title: OpenSSL: How to code in C signing CSR with CA
body: <p>I have created the CA certificate with OpenSSL commands and it is in a PEM file.</p>
  <p>In my program I have created the RSA key pair and the CSR (X509_REQ type).</p>
  <p>Now, how do I sign the CSR with the CA implementing it in C language?</p>
  <p>Thanks.</p>