SHA 安全雜湊演算法

雜湊演算法:雜湊是資訊的提煉，通常其長度要比資訊小很多，且為一個固定長度，加密性強的雜湊一定是不可逆的，這就意味著通過雜湊結果，無法推出任何部分的原始資訊，任何輸入資訊的變化，哪怕是一位，都將導致雜湊結果的明顯變化，雜湊還是防衝突的，即找不出具有相同雜湊結果的兩條資訊.具有這些特性的雜湊結果都可以用於資訊驗證是否被修改

     MD5:RSA資料安全公司開發的一種單項雜湊演算法（單項雜湊函式一般使用者與產生資訊摘要，金鑰加密等）

    SHA:可以對任意長度的資料運算生存160位的數值

    SHA1:基於MD4演算法,最安全的雜湊演算法之一

SHA1與MD5的區別:

1:對強行攻擊的安全性:SAH1摘要要比MD5摘要長32位，SHA1更加安全

2:速度上：SHA1的執行速度比MD5慢

除了圖上面的方式，依舊還有commons codec

關於commons codec的jar: commons-codec-1.10.jar  下載地址 參考

關於bouncy castle的jar: bcprov-ext-jdk15on-154.jar 下載地址 參考

jdk 方式SHA1

package com.example.encryption;

import org.apache.commons.codec.binary.Hex;

import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

/**
 * @author xuanyouwu
 * @email 
 
[email protected]
 * @time 2016-05-14 15:27
 */
public class ShaTest {

    private static String SrcData = "xuanyouwu";

    public static void log(String s) {
        System.out.println("------>" + s);
    }

    public static void main(String[] args) throws Exception {
        log("jdk sha1:"+jdkSHA1(SrcData));
    }

    private static String jdkSHA1(String src) {
        try {
            MessageDigest messageDigest = MessageDigest.getInstance("SHA");
            return Hex.encodeHexString(messageDigest.digest(src.getBytes()));
        } catch (NoSuchAlgorithmException e) {
            e.printStackTrace();
        }
        return "";
    }
}
 

------>jdk sha1:2a5c6fa5eebeef480dfc9cd911f679a4e86bc97c

commons codec方式生成sha1

package com.example.encryption;

import org.apache.commons.codec.binary.Hex;
import org.apache.commons.codec.digest.DigestUtils;

import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

/**
 * @author xuanyouwu
 * @email [email protected]
 * @time 2016-05-14 15:27
 */
public class ShaTest {

    private static String SrcData = "xuanyouwu";

    public static void log(String s) {
        System.out.println("------>" + s);
    }

    public static void main(String[] args) throws Exception {
        log("cc sha1:" + ccSHA1(SrcData));
    }

    private static String ccSHA1(String src) {
        MessageDigest sha1Digest = DigestUtils.getSha1Digest();
        byte[] digest = sha1Digest.digest(src.getBytes());
        return Hex.encodeHexString(digest);
    }
}

------>cc sha1:2a5c6fa5eebeef480dfc9cd911f679a4e86bc97c

同樣commons codec 還提供簡單的方式,使用DigestUtils

  public static String sha1Hex(String src) {
        return DigestUtils.sha1Hex(src.getBytes());
    }

bouncy castle方式生存SHA1

package com.example.encryption;

import org.apache.commons.codec.binary.Hex;
import org.apache.commons.codec.digest.DigestUtils;
import org.bouncycastle.crypto.digests.SHA1Digest;

import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

/**
 * @author xuanyouwu
 * @email [email protected]
 * @time 2016-05-14 15:27
 */
public class ShaTest {

   
    private static String SrcData = "xuanyouwu";

    public static void log(String s) {
        System.out.println("------>" + s);
    }

    public static void main(String[] args) throws Exception {
        log("bc sha1:" + bcSHA1(SrcData));
    }

    private static String bcSHA1(String src)
    {
        SHA1Digest sha1Digest=new SHA1Digest();
        sha1Digest.update(src.getBytes(),0,src.getBytes().length);
        byte[] bytes=new byte[sha1Digest.getDigestSize()];
        sha1Digest.doFinal(bytes, 0);
        return org.bouncycastle.util.encoders.Hex.toHexString(bytes);
    }
}

