mod_auth(3)

MODULE
mod_auth - User authentication using text files, dets or mnesia database.

DESCRIPTION

This module provides for basic user authentication using textual files, dets databases as well as mnesia databases. The following config directives are supported:

    *   <Directory>

    *   AuthDBType

    *   AuthAccessPassword

    *   AuthUserFile

    *   AuthGroupFile

    *   AuthName

    *   allow

    *   deny

    *   require

The Directory config directive is central to be able to restrict access to certain areas of the server. Please read about the Directory config directive.

DIRECTIVE: Directory

Syntax: <Directory regexp-filename>
 Default: - None -
 Module: mod_auth(3)
 Related: allow, deny, AuthAccessPassword AuthUserFile, AuthGroupFile, AuthName, require

<Directory> and </Directory> are used to enclose a group of directives which applies only to the named directory and sub-directories of that directory. regexp-filename is an extended regular expression (See regexp(3)). For example:
<Directory /usr/local/httpd[12]/htdocs>
     AuthAccessPassword sOmEpAsSwOrD
     AuthDBType plain
     AuthName My Secret Garden
     AuthUserFile /var/tmp/server_root/auth/user
     AuthGroupFile /var/tmp/server_root/auth/group
     require user ragnar edward
     require group group1
     allow from 123.145.244.5
</Directory>

If multiple directory sections match the directory (or its parents), then the directives are applied with the shortest match first. For example if you have one directory section for garden/ and one for garden/flowers, the garden/ section matches first.

DIRECTIVE: AuthDBType

Syntax: AuthDBType plain | dets | mnesia
 Default: - None -
 Module: mod_auth(3)
 Context: <Directory>
 Related: allow, deny, AuthAccessPassword, AuthName, AuthUserFile, AuthGroupFile, require

AuthDBType sets the type of authentication database that is used for the directory.The key difference between the different methods is that dynamic data can be saved when Mnesia and Dets is used.

If Mnesia is used as storage method, Mnesia must be started prio to the webserver. The first time Mnesia is started the schema and the tables must be created before Mnesia is started. A naive example of a module with two functions that creates and start mnesia is provided here. The function shall be sued the first time. first_start/0 creates the schema and the tables. The second function start/0 shall be used in consecutive startups. start/0 Starts Mnesia and wait for the tables to be initiated. This function must only be used when the schema and the tables already is created.

    -module(mnesia_test).
    -export([start/0,load_data/0]).
    -include("mod_auth.hrl").

    first_start()->
         mnesia:create_schema([node()]),
         mnesia:start(),
         mnesia:create_table(httpd_user,
                             [{type,bag},{disc_copies,[node()]},
                              {attributes,record_info(fields,httpd_user)}]),
         mnesia:create_table(httpd_group,
                             [{type,bag},{disc_copies,[node()]},
                             {attributes,record_info(fields,httpd_group)}]),
         mnesia:wait_for_tables([httpd_user,httpd_group],60000).
    start()->
        mnesia:start(),
        mnesia:wait_for_tables([httpd_user,httpd_group],60000).

To create the Mnesia tables we use two records defined in mod_auth.hrl so the file must be included.

The first function first_start/0 creates a schema that specify on which nodes the database shall reside. Then it starts Mnesia and creates the tables. The first argument is the name of the tables, the second argument is a list of options how the table will be created, see Mnesia documentation for more information. Since the current implementation of the mod_auth_mnesia saves one row for each user the type must be bag.

When the schema and the tables is created the second function start/0shall be used to start Mensia. It starts Mnesia and wait for the tables to be loaded. Mnesia use the directory specified as mnesia_dir at startup if specified, otherwise Mnesia use the current directory.

  Warning:

For security reasons, make sure that the Mnesia tables are stored outside the document tree of the Web server. If it is placed in the directory which it protects, clients will be able to download the tables.

  Note:

Only the dets and mnesia storage methods allow writing of dynamic user data to disk. plain is a read only method.

DIRECTIVE: AuthUserFile

Syntax: AuthUserFile filename
 Default: - None -
 Module: mod_auth(3)
 Context: <Directory>
 Related: allow, deny, AuthDBType, AuthAccessPassword, AuthGroupFile, AuthName, require

AuthUserFile sets the name of a file which contains the list of users and passwords for user authentication. filename can be either absolute or relative to the ServerRoot.

