libssh  0.6.0
Data Structures | Typedefs | Functions
The libssh server API

Data Structures

struct  ssh_bind_callbacks
 These are the callbacks exported by the ssh_bind structure. More...
 

Typedefs

typedef void(* ssh_bind_incoming_connection_callback )(ssh_bind sshbind, void *userdata)
 Incoming connection callback. More...
 

Functions

LIBSSH_API int ssh_bind_accept (ssh_bind ssh_bind_o, ssh_session session)
 Accept an incoming ssh connection and initialize the session. More...
 
LIBSSH_API int ssh_bind_accept_fd (ssh_bind ssh_bind_o, ssh_session session, socket_t fd)
 Accept an incoming ssh connection on the given file descriptor and initialize the session. More...
 
LIBSSH_API void ssh_bind_fd_toaccept (ssh_bind ssh_bind_o)
 Allow the file descriptor to accept new sessions. More...
 
LIBSSH_API void ssh_bind_free (ssh_bind ssh_bind_o)
 Free a ssh servers bind. More...
 
LIBSSH_API socket_t ssh_bind_get_fd (ssh_bind ssh_bind_o)
 Recover the file descriptor from the session. More...
 
LIBSSH_API int ssh_bind_listen (ssh_bind ssh_bind_o)
 Start listening to the socket. More...
 
LIBSSH_API ssh_bind ssh_bind_new (void)
 Creates a new SSH server bind. More...
 
LIBSSH_API int ssh_bind_options_set (ssh_bind sshbind, enum ssh_bind_options_e type, const void *value)
 Set the options for the current SSH server bind. More...
 
LIBSSH_API void ssh_bind_set_blocking (ssh_bind ssh_bind_o, int blocking)
 Set the session to blocking/nonblocking mode. More...
 
LIBSSH_API int ssh_bind_set_callbacks (ssh_bind sshbind, ssh_bind_callbacks callbacks, void *userdata)
 Set the callback for this bind. More...
 
LIBSSH_API void ssh_bind_set_fd (ssh_bind ssh_bind_o, socket_t fd)
 Set the file descriptor for a session. More...
 
LIBSSH_API int ssh_channel_open_reverse_forward (ssh_channel channel, const char *remotehost, int remoteport, const char *sourcehost, int localport)
 Open a TCP/IP reverse forwarding channel. More...
 
LIBSSH_API int ssh_channel_open_x11 (ssh_channel channel, const char *orig_addr, int orig_port)
 Open a X11 channel. More...
 
LIBSSH_API int ssh_channel_request_send_exit_signal (ssh_channel channel, const char *signum, int core, const char *errmsg, const char *lang)
 Send an exit signal to remote process (as described in RFC 4254, section 6.10). More...
 
LIBSSH_API int ssh_channel_request_send_exit_status (ssh_channel channel, int exit_status)
 Send the exit status to the remote process. More...
 
LIBSSH_API int ssh_channel_write_stderr (ssh_channel channel, const void *data, uint32_t len)
 Blocking write on a channel stderr. More...
 
LIBSSH_API ssh_gssapi_creds ssh_gssapi_get_creds (ssh_session session)
 returns the client credentials of the connected client. More...
 
LIBSSH_API int ssh_handle_key_exchange (ssh_session session)
 Handles the key exchange and set up encryption. More...
 
LIBSSH_API const char * ssh_message_auth_password (ssh_message msg)
 Get the password of the authenticated user. More...
 
LIBSSH_API ssh_key ssh_message_auth_pubkey (ssh_message msg)
 Get the publickey of the authenticated user. More...
 
LIBSSH_API const char * ssh_message_auth_user (ssh_message msg)
 Get the name of the authenticated user. More...
 
LIBSSH_API int ssh_message_reply_default (ssh_message msg)
 Reply with a standard reject message. More...
 
LIBSSH_API void ssh_set_auth_methods (ssh_session session, int auth_methods)
 Set the acceptable authentication methods to be sent to client. More...
 
LIBSSH_API void ssh_set_message_callback (ssh_session session, int(*ssh_bind_message_callback)(ssh_session session, ssh_message msg, void *data), void *data)
 defines the ssh_message callback More...
 

Detailed Description

Typedef Documentation

typedef void(* ssh_bind_incoming_connection_callback)(ssh_bind sshbind, void *userdata)

Incoming connection callback.

This callback is called when a ssh_bind has a new incoming connection.

