diff options
Diffstat (limited to 'docs/manual/mod/mod_authnz_fcgi.xml')
| -rw-r--r-- | docs/manual/mod/mod_authnz_fcgi.xml | 523 |
1 files changed, 523 insertions, 0 deletions
diff --git a/docs/manual/mod/mod_authnz_fcgi.xml b/docs/manual/mod/mod_authnz_fcgi.xml new file mode 100644 index 0000000000..e04e0d0ab6 --- /dev/null +++ b/docs/manual/mod/mod_authnz_fcgi.xml @@ -0,0 +1,523 @@ +<?xml version="1.0"?> +<!DOCTYPE modulesynopsis SYSTEM "../style/modulesynopsis.dtd"> +<?xml-stylesheet type="text/xsl" href="../style/manual.en.xsl"?> +<!-- $LastChangedRevision:$ --> + +<!-- + Licensed to the Apache Software Foundation (ASF) under one or more + contributor license agreements. See the NOTICE file distributed with + this work for additional information regarding copyright ownership. + The ASF licenses this file to You under the Apache License, Version 2.0 + (the "License"); you may not use this file except in compliance with + the License. You may obtain a copy of the License at + + http://www.apache.org/licenses/LICENSE-2.0 + + Unless required by applicable law or agreed to in writing, software + distributed under the License is distributed on an "AS IS" BASIS, + WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + See the License for the specific language governing permissions and + limitations under the License. +--> + +<modulesynopsis metafile="mod_authnz_fcgi.xml.meta"> + +<name>mod_authnz_fcgi</name> +<description>Allows a FastCGI authorizer application to handle Apache +httpd authentication and authorization</description> +<status>Extension</status> +<sourcefile>mod_authnz_fcgi.c</sourcefile> +<identifier>authnz_fcgi_module</identifier> + +<summary> + <p>This module allows FastCGI authorizer applications to + authenticate users and authorize access to resources. It supports + generic FastCGI authorizers which participate in a single phase + for authentication and authorization as well as Apache httpd-specific + authenticators and authorizors which participate in one or both + phases.</p> + + <p>FastCGI authorizers can authenticate using user id and password, + such as for Basic authentication, or can authenticate using arbitrary + mechanisms.</p> +</summary> + +<seealso><a href="../howto/auth.html">Authentication, Authorization, +and Access Control</a></seealso> +<seealso><module>mod_auth_basic</module></seealso> +<seealso><program>fcgistarter</program></seealso> + +<section id="invocations"><title>Invocation modes</title> + + <p>The invocation modes for FastCGI authorizers supported by this + module are distinguished by two characteristics, <em>type</em> and + auth <em>mechanism</em>.</p> + + <p><em>Type</em> is simply <code>authn</code> for authentication, + <code>authz</code> for authorization, or <code>authnz</code> for + combined authentication and authorization.</p> + + <p>Auth <em>mechanism</em> refers to the Apache httpd configuration + mechanisms and processing phases, and can be <code> + AuthBasicProvider</code>, <code>Require</code>, or <code> + check_user_id</code>. The first two of these + correspond to the directives used to enable participation in the + appropriate processing phase.</p> + + <p>Descriptions of each mode:</p> + + <dl> + <dt><em>Type</em> <code>authn</code>, <em>mechanism</em> + <code>AuthBasicProvider</code></dt> + + <dd>In this mode, + <code>FCGI_ROLE</code> is set to <code>AUTHORIZER</code> and + <code>FCGI_APACHE_ROLE</code> is set to <code>AUTHENTICATOR</code>. + The application must be defined as provider type <em>authn</em> + using <directive module="mod_authnz_fcgi"> + AuthnzFcgiDefineProvider</directive> and enabled with + <directive module="mod_auth_basic">AuthBasicProvider</directive>. + When invoked, the application is + expected to authenticate the client using the provided user id and + password. Example application: + +<highlight language="perl"> +#!