diff options
Diffstat (limited to 'lib/ssh/doc/src/ssh.xml')
| -rw-r--r-- | lib/ssh/doc/src/ssh.xml | 56 |
1 files changed, 55 insertions, 1 deletions
diff --git a/lib/ssh/doc/src/ssh.xml b/lib/ssh/doc/src/ssh.xml index 5c18c48f65..0e5a0706f5 100644 --- a/lib/ssh/doc/src/ssh.xml +++ b/lib/ssh/doc/src/ssh.xml @@ -61,6 +61,29 @@ </section> <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 this module, or abstractions to indicate the intended use of the data @@ -501,12 +524,43 @@ kex is implicit but public_key is set explicitly.</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()) -> boolean()}]]></c></tag> + <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: + <list type="bulleted"> + <item><c>true</c> if the user and password is valid and</item> + <item><c>false</c> otherwise.</item> + </list> + </p> + <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: + <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> + <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: + <list type="bulleted"> + <item><c>disconnect</c> if the connection should be closed immediately after sending a SSH_MSG_DISCONNECT + message.</item> + </list> + </p> + </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> |