STACK_OF
STACK_OF(X509) *certs=NULL;
verify_file(STACK_OF(X509) *cert_chain, const char *anchor,
STACK_OF(X509) *signers;
STACK_OF(X509) *certs;
STACK_OF(X509) *cert_chain;
STACK_OF(X509) *c;
sign_file(X509 *cert, EVP_PKEY *private_key, STACK_OF(X509) *cert_chain,
STACK_OF(X509_EXTENSION) *extlist;