/usr/bin/perl +use FCGI; +while (FCGI::accept >= 0) { + die if $ENV{'FCGI_APACHE_ROLE'} ne "AUTHENTICATOR"; + die if $ENV{'FCGI_ROLE'} ne "AUTHORIZER"; + die if !$ENV{'REMOTE_PASSWD'}; + die if !$ENV{'REMOTE_USER'}; + + print STDERR "This text is written to the web server error log.\n"; + + if ( ($ENV{'REMOTE_USER' } eq "foo" || $ENV{'REMOTE_USER'} eq "foo1") && + $ENV{'REMOTE_PASSWD'} eq "bar" ) { + print "Status: 200\n"; + print "Variable-AUTHN_1: authn_01\n"; + print "Variable-AUTHN_2: authn_02\n"; + print "\n"; + } + else { + print "Status: 401\n\n"; + } +} +</highlight> + + Example configuration: +<highlight language="config"> +AuthnzFcgiDefineProvider authn FooAuthn fcgi://localhost:10102/ +<Location /protected/> + AuthType Basic + AuthName "Restricted" + AuthBasicProvider FooAuthn + Require ... +</Location> +</highlight> + </dd> + + <dt><em>Type</em> <code>authz</code>, <em>mechanism</em> + <code>Require</code></dt> + <dd>In this mode, <code>FCGI_ROLE</code> is set to <code> + AUTHORIZER</code> and <code>FCGI_APACHE_ROLE</code> is set to + <code>AUTHORIZER</code>. The application must be defined as + provider type <em>authz</em> using <directive module="mod_authnz_fcgi"> + AuthnzFcgiDefineProvider</directive>. When invoked, the application + is expected to authorize the client using the provided user id and other + request data. Example application: +<highlight language="perl"> +#!/usr/bin/perl +use FCGI; +while (FCGI::accept >= 0) { + die if $ENV{'FCGI_APACHE_ROLE'} ne "AUTHORIZER"; + die if $ENV{'FCGI_ROLE'} ne "AUTHORIZER"; + die if $ENV{'REMOTE_PASSWD'}; + + print STDERR "This text is written to the web server error log.\n"; + + if ($ENV{'REMOTE_USER'} eq "foo1") { + print "Status: 200\n"; + print "Variable-AUTHZ_1: authz_01\n"; + print "Variable-AUTHZ_2: authz_02\n"; + print "\n"; + } + else { + print "Status: 403\n\n"; + } +} +</highlight> + + Example configuration: +<highlight language="config"> +AuthnzFcgiDefineProvider authz FooAuthz fcgi://localhost:10103/ +<Location /protected/> + AuthType ... + AuthName ... + AuthBasicProvider ... + Require FooAuthz +</Location> +</highlight> + </dd> + + <dt><em>Type</em> <code>authnz</code>, <em>mechanism</em> + <code>AuthBasicProvider</code> <em>+</em> <code>Require</code></dt> + + <dd>In this mode, which supports the web server-agnostic FastCGI + <code>AUTHORIZER</code> protocol, <code>FCGI_ROLE</code> is set to + <code>AUTHORIZER</code> and <code>FCGI_APACHE_ROLE</code> is not set. + The application must be defined as provider type <em>authnz</em> + using <directive module="mod_authnz_fcgi"> + AuthnzFcgiDefineProvider</directive>. The application is expected to + handle both authentication and authorization in the same invocation + using the user id, password, and other request data. The invocation + occurs during the Apache httpd API authentication phase. If the + application returns 200 and the same provider is invoked during the + authorization phase (via <directive>Require</directive>), mod_authnz_fcgi + will return success for the authorization phase without invoking the + application. Example application: +<highlight language="perl"> +#!/usr/bin/perl +use FCGI; +while (FCGI::accept >= 0) { + die if $ENV{'FCGI_APACHE_ROLE'}; + die if $ENV{'FCGI_ROLE'} ne "AUTHORIZER"; + die if !$ENV{'REMOTE_PASSWD'}; + die if !$ENV{'REMOTE_USER'}; + + print STDERR "This text is written to the web server error log.\n"; + + if ( ($ENV{'REMOTE_USER' } eq "foo" || $ENV{'REMOTE_USER'} eq "foo1") && + $ENV{'REMOTE_PASSWD'} eq "bar" && + $ENV{'REQUEST_URI'} =~ m%/bar/.