title: AWS Signature v4 for HTTP request to AWS IoT
body: <p>I have an IoTs project related to AWS. In my project, my device will transfer raw data to a cloud and then the cloud will send information decrypted in JSON format to AWS IoT. The cloud supports HTTP protocol using a REST API for both uplink/downlink so I think it will work with AWS IoT as the [link]: <a href="https://docs.aws.amazon.com/iot/latest/developerguide/protocols.html#http" rel="nofollow noreferrer">https://docs.aws.amazon.com/iot/latest/developerguide/protocols.html#http</a></p>
  
  <p>I wanna send a HTTP request using AWS Sig v4 with the Authentication as the form below:</p>
  
  <blockquote>
    <p>AWS4-HMAC-SHA256 Credential={1}/{2}/{3}/{4}/aws4_request, SignedHeaders=content-type;host;x-amz-date, Signature={5}</p>
  </blockquote>
  
  <p>However, I don't know how to generate the signature {5}. I can't use scripts to generate because my cloud doesn't support running scripts. It only has some boxes of headers &amp; values which I can leave Authorization etc in it (see the screenshot here <a href="https://imgur.com/RI815EZ" rel="nofollow noreferrer">https://imgur.com/RI815EZ</a>) 
  Any advice?
  Thanks in advance,</p>