一掖鱼、概述
1.DSA是以RSA為基礎形成的
2.java6提供了DSA的實現(xiàn),但是java6只提供了SHA1withDSA的實現(xiàn)
3.bouncycastle擴展提供了其他的DSA實現(xiàn)方式
4.遵循“私鑰簽名改含,公鑰驗證”的原則
二、模型分析
這個和RSA一樣,只是換了一個算法而已
三禽翼、代碼分析
package com.ca.test;
import java.security.Key;
import java.security.KeyFactory;
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.PrivateKey;
import java.security.PublicKey;
import java.security.SecureRandom;
import java.security.Signature;
import java.security.interfaces.DSAPrivateKey;
import java.security.interfaces.DSAPublicKey;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;
import java.util.HashMap;
import java.util.Map;
import org.apache.commons.codec.binary.Base64;
/**
* 常用數(shù)字簽名算法DSA
* 數(shù)字簽名
* @author kongqz
* */
public class DSACoder {
//數(shù)字簽名,密鑰算法
public static final String KEY_ALGORITHM="DSA";
/**
* 數(shù)字簽名
* 簽名/驗證算法
* */
public static final String SIGNATURE_ALGORITHM="SHA1withDSA";
/**
* DSA密鑰長度族跛,RSA算法的默認密鑰長度是1024
* 密鑰長度必須是64的倍數(shù)闰挡,在512到1024位之間
* */
private static final int KEY_SIZE=1024;
//公鑰
private static final String PUBLIC_KEY="DSAPublicKey";
//私鑰
private static final String PRIVATE_KEY="DSAPrivateKey";
/**
* 初始化密鑰對
* @return Map 甲方密鑰的Map
* */
public static Map<String,Object> initKey() throws Exception{
//實例化密鑰生成器
KeyPairGenerator keyPairGenerator=KeyPairGenerator.getInstance(KEY_ALGORITHM);
//初始化密鑰生成器
keyPairGenerator.initialize(KEY_SIZE,new SecureRandom());
//生成密鑰對
KeyPair keyPair=keyPairGenerator.generateKeyPair();
//甲方公鑰
DSAPublicKey publicKey=(DSAPublicKey) keyPair.getPublic();
//甲方私鑰
DSAPrivateKey privateKey=(DSAPrivateKey) keyPair.getPrivate();
//將密鑰存儲在map中
Map<String,Object> keyMap=new HashMap<String,Object>();
keyMap.put(PUBLIC_KEY, publicKey);
keyMap.put(PRIVATE_KEY, privateKey);
return keyMap;
}
/**
* 簽名
* @param data待簽名數(shù)據(jù)
* @param privateKey 密鑰
* @return byte[] 數(shù)字簽名
* */
public static byte[] sign(byte[] data,byte[] privateKey) throws Exception{
//取得私鑰
PKCS8EncodedKeySpec pkcs8KeySpec=new PKCS8EncodedKeySpec(privateKey);
KeyFactory keyFactory=KeyFactory.getInstance(KEY_ALGORITHM);
//生成私鑰
PrivateKey priKey=keyFactory.generatePrivate(pkcs8KeySpec);
//實例化Signature
Signature signature = Signature.getInstance(SIGNATURE_ALGORITHM);
//初始化Signature
signature.initSign(priKey);
//更新
signature.update(data);
return signature.sign();
}
/**
* 校驗數(shù)字簽名
* @param data 待校驗數(shù)據(jù)
* @param publicKey 公鑰
* @param sign 數(shù)字簽名
* @return boolean 校驗成功返回true,失敗返回false
* */
public static boolean verify(byte[] data,byte[] publicKey,byte[] sign) throws Exception{
//轉換公鑰材料
//實例化密鑰工廠
KeyFactory keyFactory=KeyFactory.getInstance(KEY_ALGORITHM);
//初始化公鑰
//密鑰材料轉換
X509EncodedKeySpec x509KeySpec=new X509EncodedKeySpec(publicKey);
//產生公鑰
PublicKey pubKey=keyFactory.generatePublic(x509KeySpec);
