java中的AES 256算法遇到 Illegal key size or default parameters错的解决办法

报错堆栈如下：

<code class="prettyprint" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; font-family: Consolas, Menlo, Monaco, 'Lucida Console', 'Liberation Mono', 'DejaVu Sans Mono', 'Bitstream Vera Sans Mono', 'Courier New', monospace, serif;"><span class="typ" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; color: rgb(43, 145, 175); background-color: transparent;"><span class="typ">Caused</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; background-color: transparent;"><span class="pln"> by</span></span><span class="pun" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; background-color: transparent;"><span class="pun">:</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; background-color: transparent;"><span class="pln"> java</span></span><span class="pun" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; background-color: transparent;"><span class="pun">.</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; background-color: transparent;"><span class="pln">security</span></span><span class="pun" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; background-color: transparent;"><span class="pun">.</span></span><span class="typ" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; color: rgb(43, 145, 175); background-color: transparent;"><span class="typ">InvalidKeyException</span></span><span class="pun" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; background-color: transparent;"><span class="pun">:</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; background-color: transparent;"><span class="pln"> </span></span><span class="typ" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; color: rgb(43, 145, 175); background-color: transparent;"><span class="typ">Illegal</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; background-color: transparent;"><span class="pln"> key size or </span></span><span class="kwd" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; color: rgb(0, 0, 139); background-color: transparent;"><span class="kwd">default</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; background-color: transparent;"><span class="pln"> parameters
    at javax</span></span><span class="pun" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; background-color: transparent;"><span class="pun">.</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; background-color: transparent;"><span class="pln">crypto</span></span><span class="pun" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; background-color: transparent;"><span class="pun">.</span></span><span class="typ" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; color: rgb(43, 145, 175); background-color: transparent;"><span class="typ">Cipher</span></span><span class="pun" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; background-color: transparent;"><span class="pun">.</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; background-color: transparent;"><span class="pln">a</span></span><span class="pun" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; background-color: transparent;"><span class="pun">(</span></span><span class="typ" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; color: rgb(43, 145, 175); background-color: transparent;"><span class="typ">DashoA13</span></span><span class="pun" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; background-color: transparent;"><span class="pun">*..)</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; background-color: transparent;"><span class="pln"> </span></span><span class="pun" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; background-color: transparent;"><span class="pun">~[</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; background-color: transparent;"><span class="pln">na</span></span><span class="pun" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; background-color: transparent;"><span class="pun">:</span></span><span class="lit" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; color: rgb(128, 0, 0); background-color: transparent;"><span class="lit">1.6</span></span><span class="pun" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; background-color: transparent;"><span class="pun">]</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; background-color: transparent;"><span class="pln">
    at javax</span></span><span class="pun" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; background-color: transparent;"><span class="pun">.</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; background-color: transparent;"><span class="pln">crypto</span></span><span class="pun" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; background-color: transparent;"><span class="pun">.</span></span><span class="typ" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; color: rgb(43, 145, 175); background-color: transparent;"><span class="typ">Cipher</span></span><span class="pun" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; background-color: transparent;"><span class="pun">.</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; background-color: transparent;"><span class="pln">a</span></span><span class="pun" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; background-color: transparent;"><span class="pun">(</span></span><span class="typ" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; color: rgb(43, 145, 175); background-color: transparent;"><span class="typ">DashoA13</span></span><span class="pun" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; background-color: transparent;"><span class="pun">*..)</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; background-color: transparent;"><span class="pln"> </span></span><span class="pun" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; background-color: transparent;"><span class="pun">~[</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; background-color: transparent;"><span class="pln">na</span></span><span class="pun" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; background-color: transparent;"><span class="pun">:</span></span><span class="lit" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; color: rgb(128, 0, 0); background-color: transparent;"><span class="lit">1.6</span></span><span class="pun" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; background-color: transparent;"><span class="pun">]</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; background-color: transparent;"><span class="pln">
    at javax</span></span><span class="pun" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; background-color: transparent;"><span class="pun">.</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; background-color: transparent;"><span class="pln">crypto</span></span><span class="pun" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; background-color: transparent;"><span class="pun">.</span></span><span class="typ" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; color: rgb(43, 145, 175); background-color: transparent;"><span class="typ">Cipher</span></span><span class="pun" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; background-color: transparent;"><span class="pun">.</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; background-color: transparent;"><span class="pln">a</span></span><span class="pun" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; background-color: transparent;"><span class="pun">(</span></span><span class="typ" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; color: rgb(43, 145, 175); background-color: transparent;"><span class="typ">DashoA13</span></span><span class="pun" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; background-color: transparent;"><span class="pun">*..)</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; background-color: transparent;"><span class="pln"> </span></span><span class="pun" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; background-color: transparent;"><span class="pun">~[</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; background-color: transparent;"><span class="pln">na</span></span><span class="pun" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; background-color: transparent;"><span class="pun">:</span></span><span class="lit" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; color: rgb(128, 0, 0); background-color: transparent;"><span class="lit">1.6</span></span><span class="pun" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; background-color: transparent;"><span class="pun">]</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; background-color: transparent;"><span class="pln">
