title: I need to decrypt file encrypted by gpg (in command line)
body: <p>I have a file, which I encrypted on PC from command line using <strong>aes256</strong> and a passphrase.</p>
  
  <pre><code>gpg --cipher-algo AES256 --output testfile.gpg --symmetric testfile.txt
  </code></pre>
  
  <p>Now I need to decrypt this file from my android application.</p>
  
  <p>I had expiarance with decryption data (encrypted with aes256) in android before but then I had to provide KEY (256 bit) and a salt (128 bit) to decrypt.</p>
  
  <p>How can I convert my passphrase to key/salt pair?
  Or how having key/salt pair I can encrypt a file using GPG (and using the same key/salt to decrypt later)?</p>