java公钥加密私钥解密_JAVA公钥加密，私钥解密，该怎么解决

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public abstract class RSACoder extends Coder {

public static final String KEY_ALGORITHM = "RSA";

public static final String SIGNATURE_ALGORITHM = "MD5withRSA";

private static final String PUBLIC_KEY = "RSAPublicKey";

private static final String PRIVATE_KEY = "RSAPrivateKey";

/**

* 用私钥对信息生成数字签名

*

* @param data

*            加密数据62616964757a686964616fe4b893e5b19e31333337393534

* @param privateKey

*            私钥

*

* @return

* @throws Exception

*/

public static String sign(byte[] data, String privateKey) throws Exception {

// 解密由base64编码的私钥

byte[] keyBytes = decryptBASE64(privateKey);

// 构造PKCS8EncodedKeySpec对象

PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes);

// KEY_ALGORITHM 指定的加密算法

KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);

// 取私钥匙对象

PrivateKey priKey = keyFactory.generatePrivate(pkcs8KeySpec);

// 用私钥对信息生成数字签名

Signature signature = Signature.getInstance(SIGNATURE_ALGORITHM);

signature.initSign(priKey);

signature.update(data);

return encryptBASE64(signature.sign());

}

/**

* 校验数字签名

*

* @param data

*            加密数据

* @param publicKey

*            公钥

* @param sign

*            数字签名

*

* @return 校验成功返回true 失败返回false

* @throws Exception

*

*/

public static boolean verify(byte[] data, String publicKey, String sign)

throws Exception {

// 解密由base64编码的公钥

byte[] keyBytes = decryptBASE64(publicKey);

// 构造X509EncodedKeySpec对象

X509EncodedKeySpec keySpec = new X509EncodedKeySpec(keyBytes);

// KEY_ALGORITHM 指定的加密算法

KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);

// 取公钥匙对象

PublicKey pubKey = keyFactory.generatePublic(keySpec);

Signature signature = Signature.getInstance(SIGNATURE_ALGORITHM);

signature.initVerify(pubKey);

signature.update(data);

// 验证签名是否正常

return signature.verify(decryptBASE64(sign));

}

/**

* 解密

* 用私钥解密

*

* @param data

* @param key

* @return

* @throws Exception

*/

public static byte[] decryptByPrivateKey(byte[] data, String key)

throws Exception {

// 对密钥解密

byte[] keyBytes = decryptBASE64(key);

// 取得私钥

PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes);

KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);

Key privateKey = keyFactory.generatePrivate(pkcs8KeySpec);

// 对数据解密

Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());

cipher.init(Cipher.DECRYPT_MODE, privateKey);

return cipher.doFinal(data);

}

/**

* 解密

* 用公钥解密

*

* @param data

* @param key

* @return

* @throws Exception

*/

public static byte[] decryptByPublicKey(byte[] data, String key)

throws Exception {

// 对密钥解密

byte[] keyBytes = decryptBASE64(key);

// 取得公钥

X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(keyBytes);

KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);

Key publicKey = keyFactory.generatePublic(x509KeySpec);

// 对数据解密

Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());

cipher.init(Cipher.DECRYPT_MODE, publicKey);

return cipher.doFinal(data);

}

/**

* 加密

* 用公钥加密

*

* @param data

* @param key

* @return

* @throws Exception

*/

public static byte[] encryptByPublicKey(byte[] data, String key)

throws Exception {

// 对公钥解密

byte[] keyBytes = decryptBASE64(key);

// 取得公钥

X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(keyBytes);

KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);

Key publicKey = keyFactory.generatePublic(x509KeySpec);

// 对数据加密

Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());

cipher.init(Cipher.ENCRYPT_MODE, publicKey);

return cipher.doFinal(data);

}

/**

* 加密

* 用私钥加密

*

* @param data

* @param key

* @return

* @throws Exception

*/

public static byte[] encryptByPrivateKey(byte[] data, String key)

throws Exception {

// 对密钥解密

byte[] keyBytes = decryptBASE64(key);

// 取得私钥

PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes);

KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);

Key privateKey = keyFactory.generatePrivate(pkcs8KeySpec);

// 对数据加密

Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());

cipher.init(Cipher.ENCRYPT_MODE, privateKey);

return cipher.doFinal(data);

}

/**

* 取得私钥

*

* @param keyMap

* @return

* @throws Exception

*/

public static String getPrivateKey(Map keyMap)

throws Exception {

Key key = (Key) keyMap.get(PRIVATE_KEY);

return encryptBASE64(key.getEncoded());

}

/**

* 取得公钥

*

* @param keyMap

* @return

* @throws Exception

*/

public static String getPublicKey(Map keyMap)

throws Exception {

Key key = (Key) keyMap.get(PUBLIC_KEY);

return encryptBASE64(key.getEncoded());

}

/**

* 初始化密钥

*

* @return

* @throws Exception

*/

public static Map initKey() throws Exception {

KeyPairGenerator keyPairGen = KeyPairGenerator

.getInstance(KEY_ALGORITHM);

keyPairGen.initialize(1024);

KeyPair keyPair = keyPairGen.generateKeyPair();

// 公钥

RSAPublicKey publicKey = (RSAPublicKey) keyPair.getPublic();

// 私钥

RSAPrivateKey privateKey = (RSAPrivateKey) keyPair.getPrivate();

Map keyMap = new HashMap(2);

keyMap.put(PUBLIC_KEY, publicKey);

keyMap.put(PRIVATE_KEY, privateKey);

return keyMap;

}

}