    at javax</span></span><span class="pun" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; background-color: transparent;"><span class="pun">.</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; background-color: transparent;"><span class="pln">crypto</span></span><span class="pun" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; background-color: transparent;"><span class="pun">.</span></span><span class="typ" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; color: rgb(43, 145, 175); background-color: transparent;"><span class="typ">Cipher</span></span><span class="pun" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; background-color: transparent;"><span class="pun">.</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; background-color: transparent;"><span class="pln">init</span></span><span class="pun" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; background-color: transparent;"><span class="pun">(</span></span><span class="typ" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; color: rgb(43, 145, 175); background-color: transparent;"><span class="typ">DashoA13</span></span><span class="pun" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; background-color: transparent;"><span class="pun">*..)</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; background-color: transparent;"><span class="pln"> </span></span><span class="pun" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; background-color: transparent;"><span class="pun">~[</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; background-color: transparent;"><span class="pln">na</span></span><span class="pun" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; background-color: transparent;"><span class="pun">:</span></span><span class="lit" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; color: rgb(128, 0, 0); background-color: transparent;"><span class="lit">1.6</span></span><span class="pun" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; background-color: transparent;"><span class="pun">]</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; background-color: transparent;"><span class="pln">
    at javax</span></span><span class="pun" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; background-color: transparent;"><span class="pun">.</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; background-color: transparent;"><span class="pln">crypto</span></span><span class="pun" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; background-color: transparent;"><span class="pun">.</span></span><span class="typ" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; color: rgb(43, 145, 175); background-color: transparent;"><span class="typ">Cipher</span></span><span class="pun" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; background-color: transparent;"><span class="pun">.</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; background-color: transparent;"><span class="pln">init</span></span><span class="pun" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; background-color: transparent;"><span class="pun">(</span></span><span class="typ" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; color: rgb(43, 145, 175); background-color: transparent;"><span class="typ">DashoA13</span></span><span class="pun" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; background-color: transparent;"><span class="pun">*..)</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; background-color: transparent;"><span class="pln"> </span></span><span class="pun" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; background-color: transparent;"><span class="pun">~[</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; background-color: transparent;"><span class="pln">na</span></span><span class="pun" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; background-color: transparent;"><span class="pun">:</span></span><span class="lit" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; color: rgb(128, 0, 0); background-color: transparent;"><span class="lit">1.6</span></span><span class="pun" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; background-color: transparent;"><span class="pun">]</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; background-color: transparent;"><span class="pln">
    at my</span></span><span class="pun" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; background-color: transparent;"><span class="pun">.</span></span><span class="kwd" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; color: rgb(0, 0, 139); background-color: transparent;"><span class="kwd">package</span></span><span class="pun" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; background-color: transparent;"><span class="pun">.</span></span><span class="typ" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; color: rgb(43, 145, 175); background-color: transparent;"><span class="typ">Something</span></span><span class="pun" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; background-color: transparent;"><span class="pun">.</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; background-color: transparent;"><span class="pln">decode</span></span><span class="pun" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; background-color: transparent;"><span class="pun">(</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; background-color: transparent;"><span class="pln">RC4Decoder</span></span><span class="pun" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; background-color: transparent;"><span class="pun">.</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; background-color: transparent;"><span class="pln">java</span></span><span class="pun" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; background-color: transparent;"><span class="pun">:</span></span><span class="lit" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; color: rgb(128, 0, 0); background-color: transparent;"><span class="lit">25</span></span><span class="pun" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; background-color: transparent;"><span class="pun">)</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; background-color: transparent;"><span class="pln"> </span></span><span class="pun" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; background-color: transparent;"><span class="pun">~[</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; background-color: transparent;"><span class="pln">my</span></span><span class="pun" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; background-color: transparent;"><span class="pun">.</span></span><span class="kwd" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; color: rgb(0, 0, 139); background-color: transparent;"><span class="kwd">package</span></span><span class="pun" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; background-color: transparent;"><span class="pun">.</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; background-color: transparent;"><span class="pln">jar</span></span><span class="pun" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; background-color: transparent;"><span class="pun">:</span></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; background-color: transparent;"><span class="pln">na</span></span><span class="pun" style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; background-color: transparent;"><span class="pun">]</span></span></code>

