golang中的aes加密

今天要和第三方的接口做对接，对方给了一组密钥的算法：

str = 406BF0AD11310101220213481000320000
key := ER2Fb6ts3ECX
通过 AES 加密(加解密算法 AES/工作模式 ECB /填充方式 NoPadding)并根据 base64
转码后字符串位:
rebZn7aj61hD3lfsUrhwFgVzPg4yYo9aseP/a4sNTRIh/Vtb0mziFfoHdOZBZ5uj

通过询问得知对方是java语言，所以嘛，貌似ecb nopadding这种方式在golang的标准库中是没有的，只有自力更生了，google一番，再加上大神的指点:

首先要说给你提供这个算法的人压根就不懂密码学。
因为 AES 的要求密钥的字节长度是 64 的倍数，可以是 128、192、256 等等（64 位因为不够安全已经被废弃），当成 ASCII 字符串的话长度就是 16 的倍数。随便给个字符串那不叫密钥，天知道对方用的编程语言或加密库是怎么处理这种不合法的密钥的 —— 是前补 0 了、是前补空了、是后补 0 了、是后补空了、还是怎么着？
而因为密钥的字节长度不确定，所以加密时的一个重要参数 BlockSize 也就不确定了。
得，靠猜吧。当成后补空吧。

得出下面的答案：

package main
import (

"crypto/aes"

"encoding/base64"

"log"

)
func main() {

origin := []byte("406BF0AD11310101220213481000320000")

key := []byte("ER2Fb6ts3ECX")
<span class="highlight-nx">encrypted</span> <span class="highlight-o">:=</span> <span class="highlight-nf">AesEncryptECB</span><span class="highlight-p">(</span><span class="highlight-nx">origin</span><span class="highlight-p">,</span> <span class="highlight-nx">key</span><span class="highlight-p">)</span>
<span class="highlight-nx">log</span><span class="highlight-p">.</span><span class="highlight-nf">Println</span><span class="highlight-p">(</span><span class="highlight-s">&#34;encrypted: &#34;</span><span class="highlight-p">,</span> <span class="highlight-nx">encrypted</span><span class="highlight-p">)</span>
<span class="highlight-nx">decrypted</span> <span class="highlight-o">:=</span> <span class="highlight-nf">AesDecryptECB</span><span class="highlight-p">(</span><span class="highlight-nx">encrypted</span><span class="highlight-p">,</span> <span class="highlight-nx">key</span><span class="highlight-p">)</span>
<span class="highlight-nx">log</span><span class="highlight-p">.</span><span class="highlight-nf">Println</span><span class="highlight-p">(</span><span class="highlight-s">&#34;decrypted: &#34;</span><span class="highlight-p">,</span> <span class="highlight-nb">string</span><span class="highlight-p">(</span><span class="highlight-nx">decrypted</span><span class="highlight-p">))</span>

}
func AesEncryptECB(origData []byte, key []byte) string {

cipher, _ := aes.NewCipher(generateKey(key))

length := (len(origData) + aes.BlockSize) / aes.BlockSize

plain := make([]byte, length*aes.BlockSize)

copy(plain, origData)
<span class="highlight-nx">encrypted</span> <span class="highlight-o">:=</span> <span class="highlight-nb">make</span><span class="highlight-p">([]</span><span class="highlight-kt">byte</span><span class="highlight-p">,</span> <span class="highlight-nb">len</span><span class="highlight-p">(</span><span class="highlight-nx">plain</span><span class="highlight-p">))</span>
<span class="highlight-c1">// Block encryption

	for bs, be := 0, cipher.BlockSize(); bs <= len(origData); bs, be = bs+cipher.BlockSize(), be+cipher.BlockSize() {

cipher.Encrypt(encrypted[bs:be], plain[bs:be])

}
<span class="highlight-k">return</span> <span class="highlight-nx">base64</span><span class="highlight-p">.</span><span class="highlight-nx">StdEncoding</span><span class="highlight-p">.</span><span class="highlight-nf">EncodeToString</span><span class="highlight-p">(</span><span class="highlight-nx">encrypted</span><span class="highlight-p">)</span>

