o through the chain of certificates and check that all signatures are valid and that the current time is within the limits of each certificate&#39;s first and last validity time. The final chain verification functions must return 0 on failure and 1 on success. <i>If no chain verification function is provided, the internal default function will be used instead.</i></p>

<p>X509_STORE_CTX_get1_issuer() tries to find a certificate from the <i>store</i> component of <i>ctx</i> that has a subject name matching t