sk_push
sk_push(CHECKED_STACK_OF(type, st), CHECKED_PTR_OF(type, val))
#define sk_OPENSSL_STRING_push(st, val) sk_push(CHECKED_STACK_OF(OPENSSL_STRING, st), CHECKED_PTR_OF(char, val))
#define sk_OPENSSL_BLOCK_push(st, val) sk_push(CHECKED_STACK_OF(OPENSSL_BLOCK, st), CHECKED_PTR_OF(void, val))
#define sk_OPENSSL_PSTRING_push(st, val) sk_push(CHECKED_STACK_OF(OPENSSL_PSTRING, st), CHECKED_PTR_OF(OPENSSL_STRING, val))
int sk_push(_STACK *st, void *data);