diff options
Diffstat (limited to 'lib/ssh/doc/src/ssh.xml')
| -rw-r--r-- | lib/ssh/doc/src/ssh.xml | 506 |
1 files changed, 430 insertions, 76 deletions
diff --git a/lib/ssh/doc/src/ssh.xml b/lib/ssh/doc/src/ssh.xml index d24025ca4d..acf94ff6af 100644 --- a/lib/ssh/doc/src/ssh.xml +++ b/lib/ssh/doc/src/ssh.xml @@ -4,7 +4,7 @@ <erlref> <header> <copyright> - <year>2004</year><year>2014</year> + <year>2004</year><year>2017</year> <holder>Ericsson AB. All Rights Reserved.</holder> </copyright> <legalnotice> @@ -32,28 +32,33 @@ <modulesummary>Main API of the ssh application</modulesummary> <description> <p>Interface module for the <c>ssh</c> application.</p> + <p>See <seealso marker="ssh:SSH_app#supported">ssh(6)</seealso> for details of supported version, + algorithms and unicode support.</p> </description> - <section> - <title>SSH</title> - <marker id="supported"/> - <list type="bulleted"> - <item>For application dependencies see <seealso marker="SSH_app"> ssh(6)</seealso> </item> - <item>Supported SSH version is 2.0.</item> - <item>Supported public key algorithms: ssh-rsa and ssh-dss.</item> - <item>Supported MAC algorithms: hmac-sha2-256 and hmac-sha1.</item> - <item>Supported encryption algorithms: aes128-ctr, aes128-cb and 3des-cbc.</item> - <item>Supported key exchange algorithms: diffie-hellman-group1-sha1.</item> - <item>Supported compression algorithms: none, zlib, [email protected],</item> - <item>Supports unicode filenames if the emulator and the underlaying OS support it. - See section DESCRIPTION in the - <seealso marker="kernel:file">file</seealso> manual page in <c>kernel</c> - for information about this subject.</item> - <item>Supports unicode in shell and CLI.</item> - </list> - + <section> + <title>OPTIONS</title> + <p>The exact behaviour of some functions can be adjusted with the use of options which are documented together + with the functions. Generally could each option be used at most one time in each function call. If given two or more + times, the effect is not predictable unless explicitly documented.</p> + <p>The options are of different kinds:</p> + <taglist> + <tag>Limits</tag> + <item><p>which alters limits in the system, for example number of simultaneous login attempts.</p></item> + + <tag>Timeouts</tag> + <item><p>which give some defined behaviour if too long time elapses before a given event or action, + for example time to wait for an answer.</p></item> + + <tag>Callbacks</tag> + <item><p>which gives the caller of the function the possibility to execute own code on some events, + for example calling an own logging function or to perform an own login function</p></item> + + <tag>Behaviour</tag> + <item><p>which changes the systems behaviour.</p></item> + </taglist> </section> - + <section> <title>DATA TYPES</title> <p>Type definitions that are used more than once in @@ -80,6 +85,15 @@ <item><p><c>atom()</c> - Name of the Erlang module implementing the subsystem using the <c>ssh_channel</c> behavior, see <seealso marker="ssh_channel">ssh_channel(3)</seealso></p></item> + <tag><c>key_cb() =</c></tag> + <item> + <p><c>atom() | {atom(), list()}</c></p> + <p><c>atom()</c> - Name of the erlang module implementing the behaviours + <seealso marker="ssh_client_key_api">ssh_client_key_api</seealso> or + <seealso marker="ssh_client_key_api">ssh_client_key_api</seealso> as the + case maybe.</p> + <p><c>list()</c> - List of options that can be passed to the callback module.</p> + </item> <tag><c>channel_init_args() =</c></tag> <item><p><c>list()</c></p></item> @@ -94,6 +108,9 @@ <tag><c>double_algs() =</c></tag> <item><p><c>[{client2serverlist,simple_algs()},{server2client,simple_algs()}] | simple_algs()</c></p></item> + + <tag><c>modify_algs_list() =</c></tag> + <item><p><c>list( {append,algs_list()} | {prepend,algs_list()} | {rm,algs_list()} )</c></p></item> </taglist> </section> @@ -111,8 +128,10 @@ <func> <name>connect(Host, Port, Options) -> </name> - <name>connect(Host, Port, Options, Timeout) -> {ok, - ssh_connection_ref()} | {error, Reason}</name> + <name>connect(Host, Port, Options, Timeout) -> </name> + <name>connect(TcpSocket, Options) -> </name> + <name>connect(TcpSocket, Options, Timeout) -> + {ok, ssh_connection_ref()} | {error, Reason}</name> <fsummary>Connects to an SSH server.