Parameters
sshbindCurrent sshbind session handler
userdataUserdata to be passed to the callback function.

Function Documentation

int ssh_bind_accept ( ssh_bind  ssh_bind_o,
ssh_session  session 
)

Accept an incoming ssh connection and initialize the session.

Parameters
ssh_bind_oThe ssh server bind to accept a connection.
sessionA preallocated ssh session
See Also
ssh_new
Returns
SSH_OK when a connection is established

References ssh_bind_accept_fd().

int ssh_bind_accept_fd ( ssh_bind  ssh_bind_o,
ssh_session  session,
socket_t  fd 
)

Accept an incoming ssh connection on the given file descriptor and initialize the session.

Parameters
ssh_bind_oThe ssh server bind to accept a connection.
sessionA preallocated ssh session
fdA file descriptor of an already established TCP inbound connection
See Also
ssh_new
ssh_bind_accept
Returns
SSH_OK when a connection is established

Referenced by ssh_bind_accept().

void ssh_bind_fd_toaccept ( ssh_bind  ssh_bind_o)

Allow the file descriptor to accept new sessions.

Parameters
ssh_bind_oThe ssh server bind to use.
void ssh_bind_free ( ssh_bind  ssh_bind_o)

Free a ssh servers bind.

Parameters
ssh_bind_oThe ssh server bind to free.

References ssh_key_free().

socket_t ssh_bind_get_fd ( ssh_bind  ssh_bind_o)

Recover the file descriptor from the session.

Parameters
ssh_bind_oThe ssh server bind to get the fd from.
Returns
The file descriptor.
int ssh_bind_listen ( ssh_bind  ssh_bind_o)

Start listening to the socket.

Parameters
ssh_bind_oThe ssh server bind to use.
Returns
0 on success, < 0 on error.

References ssh_init(), ssh_key_free(), ssh_key_type(), and ssh_pki_import_privkey_file().

ssh_bind ssh_bind_new ( void  )

Creates a new SSH server bind.

Returns
A newly allocated ssh_bind session pointer.
int ssh_bind_options_set ( ssh_bind  sshbind,
enum ssh_bind_options_e  type,
const void *  value 
)

Set the options for the current SSH server bind.

This function can set all possible ssh bind options.

Parameters
sshbindThe ssh server bind to configure.
typeThe option type to set. This could be one of the following:
  • SSH_BIND_OPTIONS_BINDADDR The ip address to bind (const char *).
  • SSH_BIND_OPTIONS_BINDPORT The port to bind (unsigned int).
  • SSH_BIND_OPTIONS_BINDPORT_STR The port to bind (const char *).
  • SSH_BIND_OPTIONS_HOSTKEY This specifies the file containing the private host key used by SSHv1. (const char *).
  • SSH_BIND_OPTIONS_DSAKEY This specifies the file containing the private host dsa key used by SSHv2. (const char *).
  • SSH_BIND_OPTIONS_RSAKEY This specifies the file containing the private host dsa key used by SSHv2. (const char *).
  • SSH_BIND_OPTIONS_BANNER That the server banner (version string) for SSH. (const char *).
  • SSH_BIND_OPTIONS_LOG_VERBOSITY Set the session logging verbosity (int).

    The verbosity of the messages. Every log smaller or equal to verbosity will be shown.
    • SSH_LOG_NOLOG: No logging
    • SSH_LOG_RARE: Rare conditions or warnings
    • SSH_LOG_ENTRY: API-accessible entrypoints
    • SSH_LOG_PACKET: Packet id and size
    • SSH_LOG_FUNCTIONS: Function entering and leaving
  • SSH_BIND_OPTIONS_LOG_VERBOSITY_STR Set the session logging verbosity (const char *).

    The verbosity of the messages. Every log smaller or equal to verbosity will be shown.
    • SSH_LOG_NOLOG: No logging
    • SSH_LOG_RARE: Rare conditions or warnings
    • SSH_LOG_ENTRY: API-accessible entrypoints
    • SSH_LOG_PACKET: Packet id and size
    • SSH_LOG_FUNCTIONS: Function entering and leaving
      See the corresponding numbers in libssh.h.
Parameters
valueThe value to set. This is a generic pointer and the datatype which is used should be set according to the type set.
Returns
SSH_OK on success, SSH_ERROR on invalid option or parameter.
Parameters
sshbindAn allocated ssh bind structure.
typeThe option type to set. This could be one of the following:

SSH_BIND_OPTIONS_LOG_VERBOSITY: Set the session logging verbosity (integer).

