【前言】Java加解密系列，根据实际开发进度，不定期更新

【下载】在Oracle网站上搜索， Unlimited Strength Jurisdiction Policy Files这个关键字，然后按照所安装的JDK版本选择对应的授权文件，比如我的是JDK8，就选择了这个

【安装】

下载完这个zip包后，里面有两个jar包和一个readme.txt文件。

按照README.txt里的说明进行安装。注意区别开发环境用的JRE在JDK里面，运行环境的JRE是单独的环境。在我的Mac上，JRE是装在JDK里的，对应路径是/Library/Java/JavaVirtualMachines/jdk1.8.0_102.jdk/Contents/Home/jre

进入到授权文件安装的目录下

/Library/Java/JavaVirtualMachines/jdk1.8.0_102.jdk/Contents/Home/jre/lib/security能够查看到默认是有local_policy.jar 和  US_export_policy.jar的，改个名字保存一下。

然后复制压缩包里的文件到/Library/Java/JavaVirtualMachines/jdk1.8.0_102.jdk/Contents/Home/jre/lib/security目录下，这样就安装完成了。

【验证】

可以用下面的程序验证一下

public static void securityVerify() throws Exception {

byte[] data = { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07 };

// create a 64 bit secret key from raw bytes

SecretKey key64 = new SecretKeySpec(

new byte[] { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07 },

"Blowfish");

// create a cipher and attempt to encrypt the data block with our key

Cipher c = Cipher.getInstance("Blowfish/ECB/NoPadding");

c.init(Cipher.ENCRYPT_MODE, key64);

c.doFinal(data);

System.out.println("64 bit test: passed");

// create a 192 bit secret key from raw bytes

SecretKey key192 = new SecretKeySpec(

new byte[] { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,

0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,

0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17 },

"Blowfish");

// now try encrypting with the larger key

c.init(Cipher.ENCRYPT_MODE, key192);

c.doFinal(data);

System.out.println("192 bit test: passed");

System.out.println("Tests completed");

}

如果是默认配置，

返回类似

64 bit test: passed

Exception in thread "main" java.lang.SecurityException:

Unsupported keysize or algorithm parameters

at javax.crypto.Cipher.init(...)

at chapter1.SimplePolicyTest.main(SimplePolicyTest.java:38)

如果是替换后，返回

64 bit test: passed

192 bit test: passed

Tests completed