</fsummary> <type> <v>Host = string()</v> @@ -123,6 +142,8 @@ <v>Timeout = infinity | integer()</v> <d>Negotiation time-out in milli-seconds. The default value is <c>infinity</c>. For connection time-out, use option <c>{connect_timeout, timeout()}</c>.</d> + <v>TcpSocket = port()</v> + <d>The socket is supposed to be from <seealso marker="kernel:gen_tcp#connect-3">gen_tcp:connect</seealso> or <seealso marker="kernel:gen_tcp#accept-1">gen_tcp:accept</seealso> with option <c>{active,false}</c></d> </type> <desc> <p>Connects to an SSH server. No channel is started. This is done @@ -135,7 +156,7 @@ <item> <p>IP version to use.</p> </item> - <tag><c><![CDATA[{user_dir, string()}]]></c></tag> + <tag><marker id="opt_user_dir"></marker><c><![CDATA[{user_dir, string()}]]></c></tag> <item> <p>Sets the user directory, that is, the directory containing <c>ssh</c> configuration files for the user, such as @@ -157,13 +178,67 @@ supplied with this option. </p> </item> - <tag><c><![CDATA[{silently_accept_hosts, boolean()}]]></c></tag> + <tag><c><![CDATA[{ecdsa_pass_phrase, string()}]]></c></tag> + <item> + <p>If the user ECDSA key is protected by a passphrase, it can be + supplied with this option. + </p> + </item> + <tag> + <c><![CDATA[{silently_accept_hosts, boolean()}]]></c> <br/> + <c><![CDATA[{silently_accept_hosts, CallbackFun}]]></c> <br/> + <c><![CDATA[{silently_accept_hosts, {HashAlgoSpec, CallbackFun} }]]></c> <br/> + <br/> + <c><![CDATA[HashAlgoSpec = crypto:digest_type() | [ crypto:digest_type() ] ]]></c><br/> + <c><![CDATA[CallbackFun = fun(PeerName, FingerPrint) -> boolean()]]></c><br/> + <c><![CDATA[PeerName = string()]]></c><br/> + <c><![CDATA[FingerPrint = string() | [ string() ] ]]></c> + </tag> + <item> + <p>This option guides the <c>connect</c> function how to act when the connected server presents a Host + Key that the client has not seen before. The default is to ask the user with a question on stdio of whether to + accept or reject the new Host Key. + See also the option <seealso marker="#opt_user_dir"><c>user_dir</c></seealso> + for the path to the file <c>known_hosts</c> where previously accepted Host Keys are recorded. + </p> + <p>The option can be given in three different forms as seen above:</p> + <list> + <item>The value is a <c>boolean()</c>. The value <c>true</c> will make the client accept any unknown + Host Key without any user interaction. The value <c>false</c> keeps the default behaviour of asking the + the user on stdio. + </item> + <item>A <c>CallbackFun</c> will be called and the boolean return value <c>true</c> will make the client + accept the Host Key. A return value of <c>false</c> will make the client to reject the Host Key and therefore + also the connection will be closed. The arguments to the fun are: + <list type="bulleted"> + <item><c>PeerName</c> - a string with the name or address of the remote host.</item> + <item><c>FingerPrint</c> - the fingerprint of the Host Key as + <seealso marker="public_key:public_key#ssh_hostkey_fingerprint-1">public_key:ssh_hostkey_fingerprint/1</seealso> + calculates it. + </item> + </list> + </item> + <item>A tuple <c>{HashAlgoSpec, CallbackFun}</c>. The <c>HashAlgoSpec</c> specifies which hash algorithm + shall be used to calculate the fingerprint used in the call of the <c>CallbackFun</c>. The <c>HashALgoSpec</c> + is either an atom or a list of atoms as the first argument in + <seealso marker="public_key:public_key#ssh_hostkey_fingerprint-2">public_key:ssh_hostkey_fingerprint/2</seealso>. + If it is a list of hash algorithm names, the <c>FingerPrint</c> argument in the <c>CallbackFun</c> will be + a list of fingerprints in the same order as the corresponding name in the <c>HashAlgoSpec</c> list. + </item> + </list> + </item> + + <tag><c><![CDATA[{save_accepted_host, boolean()}]]></c></tag> <item> - <p>When <c>true</c>, hosts are added to the - file <c><![CDATA[known_hosts]]></c> without asking the user. - Defaults to <c>false</c>. + <p>If <c>true</c>, the client saves an accepted host key to avoid the + accept question the next time the same host is connected. If the option + <c>key_cb</c> is not present, the key is saved in the file "known_hosts". + </p> + <p>If <c>false</c>, the key is not saved and the key will still be unknown + at the next access of the same host. </p> </item> + <tag><c><![CDATA[{user_interaction, boolean()}]]></c></tag> <item> <p>If <c>false</c>, disables the client to connect to the server @@ -172,7 +247,7 @@ supplying a password. Defaults to <c>true</c>. Even if user interaction is allowed it can be suppressed by other options, such as <c>silently_accept_hosts</c> - and <c>password</c>. However, those optins are not always desirable + and <c>password</c>. However, those options are not always desirable to use from a security point of view.</p> </item> @@ -189,36 +264,24 @@ <p><c>Peer</c> is in the format of <c>{Host,Port}</c>.</p> </item> - <tag><c><![CDATA[{public_key_alg, 'ssh-rsa' | 'ssh-dss'}]]></c></tag> - <item> - <note> - <p>This option is kept for compatibility. It is ignored if the <c>preferred_algorithms</c> - option is used. The equivalence of <c>{public_key_alg,'ssh-dss'}</c> is - <c>{preferred_algorithms, [{public_key,['ssh-dss','ssh-rsa']}]}</c>.</p> - </note> - <p>Sets the preferred public key algorithm to use for user - authentication. If the preferred algorithm fails, - the other algorithm is tried. The default is - to try <c><![CDATA['ssh-rsa']]></c> first.</p> - </item> - <tag><c><![CDATA[{pref_public_key_algs, list()}]]></c></tag> <item> - <note> - <p>This option is kept for compatibility. It is ignored if the <c>preferred_algorithms</c> - option is used. The equivalence of <c>{pref_public_key_algs,['ssh-dss']}</c> is - <c>{preferred_algorithms, [{public_key,['ssh-dss']}]}</c>.</p> - </note> - <p>List of public key algorithms to try to use. - <c>'ssh-rsa'</c> and <c>'ssh-dss'</c> are available. - Overrides <c><![CDATA[{public_key_alg, 'ssh-rsa' | 'ssh-dss'}]]></c></p> + <p>List of user (client) public key algorithms to try to use.</p> + <p>The default value is the <c>public_key</c> entry in + <seealso marker="#default_algorithms/0">ssh:default_algorithms/0</seealso>. + </p> + <p>If there is no public key of a specified type available, the corresponding entry is ignored. + Note that the available set is dependent on the underlying cryptolib and current user's public keys. + </p> </item> - <tag><c><![CDATA[{preferred_algorithms, algs_list()}]]></c></tag> + <tag><marker id="option_preferred_algorithms"></marker> + <c><![CDATA[{preferred_algorithms, algs_list()}]]></c></tag> <item> <p>List of algorithms to use in the algorithm negotiation. The default <c>algs_list()</c> can be obtained from <seealso marker="#default_algorithms/0">default_algorithms/0</seealso>. </p> + <p>If an alg_entry() is missing in the algs_list(), the default value is used for that entry.</p> <p>Here is an example of this option:</p> <code> {preferred_algorithms, @@ -227,11 +290,14 @@ {server2client,['aes128-cbc','3des-cbc']}]}, {mac,['hmac-sha2-256','hmac-sha1']}, {compression,[none,zlib]} + ] } </code> - <p>The example specifies different algorithms in the two directions (client2server and server2client), for cipher but specifies the same -algorithms for mac and compression in both directions. The kex (key exchange) and public key algorithms are set to their default values, -kex is implicit but public_key is set explicitly.</p> + <p>The example specifies different algorithms in the two directions (client2server and server2client), + for cipher but specifies the same algorithms for mac and compression in both directions. + The kex (key exchange) is implicit but public_key is set explicitly.</p> + + <p>For background and more examples see the <seealso marker="configure_algos#introduction">User's Guide</seealso>.</p> <warning> <p>Changing the values can make a connection less secure. Do not change unless you @@ -240,12 +306,84 @@ kex is implicit but public_key is set explicitly.