Google到问题原因，链接地址如下：

http://stackoverflow.com/questions/6481627/java-security-illegal-key-size-or-default-parameters

根据回答找到下载新jar包(JDK6)链接地址如下：

http://www.oracle.com/technetwork/java/javase/downloads/jce-6-download-429243.html

JDK7 的地址如下：

http://www.oracle.com/technetwork/java/javase/downloads/jce-7-download-432124.html

把里面的两个jar包：local_policy.jar 和 US_export_policy.jar 替换掉原来安装目录C:\Program Files\Java\jre6\lib\security 下的两个jar包接可以了

然后就重新运行程序，不会报错了，测试代码如下：

[java]  view plain copy

1. public class Test {  
2.     public static void main(String[] args) throws Exception {  
3.          KeyGenerator keyGen = KeyGenerator.getInstance("AES");  
4.          keyGen.init(256);  
5.          SecretKey key = keyGen.generateKey();  
6.          ObjectOutputStream oop = new ObjectOutputStream(new  
7.          FileOutputStream("c:\\key.dat"));  
8.          oop.writeObject(key);  
9.          oop.close();  
10.           
11.         String strTest = "Hello, Jason";  
12.         byte[] strAfterAES = encryptData(strTest.getBytes());  
13.         System.out.println(new String(strAfterAES));  
14.         byte[] strOriContent = decryptData(strAfterAES);  
15.         System.out.println(new String(strOriContent));  
16.     }  
17.   
18.   
19.     public static byte[] encryptData(byte[] input) throws Exception {  
20.         ObjectInputStream in = new ObjectInputStream(new FileInputStream("c:\\key.dat"));  
21.         SecretKey aeskey = (SecretKey) in.readObject();  
22.         Cipher c1 = Cipher.getInstance("AES");  
23.         c1.init(Cipher.ENCRYPT_MODE, aeskey);  
24.         byte[] cipherByte = c1.doFinal(input);  
25.         return cipherByte;  
26.     }  
27.   
28.   
29.     public static byte[] decryptData(byte[] input) throws Exception {  
30.         ObjectInputStream in = new ObjectInputStream(new FileInputStream("c:\\key.dat"));  
31.         SecretKey aeskey = (SecretKey) in.readObject();  
32.         Cipher c1 = Cipher.getInstance("AES");  
33.         c1.init(Cipher.DECRYPT_MODE, aeskey);  
34.         byte[] clearByte = c1.doFinal(input);  
35.         return clearByte;  
36.     }  
37. }  

BTW:

 If ur JVM is IBM JVM pls refer to the below link to update the unlimited key size jars

http://pic.dhe.ibm.com/infocenter/wasinfo/v7r0/index.jsp?topic=%2Fcom.ibm.websphere.nd.multiplatform.doc%2Finfo%2Fae%2Fae%2Ftwbs_tunev6wss.html