<?xml version="1.0" encoding="utf-8" ?>
<!DOCTYPE erlref SYSTEM "erlref.dtd">
<erlref>
<header>
<copyright>
<year>2018</year><year>2018</year>
<holder>Ericsson AB. All Rights Reserved.</holder>
</copyright>
<legalnotice>
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
</legalnotice>
<title>ssh_file</title>
<prepared></prepared>
<docno></docno>
<date></date>
<rev></rev>
</header>
<module>ssh_file</module>
<modulesummary>Default callback module for the client's and server's database operations in the ssh application</modulesummary>
<description>
<p>This module is the default callback handler for the client's and the server's user and host "database" operations.
</p>
<p>
The intention is to be compatible with the OpenSSH storage in files. Therefore it mimics directories and filenames
of OpenSSH.
</p>
<note>
<p>The functions are <i>Callbacks</i> for the SSH app. They are not intended to be called from the user's code!
</p>
</note>
</description>
<section>
<title>Making your own callback module</title>
<p>Ssh_file implements the <seealso marker="ssh:ssh_server_key_api">ssh_server_key_api</seealso> and
<seealso marker="ssh:ssh_client_key_api">ssh_client_key_api</seealso>.
This enables the user to make an own interface using for example a database handler.
</p>
<p>Such another callback module could be used by setting the option
<seealso marker="ssh:ssh#type-key_cb_common_option"><c>key_cb</c></seealso>
when starting a client or a server (with for example
<seealso marker="ssh:ssh#connect-3">ssh:connect</seealso>,
<seealso marker="ssh:ssh#daemon-2">ssh:daemon</seealso> of
<seealso marker="ssh:ssh#shell-1">ssh:shell</seealso>
).
</p>
</section>
<section>
<title>Files, directories and conventions</title>
<taglist>
<!--tag><marker id="REMOTEUSER"/>REMOTEUSER</tag>
<item>The user name sent by the client to the server.
<p/></item-->
<tag><marker id="LOCALUSER"/>LOCALUSER</tag>
<item>The user name of the OS process running the Erlang virtual machine (emulator).
<p/></item>
<tag><marker id="SYSDIR"/>SYSDIR</tag>
<item>SYSDIR is the directory holding the server's files:
<list>
<item><marker id="SYSDIR-ssh_host_dsa_key"/><c>ssh_host_dsa_key</c> - private dss host key (optional)</item>
<item><marker id="SYSDIR-ssh_host_rsa_key"/><c>ssh_host_rsa_key</c> - private rsa host key (optional)</item>
<item><marker id="SYSDIR-ssh_host_ecdsa_key"/><c>ssh_host_ecdsa_key</c> - private ecdsa host key (optional)</item>
</list>
<p>At least one host key must be defined. The default value of SYSDIR is <marker id="#/etc/ssh"/><c>/etc/ssh</c>.
</p>
</item>
<tag><marker id="USERDIR"/>USERDIR</tag>
<item>USERDIR is the directory holding the files:
<list>
<item><marker id="USERDIR-authorized_keys"/><c>authorized_keys</c> - list of keys allowed in public_key authorization (optional)</item>
<item><marker id="USERDIR-authorized_keys2"/><c>authorized_keys2</c> - list of keys allowed in public_key authorization (optional and unusual)</item>
<item><marker id="USERDIR-known_hosts"/><c>known_hosts</c> - list of hosts visited (created by the client)</item>
<item><marker id="USERDIR-id_dsa"/><c>id_dsa</c> - private dss user key (optional)</item>
<item><marker id="USERDIR-id_rsa"/><c>id_rsa</c> - private rsa user key (optional)</item>
<item><marker id="USERDIR-id_ecdsa"/><c>id_ecdsa</c> - private ecdsa user key (optional)</item>
</list>
<p>The default value of USERDIR is <c>/home/</c><seealso marker="#LOCALUSER"><c>LOCALUSER</c></seealso><c>/.ssh</c>.
See also the <seealso marker="ssh:ssh#type-user_dir_common_option">user_dir</seealso> common option.
</p></item>
</taglist>
</section>
<funcs>
<func>
<name>host_key(Algorithm, DaemonOptions) -> {ok, Key} | {error, Reason}</name>
<fsummary></fsummary>
<desc>
<p><strong>Types and description</strong></p>
<p>See the api description in
<seealso marker="ssh:ssh_server_key_api#Module:host_key-2">ssh_server_key_api, Module:host_key/2</seealso>.