*%) { + print "Status: 200\n"; + print "Variable-AUTHNZ_1: authnz_01\n"; + print "Variable-AUTHNZ_2: authnz_02\n"; + print "\n"; + } + else { + print "Status: 401\n\n"; + } +} +</highlight> + + Example configuration: +<highlight language="config"> +AuthnzFcgiDefineProvider authnz FooAuthnz fcgi://localhost:10103/ +<Location /protected/> + AuthType Basic + AuthName "Restricted" + AuthBasicProvider FooAuthnz + Require FooAuthnz +</Location> +</highlight> + </dd> + + <dt><em>Type</em> <code>authn</code>, <em>mechanism</em> + <code>check_user_id</code></dt> + + <dd>In this mode, <code>FCGI_ROLE</code> is set to <code> + AUTHORIZER</code> and <code>FCGI_APACHE_ROLE</code> is set to + <code>AUTHENTICATOR</code>. The application must be defined as + provider type <em>authn</em> using <directive module="mod_authnz_fcgi"> + AuthnzFcgiDefineProvider</directive>. <directive + module="mod_authnz_fcgi">AuthnzFcgiCheckAuthnProvider</directive> + specifies when it is called. Example application: +<highlight language="perl"> +#!/usr/bin/perl +use FCGI; +while (FCGI::accept >= 0) { + die if $ENV{'FCGI_APACHE_ROLE'} ne "AUTHENTICATOR"; + die if $ENV{'FCGI_ROLE'} ne "AUTHORIZER"; + + # This authorizer assumes that the RequireBasicAuth option of + # AuthnzFcgiCheckAuthnProvider is On: + die if !$ENV{'REMOTE_PASSWD'}; + die if !$ENV{'REMOTE_USER'}; + + print STDERR "This text is written to the web server error log.\n"; + + if ( ($ENV{'REMOTE_USER' } eq "foo" || $ENV{'REMOTE_USER'} eq "foo1") && + $ENV{'REMOTE_PASSWD'} eq "bar" ) { + print "Status: 200\n"; + print "Variable-AUTHNZ_1: authnz_01\n"; + print "Variable-AUTHNZ_2: authnz_02\n"; + print "\n"; + } + else { + print "Status: 401\n\n"; + # If a response body is written here, it will be returned to + # the client. + } +} +</highlight> + + Example configuration: +<highlight language="config"> +AuthnzFcgiDefineProvider authn FooAuthn fcgi://localhost:10103/ +<Location /protected/> + AuthType ... + AuthName ... + AuthnzFcgiCheckAuthnProvider FooAuthn \ + Authoritative On \ + RequireBasicAuth Off \ + UserExpr "%{reqenv:REMOTE_USER}" + Require ... +</Location> +</highlight> + </dd> + + </dl> + +</section> + +<section id="examples"><title>Additional examples</title> + + <ol> + <li>If your application supports the separate authentication and + authorization roles (<code>AUTHENTICATOR</code> and <code>AUTHORIZER</code>), define + separate providers as follows, even if they map to the same + application: + +<highlight language="config"> +AuthnzFcgiDefineProvider authn FooAuthn fcgi://localhost:10102/ +AuthnzFcgiDefineProvider authz FooAuthz fcgi://localhost:10102/ +</highlight> + + Specify the authn provider on + <directive module="mod_auth_basic">AuthBasicProvider</directive> + and the authz provider on + <directive module="mod_authz_core">Require</directive>: + +<highlight language="config"> +AuthType Basic +AuthName "Restricted" +AuthBasicProvider FooAuthn +Require FooAuthz +</highlight> + </li> + + <li>If your application supports the generic <code>AUTHORIZER</code> role + (authentication and authorizer in one invocation), define a + single provider as follows: + +<highlight language="config"> +AuthnzFcgiDefineProvider authnz FooAuthnz fcgi://localhost:10103/ +</highlight> + + Specify the authnz provider on both <directive>AuthBasicProvider</directive> + and <directive>Require</directive>: + +<highlight language="config"> +AuthType Basic +AuthName "Restricted" +AuthBasicProvider FooAuthnz +Require FooAuthnz +</highlight> + </li> +</ol> +</section> + +<section id="limitations"><title>Limitations</title> + + <p>The following are potential features which are not currently + implemented:</p> + + <dl> + <dt>Apache httpd access checker</dt> + <dd>The Apache httpd API <em>access check</em> phase is a separate + phase from authentication and authorization. Some other FastCGI + implementations implement this phase, which is denoted by the + setting of <code>FCGI_APACHE_ROLE</code> to <code>ACCESS_CHECKER</code>.