How to decrypt password from JavaScript CryptoJS.AES.encrypt(password, passphrase) in Python
<p>I have a password which is encrypt from JavaScript via</p>

<pre class="lang-js prettyprint-override"><code>  var password = 'sample'
  var passphrase ='sample_passphrase'
  CryptoJS.AES.encrypt(password, passphrase)
</code></pre>

<p>Then I tried to decrypt the password comes from JavaScript in Python:</p>

<pre class="lang-py prettyprint-override"><code>  from Crypto.Cipher import AES
  import base64

  PADDING = '\0'

  pad_it = lambda s: s+(16 - len(s)%16)*PADDING
  key = 'sample_passphrase'
  iv='11.0.0.101'        #------&gt; here is my question, how can I get this iv to restore password, what should I put here?
  key=pad_it(key)        #------&gt; should I add padding to keys and iv?
  iv=pad_it(iv)          ##
  source = 'sample'
  generator = AES.new(key, AES.MODE_CFB,iv)
  crypt = generator.encrypt(pad_it(source))
  cryptedStr = base64.b64encode(crypt)
  print cryptedStr
  generator = AES.new(key, AES.MODE_CBC,iv)
  recovery = generator.decrypt(crypt)
  print recovery.rstrip(PADDING)
</code></pre>

<p>I checked JS from browser console, it shows IV in <code>CryptoJS.AES.encrypt(password, passphrase)</code> is a object with some attributes( like <code>sigBytes:16, words: [-44073646, -1300128421, 1939444916, 881316061]</code>). It seems generated randomly. </p>

<p>From one web page, it tells me that JS has two way to encrypt password 
(<a href="http://www.cnblogs.com/Lifehacker/p/nodejs_aes_encrypt_problem.html" rel="noreferrer">reference link</a> ):</p>

<blockquote>
  <ul>
  <li>a. <code>crypto.createCipher(algorithm, password)</code></li>
  <li>b. <code>crypto.createCipheriv(algorithm, key, iv)</code></li>
  </ul>
</blockquote>

<p>What I saw in JavaScript should be option a. However, only option b is equivalent to AES.new() in python.</p>

<p><strong>The questions are</strong>:</p>

<ol>
<li><p>How can I restore this password in Python without changing JavaScript code? </p></li>
<li><p>If I need IV in Python, how can I get it from the password that is used in JavaScript? </p></li>
</ol>