.TH ssh_agent 3erl "ssh 4.10.8" "Ericsson AB" "Erlang Module Definition"
.SH NAME
ssh_agent \- Callback module for using an SSH agent instead of the default ssh_file callback.
.SH DESCRIPTION
.LP
This module defines a callback handler for the communication with an SSH Agent and can be used to replace the default callback\&. This allows to issue signing requests to an agent that stores SSH private keys to perform authentication\&.
.LP
Ssh_agent implements the ssh_client_key_api, to allow it to be used by setting the option \fIkey_cb\fR\& when starting a client (with for example ssh:connect, ssh:shell )\&.
.LP
.nf

      {key_cb, {ssh_agent, []}}
    
.fi
.LP
The agent communication is established through a UNIX domain socket\&. By default, the socket path will be fetched from the \fISSH_AUTH_SOCK\fR\& enviroment variable, which is the default socket path in the agent implementation of OpenSSH\&.
.LP
In order to set a different socket path the \fIsocket_path\fR\& option can be set\&.
.LP
.nf

      {key_cb, {ssh_agent, [{socket_path, SocketPath}]}}
    
.fi
.LP

.RS -4
.B
Note:
.RE
The functions are \fICallbacks\fR\&  for the SSH app\&. They are not intended to be called from the user\&'s code!

.SH DATA TYPES
.SS Options for the ssh_agent callback module
.nf

\fBsocket_path_option()\fR\& = {socket_path, string()}
.br
.fi
.RS
.LP
Sets the socket path for the communication with the agent\&.
.RE

.nf

\fBtimeout_option()\fR\& = {timeout, integer()}
.br
.fi
.RS
.LP
Sets the time-out in milliseconds when communicating with the agent via the socket\&. The default value is \fI1000\fR\&\&.
.RE

.nf

\fBcall_ssh_file_option()\fR\& = {call_ssh_file, atom()}
.br
.fi
.RS
.LP
The module which the \fIadd_host_key\fR\& and \fIis_host_key\fR\& callbacks are delegated to\&. Defaults to the ssh_file module\&.
.RE

.SH EXPORTS
.LP
.nf

.B
add_host_key(Host :: string(),
.B
             PublicKey :: public_key:public_key(),
.B
             Options) ->
.B
                ok | {error, Error :: term()}
.br
.fi
.br
.nf

.B
add_host_key(Host,
.B
             Port :: inet:port_number(),
.B
             PublicKey :: public_key:public_key(),
.B
             Options) ->
.B
                Result
.br
.fi
.br
.RS
.LP
Types:

.RS 3
Host = 
.br
    inet:ip_address() |
.br
    inet:hostname() |
.br
    [inet:ip_address() | inet:hostname()]
.br
Options = 
.br
    ssh_client_key_api:client_key_cb_options(call_ssh_file_option())
.br
Result = ok | {error, Error :: term()}
.br
.RE
.RE
.RS
.LP
This callback is delegated to the ssh_file module\&.
.RE

.LP
.nf

.B
is_host_key(Key :: public_key:public_key(),
.B
            Host :: string(),
.B
            Algorithm :: ssh:pubkey_alg(),
.B
            Options) ->
.B
               boolean()
.br
.fi
.br
.nf

.B
is_host_key(Key :: public_key:public_key(),
.B
            Host,
.B
            Port :: inet:port_number(),
.B
            Algorithm :: ssh:pubkey_alg(),
.B
            Options) ->
.B
               boolean()
.br
.fi
.br
.RS
.LP
Types:

.RS 3
Host = 
.br
    inet:ip_address() |
.br
    inet:hostname() |
.br
    [inet:ip_address() | inet:hostname()]
.br
Options = 
.br
    ssh_client_key_api:client_key_cb_options(call_ssh_file_option())
.br
.RE
.RE
.RS
.LP
This callback is delegated to the ssh_file module\&.
.RE

.LP
.nf

.B
user_key(Algorithm :: ssh:pubkey_alg(), Options) -> Result
.br
.fi
.br
.RS
.LP
Types:

.RS 3
Result = 
.br
    {ok, public_key:private_key()} |
.br
    {ok, {ssh2_pubkey, PubKeyBlob :: binary()}} |
.br
    {error, string()}
.br
Options = 
.br
    ssh_client_key_api:client_key_cb_options(socket_path_option() |
.br
                                             timeout_option())
.br
.RE
.RE
.RS
.LP
\fBTypes and description\fR\& 
.LP
See the api description in ssh_client_key_api, Module:user_key/2\&.
.RE