</p> </warning> </item> + <tag><marker id="option_modify_algorithms"></marker> + <c><![CDATA[{modify_algorithms, modify_algs_list()}]]></c></tag> + <item> + <p>Modifies the list of algorithms to use in the algorithm negotiation. The modifications are + applied after the option <c>preferred_algorithms</c> (if existing) is applied.</p> + <p>The algoritm for modifications works like this:</p> + <list> + <item> + <p>Input is the <c>modify_algs_list()</c> and a set of algorithms <c>A</c> + obtained from the <c>preferred_algorithms</c> option if existing, or else from the + <seealso marker="ssh#default_algorithms-0">ssh:default_algorithms/0</seealso>. + </p> + </item> + <item> + <p>The head of the <c>modify_algs_list()</c> modifies <c>A</c> giving the result <c>A'</c>.</p> + <p>The possible modifications are:</p> + <list> + <item> + <p>Append or prepend supported but not enabled algorithm(s) to the list of + algorithms. If the wanted algorithms already are in <c>A</c> they will first + be removed and then appended or prepended, + </p> + </item> + <item> + <p>Remove (rm) one or more algorithms from <c>A</c>. + </p> + </item> + </list> + </item> + <item> + <p>Repeat the modification step with the tail of <c>modify_algs_list()</c> and the resulting + <c>A'</c>. + </p> + </item> + </list> + <p>If an unsupported algorithm is in the <c>modify_algs_list()</c>, it will be silently ignored</p> + <p>If there are more than one modify_algorithms options, the result is undefined.</p> + <p>Here is an example of this option:</p> + <code> +{modify_algorithms, + [{prepend, [{kex, ['diffie-hellman-group1-sha1']}], + {rm, [{compression, [none]}]} + ] +} +</code> + <p>The example specifies that:</p> + <list> + <item><p>the old key exchange algorithm 'diffie-hellman-group1-sha1' should be + the main alternative. It will be the main alternative since it is prepened to the list</p> + </item> + <item><p>The compression algorithm none (= no compression) is removed so compression is enforced</p> + </item> + </list> + <p>For background and more examples see the <seealso marker="configure_algos#introduction">User's Guide</seealso>.</p> + </item> + + <tag><c><![CDATA[{dh_gex_limits,{Min=integer(),I=integer(),Max=integer()}}]]></c></tag> + <item> + <p>Sets the three diffie-hellman-group-exchange parameters that guides the connected server in choosing a group. + See RFC 4419 for the function of thoose. The default value is <c>{1024, 6144, 8192}</c>. + </p> + </item> + <tag><c><![CDATA[{connect_timeout, timeout()}]]></c></tag> <item> <p>Sets a time-out on the transport layer connection. For <c>gen_tcp</c> the time is in milli-seconds and the default value is <c>infinity</c>.</p> </item> + + <tag><c><![CDATA[{auth_methods, string()}]]></c></tag> + <item> + <p>Comma-separated string that determines which + authentication methods that the client shall support and + in which order they are tried. Defaults to + <c><![CDATA["publickey,keyboard-interactive,password"]]></c></p> + </item> + <tag><c><![CDATA[{user, string()}]]></c></tag> <item> <p>Provides a username. If this option is not given, <c>ssh</c> @@ -253,6 +391,7 @@ kex is implicit but public_key is set explicitly.</p> <c><![CDATA[USER]]></c> on UNIX, <c><![CDATA[USERNAME]]></c> on Windows).</p> </item> + <tag><c><![CDATA[{password, string()}]]></c></tag> <item> <p>Provides a password for password authentication. @@ -260,13 +399,40 @@ kex is implicit but public_key is set explicitly.</p> password, if the password authentication method is attempted.</p> </item> - <tag><c><![CDATA[{key_cb, atom()}]]></c></tag> + + <!--tag><c><![CDATA[{send_ext_info, boolean()}]]></c></tag> + <item> + <p>Send a list of extensions to the server if the server has asked for it. See + <url href="https://tools.ietf.org/html/draft-ietf-curdle-ssh-ext-info">Draft-ietf-curdle-ssh-ext-info (work in progress)</url> for details. + </p> + <p>Currently the client do not react on any extensions. + </p> + <p>Default value is <c>true</c>. + </p> + </item--> + + <tag><c><![CDATA[{recv_ext_info, boolean()}]]></c></tag> + <item> + <p>Tell the server that the client accepts extension negotiation. See + <url href="https://tools.ietf.org/html/draft-ietf-curdle-ssh-ext-info">Draft-ietf-curdle-ssh-ext-info (work in progress)</url> for details. + </p> + <p>Currently implemented extension is <c>server-sig-algs</c> which is the list of the server's preferred + user's public key algorithms. + </p> + <p>Default value is <c>true</c>. + </p> + </item> + + <tag><c><![CDATA[{key_cb, key_cb()}]]></c></tag> <item> - <p>Module implementing the behaviour - <seealso marker="ssh_client_key_api">ssh_client_key_api</seealso>. - Can be used to customize the handling of public keys. + <p>Module implementing the behaviour <seealso + marker="ssh_client_key_api">ssh_client_key_api</seealso>. Can be used to + customize the handling of public keys. If callback options are provided + along with the module name, they are made available to the callback + module via the options passed to it under the key 'key_cb_private'. </p> </item> + <tag><c><![CDATA[{quiet_mode, atom() = boolean()}]]></c></tag> <item> <p>If <c>true</c>, the client does not print anything on authorization.</p> @@ -323,20 +489,44 @@ kex is implicit but public_key is set explicitly.</p> <func> <name>daemon(Port) -> </name> <name>daemon(Port, Options) -> </name> - <name>daemon(HostAddress, Port, Options) -> {ok, - ssh_daemon_ref()} | {error, atom()}</name> + <name>daemon(HostAddress, Port, Options) -> </name> + <name>daemon(TcpSocket) -> </name> + <name>daemon(TcpSocket, Options) -> {ok, ssh_daemon_ref()} | {error, atom()}</name> <fsummary>Starts a server listening for SSH connections on the given port.</fsummary> <type> <v>Port = integer()</v> - <v>HostAddress = ip_address() | any</v> + <v>HostAddress = ip_address() | any | loopback</v> <v>Options = [{Option, Value}]</v> <v>Option = atom()</v> <v>Value = term()</v> + <v>TcpSocket = port()</v> + <d>The socket is supposed to be from <seealso marker="kernel:gen_tcp#connect-3">gen_tcp:connect</seealso> or <seealso marker="kernel:gen_tcp#accept-1">gen_tcp:accept</seealso> with option <c>{active,false}</c></d> </type> <desc> <p>Starts a server listening for SSH connections on the given - port.</p> + port. If the <c>Port</c> is 0, a random free port is selected. See + <seealso marker="#daemon_info/1">daemon_info/1</seealso> about how to find the selected port number.</p> + + <p>Please note that by historical reasons both the <c>HostAddress</c> argument and the inet socket option + <c>ip</c> set the listening address. This is a source of possible inconsistent settings.</p> + + <p>The rules for handling the two address passing options are:</p> + <list> + <item>if <c>HostAddress</c> is an IP-address, that IP-address is the listening address. + An 'ip'-option will be discarded if present.</item> + + <item>if <c>HostAddress</c> is <c>loopback</c>, the listening address + is <c>loopback</c> and an loopback address will be choosen by the underlying layers. + An 'ip'-option will be discarded if present.</item> + + <item>if <c>HostAddress</c> is <c>any</c> and no 'ip'-option is present, the listening address is + <c>any</c> and the socket will listen to all addresses</item> + + <item>if <c>HostAddress</c> is <c>any</c> and an 'ip'-option is present, the listening address is + set to the value of the 'ip'-option</item> + </list> + <p>Options:</p> <taglist> <tag><c><![CDATA[{inet, inet | inet6}]]></c></tag> @@ -393,12 +583,13 @@ kex is implicit but public_key is set explicitly.</p> authentication methods that the server is to support and in what order they are tried. Defaults to <c><![CDATA["publickey,keyboard-interactive,password"]]></c></p> + <p>Note that the client is free to use any order and to exclude methods.</p> </item> - <tag><c><![CDATA[{auth_method_kb_interactive_data, PromptTexts}]]> - <br/>where: - <br/>PromptTexts = kb_int_tuple() | fun(Peer::{IP::tuple(),Port::integer()}, User::string(), Service::string()) -> kb_int_tuple() - <br/>kb_int_tuple() = {Name::string(), Instruction::string(), Prompt::string(), Echo::boolean()}</c> + <tag><c><![CDATA[{auth_method_kb_interactive_data, PromptTexts}]]></c> + <br/><c>where:</c> + <br/><c>PromptTexts = kb_int_tuple() | fun(Peer::{IP::tuple(),Port::integer()}, User::string(), Service::string()) -> kb_int_tuple()</c> + <br/><c>kb_int_tuple() = {Name::string(), Instruction::string(), Prompt::string(), Echo::boolean()}</c> </tag> <item> <p>Sets the text strings that the daemon sends to the client for presentation to the user when using <c>keyboar-interactive</c> authentication. If the fun/3 is used, it is called when the actual authentication occurs and may therefore return dynamic data like time, remote ip etc.