//實例化Signature
Signature signature = Signature.getInstance(SIGNATURE_ALGORITHM);
//初始化Signature
signature.initVerify(pubKey);
//更新
signature.update(data);
//驗證
return signature.verify(sign);
}
/**
* 取得私鑰
* @param keyMap 密鑰map
* @return byte[] 私鑰
* */
public static byte[] getPrivateKey(Map<String,Object> keyMap){
Key key=(Key)keyMap.get(PRIVATE_KEY);
return key.getEncoded();
}
/**
* 取得公鑰
* @param keyMap 密鑰map
* @return byte[] 公鑰
* */
public static byte[] getPublicKey(Map<String,Object> keyMap) throws Exception{
Key key=(Key) keyMap.get(PUBLIC_KEY);
return key.getEncoded();
}
/**
* @param args
* @throws Exception
*/
public static void main(String[] args) throws Exception {
//初始化密鑰
//生成密鑰對
Map<String,Object> keyMap=DSACoder.initKey();
//公鑰
byte[] publicKey=DSACoder.getPublicKey(keyMap);
//私鑰
byte[] privateKey=DSACoder.getPrivateKey(keyMap);
System.out.println("公鑰:/n"+Base64.encodeBase64String(publicKey));
System.out.println("私鑰:/n"+Base64.encodeBase64String(privateKey));
System.out.println("================密鑰對構造完畢,甲方將公鑰公布給乙方礁哄,開始進行加密數(shù)據(jù)的傳輸=============");
String str="DSA數(shù)字簽名算法";
System.out.println("原文:"+str);
//甲方進行數(shù)據(jù)的加密
byte[] sign=DSACoder.sign(str.getBytes(), privateKey);
System.out.println("產生簽名:"+Base64.encodeBase64String(sign));
//驗證簽名
boolean status=DSACoder.verify(str.getBytes(), publicKey, sign);
System.out.println("狀態(tài):"+status+"/n/n");
}
}
控制臺輸出:
公鑰:
MIIBtzCCASwGByqGSM44BAEwggEfAoGBAP1/U4EddRIpUt9KnC7s5Of2EbdSPO9EAMMeP4C2USZp
RV1AIlH7WT2NWPq/xfW6MPbLm1Vs14E7gB00b/JmYLdrmVClpJ+f6AR7ECLCT7up1/63xhv4O1fn
xqimFQ8E+4P208UewwI1VBNaFpEy9nXzrith1yrv8iIDGZ3RSAHHAhUAl2BQjxUjC8yykrmCouuE
C/BYHPUCgYEA9+GghdabPd7LvKtcNrhXuXmUr7v6OuqC+VdMCz0HgmdRWVeOutRZT+ZxBxCBgLRJ
FnEj6EwoFhO3zwkyjMim4TwWeotUfI0o4KOuHiuzpnWRbqN/C/ohNWLx+2J6ASQ7zKTxvqhRkImo
g9/hWuWfBpKLZl6Ae1UlZAFMO/7PSSoDgYQAAoGAdLUOPbXqOQi4MFUm5tgBs2zQO20P7P1iPCC9
pslWvixp13NX9dTwdddkwqQtwKAfm/Ao2Gqe7VGq48kTIPr0wz01LKlCLbbw6VLikuFcgVNN+sVx
mwVTm54aFpiOaenS575Qtyek3zjVV+eMtRNKn91rMMWpsP6pucqku6xO5uY=
私鑰:
MIIBSwIBADCCASwGByqGSM44BAEwggEfAoGBAP1/U4EddRIpUt9KnC7s5Of2EbdSPO9EAMMeP4C2
USZpRV1AIlH7WT2NWPq/xfW6MPbLm1Vs14E7gB00b/JmYLdrmVClpJ+f6AR7ECLCT7up1/63xhv4
O1fnxqimFQ8E+4P208UewwI1VBNaFpEy9nXzrith1yrv8iIDGZ3RSAHHAhUAl2BQjxUjC8yykrmC
ouuEC/BYHPUCgYEA9+GghdabPd7LvKtcNrhXuXmUr7v6OuqC+VdMCz0HgmdRWVeOutRZT+ZxBxCB
gLRJFnEj6EwoFhO3zwkyjMim4TwWeotUfI0o4KOuHiuzpnWRbqN/C/ohNWLx+2J6ASQ7zKTxvqhR
kImog9/hWuWfBpKLZl6Ae1UlZAFMO/7PSSoEFgIUQhtJHLosUo0sxPKmCxC8NFVjD9c=
================密鑰對構造完畢,甲方將公鑰公布給乙方长酗,開始進行加密數(shù)據(jù)的傳輸=============
原文:DSA數(shù)字簽名算法
產生簽名:MCwCFAsJPC7xUfrvGYXtsxiWcS6GHAe1AhRnZLZ1CJe8I41vaScvJ7UZ8yk0oA==
狀態(tài):true
四、總結
1.DSA的公鑰長度略長于私鑰桐绒,這個和RSA有較大差別夺脾。可以通過兩個算法的控制臺輸出公鑰私鑰長度比對
2.DSA算法的簽名長度與密鑰長度無關茉继±秃玻可能和待簽名數(shù)據(jù)有聯(lián)系...