</dd> + + <dt>Local (Unix) sockets or pipes</dt> + <dd>Only TCP sockets are currently supported.</dd> + + <dt>Support for mod_authn_socache</dt> + <dd>mod_authn_socache interaction should be implemented for + applications which participate in Apache httpd-style + authentication.</dd> + + <dt>Support for digest authentication using AuthDigestProvider</dt> + <dd>This is expected to be a permanent limitation as there is + no authorizer flow for retrieving a hash.</dd> + + <dt>Application process management</dt> + <dd>This is expected to be permanently out of scope for + this module. Application processes must be controlled by + other means. For example, <program>fcgistarter</program> can be used to + start them.</dd> + + <dt>AP_AUTH_INTERNAL_PER_URI</dt> + <dd>All providers are currently registered as + AP_AUTH_INTERNAL_PER_CONF, which means that checks are not + performed again for internal subrequests with the same + access control configuration as the initial request.</dd> + + <dt>Protocol data charset conversion</dt> + <dd>If mod_authnz_fcgi runs in an EBCDIC compilation + environment, all FastCGI protocol data is written in EBCDIC + and expected to be received in EBCDIC.</dd> + + <dt>Multiple requests per connection</dt> + <dd>Currently the connection to the FastCGI authorizer is + closed after every phase of processing. For example, if the + authorizer handles separate <em>authn</em> and <em>authz</em> + phases then two connections will be used.</dd> + + <dt>URI Mapping</dt> + <dd>URIs from clients can't be mapped, such as with the <directive> + ProxyPass</directive> used with FastCGI responders.</dd> + + </dl> + +</section> + +<section id="logging"><title>Logging</title> + + <ol> + <li>Processing errors are logged at log level <code>error</code> + and higher.</li> + <li>Messages written by the application are logged at log + level <code>warn</code>.</li> + <li>General messages for debugging are logged at log level + <code>debug</code>.</li> + <li>Environment variables passed to the application are + logged at log level <code>trace2</code>. The value of the + <code>REMOTE_PASSWD</code> variable will be obscured, + but <strong>any other sensitive data will be visible in the + log</strong>.</li> + <li>All I/O between the module and the FastCGI application, + including all environment variables, will be logged in printable + and hex format at log level <code>trace5</code>. <strong>All + sensitive data will be visible in the log.</strong></li> + </ol> + + <p><directive module="core">LogLevel</directive> can be used + to configure a log level specific to mod_authnz_fcgi. For + example:</p> + +<highlight language="config"> +LogLevel info authnz_fcgi:trace8 +</highlight> + +</section> + +<directivesynopsis> +<name>AuthnzFcgiDefineProvider</name> +<description>Defines a FastCGI application as a provider for +authentication and/or authorization</description> +<syntax>AuthnzFcgiDefineProvider <em>type</em> <em>provider-name</em> +<em>backend-address</em></syntax> +<default>none</default> +<contextlist><context>server config</context></contextlist> +<usage> + <p>This directive is used to define a FastCGI application as + a provider for a particular phase of authentication or + authorization.</p> + + <dl> + <dt><em>type</em></dt> + <dd>This must be set to <em>authn</em> for authentication, + <em>authz</em> for authentication, or <em>authnz</em> for + a generic FastCGI authorizer which performs both checks.