If using the plain storage method, this file is a plain text file, where each line contains a user name followed by a colon, followed by the non-encrypted password. The behavior is undefined if user names are duplicated. For example:
ragnar:s7Xxv7
edward:wwjau8

If using the dets storage method, the user database is maintained by dets and should not be edited by hand. Use the API in this module to create / edit the user database.

This directive is ignored if using the mnesia storage method.

  Warning:

For security reasons, make sure that the AuthUserFile is stored outside the document tree of the Web server. If it is placed in the directory which it protects, clients will be able to download it.

DIRECTIVE: AuthGroupFile

Syntax: AuthGroupFile filename
 Default: - None -
 Module: mod_auth(3)
 Context: <Directory>
 Related: allow, deny, AuthName, AuthUserFile, AuthDBType, AuthAccessPassword, require

AuthGroupFile sets the name of a file which contains the list of user groups for user authentication. filename can be either absolute or relative to the ServerRoot.

If you use the plain storage method, the group file is a plain text file, where each line contains a group name followed by a colon, followed by the member user names separated by spaces. For example:
group1: bob joe ante

If using the dets storage method, the group database is maintained by dets and should not be edited by hand. Use the API in this module to create / edit the group database.

This directive is ignored if using the mnesia storage method.

  Warning:

For security reasons, make sure that the AuthGroupFile is stored outside the document tree of the Web server. If it is placed in the directory which it protects, clients will be able to download it.

DIRECTIVE: AuthName

Syntax: AuthName auth-domain
 Default: - None -
 Module: mod_auth(3)
 Context: <Directory>
 Related: allow, deny, AuthGroupFile, AuthUserFile, AuthDBType, AuthAccessPassword, require

AuthName sets the name of the authorization realm (auth-domain) for a directory. This string informs the client about which user name and password to use.

DIRECTIVE: AuthAccessPassword

Syntax: AuthAccessPassword password
 Default: NoPassword
 Module: mod_auth(3)
 Context: <Directory>
 Related: allow, deny, AuthGroupFile, AuthUserFile, AuthDBType, AuthName, require

If AuthAccessPassword is set to other than NoPassword the password is required for all API calls. If the password is set to DummyPassword the password must be changed before any other API calls. To secure the authenticating data the password must be changed after the webserver is started since it otherwise is written in clear text in the configuration file.

DIRECTIVE: allow

Syntax: allow from host host ...
 Default: allow from all
 Module: mod_auth(3)
 Context: <Directory>
 Related: AuthAccessPassword, deny, AuthUserFile, AuthGroupFile, AuthName, AuthDBType require

allow defines a set of hosts which should be granted access to a given directory. host is one of the following:

    all:
        All hosts are allowed access.

    A regular expression (Read regexp(3)):
        All hosts having a numerical IP address matching the specific regular expression are allowed access.

For example:
allow from 123.34.56.11 150.100.23

The host 123.34.56.11 and all machines on the 150.100.23 subnet are allowed access.

DIRECTIVE: deny

Syntax: deny from host host ...
 Default: deny from all
 Module: mod_auth(3)
 Context: <Directory>
 Related: allow, AuthUserFile, AuthGroupFile, AuthName, AuthDBType, AuthAccessPassword, require

deny defines a set of hosts which should not be granted access to a given directory. host is one of the following:

    all:
        All hosts are denied access.

    A regular expression (Read regexp(3)):
        All hosts having a numerical IP address matching the specific regular expression are denied access.

For example:
deny from 123.34.56.11 150.100.23

The host 123.34.56.11 and all machines on the 150.100.23 subnet are denied access.

DIRECTIVE: require

Syntax: require entity-name entity entity ...
 Default: - None -
 Module: mod_auth(3)
 Context: <Directory>
 Related: allow, deny, AuthUserFile, AuthGroupFile, AuthName, AuthDBType, AuthAccessPassword

require defines users which should be granted access to a given directory using a secret password. The allowed syntaxes are:

    require user user-name user-name ...:
        Only the named users can access the directory.

    require group group-name group-name ...:
        Only users in the named groups can access the directory.