The verbosity of the messages. Every log smaller or equal to verbosity will be shown. SSH_LOG_NOLOG: No logging SSH_LOG_RARE: Rare conditions or warnings SSH_LOG_ENTRY: API-accessible entrypoints SSH_LOG_PACKET: Packet id and size SSH_LOG_FUNCTIONS: Function entering and leaving

SSH_BIND_OPTIONS_LOG_VERBOSITY_STR: Set the session logging verbosity (integer).

The verbosity of the messages. Every log smaller or equal to verbosity will be shown. SSH_LOG_NOLOG: No logging SSH_LOG_RARE: Rare conditions or warnings SSH_LOG_ENTRY: API-accessible entrypoints SSH_LOG_PACKET: Packet id and size SSH_LOG_FUNCTIONS: Function entering and leaving

SSH_BIND_OPTIONS_BINDADDR: Set the bind address.

SSH_BIND_OPTIONS_BINDPORT: Set the bind port, default is 22.

SSH_BIND_OPTIONS_HOSTKEY: Set the server public key type: ssh-rsa or ssh-dss (string).

SSH_BIND_OPTIONS_DSAKEY: Set the path to the dsa ssh host key (string).

SSH_BIND_OPTIONS_RSAKEY: Set the path to the ssh host rsa key (string).

SSH_BIND_OPTIONS_BANNER: Set the server banner sent to clients (string).

Parameters
valueThe value to set. This is a generic pointer and the datatype which is used should be set according to the type set.
Returns
0 on success, < 0 on error.

References ssh_set_log_level().

void ssh_bind_set_blocking ( ssh_bind  ssh_bind_o,
int  blocking 
)

Set the session to blocking/nonblocking mode.

Parameters
ssh_bind_oThe ssh server bind to use.
blockingZero for nonblocking mode.
int ssh_bind_set_callbacks ( ssh_bind  sshbind,
ssh_bind_callbacks  callbacks,
void *  userdata 
)

Set the callback for this bind.

Parameters
[in]sshbindThe bind to set the callback on.
[in]callbacksAn already set up ssh_bind_callbacks instance.
[in]userdataA pointer to private data to pass to the callbacks.
Returns
SSH_OK on success, SSH_ERROR if an error occured.
* struct ssh_callbacks_struct cb = {
* .userdata = data,
* .auth_function = my_auth_function
* };
* ssh_bind_set_callbacks(session, &cb);
*
void ssh_bind_set_fd ( ssh_bind  ssh_bind_o,
socket_t  fd 
)

Set the file descriptor for a session.

Parameters
ssh_bind_oThe ssh server bind to set the fd.
fdThe file descriptssh_bind B
LIBSSH_API int ssh_channel_open_reverse_forward ( ssh_channel  channel,
const char *  remotehost,
int  remoteport,
const char *  sourcehost,
int  localport 
)

Open a TCP/IP reverse forwarding channel.

Parameters
[in]channelAn allocated channel.
[in]remotehostThe remote host to connected (host name or IP).
[in]remoteportThe remote port.
[in]sourcehostThe source host (your local computer). It's optional and for logging purpose.
[in]localportThe source port (your local computer). It's optional and for logging purpose.
Returns
SSH_OK on success, SSH_ERROR if an error occurred, SSH_AGAIN if in nonblocking mode and call has to be done again.
Warning
This function does not bind the local port and does not automatically forward the content of a socket to the channel. You still have to use channel_read and channel_write for this.

References ssh_buffer_free(), ssh_buffer_new(), ssh_string_free(), and ssh_string_from_char().

LIBSSH_API int ssh_channel_open_x11 ( ssh_channel  channel,
const char *  orig_addr,
int  orig_port 
)

Open a X11 channel.

Parameters
[in]channelAn allocated channel.
[in]orig_addrThe source host (the local server).
[in]orig_portThe source port (the local server).
Returns
SSH_OK on success, SSH_ERROR if an error occurred, SSH_AGAIN if in nonblocking mode and call has to be done again.
Warning
This function does not bind the local port and does not automatically forward the content of a socket to the channel. You still have to use channel_read and channel_write for this.

References ssh_buffer_free(), ssh_buffer_new(), ssh_string_free(), and ssh_string_from_char().

