I have an X509_PUBKEY structure holding the algorithm and public key. I want to set it in the X509 structure. In 1.1.1 and up, I can use evpPubkey = X509_PUBKEY_get0(addToCert->key); /* X509_PUBKEY */ X509_set_pubkey(x509Certificate, evpPubkey); However, 1.0.2 doesn't have these. What's a good approach? I could access the X509.cert_info.key and set the value, but I expect that would cause a double free later when I free both the X509 and the structure holding the X509_PUBKEY. Is the something like a X509_PUBKEY_dup function? (Yes, I know that 1.0.2 is obsolete, but there are some LTS distros, and I'd rather not drop support for 1.0.2 if I can figure this out.)