
// 使用默认RSA
cipher = Cipher.getInstance("RSA");
cipher.init(Cipher.ENCRYPT_MODE, publicKey);
byte[] output = cipher.doFinal(plainTextData);
return base64ToStr(output);
} catch (NoSuchAlgorithmException e) {
throw new Exception("无此加密算法");
} catch (NoSuchPaddingException e) {
e.printStackTrace();
return null;
} catch (InvalidKeyException e) {
throw new Exception("加密公钥非法,请检查");
} catch (IllegalBlockSizeException e) {
throw new Exception("明文长度非法");
} catch (BadPaddingException e) {
throw new Exception("明文数据已损坏");
}
}
public static String encrypt(byte[] plainTextData) throws Exception {
Cipher cipher = null;
try {
// 使用默认RSA
cipher = Cipher.getInstance("RSA");
cipher.init(Cipher.ENCRYPT_MODE, RSACrypt.loadPublicKey(pk));
byte[] output = cipher.doFinal(plainTextData);
return base64ToStr(output);
} catch (NoSuchAlgorithmException e) {
throw new Exception("无此加密算法");
} catch (NoSuchPaddingException e) {
e.printStackTrace();
return null;
} catch (InvalidKeyException e) {
throw new Exception("加密公钥非法,请检查");
} catch (IllegalBlockSizeException e) {
throw new Exception("明文长度非法");
} catch (BadPaddingException e) {
throw new Exception("明文数据已损坏");
}
}
/**
* 私钥解密
*
* @param privateKey 私钥
* @param cipherData 密文数据
* @return 明文
* @throws Exception 解密过程中的异常信息
*/
public static String decrypt(RSAPrivateKey privateKey, byte[] cipherData) throws Exception {
if (privateKey == null) {
throw new Exception("解密私钥为空, 请设置");
}
Cipher cipher = null;
try {
// 使用默认RSA
cipher = Cipher.getInstance("RSA");
cipher.init(Cipher.DECRYPT_MODE, privateKey);
byte[] output = cipher.doFinal(cipherData);
return new String(output);
} catch (NoSuchAlgorithmException e) {
throw new Exception("无此解密算法");
} catch (NoSuchPaddingException e) {
e.printStackTrace();
return null;
} catch (InvalidKeyException e) {
throw new Exception("解密私钥非法,请检查");
} catch (IllegalBlockSizeException e) {
e.printStackTrace();
throw new Exception("密文长度非法");
} catch (BadPaddingException e) {
e.printStackTrace();
throw new Exception("密文数据已损坏");
}
}
public static String decrypt(byte[] cipherData) throws Exception {
Cipher cipher = null;
try {
// 使用默认RSA
cipher = Cipher.getInstance("RSA");
cipher.init(Cipher.DECRYPT_MODE, RSACrypt.loadPrivateKey(sk));
byte[] output = cipher.doFinal(cipherData);
return new String(output);
} catch (NoSuchAlgorithmException e) {
throw new Exception("无此解密算法");
} catch (NoSuchPaddingException e) {
e.printStackTrace();
return null;
} catch (InvalidKeyException e) {
throw new Exception("解密私钥非法,请检查");
} catch (IllegalBlockSizeException e) {
e.printStackTrace();
throw new Exception("密文长度非法");
} catch (BadPaddingException e) {
e.printStackTrace();
throw new Exception("密文数据已损坏");
}
}
public static String base64ToStr(byte[] b) {
return javax.xml.bind.DatatypeConverter.printBase64Binary(b);
}
public static byte[] strToBase64(String str) {
return javax.xml.bind.DatatypeConverter.parseBase64Binary(str);
}
}
生成秘钥对，加密数据、解密数据
public static void main(String[] args) throws Exception {
//初始化阶段，初始化后生成秘钥对
//公钥发送给消息发送方用于加密传输数据；私钥严格保存于消息接收方，收到加密的消息之后进行解密
HashMap<String, String> map = RSACrypt.getKeys();
String privateKeyStr=map.get("privateKey");
String publicKeyStr=map.get("publicKey");
System.out.println("初始化私钥为："+privateKeyStr);
System.out.println("初始化共钥为："+publicKeyStr);
//消息发送方
String originData="你是收破烂的么？";
System.out.println("信息原文："+originData);
String encryptData=RSACrypt.encrypt(RSACrypt.loadPublicKey(publicKeyStr),originData.getBytes());
System.out.println("加密后："+encryptData);
//消息接收方
String decryptData=RSACrypt.decrypt(RSACrypt.loadPrivateKey(privateKeyStr),RSACrypt.strToBase64(encryptData));
System.out.println("解密后："+decryptData);
}
结果输出
初始化私钥为：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 初始化共钥为：MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQCNkskbzMWU65UceqB2r/JQhAh1+cGf6T5ALJdUSIfzTH1ecIzft5BmaxujRLyPsQrsMBRp/BsFA4Kguh8OZwNeXIbkaa2RQ2l2vYRawuq+o7UOjDzrKnWgyUn6SSGOuH2aqFSynYm1e/N5ny9e+Z/SJGg7sN5rLpicgzrIKZSCfwIDAQAB 信息原文：你是收破烂的么？ 加密后：XeIAoNZlyn+Mk17wsdPpl8SDlaq0B8NbIvQFVg9Ja+YHxuKretNMu61IRY5EFyPL/dXC/6KiDDINglP2HRX4JNbRZgzZd1rkqExW219psHQOhFzbFYZ3yKuI72C7S4/sqIM1eqlnkvIGBhJNLwOfzF6VjplsbHAiQ4fDhA57XI8= 解密后：你是收破烂的么？
