用Java编写的密码算法类
2024年03月07日
package data;import java.security.*;
import javax.crypto.*;
import javax.crypto.spec.*;
import java.io.*;
/**
*Security提供了一个安全算法类,其中包括对称密码算法和散列算法
*/
public final class Security
{
/**
*对称加密方法
* param byteSource需要加密的数据
* return经过加密的数据
* throws Exception
*/
public static byte[]symmetricEncrypto(byte[]byteSource)throws Exception
{
ByteArrayOutputStream baos=new ByteArrayOutputStream();
try
{
int mode=Cipher.ENCRYPT_MODE;
SecretKeyFactory keyFactory=SecretKeyFactory.getInstance("DES");
byte[]keyData={1,9,8,2,0,8,2,1};
DESKeySpec keySpec=new DESKeySpec(keyData);
Key key=keyFactory.generateSecret(keySpec);
Cipher cipher=Cipher.getInstance("DES");
cipher.init(mode,key);
int blockSize=cipher.getBlockSize();
int position=0;
int length=byteSource.length;
boolean more=true;
while(more)
{
if(position+blockSize<=length)
{
baos.write(cipher.update(byteSource,position,blockSize));
position+=blockSize;
}
else
{
more=false;
}
}
if(position<length)
{
baos.write(cipher.doFinal(byteSource,position,length-position));
}
else
{
baos.write(cipher.doFinal());
}
return baos.toByteArray();
}
catch(Exception e)
{
throw e;
}
finally
{
baos.close();
}
}
/**
*对称解密方法
* param byteSource需要解密的数据
* return经过解密的数据
* throws Exception
*/
public static byte[]symmetricDecrypto(byte[]byteSource)throws Exception
{
ByteArrayOutputStream baos=new ByteArrayOutputStream();
try
{
int mode=Cipher.DECRYPT_MODE;
SecretKeyFactory keyFactory=SecretKeyFactory.getInstance("DES");
byte[]keyData={1,9,8,2,0,8,2,1};
DESKeySpec keySpec=new DESKeySpec(keyData);
Key key=keyFactory.generateSecret(keySpec);
Cipher cipher=Cipher.getInstance("DES");
cipher.init(mode,key);
int blockSize=cipher.getBlockSize();
int position=0;
int length=byteSource.length;
boolean more=true;
while(more)
{
if(position+blockSize<=length)
{
baos.write(cipher.update(byteSource,position,blockSize));
position+=blockSize;
}
else
{
more=false;
}
}
if(position<length)
{
baos.write(cipher.doFinal(byteSource,position,length-position));
}
else
{
baos.write(cipher.doFinal());
}
return baos.toByteArray();
}
catch(Exception e)
{
throw e;
}
finally
{
baos.close();
}
}
/**
*散列算法
* param byteSource需要散列计算的数据
* return经过散列计算的数据
* throws Exception
*/
public static byte[]hashMethod(byte[]byteSource)throws Exception
{
try
{
MessageDigest currentAlgorithm=MessageDigest.getInstance("SHA-1");
currentAlgorithm.reset();
currentAlgorithm.update(byteSource);
return currentAlgorithm.digest();
}
catch(Exception e)
{
throw e;
}
}
}
