java签名证书

import java.io.FileInputStream;
import java.security.KeyStore;
import java.security.PrivateKey;
import java.security.PublicKey;
import java.security.Signature;
import java.security.cert.Certificate;
import java.security.cert.CertificateFactory;
import java.security.cert.X509Certificate;

import javax.crypto.Cipher;

public class CertificateCoder {

public static final String CERT_TYPE="X.509";

/**
* 获取私匙
* @param keyStorePath
* @param pwd
* @param alias
* @return PrivateKey 私匙
* @throws Exception
*/
private static PrivateKey getPrivateKey(String keyStorePath,String pwd,String alias) throws Exception{
KeyStore ks=getKeyStore(keyStorePath, pwd);
return (PrivateKey)ks.getKey(alias, pwd.toCharArray());

}

/**
*
* @param keyStorePath
* @param pwd
* @return keyStore 密匙库
* @throws Exception
*/
private static KeyStore getKeyStore(String keyStorePath,String pwd) throws Exception{
KeyStore ks=KeyStore.getInstance(KeyStore.getDefaultType());
FileInputStream in=new FileInputStream(keyStorePath);
ks.load(in,pwd.toCharArray());
in.close();
return ks;
}

/**
*
* @param certificatePath
* @return Certificate 证书
* @throws Exception
*/
private static Certificate getCertificate(String certificatePath) throws Exception{
CertificateFactory factory=CertificateFactory.getInstance(CERT_TYPE);
FileInputStream in=new FileInputStream(certificatePath);
Certificate certificate=factory.generateCertificate(in);
in.close();
return certificate;

}

/**
* 通过证书返回公匙
* @param certificatePath
* @return Publickey 返回公匙
* @throws Exception
*/
private static PublicKey getPublicKeyByCertificate(String certificatePath) throws Exception{
Certificate certificate=getCertificate(certificatePath);
return certificate.getPublicKey();
}

/**
*
* @param keyStorePath
* @param alias
* @param pwd
* @return Certificate 证书
* @throws Exception
*/
private static Certificate getCertificate(String keyStorePath,String alias,String pwd) throws Exception{
KeyStore ks=getKeyStore(keyStorePath, pwd);
//获取证书
return ks.getCertificate(alias);
}

/**
* 私匙加密
* @param data
* @param keyStorePath
* @param alias
* @param pwd
* @return byte[] 被私匙加密的数据
* @throws Exception
*/
public static byte[] encryptByPrivateKey(byte[] data,String keyStorePath,String alias,String pwd) throws Exception{
PrivateKey privateKey=getPrivateKey(keyStorePath, pwd, alias);
//对数据进行加密
Cipher cipher=Cipher.getInstance(privateKey.getAlgorithm());
cipher.init(Cipher.ENCRYPT_MODE, privateKey);
return cipher.doFinal(data);

}

/**
* 私匙解密
* @param data
* @param keyStorePath
* @param alias
* @param pwd
* @return byte[] 私匙解密的数据
* @throws Exception
*/
public static byte[] decryptByPrivateKey(byte[] data,String keyStorePath,String alias,String pwd) throws Exception{
PrivateKey privateKey=getPrivateKey(keyStorePath, pwd, alias);
Cipher cipher=Cipher.getInstance(privateKey.getAlgorithm());
cipher.init(cipher.DECRYPT_MODE, privateKey);
return cipher.doFinal(data);
}

/**
* 公匙加密
* @param data
* @param cerPath
* @return byte[] 被公匙加密的数据
* @throws Exception
*/
public static byte[] encryptByPublicKey(byte[] data,String cerPath) throws Exception{
//获取公匙
PublicKey publicKey=getPublicKeyByCertificate(cerPath);
System.out.println(publicKey.getAlgorithm());
Cipher cipher=Cipher.getInstance(publicKey.getAlgorithm());
cipher.init(Cipher.ENCRYPT_MODE, publicKey);
return cipher.doFinal(data);
}

/**
* 公匙解密
* @param data
* @param cerPath
* @return
* @throws Exception
*/
public static byte[] decryptByPublicKey(byte[] data,String cerPath) throws Exception{
PublicKey publicKey=getPublicKeyByCertificate(cerPath);
Cipher cipher=Cipher.getInstance(publicKey.getAlgorithm());
cipher.init(Cipher.DECRYPT_MODE, publicKey);
return cipher.doFinal(data);
}

/**
* 签名
* @param sign
* @param keyStorePath
* @param pwd
* @param alias
* @return
* @throws Exception
*/
public static byte[] sign(byte[] sign,String keyStorePath,String pwd,String alias) throws Exception{
//获取证书
X509Certificate x509=(X509Certificate)getCertificate(keyStorePath, alias, pwd);
//构建签名,由证书指定签名算法
Signature sa=Signature.getInstance(x509.getSigAlgName());
//获取私匙
PrivateKey privateKey=getPrivateKey(keyStorePath, pwd, alias);
sa.initSign(privateKey);
sa.update(sign);
return sa.sign();
}

/**
* 验证签名
* @param data
* @param sign
* @param cerPath
* @return
* @throws Exception
*/
public static boolean verify(byte[] data,byte[] sign,String cerPath) throws Exception{
X509Certificate x509=(X509Certificate)getCertificate(cerPath);
Signature sa=Signature.getInstance(x509.getSigAlgName());
sa.initVerify(x509);
sa.update(data);
return sa.verify(sign);
}
}