Convenience macro for libssh2_userauth_publickey_fromfile_ex(3) calls
#include <libssh2.h>
int libssh2_userauth_publickey_fromfile(LIBSSH2_SESSION *session,
const char *username, const char *publickey, const char *privatekey, const char *passphrase);
This is a macro defined in a public libssh2 header file that is using the underlying function libssh2_userauth_publickey_fromfile_ex(3).