.g. for reading and writing digital certificates (also known as X.509 certificates). Finally it also supplies various additional supporting APIs that are not directly cryptography related but are nonetheless useful and depended upon by other APIs. For example the &quot;BIO&quot; functions provide capabilities for abstracting I/O, e.g. via a file or over a network.</p>

<p>The <code>libssl</code> library provides functions to perform secure communication between two peers across a network. Most significantly