ssh(3erl)						     Erlang Module Definition							 ssh(3erl)

NAME

       ssh - Main API of the SSH application

DESCRIPTION

       Interface module for the SSH application

COMMON DATA TYPES

       Type definitions that are used more than once in this module:

       boolean() = true | false

       string() = list of ASCII characters

       ssh_daemon_ref() - opaque to the user returned by ssh:daemon/[1,2,3]

       ssh_connection_ref() - opaque to the user returned by ssh:connect/3

       ip_address() - {N1,N2,N3,N4} % IPv4 | {K1,K2,K3,K4,K5,K6,K7,K8} % IPv6

       subsystem_spec() = {subsystem_name(), {channel_callback(), channel_init_args()}}

       subsystem_name() = string()

       channel_callback() = atom() - Name of the erlang module implementing the subsystem using the ssh_channel behavior see ssh_channel(3erl)

       channel_init_args() = list()

EXPORTS

       close(ConnectionRef) -> ok

	      Types  ConnectionRef = ssh_connection_ref()

	      Closes a ssh connection.

       connect(Host, Port, Options) ->
       connect(Host, Port, Options, Timeout) -> {ok, ssh_connection_ref()} | {error, Reason}

	      Types  Host = string()
		     Port = integer()
		     The default is 22 , the registered port for SSH.
		     Options = [{Option, Value}]
		     Timeout = infinity | integer(milliseconds)

	      Connects to an SSH server. No channel is started this is done by calling ssh_connect:session_channel/2.

	      Options are:

		{user_dir, String} :
		  Sets	the user directory e.i. the directory containing ssh configuration files for the user such as known_hosts , id_rsa, id_dsa
		  and authorized_key . Defaults to the directory normally referred to as ~/.ssh

		{silently_accept_hosts, boolean()} :
		  When true hosts are added to the file known_hosts without asking the user. Defaults to false.

		{user_interaction, boolean()} :
		  If false disables the client to connect to the server if any user interaction is needed such as accepting that the  server  will
		  be  added  to the known_hosts file or supplying a password. Defaults to true. Even if user interaction is allowed it can be sup-
		  pressed by other options such as silently_accept_hosts and password. Do note that it may not always be desirable  to	use  those
		  options from a security point of view.

		{public_key_alg, ssh_rsa | ssh_dsa} :
		  Sets the preferred public key algorithm to use for user authentication. If the the preferred algorithm fails of some reason, the
		  other algorithm is tried. The default is to try ssh_rsa first.

		{connect_timeout, timeout()} :
		  Sets a timeout on the transport layer connection. Defaults to infinity.

		{user, String} :
		  Provide a user name. If this option is not given, ssh reads from the environment ( LOGNAME or USER on  unix,	USERNAME  on  Win-
		  dows).

		{password, string()} :
		  Provide  a password for password authentication. If this option is not given, the user will be asked for a password if the pass-
		  word authentication method is attempted.

		{user_auth, Fun/3} :
		  Provide a fun for password authentication. The fun will be called as fun(User, Password, Opts) and should return true or false .

		{key_cb, atom() = KeyCallbackModule} :
		  Provide a special call-back module for key handling. The call-back module should be modeled after the ssh_file module. The func-
		  tions  that  must be exported are: private_host_rsa_key/2 , private_host_dsa_key/2 , lookup_host_key/3 and add_host_key/3 . This
		  is considered somewhat experimental and will be better documented later on.

		{fd, file_descriptor()} :
		  Allow an existing file-descriptor to be used (simply passed on to the transport protocol).

		{ip_v6_disabled, boolean()} :
		  Determines if SSH shall use IPv6 or not.

       connection_info(ConnectionRef, [Option]) ->[{Option, Value}]

	      Types  Option = client_version | server_version | peer
		     Value = term()

	      Retrieves information about a connection.

       daemon(Port) ->
       daemon(Port, Options) ->
       daemon(HostAddress, Port, Options) -> ssh_daemon_ref()

	      Types  Port = integer()
		     HostAddress = ip_address() | any
		     Options = [{Option, Value}]
		     Option = atom()
		     Value = term()

	      Starts a server listening for SSH connections on the given port.

