cate except if the issuer certificate is the same as the current one and it is not self-signed. The hash of the public key related to the signing key is taken as fallback if the issuer certificate is the same as the current certificate. If <b>always</b> is present but no value can be obtained, an error is returned.</p>

<p>If <b>issuer</b> is present, and in addition it has the option <b>always</b> specified or <b>keyid</b> is not present, then the issuer DN and serial number are copied from the issuer cert