title: How to encrypt a ReadableStream
body: <p>I'm looking for a way to encrypt arbitrary large files on client side in the browser before to send it to a web server. Ideally I would like to encrypt in aes-256-cbc and to be compatible with openssl format.</p>
  
  <p>Using the Stream API I'm now able to read a file chunk by chunk, to process it and to pipe it into the XHR POST request body which is great.</p>
  
  <p>I now need a way to encrypt it using AES. Unfortunately the WebCrypto API is not compatible with ReadableStreams for now.</p>
  
  <p><a href="https://github.com/w3c/webcrypto/issues/73" rel="nofollow noreferrer">https://github.com/w3c/webcrypto/issues/73</a></p>
  
  <p>In the mean time what could be the best alternatives?</p>