Question

   KeyGenerator kgen = KeyGenerator.getInstance("AES");
   kgen.init(128); // 192 and 256 bits may not be available

在eclipse中，当我选择KeyGenerator并右键单击打开声明时，我会打开一个窗口。

click here to see error image （图像链接已损坏）

你能解释一下这里有什么不对吗？顺便说一下这里是完整的代码

package org.temp2.cod1;

import java.security.*;
import javax.crypto.*;
import javax.crypto.spec.*;
import java.io.*;

/**
* This program generates a AES key, retrieves its raw bytes, and
* then reinstantiates a AES key from the key bytes.
* The reinstantiated key is used to initialize a AES cipher for
* encryption and decryption.
*/

public class AES1
{

    /**
    * Turns array of bytes into string
    *
    * @param buf    Array of bytes to convert to hex string
    * @return   Generated hex string
    */
    public static String asHex (byte buf[])
    {
        StringBuffer strbuf = new StringBuffer(buf.length * 2);
        int i;

        for (i = 0; i < buf.length; i++)
        {
            if (((int) buf[i] & 0xff) < 0x10)
                strbuf.append("0");

            strbuf.append(Long.toString((int) buf[i] & 0xff, 16));
        }

        return strbuf.toString();
    }

    public static void main(String[] args) throws Exception
    {

        String message="This is just an example";

        // Get the KeyGenerator

        KeyGenerator kgen = KeyGenerator.getInstance("AES");
        kgen.init(128); // 192 and 256 bits may not be available


        // Generate the secret key specs.
        SecretKey skey = kgen.generateKey();
        byte[] raw = skey.getEncoded();

        SecretKeySpec skeySpec = new SecretKeySpec(raw, "AES");


        // Instantiate the cipher

        Cipher cipher = Cipher.getInstance("AES");

        cipher.init(Cipher.ENCRYPT_MODE, skeySpec);

        byte[] encrypted =
        cipher.doFinal((args.length == 0 ?
        "This is just an example" : args[0]).getBytes());
        System.out.println("encrypted string: " + asHex(encrypted));

        cipher.init(Cipher.DECRYPT_MODE, skeySpec);
        byte[] original =
        cipher.doFinal(encrypted);
        String originalString = new String(original);
        System.out.println("Original string: " +
        originalString + " " + asHex(original));
    }
}

Answer 1

它只显示JDK未附带KeyGenerator类的源代码 - 可能会违反出口限制或类似内容。（我在Eclipse安装上也得到了相同的消息，尽管其他类显示源没有问题，所以我怀疑这不是配置问题。）

您真的需要查看KeyGenerator的来源吗？你想知道什么？

开放声明中的这个错误是什么？

1 个答案: