aes.lua貌似有些不对劲

[netyum]

你好，春哥
查看源码，感觉好像password(salt)没有起做用，使用的是key做为password了，那么，只有在lua下加密，lua下解密了，和其他语言无法交换数据！
代码片段

local aes = require "resty.aes"
local str = require "resty.string"
local hash = {
        iv = "fedcba9876543210",
        method = nil
}
local salt = "0123456789abcdef"
local data = "hello"
local aes_128_cbc, err = aes:new("AKeyForAES128CBC", salt, aes.cipher(128,"cbc"), hash)
if err  then
        ngx.say(err)
        ngx.exit(200)
end
local encrypted = aes_128_cbc:encrypt(data)
ngx.say("AES 128 CBC Encrypted HEX: ", str.to_hex(encrypted) .. "<br />")
ngx.say("AES 128 CBC Decrypted: ", aes_128_cbc:decrypt(encrypted))

屏幕回显是

AES 128 CBC Encrypted HEX: 5dff16410bf805de1d14d96fbffcab7c
AES 128 CBC Decrypted: hello

这里我使用了AKeyForAES128CBC 做为key，但这个更好的写法应该是aes-128-cbc，或者说这个key跟本也没有什么用吧，因为后面的cipher才确定了使用什么算法，因为我要自定义向量iv，查看源码结构，构造了一个hash table，确定初始化向量，这样问题就来了，这个key你源代码里写的一个检查长度，以上面为例，则必须是长度16,

好的，也这可以，但是在下面生成gen_key的时候，你使用的就是这个key，而不是salt,
当我将源码中的#key改成#salt,key改成slat后，得到的结束是正确的，另一种不指定hash或指定一个hash在aes中的hash table中的一个算法时，不知道有没有问题，可能也有问题，因为貌似也使用到了key

我不清楚这个key与salt的区别，不知道你的初衷是key只做为一个描述存在的吗？如果参与计算，貌似比较麻烦。
下面是php的代码片段

<?php
$iv = 'fedcba9876543210';
$salt = '0123456789abcdef';
$data = 'hello';
echo bin2hex(openssl_encrypt($data, "aes-128-cbc", $salt, true, $iv));

屏幕回显是

7bedceb0655f38941069789f36462091

[chase]

<?php
$iv = 'fedcba9876543210';
$salt = '0123456789abcdef';
$key = 'AKeyForAES128CBC';
$data = 'hello';
echo bin2hex(openssl_encrypt($data, "aes-128-cbc", $key.$salt, true, $iv));

Outputs:
5dff16410bf805de1d14d96fbffcab7c

The string AKeyForAES128CBC is just an example for a key. The call to aes.cipher(128,"cbc") is what changes the encryption method.

PHP's OpenSSL bindings are very poor and don't support salting directly. Under the openssl_decrypt function, a user on the PHP website contributed an example that uses the OpenSSL default for salting encryption keys.

[turbidsoul]

我在java下使用bouncycastle扩展的算法

public static byte[] encrypt(String content, String pw) throws Exception {
    KeyGenerator keyGen = KeyGenerator.getInstance("AES");
    keyGen.init(128, new SecureRandom(pw.getBytes()));
    SecretKey secretKey = keyGen.generateKey();
    byte[] encodes = secretKey.getEncoded();
        SecretKeySpec key = new SecretKeySpec(encodes, "AES");
        Cipher cipher = Cipher.getInstance("PBEWITHMD5AND128BITAES-CBC-OPENSSL", "BC");
        byte[] byteContent = content.getBytes("utf-8");
        IvParameterSpec iv = new IvParameterSpec("1234567890123456".getBytes());
        cipher.init(Cipher.ENCRYPT_MODE, key, iv);  
        return cipher.doFinal(byteContent);
}

public static void main(String[] args) throws Exception {
    Security.addProvider(new BouncyCastleProvider());
    String content = "Secret message!";
    String pw = "AKeyForAES128CBC";
    byte[] result = encrypt(content, pw);
    String encryptstr = Base16.encode(result);
    System.out.println("加密后：" + encryptstr
}

输入的结果是：9513B1ED980B875E895E439220A10A96

但是在resty.aes:

local aes = require "resty.aes"
local str = require "resty.string"
local hash = {
    iv = "1234567890123456",
    method = nil
}        
local salt = "1234567890abcdef"
local aes_128_cbc_md5, err = aes:new("AKeyForAES128CBC", nil, nil, hash)
    -- the default cipher is AES 128 CBC with 1 round of MD5
    -- for the key and a nil salt
if err then  
        ngx.say(err)
        ngx.exit(200)
end 
local encrypted = aes_128_cbc_md5:encrypt("Secret message!")
ngx.say("AES 128 CBC (MD5) Encrypted HEX: ", str.to_hex(encrypted))
ngx.say("AES 128 CBC (MD5) Decrypted: ", aes_128_cbc_md5:decrypt(encrypted))
ngx.say("hello end")

执行的结果：AES 128 CBC (MD5) Encrypted HEX: 110cd2591c318024e32acb2964cfc2cd

我不知道在resty.aes和java如何对接的，希望能给予指导。Thinks！

[cabbage89]

我也不知道这个aes-128-cbc在java和c#如何写，我在网上很多地址测试过结果都与 aes.lua的结果不一样

[agentzh]

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[Vortexxxx]

Cryptography is too difficult to understand.

I leave behind an example of Go language and I hope to help later people.

package main

import (
	"bytes"
	"crypto/aes"
	"crypto/cipher"
	"fmt"
)

func PKCS7Padding(ciphertext []byte, blockSize int) []byte {
	padding := blockSize - len(ciphertext)%blockSize
	padtext := bytes.Repeat([]byte{byte(padding)}, padding)
	return append(ciphertext, padtext...)
}

func main() {
	src := []byte("hello")
	key := []byte("AKeyForAES128CBC")
	iv := []byte("fedcba9876543210")

	block, err := aes.NewCipher(key)
	if err != nil {
		fmt.Println("key error1", err)
	}
	if len(src) == 0 {
		fmt.Println("plain src empty")
	}
	ecb := cipher.NewCBCEncrypter(block, iv)
	src = PKCS7Padding(src, block.BlockSize())
	crypted := make([]byte, len(src))
	ecb.CryptBlocks(crypted, src)
	fmt.Printf("%x\n", crypted)
}

output: 5dff16410bf805de1d14d96fbffcab7c