'crypto_engine' not used.

  char *key;            /* private key */

  char *key_type;       /* format for private key (default: PEM) */

  char *key_passwd;     /* plain text private key password */

  char *crypto_engine;  /* name of the crypto engine to use */

  char *cookiejar;      /* dump all cookies to this file */

  bool cookiesession;   /* new cookie session? */

  bool crlf;            /* convert crlf on ftp upload(?) */