title: How can I use a .ppk file for curl sftp file transfer?
body: <p>I'm trying to send a file transfer in windows using cURL, the command is stored as a batch file so i can schedule it when it works. I've generated a public and private key using putty. The private key is stored as a .ppk file and the public key has no file extension.</p>
  
  <p>I've tried converting the file back into a regular private key using puttygen but no luck</p>
  
  <pre><code>C:\curl\bin\curl -T D:\myFile.csv -u myUsername: --key C:\keys\private-key.ppk  sftp://remote.site.com/incoming
  </code></pre>
  
  <p>When i run the command i get the following error message:
  curl: (51) SSL peer certificate or SSH remote key was not OK</p>