------>bc sha1:2a5c6fa5eebeef480dfc9cd911f679a4e86bc97c

bouncy castle對SHA1的擴充套件

在其jar包中 org.bouncycastle.digests包下面

分別有SHA1Digest   SHA3Digest,SHA224Digest,SHA256Digest,SHA384Digest,SHA512Digest....很多實現,不一一演示,用法基本一致，只是摘要長度不一致，拿SHA224做演示：

package com.example.encryption;

import org.apache.commons.codec.binary.Hex;
import org.apache.commons.codec.digest.DigestUtils;
import org.bouncycastle.crypto.digests.SHA1Digest;
import org.bouncycastle.crypto.digests.SHA224Digest;

import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

/**
 * @author xuanyouwu
 * @email [email protected]
 * @time 2016-05-14 15:27
 */
public class ShaTest {

    private static String SrcData = "xuanyouwu";

    public static void log(String s) {
        System.out.println("------>" + s);
    }

    public static void main(String[] args) throws Exception {
        log("bc sha1:" + bcSHA1(SrcData));
        log("bc sha224:" + bcSHA224(SrcData));
    }

    private static String bcSHA1(String src) {
        SHA1Digest sha1Digest = new SHA1Digest();
        sha1Digest.update(src.getBytes(), 0, src.getBytes().length);
        byte[] bytes = new byte[sha1Digest.getDigestSize()];
        sha1Digest.doFinal(bytes, 0);
        return org.bouncycastle.util.encoders.Hex.toHexString(bytes);
    }

    private static String bcSHA224(String src) {
        SHA224Digest sha224 = new SHA224Digest();
        sha224.update(src.getBytes(), 0, src.getBytes().length);
        byte[] bytes = new byte[sha224.getDigestSize()];
        sha224.doFinal(bytes, 0);
        return org.bouncycastle.util.encoders.Hex.toHexString(bytes);
    }
}

------>bc sha1:2a5c6fa5eebeef480dfc9cd911f679a4e86bc97c
------>bc sha224:2123aac1b225dd0379191e0495e7a0ebae85a464bfaebdfb47720789

可以看到SHA224比SHA1的摘要長很多

JDK 擴充套件SHA224 

由於jdk本身並未提供SHA224的實現，但是提供擴充套件,而bouncy castle就很好結合起來

package com.example.encryption;

import org.apache.commons.codec.binary.Hex;
import org.apache.commons.codec.digest.DigestUtils;
import org.bouncycastle.crypto.digests.SHA1Digest;
import org.bouncycastle.crypto.digests.SHA224Digest;
import org.bouncycastle.jce.provider.BouncyCastleProvider;

import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.security.Security;

/**
 * @author xuanyouwu
 * @email [email protected]
 * @time 2016-05-14 15:27
 */
public class ShaTest {

    private static String SrcData = "xuanyouwu";

    public static void log(String s) {
        System.out.println("------>" + s);
    }

    public static void main(String[] args) throws Exception {
        log("jdk sha224:" + jdkSHA224(SrcData));
        log("jdk bc sha224:" + jdkSHA224WithBc(SrcData));
    }


    /**
     * 將發生異常
     *  java.security.NoSuchAlgorithmException: SHA224 MessageDigest not available
     * @param src
     * @return
     */
    public static String jdkSHA224(String src) {
        try {
            MessageDigest md = MessageDigest.getInstance("SHA224");
            md.update(src.getBytes());
            return Hex.encodeHexString(md.digest());
        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }

    // 擴充套件jdk 實現SHA224
    public static String jdkSHA224WithBc(String src) {
        try {
            Security.addProvider(new BouncyCastleProvider());
            MessageDigest md = MessageDigest.getInstance("SHA224");
            md.update(src.getBytes());
            return Hex.encodeHexString(md.digest());
        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }
}

java.security.NoSuchAlgorithmException: SHA224 MessageDigest not available
at sun.security.jca.GetInstance.getInstance(GetInstance.java:159)
at java.security.Security.getImpl(Security.java:695)
at java.security.MessageDigest.getInstance(MessageDigest.java:167)
at com.example.encryption.ShaTest.jdkSHA224(ShaTest.java:74)
at com.example.encryption.ShaTest.main(ShaTest.java:36)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:497)
at com.intellij.rt.execution.application.AppMain.main(AppMain.java:144)
------>jdk bc sha224:2123aac1b225dd0379191e0495e7a0ebae85a464bfaebdfb47720789