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Apache HTTP Server Version 1.3
Module mod_auth
This module provides for user authentication using text files.
Status:
Base
Source
File: mod_auth.c
Module
Identifier: auth_module
Summary
This module allows the use of HTTP Basic Authentication to restrict access by looking up
users in plain text password and group files. Similar functionality and greater scalability is
provided by mod_auth_dbm and
mod_auth_db. HTTP Digest
Authentication is provided by
mod_auth_digest.
Note that these credential-based security mechanisms are only as strong as your Web
server's security. As a rule, they are not as strong as the operating system's own
security system.
Directives
See also: require,
satisfy, and
mod_auth
require keywords.
The mod_auth module supports the following keywords that can be given to the
Require directive:
user username [...]
- The supplied username and password must be in the
AuthUserFile
database, and the username must also be one of those listed on the Require directive.
group groupname [...]
- The supplied username and password must be in the
AuthUserFile
database, and the username must also be a member of one of the named groups in the
AuthGroupFile database.
valid-user
- The supplied username and password must be in the
AuthUserFile
database. Any valid username from that file will be allowed.
file-owner
- [Available after Apache 1.3.20] The supplied username and password must be in the
AuthUserFile database, and the username must also match the
system's name for the owner of the file being requested. That is, if the operating system
say the requested file is owned by
jones, then the username used to access it
through the Web must be jones as well.
file-group
- [Available after Apache 1.3.20] The supplied username and password must be in the
AuthUserFile database, the name of the group that owns the file
must be in the AuthGroupFile database, and the username must
be a member of that group. For example, if the operating system says the requested file is
owned by group
accounts, the group accounts must be in the
AuthGroupFile database and the username used in the request must be a member of that
group.
Consider a multi-user system running the Apache Web server, with each user having his or
her own files in ~/public_html/private. Assuming that there is a single
AuthUserFile database that lists all of their usernames, and that their Web usernames match
the ones that actually own the files on the server, then the following stanza would allow only
the user himself access to his own files. User jones would not be allowed to
access files in /home/smith/public_html/private unless they were owned by jones
instead of smith.
<Directory /home/*/public_html/private>
AuthType Basic
AuthName MyPrivateFile
AuthUserFile /usr/local/apache/etc/.htpasswd-allusers
Satisfy All
Require file-owner
</Directory>
Syntax:
AuthGroupFile file-path
Context:
directory, .htaccess
Override:
AuthConfig
Status:
Base
Module:
mod_auth
The AuthGroupFile directive sets the name of a textual file containing the list of user
groups for user authentication. File-path is the path to the group file. If it is not
absolute (i.e., if it doesn't begin with a slash), it is treated as relative to the
ServerRoot.
Each line of the group file contains a groupname followed by a colon, followed by the
member usernames separated by spaces. Example:
mygroup: bob joe anne
Note that searching large text files is very inefficient;
AuthDBMGroupFile
should be used instead.
Security: make sure that the AuthGroupFile is stored outside the document tree of the
web-server; do not put it in the directory that it protects. Otherwise, clients will
be able to download the AuthGroupFile.
See also AuthName,
AuthType and
AuthUserFile.
Syntax:
AuthUserFile file-path
Context:
directory, .htaccess
Override:
AuthConfig
Status:
Base
Module:
mod_auth
The AuthUserFile directive sets the name of a textual file containing the list of users and
passwords for user authentication. File-path is the path to the user file. If it is
not absolute (i.e., if it doesn't begin with a slash), it is treated as relative to
the ServerRoot.
Each line of the user file contains a username followed by a colon, followed by the crypt()
encrypted password. The behavior of multiple occurrences of the same user is undefined.
The utility
htpasswd
which is installed as part of the binary distribution, or which can be found in src/support,
is used to maintain this password file. See the man page for more details. In
short
htpasswd -c Filename username
Create a password file 'Filename' with 'username' as the initial ID. It will prompt for the
password. htpasswd Filename username2
Adds or modifies in password file 'Filename' the 'username'.
Note that searching large text files is very inefficient;
AuthDBMUserFile
should be used instead.
- Security:
- Make sure that the AuthUserFile is stored outside the document tree of the web-server;
do not put it in the directory that it protects. Otherwise, clients may be able
to download the AuthUserFile.
- Also be aware that null usernames are permitted, and null passwords as well (through
Apache 1.3.20). If your AuthUserFile includes a line containing only a colon (':'), a '
Require
valid-user' will allow access if both the username and password in the credentials
are omitted.
See also AuthName,
AuthType and
AuthGroupFile.
Syntax:
AuthAuthoritative on|off
Default:
AuthAuthoritative on
Context:
directory, .htaccess
Override:
AuthConfig
Status:
Base
Module:
mod_auth
Setting the AuthAuthoritative directive explicitly to 'off' allows for
both authentication and authorization to be passed on to lower level modules (as defined in
the Configuration and modules.c files) if there is no userID
or rule matching the supplied userID. If there is a userID and/or rule
specified; the usual password and access checks will be applied and a failure will give an
Authorization Required reply.
So if a userID appears in the database of more than one module; or if a valid Require
directive applies to more than one module; then the first module will verify the credentials;
and no access is passed on; regardless of the AuthAuthoritative setting.
A common use for this is in conjunction with one of the database modules; such as
mod_auth_db.c,
mod_auth_dbm.c, mod_auth_msql.c,
and mod_auth_anon.c.
These modules supply the bulk of the user credential checking; but a few (administrator)
related accesses fall through to a lower level with a well protected AuthUserFile.
Default:
By default; control is not passed on; and an unknown userID or rule will result in an
Authorization Required reply. Not setting it thus keeps the system secure; and forces an NCSA
compliant behavior.
Security: Do consider the implications of allowing a user to allow fall-through in his .htaccess
file; and verify that this is really what you want; Generally it is easier to just secure a
single .htpasswd file, than it is to secure a database such as mSQL. Make sure that the
AuthUserFile is stored outside the document tree of the web-server; do not put it in
the directory that it protects. Otherwise, clients will be able to download the AuthUserFile.
See also AuthName,
AuthType and
AuthGroupFile.
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