</dd> + + <dt><em>provider-name</em></dt> + <dd>This is used to assign a name to the provider which is + used in other directives such as + <directive module="mod_auth_basic">AuthBasicProvider</directive> + and + <directive module="mod_authz_core">Require</directive>.</dd> + + <dt><em>backend-address</em></dt> + <dd>This specifies the address of the application, in the form + <em>fcgi://hostname:port/</em>. The application process(es) + must be managed independently, such as with + <program>fcgistarter</program>.</dd> + </dl> +</usage> +</directivesynopsis> + +<directivesynopsis> +<name>AuthnzFcgiCheckAuthnProvider</name> +<description>Enables a FastCGI application to handle the check_authn +authentication hook.</description> +<syntax>AuthnzFcgiCheckAuthnProvider <em>provider-name</em>|<code>None</code> +<em>option</em> ...</syntax> +<default>none</default> +<contextlist><context>directory</context></contextlist> +<usage> + <p>This directive is used to enable a FastCGI authorizer to + handle a specific processing phase of authentication or + authorization.</p> + + <p>Some capabilities of FastCGI authorizers require enablement + using this directive instead of + <directive>AuthBasicProvider</directive>:</p> + + <ul> + <li>Non-Basic authentication; generally, determining the user + id of the client and returning it from the authorizer; see the + <code>UserExpr</code> option below</li> + <li>Selecting a custom response code; for a non-200 response + from the authorizer, the code from the authorizer will be the + status of the response</li> + <li>Setting the body of a non-200 response; if the authorizer + provides a response body with a non-200 response, that body + will be returned to the client; up to 8192 bytes of text are + supported</li> + </ul> + + <dl> + <dt><em>provider-name</em></dt> + <dd>This is the name of a provider defined with <directive> + AuthnzFcgiDefineProvider</directive>.</dd> + + <dt><code>None</code></dt> + <dd>Specify <code>None</code> to disable a provider enabled + with this directive in an outer scope, such as in a parent + directory.</dd> + + <dt><em>option</em></dt> + <dd>The following options are supported: + + <dl> + <dt>Authoritative On|Off (default On)</dt> + <dd>This controls whether or not other modules are allowed + to run when this module has a FastCGI authorizer configured + and it fails the request.</dd> + + <dt>DefaultUser <em>userid</em></dt> + <dd>When the authorizer returns success and <code>UserExpr</code> + is configured and evaluates to an empty string (e.g., authorizer + didn't return a variable), this value will be used as the user + id. This is typically used when the authorizer has a concept of + guest, or unauthenticated, users and guest users are mapped to + some specific user id for logging and other purposes.</dd> + + <dt>RequireBasicAuth On|Off (default Off)</dt> + <dd>This controls whether or not Basic auth is required + before passing the request to the authorizer. If required, + the authorizer won't be invoked without a user id and + password; 401 will be returned for a request without that.</dd> + + <dt>UserExpr <em>expr</em> (no default)</dt> + <dd>When Basic authentication isn't provided by the client + and the authorizer determines the user, this expression, + evaluated after calling the authorizer, determines the + user. The expression follows <a href="../expr.html"> + ap_expr syntax</a> and must resolve to a string. A typical + use is to reference a <code>Variable-<em>XXX</em></code> + setting returned by the authorizer using an option like + <code>UserExpr "%{reqenv:<em>XXX</em>}"</code>. If + this option is specified and the user id can't be retrieved + using the expression after a successful authentication, the + request will be rejected with a 500 error.</dd> + + </dl> + </dd> + </dl> +</usage> +</directivesynopsis> + +</modulesynopsis> |