Java的安全学习(包括加密，数字签名，证书和认证) JCA JCE
packagedemo.jca.rsa;
importstaticorg.junit.Assert.*;
importorg.junit.Before;
importorg.junit.Test;
importdemo.jca.keystore.Coder;
importjava.security.Key;
importjava.security.KeyFactory;
importjava.security.KeyPair;
importjava.security.KeyPairGenerator;
importjava.security.PrivateKey;
importjava.security.PublicKey;
importjava.security.Signature;
importjava.security.interfaces.RSAPrivateKey;
importjava.security.interfaces.RSAPublicKey;
importjava.security.spec.PKCS8EncodedKeySpec;
importjava.security.spec.X509EncodedKeySpec;
importjava.util.HashMap;
importjava.util.Map;
importjavax.crypto.Cipher;
/**
*
*RSA这种算法1978年就出现了，它是第一个既能用于数据加密也能用于数字签名的算法。<br>
*RSA同时有两把钥匙，公钥与私钥。同时支持数字签名。<br>
*数字签名的意义在于，对传输过来的数据进行校验。确保数据在传输过程中不被修改。
*<ul>
*流程分析：
*<li>甲方构建密钥对儿，将公钥公布给乙方，将私钥保留。</li>
*<li>甲方使用私钥加密数据，然后用私钥对加密后的数据签名，发送给乙方签名以及加密后的数据；乙方使用公钥、签名来验证待解密数据是否有效，如果有效使用公钥对数据解密。</li>
*<li>乙方使用公钥加密数据，向甲方发送经过加密后的数据；甲方获得加密数据，通过私钥解密。</li>
*<ul>
*
*@authorXinZhang
*@version1.0
*@since1.0
*/
publicclassRSACoderTest{
privateStringpublicKey;
privateStringprivateKey;
@Before
publicvoidsetUp()throwsException{
Map<String,Object>keyMap=RSACoder.initKey();
publicKey=RSACoder.getPublicKey(keyMap);
privateKey=RSACoder.getPrivateKey(keyMap);
System.err.println("公钥:\n\r"+publicKey);
System.err.println("私钥：\n\r"+privateKey);
}
@Test
publicvoidtest()throwsException{
System.err.println("公钥加密——私钥解密");
StringinputStr="abc";
byte[]data=inputStr.getBytes();
byte[]encodedData=RSACoder.encryptByPublicKey(data,publicKey);
byte[]decodedData=RSACoder.decryptByPrivateKey(encodedData,privateKey);
StringoutputStr=newString(decodedData);
System.err.println("加密前:"+inputStr+"\n\r"+"解密后:"+outputStr);
assertEquals(inputStr,outputStr);
}
@Test
publicvoidtestSign()throwsException{
System.err.println("私钥加密——公钥解密");
StringinputStr="sign";
byte[]data=inputStr.getBytes();
byte[]encodedData=RSACoder.encryptByPrivateKey(data,privateKey);
byte[]decodedData=RSACoder.decryptByPublicKey(encodedData,publicKey);
StringoutputStr=newString(decodedData);
System.err.println("加密前:"+inputStr+"\n\r"+"解密后:"+outputStr);
assertEquals(inputStr,outputStr);
System.err.println("私钥签名——公钥验证签名");
//产生签名
Stringsign=RSACoder.sign(encodedData,privateKey);
System.err.println("签名:\r"+sign);
//验证签名
booleanstatus=RSACoder.verify(encodedData,publicKey,sign);
System.err.println("状态:\r"+status);
assertTrue(status);
}
}
abstractclassRSACoderextendsCoder{
publicstaticfinalStringKEY_ALGORITHM="RSA";
publicstaticfinalStringSIGNATURE_ALGORITHM="MD5withRSA";
privatestaticfinalStringPUBLIC_KEY="RSAPublicKey";
privatestaticfinalStringPRIVATE_KEY="RSAPrivateKey";
/**
*用私钥对信息生成数字签名
*
*@paramdata
*加密数据
*@paramprivateKey
*私钥
*
*@return
*@throwsException
*/
publicstaticStringsign(byte[]data,StringprivateKey)throwsException{
//解密由base64编码的私钥
byte[]keyBytes=decryptBASE64(privateKey);
//构造PKCS8EncodedKeySpec对象
PKCS8EncodedKeySpecpkcs8KeySpec=newPKCS8EncodedKeySpec(keyBytes);
//KEY_ALGORITHM指定的加密算法
KeyFactorykeyFactory=KeyFactory.getInstance(KEY_ALGORITHM);
//取私钥匙对象
PrivateKeypriKey=keyFactory.generatePrivate(pkcs8KeySpec);
//用私钥对信息生成数字签名
Signaturesignature=Signature.getInstance(SIGNATURE_ALGORITHM);
signature.initSign(priKey);
signature.update(data);
returnencryptBASE64(signature.sign());
}
/**
*校验数字签名
*
*@paramdata
*加密数据
*@parampublicKey
*公钥
*@paramsign
*数字签名
*
*@return校验成功返回true失败返回false
*@throwsException
*
*/
publicstaticbooleanverify(byte[]data,StringpublicKey,Stringsign)
throwsException{
//解密由base64编码的公钥
