diff options
Diffstat (limited to 'lib/ssh/doc/src/ssh.xml')
| -rw-r--r-- | lib/ssh/doc/src/ssh.xml | 272 |
1 files changed, 234 insertions, 38 deletions
diff --git a/lib/ssh/doc/src/ssh.xml b/lib/ssh/doc/src/ssh.xml index 6b49f89449..d9516fff12 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>2016</year> + <year>2004</year><year>2017</year> <holder>Ericsson AB. All Rights Reserved.</holder> </copyright> <legalnotice> @@ -108,6 +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> @@ -153,7 +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 @@ -175,22 +178,48 @@ supplied with this option. </p> </item> - <tag><c><![CDATA[{silently_accept_hosts, boolean() | accept_fun() | {crypto:digest_type(), accept_fun()} }]]></c> - <br/> - <c><![CDATA[accept_fun() :: fun(PeerName::string(), FingerPrint::string()) -> boolean()]]></c> + <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>When <c>true</c>, hosts are added to the - file <c><![CDATA[known_hosts]]></c> without asking the user. - Defaults to <c>false</c> which will give a user question on stdio of whether to accept or reject a previously - unseen host.</p> - <p>If the option value is has an <c>accept_fun()</c>, that fun will called with the arguments - <c>(PeerName, PeerHostKeyFingerPrint)</c>. The fingerprint is calculated on the Peer's Host Key with - <seealso marker="public_key:public_key#ssh_hostkey_fingerprint-1">public_key:ssh_hostkey_fingerprint/1</seealso>. - </p> - <p>If the <c>crypto:digest_type()</c> is present, the fingerprint is calculated with that digest type by the function - <seealso marker="public_key:public_key#ssh_hostkey_fingerprint-2">public_key:ssh_hostkey_fingerprint/2</seealso>. - </p> + <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[{user_interaction, boolean()}]]></c></tag> <item> @@ -200,7 +229,7 @@ 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> @@ -217,31 +246,19 @@ <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 will be removed in OTP 20, but is kept for compatibility. It is ignored if - the preferred <c>pref_public_key_algs</c> option is used.</p> - </note> - <p>Sets the preferred public key algorithm to use for user - authentication. If the preferred algorithm fails, - the other algorithm is tried. If <c>{public_key_alg, 'ssh-rsa'}</c> is set, it is translated - to <c>{pref_public_key_algs, ['ssh-rsa','ssh-dss']}</c>. If it is - <c>{public_key_alg, 'ssh-dss'}</c>, it is translated - to <c>{pref_public_key_algs, ['ssh-dss','ssh-rsa']}</c>. - </p> - </item> - <tag><c><![CDATA[{pref_public_key_algs, list()}]]></c></tag> <item> <p>List of user (client) public key algorithms to try to use.</p> - <p>The default value is - <c><![CDATA[['ssh-rsa','ssh-dss','ecdsa-sha2-nistp256','ecdsa-sha2-nistp384','ecdsa-sha2-nistp521'] ]]></c> + <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> - <p>If there is no public key of a specified type available, the corresponding entry is ignored.</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>. @@ -262,6 +279,8 @@ 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 know exactly what you are doing. If you do not understand the values then you @@ -269,6 +288,62 @@ </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. @@ -282,6 +357,15 @@ 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> @@ -289,6 +373,7 @@ <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. @@ -296,6 +381,30 @@ password, if the password authentication method is attempted.</p> </item> + + <!--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 @@ -305,6 +414,7 @@ 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> @@ -368,7 +478,7 @@ 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> @@ -379,6 +489,26 @@ <p>Starts a server listening for SSH connections on the given 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> @@ -435,6 +565,7 @@ 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}]]></c> @@ -486,6 +617,8 @@ 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 know exactly what you are doing. If you do not understand the values then you @@ -493,6 +626,41 @@ </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> 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. @@ -639,6 +807,27 @@ </p> </item> + <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 @@ -688,6 +877,12 @@ <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> @@ -700,9 +895,10 @@ </func> <func> - <name>daemon_info(Daemon) -> {ok, [{port,Port}]} | {error,Error}</name> + <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> |