LIBSSH_API int ssh_channel_request_send_exit_signal ( ssh_channel  channel,
const char *  sig,
int  core,
const char *  errmsg,
const char *  lang 
)

Send an exit signal to remote process (as described in RFC 4254, section 6.10).

Sends a signal 'sig' to the remote process. Note, that remote system may not support signals concept. In such a case this request will be silently ignored. Only SSH-v2 is supported (I'm not sure about SSH-v1).

Parameters
[in]channelThe channel to send signal.
[in]sigThe signal to send (without SIG prefix) (e.g. "TERM" or "KILL").
[in]coreA boolean to tell if a core was dumped
[in]errmsgA CRLF explanation text about the error condition
[in]langThe language used in the message (format: RFC 3066)
Returns
SSH_OK on success, SSH_ERROR if an error occurred (including attempts to send signal via SSH-v1 session).

References ssh_buffer_free(), ssh_buffer_new(), ssh_string_free(), and ssh_string_from_char().

LIBSSH_API int ssh_channel_request_send_exit_status ( ssh_channel  channel,
int  exit_status 
)

Send the exit status to the remote process.

Sends the exit status to the remote process (as described in RFC 4254, section 6.10). Only SSH-v2 is supported (I'm not sure about SSH-v1).

Parameters
[in]channelThe channel to send exit status.
[in]exit_statusThe exit status to send
Returns
SSH_OK on success, SSH_ERROR if an error occurred. (including attempts to send exit status via SSH-v1 session).

References ssh_buffer_free(), and ssh_buffer_new().

LIBSSH_API int ssh_channel_write_stderr ( ssh_channel  channel,
const void *  data,
uint32_t  len 
)

Blocking write on a channel stderr.

Parameters
[in]channelThe channel to write to.
[in]dataA pointer to the data to write.
[in]lenThe length of the buffer to write to.
Returns
The number of bytes written, SSH_ERROR on error.
See Also
channel_read()

Referenced by ssh::Channel::write().

LIBSSH_API ssh_gssapi_creds ssh_gssapi_get_creds ( ssh_session  session)

returns the client credentials of the connected client.

If the client has given a forwardable token, the SSH server will retrieve it.

Returns
gssapi credentials handle.
NULL if no forwardable token is available.
int ssh_handle_key_exchange ( ssh_session  session)

Handles the key exchange and set up encryption.

Parameters
sessionA connected ssh session
See Also
ssh_bind_accept
Returns
SSH_OK if the key exchange was successful

References SSH_LOG_PACKET.

const char * ssh_message_auth_password ( ssh_message  msg)

Get the password of the authenticated user.

Parameters
[in]msgThe message to get the password from.
Returns
The username or NULL if an error occured.
See Also
ssh_message_get()
ssh_message_type()
ssh_key ssh_message_auth_pubkey ( ssh_message  msg)

Get the publickey of the authenticated user.

If you need the key for later user you should duplicate it.

Parameters
[in]msgThe message to get the public key from.
Returns
The public key or NULL.
See Also
ssh_key_dup()
ssh_key_cmp()
ssh_message_get()
ssh_message_type()
const char * ssh_message_auth_user ( ssh_message  msg)

Get the name of the authenticated user.

Parameters
[in]msgThe message to get the username from.
Returns
The username or NULL if an error occured.
See Also
ssh_message_get()
ssh_message_type()
int ssh_message_reply_default ( ssh_message  msg)

Reply with a standard reject message.

Use this function if you don't know what to respond or if you want to reject a request.

Parameters
[in]msgThe message to use for the reply.
Returns
0 on success, -1 on error.
See Also
ssh_message_get()

References SSH_LOG_PACKET.

void ssh_set_auth_methods ( ssh_session  session,
int  auth_methods 
)

Set the acceptable authentication methods to be sent to client.

Parameters
[in]sessionthe SSH server session
[in]auth_methodsBitfield of authentication methods to be accepted, e.g. SSH_AUTH_METHOD_PUBLICKEY
void ssh_set_message_callback ( ssh_session  session,
int(*)(ssh_session session, ssh_message msg, void *data)  ssh_bind_message_callback,
void *  data 
)

defines the ssh_message callback

Parameters
sessionthe current ssh session
[in]ssh_bind_message_callbacka function pointer to a callback taking the current ssh session and received message as parameters. the function returns 0 if the message has been parsed and treated successfully, 1 otherwise (libssh must take care of the response).
[in]datavoid pointer to be passed to callback functions