Libssh2 userauth hostbased fromfile ex

From Libssh2

int libssh2_userauth_hostbased_fromfile_ex(LIBSSH2_SESSION *session,
                     const char *username, int username_len,
                     const char *publickey, const char *privatekey,
                     const char *passphrase,
                     const char *hostname, int hostname_len,
                     const char *local_username, int local_username_len);
#define libssh2_userauth_hostbased_fromfile(session, username, publickey, privatekey, passphrase, hostname) \
        libssh2_userauth_hostbased_fromfile_ex((session), \
                         (username), strlen(username), \
                         (publickey), (privatekey), (passphrase), \
                         (hostname), strlen(hostname), \
                         (username), strlen(username))

About

Attempt host-based public key authentication using a PEM encoded private key file stored on disk. This allows the connecting application to use a single key to authenticate any of its local users to any remote account, however because of the high degree of trust necessary between hosts, the private key is typically only readable by the root user.

Parameters

• session

  Session instance as returned by libssh2_session_init().

• username

  Remote user name to authenticate as.

• username_len

  Length of username.

• publickey

  Path and name of public key file. (e.g. /etc/ssh/hostkey.pub)

• privatekey

  Path and name of private key file. (e.g. /etc/ssh/hostkey)

• passphrase

  Passphrase to use when decoding private key file.

• hostname

  Host name client will declare itself as to the server. Not necessarily the cannonical hostname.

• hostname_len

  Length of hostname parameter.

• local_username

  Name of local user requesting authentication as remote username. Sometimes used for additional ACL by remote host.

• local_username_len

  Length of local_username.

Returns

• On Success: 0
• On Failure: -1