</p>
<p><strong>Options</strong></p>
<list>
<item><c>{system_dir, </c><seealso marker="#SYSDIR">SYSDIR</seealso><c>}</c></item>
<!-- item>dsa_pass_phrase</item -->
<!-- item>rsa_pass_phrase</item -->
<!-- item>ecdsa_pass_phrase</item -->
</list>
<p><strong>Files</strong></p>
<list>
<item><seealso marker="#SYSDIR-ssh_host_rsa_key"><c>SYSDIR/ssh_host_rsa_key</c></seealso></item>
<item><seealso marker="#SYSDIR-ssh_host_dsa_key"><c>SYSDIR/ssh_host_dsa_key</c></seealso></item>
<item><seealso marker="#SYSDIR-ssh_host_ecdsa_key"><c>SYSDIR/ssh_host_ecdsa_key</c></seealso></item>
</list>
<p> </p>
</desc>
</func>
<func>
<name>is_auth_key(PublicUserKey, User, DaemonOptions) -> Result</name>
<fsummary></fsummary>
<desc>
<p><strong>Types and description</strong></p>
<p>See the api description in
<seealso marker="ssh:ssh_server_key_api#Module:is_auth_key-3">ssh_server_key_api: Module:is_auth_key/3</seealso>.
</p>
<p><strong>Options</strong></p>
<list>
<item><marker id="user_dir_fun"/><c>{user_dir_fun, fun(RemoteUser) -> USERDIR end}</c></item>
<item><c>{user_dir, </c><seealso marker="#USERDIR"><c>USERDIR</c></seealso><c>}</c></item>
</list>
<p><strong>Files</strong></p>
<list>
<item><seealso marker="#USERDIR-authorized_keys"><c>USERDIR/authorized_keys</c></seealso></item>
<item><seealso marker="#USERDIR-authorized_keys2"><c>USERDIR/authorized_keys2</c></seealso></item>
</list>
<p> </p>
</desc>
</func>
<func>
<name>add_host_key(HostNames, PublicHostKey, ConnectOptions) -> ok | {error, Reason}</name>
<fsummary></fsummary>
<desc>
<p><strong>Types and description</strong></p>
<p>See the api description in
<seealso marker="ssh:ssh_client_key_api#Module:add_host_key-3">ssh_client_key_api, Module:add_host_key/3</seealso>.
</p>
<p><strong>Option</strong></p>
<list>
<item><c>{user_dir, </c><seealso marker="#USERDIR"><c>USERDIR</c></seealso><c>}</c></item>
</list>
<p><strong>File</strong></p>
<list>
<item><seealso marker="#USERDIR-known_hosts"><c>USERDIR/known_hosts</c></seealso></item>
</list>
<p> </p>
</desc>
</func>
<func>
<name>is_host_key(Key, Host, Algorithm, ConnectOptions) -> Result</name>
<fsummary></fsummary>
<desc>
<p><strong>Types and description</strong></p>
<p>See the api description in
<seealso marker="ssh:ssh_client_key_api#Module:is_host_key-4">ssh_client_key_api, Module:is_host_key/4</seealso>.
</p>
<p><strong>Option</strong></p>
<list>
<item><c>{user_dir, </c><seealso marker="#USERDIR"><c>USERDIR</c></seealso><c>}</c></item>
</list>
<p><strong>File</strong></p>
<list>
<item><seealso marker="#USERDIR-known_hosts"><c>USERDIR/known_hosts</c></seealso></item>
</list>
<p> </p>
</desc>
</func>
<func>
<name>user_key(Algorithm, ConnectOptions) -> {ok, PrivateKey} | {error, Reason}</name>
<fsummary></fsummary>
<desc>
<p><strong>Types and description</strong></p>
<p>See the api description in
<seealso marker="ssh:ssh_client_key_api#Module:user_key-2">ssh_client_key_api, Module:user_key/2</seealso>.
</p>
<p><strong>Options</strong></p>
<list>
<item><c>{user_dir, </c><seealso marker="#USERDIR"><c>USERDIR</c></seealso><c>}</c></item>
<item><seealso marker="ssh:ssh#type-pubkey_passphrase_client_options"><c>{dsa_pass_phrase, PWD}</c></seealso></item>
<item><seealso marker="ssh:ssh#type-pubkey_passphrase_client_options"><c>{rsa_pass_phrase, PWD}</c></seealso></item>
<item><seealso marker="ssh:ssh#type-pubkey_passphrase_client_options"><c>{ecdsa_pass_phrase, PWD}</c></seealso></item>
</list>
<p><strong>Files</strong></p>
<list>
<item><seealso marker="#USERDIR-id_dsa"><c>USERDIR/id_dsa</c></seealso></item>
<item><seealso marker="#USERDIR-id_rsa"><c>USERDIR/id_rsa</c></seealso></item>
<item><seealso marker="#USERDIR-id_ecdsa"><c>USERDIR/id_ecdsa</c></seealso></item>
</list>
</desc>
</func>
</funcs>
</erlref>
