ULL to select the defaults. In case the method is OSSL_CRMF_POPO_SIGNATURE the POPO is calculated using the private key <i>pkey</i> and the digest method <i>digest</i>, where the <i>digest</i> argument is ignored if <i>pkey</i> is of a type (such as Ed25519 and Ed448) that is implicitly associated with a digest algorithm.</p>

<p><i>meth</i> can be one of the following:</p>

<ul>

<li><p>OSSL_CRMF_POPO_NONE - RFC 4211, section 4, POP field omitted. CA/RA uses out-of-band method to verify POP. Note that serv