EWSAPI MODULE INTERACTION

Uses the following EWSAPI interaction data, if available:

    {real_name, {Path, AfterPath}}:
        as defined in mod_alias(3).

Exports the following EWSAPI interaction data, if possible:

    {remote_user, User}:
        The user name with which the user has authenticated himself.

Uses the following exported EWSAPI functions:

    *   mod_alias:path/3

EXPORTS

add_user(UserName, Options) -> true| {error, Reason}
add_user(UserName, Password, UserData, Port, Dir) -> true | {error, Reason}
add_user(UserName, Password, UserData, Address, Port, Dir) -> true | {error, Reason}

    Types
        UserName = string()
        Options = [Option]
        Option = {password, Password} | {userData, UserData} | {port, Port} | {addr, Address} | {dir, Directory} | {authPassword, AuthPassword}
        Password = string()
        UserData = term()
        Port = integer()
        Address = {A, B, C, D} | string() | undefined
        Dir = string()
        AuthPassword =string()
        Reason = term()

    add_user/2, add_user/5 and add_user/6 adds a user to the user database. If the operation is succesful, this function returns true. If an error occurs, {error, Reason} is returned. When add_user/2 is called the Password, UserData Port and Dir options is mandatory.

delete_user(UserName,Options) -> true | {error, Reason}
delete_user(UserName, Port, Dir) -> true | {error, Reason}
delete_user(UserName, Address, Port, Dir) -> true | {error, Reason}

    Types
        UserName = string()
        Options = [Option]
        Option = {port, Port} | {addr, Address} | {dir, Directory} | {authPassword, AuthPassword}
        Port = integer()
        Address = {A, B, C, D} | string() | undefined
        Dir = string()
        AuthPassword = string()
        Reason = term()

    delete_user/2, delete_user/3 and delete_user/4 deletes a user from the user database. If the operation is succesful, this function returns true. If an error occurs, {error, Reason} is returned. When delete_user/2 is called the Port and Dir options are mandatory.

get_user(UserName,Options) -> {ok, #httpd_user} |{error, Reason}
get_user(UserName, Port, Dir) -> {ok, #httpd_user} | {error, Reason}
get_user(UserName, Address, Port, Dir) -> {ok, #httpd_user} | {error, Reason}

    Types
        UserName = string()
        Options = [Option]
        Option = {port, Port} | {addr, Address} | {dir, Directory} | {authPassword, AuthPassword}
        Port = integer()
        Address = {A, B, C, D} | string() | undefined
        Dir = string()
        AuthPassword = string()
        Reason = term()

    get_user/2, get_user/3 and get_user/4 returns a httpd_user record containing the userdata for a specific user. If the user cannot be found, {error, Reason} is returned. When get_user/2 is called the Port and Dir options are mandatory.

list_users(Options) -> {ok, Users} | {error, Reason} <name>list_users(Port, Dir) -> {ok, Users} | {error, Reason}
list_users(Address, Port, Dir) -> {ok, Users} | {error, Reason}

    Types
        Options = [Option]
        Option = {port, Port} | {addr, Address} | {dir, Directory} | {authPassword, AuthPassword}
        Port = integer()
        Address = {A, B, C, D} | string() | undefined
        Dir = string()
        Users = list()
        AuthPassword = string()
        Reason = atom()

    list_users/1, list_users/2 and list_users/3 returns a list of users in the user database for a specific Port/Dir. When list_users/1 is called the Port and Dir options are mandatory.

add_group_member(GroupName, UserName, Options) -> true | {error, Reason}
add_group_member(GroupName, UserName, Port, Dir) -> true | {error, Reason}
add_group_member(GroupName, UserName, Address, Port, Dir) -> true | {error, Reason}

    Types
        GroupName = string()
        UserName = string()
        Options = [Option]
        Option = {port, Port} | {addr, Address} | {dir, Directory} | {authPassword, AuthPassword}
        Port = integer()
        Address = {A, B, C, D} | string() | undefined
        Dir = string()
        AuthPassword = string()
        Reason = term()

    add_group_member/3, add_group_member/4 and add_group_member/5 adds a user to a group. If the group does not exist, it is created and the user is added to the group. Upon successful operation, this function returns true. When add_group_members/3 is called the Port and Dir options are mandatory.