	      Options are:

		{subsystems, [subsystem_spec()] :
		  Provides specifications for handling of subsystems. The "sftp" subsystem-spec can  be  retrieved  by	calling  ssh_sftpd:subsys-
		  tem_spec/1.  If  the	subsystems option in not present the value of [ssh_sftpd:subsystem_spec([])] will be used. It is of course
		  possible to set the option to the empty list if you do not want the daemon to run any subsystems at all.

		{shell, {Module, Function, Args} | fun(string() = User) - > pid() | fun(string() = User, ip_address() = PeerAddr) -> pid()} :
		  Defines the read-eval-print loop used when a shell is requested by the client. Example use the erlang shell: {shell, start,  []}
		  which is the default behavior.

		{ssh_cli,{channel_callback(), channel_init_args()}} :
		  Provide your own cli implementation, e.i. a channel callback module that implements a shell and command execution. Note that you
		  may customize the shell read-eval-print loop using the option shell which is much less work than implementing your own cli chan-
		  nel.

		{system_dir, string()} :
		  Sets	the  system directory, containing the host files that identifies the host for ssh. The default is /etc/ssh , note that SSH
		  normally requires the host files there to be readable only by root.

		{user_passwords, [{string() = User, string() = Password}]} :
		  Provide passwords for password authentication.They will be used when someone tries to connect to the server and public key  user
		  authentication fails. The option provides a list of valid user names and the corresponding password.

		{password, string()} :
		  Provide a global password that will authenticate any user. From a security perspective this option makes the server very vulner-
		  able.

		{pwdfun, fun/2} :
		  Provide a function for password validation. This is called with user and password as strings, and  should  return  true  if  the
		  password is valid and false otherwise.

		{fd, file_descriptor()} :
		  Allow an existing file-descriptor to be used (simply passed on to the transport protocol).

		{ip_v6_disabled, boolean()} :
		  Determines if SSH shall use IPv6 or not (only used when HostAddress is set to any).

       shell(Host) ->
       shell(Host, Option) ->
       shell(Host, Port, Option) -> _

	      Types  Host = string()
		     Port = integer()
		     Options - see ssh:connect/3

	      Starts  an  interactive  shell to an SSH server on the given Host . The function waits for user input, and will not return until the
	      remote shell is ended (e.g. on exit from the shell).

       sign_data(Data, Algorithm) -> Signature | {error, Reason}

	      Types  Data = binary()
		     Algorithm = "ssh-rsa"
		     Signature = binary()
		     Reason = term()

	      Signs the supplied binary using the SSH key.

       start() ->
       start(Type) -> ok | {error, Reason}

	      Types  Type = permanent | transient | temporary
		     Reason = term()

	      Starts the Ssh application. Default type is temporary. See also application(3erl) Requires that  the  crypto  application  has  been
	      started.

       stop() -> ok

	      Stops the Ssh application. See also application(3erl)

       stop_daemon(DaemonRef) ->
       stop_daemon(Address, Port) -> ok

	      Types  DaemonRef = ssh_daemon_ref()
		     Address = ip_address()
		     Port = integer()

	      Stops the listener and all connections started by the listener.

       stop_listener(DaemonRef) ->
       stop_listener(Address, Port) -> ok

	      Types  DaemonRef = ssh_daemon_ref()
		     Address = ip_address()
		     Port = integer()

	      Stops the listener, but leaves existing connections started by the listener up and running.

       verify_data(Data, Signature, Algorithm) -> ok | {error, Reason}

	      Types  Data = binary()
		     Algorithm = "ssh-rsa"
		     Signature = binary()
		     Reason = term()

	      Verifies the supplied binary against the binary signature.

Ericsson AB							     ssh 2.0.4								 ssh(3erl)