mod_authn_alias Provides the ability to create extended authentication providers based on actual providers Extension mod_authn_alias.c authn_alias_module Available in Apache 2.1 and later

This module allows extended authentication providers to 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 LoadModule authn_alias_module modules/mod_authn_alias.so

<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>
Order deny,allow
Allow from all

AuthBasicProvider ldap-other-alias ldap-alias1

AuthType Basic
AuthName LDAP_Protected_Place
AuthzLDAPAuthoritative off
Require valid-user
 </Directory>
AuthnProviderAlias Enclose a group of directives that represent an extension of a base authentication provider and referenced by the specified alias <AuthnProviderAlias baseProvider Alias> ... </AuthnProviderAlias> server config

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.