byte[]keyBytes=decryptBASE64(publicKey);
//构造X509EncodedKeySpec对象
X509EncodedKeySpeckeySpec=newX509EncodedKeySpec(keyBytes);
//KEY_ALGORITHM指定的加密算法
KeyFactorykeyFactory=KeyFactory.getInstance(KEY_ALGORITHM);
//取公钥匙对象
PublicKeypubKey=keyFactory.generatePublic(keySpec);
Signaturesignature=Signature.getInstance(SIGNATURE_ALGORITHM);
signature.initVerify(pubKey);
signature.update(data);
//验证签名是否正常
returnsignature.verify(decryptBASE64(sign));
}
/**
*解密<br>
*用私钥解密http://www.5a520.cnhttp://www.feng123.com
*
*@paramdata
*@paramkey
*@return
*@throwsException
*/
publicstaticbyte[]decryptByPrivateKey(byte[]data,Stringkey)
throwsException{
//对密钥解密
byte[]keyBytes=decryptBASE64(key);
//取得私钥
PKCS8EncodedKeySpecpkcs8KeySpec=newPKCS8EncodedKeySpec(keyBytes);
KeyFactorykeyFactory=KeyFactory.getInstance(KEY_ALGORITHM);
KeyprivateKey=keyFactory.generatePrivate(pkcs8KeySpec);
//对数据解密
Ciphercipher=Cipher.getInstance(keyFactory.getAlgorithm());
cipher.init(Cipher.DECRYPT_MODE,privateKey);
returncipher.doFinal(data);
}
/**
*解密<br>
*用私钥解密
*
*@paramdata
*@paramkey
*@return
*@throwsException
*/
publicstaticbyte[]decryptByPublicKey(byte[]data,Stringkey)
throwsException{
//对密钥解密
byte[]keyBytes=decryptBASE64(key);
//取得公钥
X509EncodedKeySpecx509KeySpec=newX509EncodedKeySpec(keyBytes);
KeyFactorykeyFactory=KeyFactory.getInstance(KEY_ALGORITHM);
KeypublicKey=keyFactory.generatePublic(x509KeySpec);
//对数据解密
Ciphercipher=Cipher.getInstance(keyFactory.getAlgorithm());
cipher.init(Cipher.DECRYPT_MODE,publicKey);
returncipher.doFinal(data);
}
/**
*加密<br>
*用公钥加密
*
*@paramdata
*@paramkey
*@return
*@throwsException
*/
publicstaticbyte[]encryptByPublicKey(byte[]data,Stringkey)
throwsException{
//对公钥解密
byte[]keyBytes=decryptBASE64(key);
//取得公钥
X509EncodedKeySpecx509KeySpec=newX509EncodedKeySpec(keyBytes);
KeyFactorykeyFactory=KeyFactory.getInstance(KEY_ALGORITHM);
KeypublicKey=keyFactory.generatePublic(x509KeySpec);
//对数据加密
Ciphercipher=Cipher.getInstance(keyFactory.getAlgorithm());
cipher.init(Cipher.ENCRYPT_MODE,publicKey);
returncipher.doFinal(data);
}
/**
*加密<br>
*用私钥加密
*
*@paramdata
*@paramkey
*@return
*@throwsException
*/
publicstaticbyte[]encryptByPrivateKey(byte[]data,Stringkey)
throwsException{
//对密钥解密
byte[]keyBytes=decryptBASE64(key);
//取得私钥
PKCS8EncodedKeySpecpkcs8KeySpec=newPKCS8EncodedKeySpec(keyBytes);
KeyFactorykeyFactory=KeyFactory.getInstance(KEY_ALGORITHM);
KeyprivateKey=keyFactory.generatePrivate(pkcs8KeySpec);
//对数据加密
Ciphercipher=Cipher.getInstance(keyFactory.getAlgorithm());
cipher.init(Cipher.ENCRYPT_MODE,privateKey);
returncipher.doFinal(data);
}
/**
*取得私钥
*
*@paramkeyMap
*@return
*@throwsException
*/
publicstaticStringgetPrivateKey(Map<String,Object>keyMap)
throwsException{
Keykey=(Key)keyMap.get(PRIVATE_KEY);
returnencryptBASE64(key.getEncoded());
}
/**
*取得公钥
*
*@paramkeyMap
*@return
*@throwsException
*/
publicstaticStringgetPublicKey(Map<String,Object>keyMap)
throwsException{
Keykey=(Key)keyMap.get(PUBLIC_KEY);
returnencryptBASE64(key.getEncoded());
}
/**
*初始化密钥
*
*@return
*@throwsException
*/
publicstaticMap<String,Object>initKey()throwsException{
KeyPairGeneratorkeyPairGen=KeyPairGenerator.getInstance(KEY_ALGORITHM);
keyPairGen.initialize(1024);
KeyPairkeyPair=keyPairGen.generateKeyPair();
//公钥
RSAPublicKeypublicKey=(RSAPublicKey)keyPair.getPublic();
//私钥
RSAPrivateKeyprivateKey=(RSAPrivateKey)keyPair.getPrivate();
Map<String,Object>keyMap=newHashMap<String,Object>(2);
keyMap.put(PUBLIC_KEY,publicKey);
keyMap.put(PRIVATE_KEY,privateKey);
returnkeyMap;
}
}