</p> @@ -428,6 +619,7 @@ kex is implicit but public_key is set explicitly.</p> <p>List of algorithms to use in the algorithm negotiation. The default <c>algs_list()</c> can be obtained from <seealso marker="#default_algorithms/0">default_algorithms/0</seealso>. </p> + <p>If an alg_entry() is missing in the algs_list(), the default value is used for that entry.</p> <p>Here is an example of this option:</p> <code> {preferred_algorithms, @@ -436,11 +628,14 @@ kex is implicit but public_key is set explicitly.</p> {server2client,['aes128-cbc','3des-cbc']}]}, {mac,['hmac-sha2-256','hmac-sha1']}, {compression,[none,zlib]} + ] } </code> - <p>The example specifies different algorithms in the two directions (client2server and server2client), for cipher but specifies the same -algorithms for mac and compression in both directions. The kex (key exchange) and public key algorithms are set to their default values, -kex is implicit but public_key is set explicitly.</p> + <p>The example specifies different algorithms in the two directions (client2server and server2client), + for cipher but specifies the same algorithms for mac and compression in both directions. + The kex (key exchange) is implicit but public_key is set explicitly.</p> + + <p>For background and more examples see the <seealso marker="configure_algos#introduction">User's Guide</seealso>.</p> <warning> <p>Changing the values can make a connection less secure. Do not change unless you @@ -449,12 +644,117 @@ kex is implicit but public_key is set explicitly.</p> </warning> </item> - <tag><c><![CDATA[{pwdfun, fun(User::string(), password::string()) -> boolean()}]]></c></tag> + <tag><marker id="option_modify_algorithms"></marker> + <c><![CDATA[{modify_algorithms, modify_algs_list()}]]></c></tag> + <item> + <p>Modifies the list of algorithms to use in the algorithm negotiation. The modifications are + applied after the option <c>preferred_algorithms</c> is applied (if existing)</p> + <p>The possible modifications are to:</p> + <list> + <item><p>Append or prepend supported but not enabled algorithm(s) to the list of + algorithms.</p><p>If the wanted algorithms already are in the list of algorithms, they will first + be removed and then appended or prepended. + </p> + </item> + <item><p>Remove (rm) one or more algorithms from the list of algorithms.</p></item> + </list> + <p>If an unsupported algorithm is in the list, it will be silently ignored</p> + + <p>Here is an example of this option:</p> + <code> +{modify_algorithms, + [{prepend, [{kex, ['diffie-hellman-group1-sha1']}], + {rm, [{compression, [none]}]} + ] +} +</code> + <p>The example specifies that:</p> + <list> + <item><p>the old key exchange algorithm 'diffie-hellman-group1-sha1' should be + the main alternative. It will be the main alternative since it is prepened to the list</p> + </item> + <item><p>The compression algorithm none (= no compression) is removed so compression is enforced</p> + </item> + </list> + <p>For background and more examples see the <seealso marker="configure_algos#introduction">User's Guide</seealso>.</p> + </item> + + <tag><c><![CDATA[{dh_gex_groups, [{Size=integer(),G=integer(),P=integer()}] | {file,filename()} {ssh_moduli_file,filename()} }]]></c></tag> + <item> + <p>Defines the groups the server may choose among when diffie-hellman-group-exchange is negotiated. + See RFC 4419 for details. The three variants of this option are: + </p> + <taglist> + <tag><c>{Size=integer(),G=integer(),P=integer()}</c></tag> + <item>The groups are given explicitly in this list. There may be several elements with the same <c>Size</c>. + In such a case, the server will choose one randomly in the negotiated Size. + </item> + <tag><c>{file,filename()}</c></tag> + <item>The