delete_group_member(GroupName, UserName, Options) -> true | {error, Reason}
delete_group_member(GroupName, UserName, Port, Dir) -> true | {error, Reason}
delete_group_member(GroupName, UserName, Address, Port, Dir) -> true | {error, Reason}

    Types
        GroupName = string()
        UserName = string()
        Options = [Option]
        Option = {port, Port} | {addr, Address} | {dir, Directory} | {authPassword, AuthPassword}
        Port = integer()
        Address = {A, B, C, D} | string() | undefined
        Dir = string()
        AuthPassword = string()
        Reason = term()

    delete_group_member/3, delete_group_member/4 and delete_group_member/5 deletes a user from a group. If the group or the user does not exist, this function returns an error, otherwise it returns true. When delete_group_member/3 is called the Port and Dir options are mandatory.

list_group_members(GroupName, Options) -> {ok, Users} | {error, Reason}
list_group_members(GroupName, Port, Dir) -> {ok, Users} | {error, Reason}
list_group_members(GroupName, Address, Port, Dir) -> {ok, Users} | {error, Reason}

    Types
        GroupName = string()
        Options = [Option]
        Option = {port, Port} | {addr, Address} | {dir, Directory} | {authPassword, AuthPassword}
        Port = integer()
        Address = {A, B, C, D} | string() | undefined
        Dir = string()
        Users = list()
        AuthPassword = string()
        Reason = term()

    list_group_members/2, list_group_members/3 and list_group_members/4 lists the members of a specified group. If the group does not exist or there is an error, {error, Reason} is returned. When list_group_members/2 is called the Port and Dir options are mandatory.

list_groups(Options) -> {ok, Groups} | {error, Reason}
list_groups(Port, Dir) -> {ok, Groups} | {error, Reason}
list_groups(Address, Port, Dir) -> {ok, Groups} | {error, Reason}

    Types
        Options = [Option]
        Option = {port, Port} | {addr, Address} | {dir, Directory} | {authPassword, AuthPassword}
        Port = integer()
        Address = {A, B, C, D} | string() | undefined
        Dir = string()
        Groups = list()
        AuthPassword = string()
        Reason = term()

    list_groups/1, list_groups/2 and list_groups/3 lists all the groups available. If there is an error, {error, Reason} is returned. When list_groups/1 is called the Port and Dir options are mandatory.

delete_group(GroupName, Options) -> true | {error,Reason} <name>delete_group(GroupName, Port, Dir) -> true | {error, Reason}
delete_group(GroupName, Address, Port, Dir) -> true | {error, Reason}

    Types
        Options = [Option]
        Option = {port, Port} | {addr, Address} | {dir, Directory} | {authPassword, AuthPassword}
        Port = integer()
        Address = {A, B, C, D} | string() | undefined
        Dir = string()
        GroupName = string()
        AuthPassword = string()
        Reason = term()

    delete_group/2, delete_group/3 and delete_group/4 deletes the group specified and returns true. If there is an error, {error, Reason} is returned. When delete_group/2 is called the Port and Dir options are mandatory.

update_password(Port, Dir, OldPassword, NewPassword, NewPassword) -> ok | {error, Reason}
update_password(Address,Port, Dir, OldPassword, NewPassword, NewPassword) -> ok | {error, Reason}

    Types
        Port = integer()
        Address = {A, B, C, D} | string() | undefined
        Dir = string()
        GroupName = string()
        OldPassword = string()
        NewPassword = string()
        Reason = term()

    update_password/5 and update_password/6 Updates the AuthAccessPassword for the specified directory. If NewPassword is equal to "NoPassword" no password is requires to change authorisation data. If NewPassword is equal to "DummyPassword" no changes can be done without changing the password first.

SEE ALSO

httpd(3), mod_alias(3),

AUTHORS
Mattias Nilsson  - support@erlang.ericsson.se
Original implementation: Joakim Grebenö  - support@erlang.ericsson.se