Apache HTTP Server Version 2.5

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# Apache Module mod_authn_core

Description: | Core Authentication
Status: | Base
Module Identifier: | authn_core_module
Source File: | mod_authn_core.c
Compatibility: | Available in Apache 2.3 and later

### Summary

This module provides core authentication capabilities to allow or deny access to portions of the web site. `mod_authn_core` provides directives that are common to all authentication providers.

### Topics

- Creating Authentication Provider Aliases

### Directives

### Bugfix checklist

- httpd changelog
- Known issues
- Report a bug

## Creating Authentication Provider Aliases ¶

Extended authentication providers can be created within the configuration file and assigned an alias name. The alias providers can then be referenced through the directives `AuthBasicProvider` or `AuthDigestProvider` in the same way as a base authentication provider. Besides the ability to create and alias an extended provider, it also allows the same extended authentication provider to be reference by multiple locations.

### Examples

This example checks for passwords in two different text files.

### Checking multiple text password files

    # Check here first
    <AuthnProviderAlias file file1>
        AuthUserFile "/www/conf/passwords1"
    </AuthnProviderAlias>

    # Then check here
    <AuthnProviderAlias file file2>
        AuthUserFile "/www/conf/passwords2"
    </AuthnProviderAlias>

    <Directory "/var/web/pages/secure">
        AuthBasicProvider file1 file2

        AuthType Basic
        AuthName "Protected Area"
        Require valid-user
    </Directory>

The example below creates two different ldap authentication provider aliases based on the ldap provider. This allows a single authenticated location to be serviced by multiple ldap hosts:

### Checking multiple LDAP servers

    <AuthnProviderAlias ldap ldap-alias1>
        AuthLDAPBindDN "cn=youruser,o=ctx"
        AuthLDAPBindPassword yourpassword
        AuthLDAPURL "ldap://ldap.host/o=ctx"
    </AuthnProviderAlias>
    <AuthnProviderAlias ldap ldap-other-alias>
        AuthLDAPBindDN "cn=yourotheruser,o=dev"
        AuthLDAPBindPassword yourotherpassword
        AuthLDAPURL "ldap://other.ldap.host/o=dev?cn"
    </AuthnProviderAlias>

    Alias "/secure" "/webpages/secure"
    <Directory "/webpages/secure">
        AuthBasicProvider ldap-other-alias  ldap-alias1

        AuthType Basic
        AuthName "LDAP Protected Place"
        Require valid-user
        # Note that Require ldap-* would not work here, since the
        # AuthnProviderAlias does not provide the config to authorization providers
        # that are implemented in the same module as the authentication provider.
    </Directory>

## AuthName Directive ¶

Description: | Authorization realm for use in HTTP authentication
Syntax: | `AuthName auth-domain`
Context: | directory, .htaccess
Override: | AuthConfig
Status: | Base
Module: | mod_authn_core

This directive sets the name of the authorization realm for a directory. This realm is given to the client so that the user knows which username and password to send. `AuthName` takes a single argument; if the realm name contains spaces, it must be enclosed in quotation marks. It must be accompanied by `AuthType` and `Require` directives, and directives such as `AuthUserFile` and `AuthGroupFile` to work.

For example:

    AuthName "Top Secret"

The string provided for the `AuthName` is what will appear in the password dialog provided by most browsers.

From 2.5.0, expression syntax can be used inside the directive to produce the name dynamically.

For example:

    AuthName "%{HTTP_HOST}"

### See also

- Authentication, Authorization, and Access Control
- `mod_authz_core`

## <AuthnProviderAlias> Directive ¶

Description: | Enclose a group of directives that represent an extension of a base authentication provider and referenced by the specified alias
Syntax: | `<AuthnProviderAlias baseProvider Alias> ... </AuthnProviderAlias>`
Context: | server config
Status: | Base
Module: | mod_authn_core

`<AuthnProviderAlias>` and `</AuthnProviderAlias>` are used to enclose a group of authentication directives that can be referenced by the alias name using one of the directives `AuthBasicProvider` or `AuthDigestProvider`.

This directive has no affect on authorization, even for modules that provide both authentication and authorization.

## AuthType Directive ¶

Description: | Type of user authentication
Syntax: | `AuthType None|Basic|Digest|Form`
Context: | directory, .htaccess
Override: | AuthConfig
Status: | Base
Module: | mod_authn_core

This directive selects the type of user authentication for a directory. The authentication types available are `None`, `Basic` (implemented by `mod_auth_basic`), `Digest` (implemented by `mod_auth_digest`), and `Form` (implemented by `mod_auth_form`).

To implement authentication, you must also use the `AuthName` and `Require` directives. In addition, the server must have an authentication-provider module such as `mod_authn_file` and an authorization module such as `mod_authz_user`.

The authentication type `None` disables authentication. When authentication is enabled, it is normally inherited by each subsequent configuration section, unless a different authentication type is specified. If no authentication is desired for a subsection of an authenticated section, the authentication type `None` may be used; in the following example, clients may access the `/www/docs/public` directory without authenticating:

    <Directory "/www/docs">
        AuthType Basic
        AuthName Documents
        AuthBasicProvider file
        AuthUserFile "/usr/local/apache/passwd/passwords"
        Require valid-user
    </Directory>

    <Directory "/www/docs/public">
        AuthType None
        Require all granted
    </Directory>

From 2.5.0, expression syntax can be used inside the directive to specify the type dynamically.

When disabling authentication, note that clients which have already authenticated against another portion of the server's document tree will typically continue to send authentication HTTP headers or cookies with each request, regardless of whether the server actually requires authentication for every resource.

### See also

- Authentication, Authorization, and Access Control