file must have one or more three-tuples <c>{Size=integer(),G=integer(),P=integer()}</c> + terminated by a dot. The file is read when the daemon starts. + </item> + <tag><c>{ssh_moduli_file,filename()}</c></tag> + <item>The file must be in + <seealso marker="public_key:public_key#dh_gex_group/4">ssh-keygen moduli file format</seealso>. + The file is read when the daemon starts. + </item> + </taglist> + <p>The default list is fetched from the + <seealso marker="public_key:public_key#dh_gex_group/4">public_key</seealso> application. + </p> + </item> + + <tag><c><![CDATA[{dh_gex_limits,{Min=integer(),Max=integer()}}]]></c></tag> + <item> + <p>Limits what a client can ask for in diffie-hellman-group-exchange. + The limits will be + <c>{MaxUsed = min(MaxClient,Max), MinUsed = max(MinClient,Min)}</c> where <c>MaxClient</c> and + <c>MinClient</c> are the values proposed by a connecting client. + </p> + <p>The default value is <c>{0,infinity}</c>. + </p> + <p>If <c>MaxUsed < MinUsed</c> in a key exchange, it will fail with a disconnect. + </p> + <p>See RFC 4419 for the function of the Max and Min values.</p> + </item> + + <tag><c><![CDATA[{pwdfun, fun(User::string(), Password::string(), PeerAddress::{ip_adress(),port_number()}, State::any()) -> boolean() | disconnect | {boolean(),any()} }]]></c></tag> + <item> + <p>Provides a function for password validation. This could used for calling an external system or if + passwords should be stored as a hash. The fun returns: + </p> + <list type="bulleted"> + <item><c>true</c> if the user and password is valid and</item> + <item><c>false</c> otherwise.</item> + </list> + <p>This fun can also be used to make delays in authentication tries for example by calling + <seealso marker="stdlib:timer#sleep/1">timer:sleep/1</seealso>. To facilitate counting of failed tries + the <c>State</c> variable could be used. This state is per connection only. The first time the pwdfun + is called for a connection, the <c>State</c> variable has the value <c>undefined</c>. + The pwdfun can return - in addition to the values above - a new state + as: + </p> + <list type="bulleted"> + <item><c>{true, NewState:any()}</c> if the user and password is valid or</item> + <item><c>{false, NewState:any()}</c> if the user or password is invalid</item> + </list> + <p>A third usage is to block login attempts from a missbehaving peer. The <c>State</c> described above + can be used for this. In addition to the responses above, the following return value is introduced: + </p> + <list type="bulleted"> + <item><c>disconnect</c> if the connection should be closed immediately after sending a SSH_MSG_DISCONNECT + message.</item> + </list> + </item> + + <tag><c><![CDATA[{pwdfun, fun(User::string(), Password::string()) -> boolean()}]]></c></tag> <item> <p>Provides a function for password validation. This function is called with user and password as strings, and returns <c><![CDATA[true]]></c> if the password is valid and <c><![CDATA[false]]></c> otherwise.</p> + <p>This option (<c>{pwdfun,fun/2}</c>) is the same as a subset of the previous + (<c>{pwdfun,fun/4}</c>). It is kept for compatibility.</p> </item> <tag><c><![CDATA[{negotiation_timeout, integer()}]]></c></tag> @@ -485,6 +785,15 @@ kex is implicit but public_key is set explicitly.</p> </p> </item> + <tag><c><![CDATA[{max_channels, pos_integer()}]]></c></tag> + <item> + <p>The maximum number of channels with active remote subsystem that are accepted for + each connection to this daemon</p> + <p>By default, this option is not set. This means that the number is not limited. + </p> + </item> + + <tag><c><![CDATA[{parallel_login, boolean()}]]></c></tag> <item> <p>If set to false (the default value), only one login is handled at a time. @@ -516,11 +825,34 @@ kex is implicit but public_key is set explicitly.</p> </p> </item> - <tag><c><![CDATA[{key_cb, atom()}]]></c></tag> + <tag><c><![CDATA[{send_ext_info, boolean()}]]></c></tag> + <item> + <p>Send a list of extensions to the client if the client has asked for it. See + <url href="https://tools.ietf.org/html/draft-ietf-curdle-ssh-ext-info">Draft-ietf-curdle-ssh-ext-info (work in progress)</url> for details. + </p> + <p>Currently implemented extension is sending <c>server-sig-algs</c> which is the list of the server's preferred + user's public key algorithms. + </p> + <p>Default value is <c>true</c>. + </p> + </item> + + <!