java对称解密问题

Question

 //encodedata BASE64编码后加密密文

    //key  BASE64编码后对称密钥对

    //algorithmName 加密算法

    public static String decodeforp1(String encodedata,String key,String algorithmName){

        try {

            SecretKeySpec k = new SecretKeySpec(Base64.decode(key.getBytes()),algorithmName);


            //解密


            Cipher cp = Cipher.getInstance(algorithmName);


            cp.init(Cipher.DECRYPT_MODE, k);


            byte[] ptext = cp.doFinal(Base64.decode(encodedata.getBytes()));   

        String s = new String(Base64.encode(ptext));
        return s;
    } catch (InvalidKeyException e) {           
        e.printStackTrace();
    } catch (NoSuchAlgorithmException e) {          
        e.printStackTrace();
    } catch (NoSuchPaddingException e) {            
        e.printStackTrace();
    } catch (IllegalBlockSizeException e) {         
        e.printStackTrace();
    } catch (BadPaddingException e) {           
        e.printStackTrace();
    }
    return null;
}</pre><br /><br />调用过程<br /><pre name="code" class="java">String key="HK6Jy6OrfB7ZkZg6WD/rQIZfNeFn+nrrXQCTfN7Cv3cAADoAAAAAAOPCv3cAAAAAAM35CFzU/wsIAAAAVNT/C8LWWgwUwXwDkMB8A+GrWgzEwXwDlFzAd3AgvncAAAAAZAYAAK8nVQwUwXwDZAAAAEAAAABn0/8LXNT/C9PAWgwUwXwDQAAAAATBfAMJTRN4SLuBCnzBfAMAAAAAEAAAAAAAAAAAAAAAAAAAAAAAAABEWnGJorzX8xAuTW1+kKO3zOL5ESpEX3uYttX1BhgrP1RqgZmyzOcDID5dfY6gs8fc8gkhOlRvi6jG5QUWKDtPO7f8CyC1YQxQvmEMAAAAAASCwBckn0F6gAAAAGjT/ws=";


String encodedata="MWY4OWQ5M2ZmMWFiNzk5N2VlOGViYzgwZGFlMDZhNTExYjBiNzk4Yd4j2eRQnsXNu5BWFsvJGXw=";

String algorithmName="DESede";

String date=encodeforp1(data, key, algorithmName);

        System.out.println(date);

但会报错

java.security.InvalidKeyException: Wrong key size
at com.sun.crypto.provider.SunJCE_y.a(DashoA13*..)
at com.sun.crypto.provider.SunJCE_g.a(DashoA13*..)
at com.sun.crypto.provider.SunJCE_f.a(DashoA13*..)
at com.sun.crypto.provider.SunJCE_f.a(DashoA13*..)
at com.sun.crypto.provider.DESedeCipher.engineInit(DashoA13*..)
at javax.crypto.Cipher.a(DashoA13*..)
at javax.crypto.Cipher.a(DashoA13*..)
at javax.crypto.Cipher.init(DashoA13*..)
at javax.crypto.Cipher.init(DashoA13*..)
at com.szca.authenti.util.CAUtil.encodeforp1(CAUtil.java:67)
at com.szca.authenti.util.Test.main(Test.java:61)
求解
问题补充
没人自己顶下
问题补充
已经找出原因了 JDK对DESede算法密钥对长度是112位和168位 而我的这个密钥对是192位的
问题补充
谢谢 fastbo
问题补充
而且KEY也有很大的问题,KEY是C产生的密钥对,它把整个对象都包装在一起再返回的,所以用它来封装密钥是有问题的
问题补充
进行两天的努力已经把问题得到解决,学到的东西还真不少

Answer 1

[quote]java.security.InvalidKeyException: Wrong key size[/quote]
这里不是很明显写着原因吗？错误的key大小。
我以前做过一个AES-128-CBC加密模式的加解密的东西，key需要为16位，程序里还做了判断。DES算法里的key位数估计也是有规定的。代码供你参考。
[code="java"] // 解密
public static String decrypt(String sSrc, String sKey) throws Exception {
try {
// 判断Key是否正确
if (sKey == null) {
System.out.print("Key为空null");
return null;
}
// 判断Key是否为16位
if (sKey.length() != 16) {
System.out.print("Key长度不是16位");
return null;
}
byte[] raw = sKey.getBytes("ASCII");
SecretKeySpec skeySpec = new SecretKeySpec(raw, "AES");
Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
IvParameterSpec iv = new IvParameterSpec("0102030405060708"
.getBytes());
cipher.init(Cipher.DECRYPT_MODE, skeySpec, iv);
byte[] encrypted1 = new BASE64Decoder().decodeBuffer(sSrc);// 先用base64解密
try {
byte[] original = cipher.doFinal(encrypted1);
String originalString = new String(original);
return originalString;
} catch (Exception e) {
System.out.println(e.toString());
return null;
}
} catch (Exception ex) {
System.out.println(ex.toString());
return null;
}
}[/code]