}
func AesDecryptECB(str string, key []byte) (decrypted []byte) {

encrypted, _ := base64.StdEncoding.DecodeString(str)
<span class="highlight-nx">cipher</span><span class="highlight-p">,</span> <span class="highlight-nx">_</span> <span class="highlight-o">:=</span> <span class="highlight-nx">aes</span><span class="highlight-p">.</span><span class="highlight-nf">NewCipher</span><span class="highlight-p">(</span><span class="highlight-nf">generateKey</span><span class="highlight-p">(</span><span class="highlight-nx">key</span><span class="highlight-p">))</span>
<span class="highlight-nx">decrypted</span> <span class="highlight-p">=</span> <span class="highlight-nb">make</span><span class="highlight-p">([]</span><span class="highlight-kt">byte</span><span class="highlight-p">,</span> <span class="highlight-nb">len</span><span class="highlight-p">(</span><span class="highlight-nx">encrypted</span><span class="highlight-p">))</span>
<span class="highlight-k">for</span> <span class="highlight-nx">bs</span><span class="highlight-p">,</span> <span class="highlight-nx">be</span> <span class="highlight-o">:=</span> <span class="highlight-mi">0</span><span class="highlight-p">,</span> <span class="highlight-nx">cipher</span><span class="highlight-p">.</span><span class="highlight-nf">BlockSize</span><span class="highlight-p">();</span> <span class="highlight-nx">bs</span> <span class="highlight-p">&lt;</span> <span class="highlight-nb">len</span><span class="highlight-p">(</span><span class="highlight-nx">encrypted</span><span class="highlight-p">);</span> <span class="highlight-nx">bs</span><span class="highlight-p">,</span> <span class="highlight-nx">be</span> <span class="highlight-p">=</span> <span class="highlight-nx">bs</span><span class="highlight-o">+</span><span class="highlight-nx">cipher</span><span class="highlight-p">.</span><span class="highlight-nf">BlockSize</span><span class="highlight-p">(),</span> <span class="highlight-nx">be</span><span class="highlight-o">+</span><span class="highlight-nx">cipher</span><span class="highlight-p">.</span><span class="highlight-nf">BlockSize</span><span class="highlight-p">()</span> <span class="highlight-p">{</span>
	<span class="highlight-nx">cipher</span><span class="highlight-p">.</span><span class="highlight-nf">Decrypt</span><span class="highlight-p">(</span><span class="highlight-nx">decrypted</span><span class="highlight-p">[</span><span class="highlight-nx">bs</span><span class="highlight-p">:</span><span class="highlight-nx">be</span><span class="highlight-p">],</span> <span class="highlight-nx">encrypted</span><span class="highlight-p">[</span><span class="highlight-nx">bs</span><span class="highlight-p">:</span><span class="highlight-nx">be</span><span class="highlight-p">])</span>
<span class="highlight-p">}</span>

<span class="highlight-nx">trim</span> <span class="highlight-o">:=</span> <span class="highlight-mi">0</span>
<span class="highlight-k">if</span> <span class="highlight-nb">len</span><span class="highlight-p">(</span><span class="highlight-nx">decrypted</span><span class="highlight-p">)</span> <span class="highlight-p">&gt;</span> <span class="highlight-mi">0</span> <span class="highlight-p">{</span>
	<span class="highlight-nx">trim</span> <span class="highlight-p">=</span> <span class="highlight-nb">len</span><span class="highlight-p">(</span><span class="highlight-nx">decrypted</span><span class="highlight-p">)</span> <span class="highlight-o">-</span> <span class="highlight-nb">int</span><span class="highlight-p">(</span><span class="highlight-nx">decrypted</span><span class="highlight-p">[</span><span class="highlight-nb">len</span><span class="highlight-p">(</span><span class="highlight-nx">decrypted</span><span class="highlight-p">)</span><span class="highlight-o">-</span><span class="highlight-mi">1</span><span class="highlight-p">])</span>
<span class="highlight-p">}</span>
<span class="highlight-k">return</span> <span class="highlight-nx">decrypted</span><span class="highlight-p">[:</span><span class="highlight-nx">trim</span><span class="highlight-p">]</span>

}
func generateKey(key []byte) (genKey []byte) {

genKey = make([]byte, 16)

copy(genKey, key)

for i := 16; i < len(key); {

for j := 0; j < 16 && i < len(key); j, i = j+1, i+1 {

genKey[j] ^= key[i]

}

}

return genKey

}