--tag><c><![CDATA[{recv_ext_info, boolean()}]]></c></tag> + <item> + <p>Tell the client that the server accepts extension negotiation. See + <url href="https://tools.ietf.org/html/draft-ietf-curdle-ssh-ext-info">Draft-ietf-curdle-ssh-ext-info (work in progress)</url> for details. + </p> + <p>Default value is <c>true</c>. + </p> + </item--> + + <tag><c><![CDATA[{key_cb, key_cb()}]]></c></tag> <item> - <p>Module implementing the behaviour - <seealso marker="ssh_server_key_api">ssh_server_key_api</seealso>. - Can be used to customize the handling of public keys. + <p>Module implementing the behaviour <seealso + marker="ssh_server_key_api">ssh_server_key_api</seealso>. Can be used to + customize the handling of public keys. If callback options are provided + along with the module name, they are made available to the callback + module via the options passed to it under the key 'key_cb_private'. </p> </item> @@ -563,6 +895,12 @@ kex is implicit but public_key is set explicitly.</p> <p><c>Peer</c> is in the format of <c>{Host,Port}</c>.</p> </item> + <tag><c><![CDATA[{idle_time, integer()}]]></c></tag> + <item> + <p>Sets a time-out on a connection when no channels are active. + Defaults to <c>infinity</c>.</p> + </item> + <tag><c><![CDATA[{ssh_msg_debug_fun, fun(ConnectionRef::ssh_connection_ref(), AlwaysDisplay::boolean(), Msg::binary(), LanguageTag::binary()) -> _}]]></c></tag> <item> <p>Provide a fun to implement your own logging of the SSH message SSH_MSG_DEBUG. The last three parameters are from the message, see RFC4253, section 11.3. The <c>ConnectionRef</c> is the reference to the connection on which the message arrived. The return value from the fun is not checked.</p> @@ -575,6 +913,19 @@ kex is implicit but public_key is set explicitly.</p> </func> <func> + <name>daemon_info(Daemon) -> {ok, [DaemonInfo]} | {error,Error}</name> + <fsummary>Get info about a daemon</fsummary> + <type> + <v>DaemonInfo = {port,Port::pos_integer()} | {listen_address, any|ip_address()} | {profile,atom()}</v> + <v>Port = integer()</v> + <v>Error = bad_daemon_ref</v> + </type> + <desc> + <p>Returns a key-value list with information about the daemon. For now, only the listening port is returned. This is intended for the case the daemon is started with the port set to 0.</p> + </desc> + </func> + + <func> <name>default_algorithms() -> algs_list()</name> <fsummary>Get a list declaring the supported algorithms</fsummary> <desc> @@ -598,12 +949,15 @@ kex is implicit but public_key is set explicitly.</p> <func> <name>shell(Host) -> </name> <name>shell(Host, Option) -> </name> - <name>shell(Host, Port, Option) -> _</name> + <name>shell(Host, Port, Option) -> </name> + <name>shell(TcpSocket) -> _</name> <fsummary>Starts an interactive shell over an SSH server.</fsummary> <type> <v>Host = string()</v> <v>Port = integer()</v> <v>Options - see ssh:connect/3</v> + <v>TcpSocket = port()</v> + <d>The socket is supposed to be from <seealso marker="kernel:gen_tcp#connect-3">gen_tcp:connect</seealso> or <seealso marker="kernel:gen_tcp#accept-1">gen_tcp:accept</seealso> with option <c>{active,false}</c></d> </type> <desc> <p>Starts an interactive shell over an SSH server on the @@ -626,7 +980,7 @@ kex is implicit but public_key is set explicitly.</p> <p>Utility function that starts the applications <c>crypto</c>, <c>public_key</c>, and <c>ssh</c>. Default type is <c>temporary</c>. For more information, see the <seealso marker="kernel:application">application(3)</seealso> - manual page in <c>kernel</c>.</p> + manual page in Kernel.</p> </desc> </func> @@ -639,7 +993,7 @@ kex is implicit but public_key is set explicitly.</p> <desc> <p>Stops the <c>ssh</c> application. For more information, see the <seealso marker="kernel:application">application(3)</seealso> - manual page in <c>kernel</c>.</p> + manual page in Kernel.</p> </desc> </func> |