Apache HTTP Server Documentation Version 2.4 Apache Software Foundation January 24, 2015 ii About The PDF Documentation Licensed to the Apache Software Foundation (ASF) under one or more contributor license agreements. See the NO- TICE 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 This version of the Apache HTTP Server Documentation is converted from XML source files to LATEX using XSLT with the help of Apache Ant, Apache XML Xalan, and Apache XML Xerces. Since the HTML version of the documentation is more commonly checked during development, the PDF ver- sion may contain some errors and inconsistencies, especially in formatting. If you have difficulty reading a part of this file, please consult the HTML version of the documentation on the Apache HTTP Server website at http://httpd.apache.org/docs/2.4/ The Apache HTTP Server Documentation is maintained by the Apache HTTP Server Documentation Project. More information is available at http://httpd.apache.org/docs-project/ Contents 1 Release Notes 1 1.1 Upgrading to 2.4 from 2.2.......................................2 1.2 Overview of new features in Apache HTTP Server 2.4........................7 1.3 Overview of new features in Apache HTTP Server 2.2........................ 11 1.4 Overview of new features in Apache HTTP Server 2.0........................ 14 1.5 The Apache License, Version 2.0................................... 16 2 Using the Apache HTTP Server 19 2.1 Compiling and Installing....................................... 20 2.2 Starting Apache............................................ 25 2.3 Stopping and Restarting Apache HTTP Server............................ 27 2.4 Configuration Files.......................................... 30 2.5 Configuration Sections........................................ 33 2.6 Caching Guide............................................. 40 2.7 Server-Wide Configuration...................................... 51 2.8 Log Files................................................ 53 2.9 Mapping URLs to Filesystem Locations............................... 61 2.10 Dynamic Shared Object (DSO) Support............................... 65 2.11 Content Negotiation.......................................... 68 2.12 Custom Error Responses....................................... 75 2.13 Binding to Addresses and Ports.................................... 78 2.14 Multi-Processing Modules (MPMs).................................. 80 2.15 Environment Variables in Apache................................... 82 2.16 Expressions in Apache HTTP Server................................. 89 2.17 Apache’s Handler Use......................................... 98 2.18 Filters................................................. 100 2.19 Shared Object Cache in Apache HTTP Server............................ 104 2.20 suEXEC Support........................................... 105 2.21 Issues Regarding DNS and Apache HTTP Server.......................... 111 iii iv CONTENTS 3 Apache Virtual Host documentation 113 3.1 Apache Virtual Host documentation................................. 114 3.2 Name-based Virtual Host Support................................... 115 3.3 Apache IP-based Virtual Host Support................................ 118 3.4 Dynamically Configured Mass Virtual Hosting............................ 120 3.5 VirtualHost Examples......................................... 124 3.6 An In-Depth Discussion of Virtual Host Matching.......................... 131 3.7 File Descriptor Limits......................................... 134 4 URL Rewriting Guide 135 4.1 Apache mod rewrite.......................................... 136 4.2 Apache mod rewrite Introduction................................... 137 4.3 Redirecting and Remapping with mod rewrite............................ 142 4.4 Using mod rewrite to control access................................. 149 4.5 Dynamic mass virtual hosts with mod rewrite............................ 152 4.6 Using mod rewrite for Proxying................................... 155 4.7 Using RewriteMap........................................... 156 4.8 Advanced Techniques with mod rewrite............................... 162 4.9 When not to use mod rewrite..................................... 165 4.10 RewriteRule Flags........................................... 168 4.11 Apache mod rewrite Technical Details................................ 177 5 Apache SSL/TLS Encryption 181 5.1 Apache SSL/TLS Encryption..................................... 182 5.2 SSL/TLS Strong Encryption: An Introduction............................ 183 5.3 SSL/TLS Strong Encryption: Compatibility............................. 192 5.4 SSL/TLS Strong Encryption: How-To................................ 196 5.5 SSL/TLS Strong Encryption: FAQ.................................. 202 6 Guides, Tutorials, and HowTos 215 6.1 How-To / Tutorials........................................... 216 6.2 Authentication and Authorization................................... 217 6.3 Access Control............................................. 224 6.4 Apache Tutorial: Dynamic Content with CGI............................ 226 6.5 Apache httpd Tutorial: Introduction to Server Side Includes..................... 233 6.6 Apache HTTP Server Tutorial: .htaccess files............................ 239 6.7 Per-user web directories........................................ 245 CONTENTS v 7 Platform-specific Notes 249 7.1 Platform Specific Notes........................................ 250 7.2 Using Apache HTTP Server on Microsoft Windows......................... 251 7.3 Compiling Apache for Microsoft Windows.............................. 259 7.4 Using Apache With RPM Based Systems (Redhat / CentOS / Fedora)................ 265 7.5 Using Apache With Novell NetWare................................. 268 7.6 Running a High-Performance Web Server on HPUX......................... 276 7.7 The Apache EBCDIC Port...................................... 277 8 Apache HTTP Server and Supporting Programs 281 8.1 Server and Supporting Programs................................... 282 8.2 httpd - Apache Hypertext Transfer Protocol Server.......................... 283 8.3 ab - Apache HTTP server benchmarking tool............................. 285 8.4 apachectl - Apache HTTP Server Control Interface.......................... 289 8.5 apxs - APache eXtenSion tool..................................... 291 8.6 configure - Configure the source tree................................. 295 8.7 dbmmanage - Manage user authentication files in DBM format................... 303 8.8 fcgistarter - Start a FastCGI program................................. 305 8.9 htcacheclean - Clean up the disk cache................................ 306 8.10 htdbm - Manipulate DBM password databases............................ 308 8.11 htdigest - manage user files for digest authentication......................... 311 8.12 htpasswd - Manage user files for basic authentication........................ 312 8.13 httxt2dbm - Generate dbm files for use with RewriteMap...................... 315 8.14 logresolve - Resolve IP-addresses to hostnames in Apache log files................. 316 8.15 log server status - Log periodic status summaries.......................... 317 8.16 rotatelogs - Piped logging program to rotate Apache logs...................... 318 8.17 split-logfile - Split up multi-vhost logfiles............................... 321 8.18 suexec - Switch user before executing external programs....................... 322 8.19 Other Programs............................................ 323 9 Apache Miscellaneous Documentation 325 9.1 Apache Miscellaneous Documentation................................ 326 9.2 Apache Performance Tuning..................................... 327 9.3 Security Tips.............................................. 338 9.4 Relevant Standards.......................................... 343 9.5 Password Formats........................................... 345 vi CONTENTS 10 Apache modules 349 10.1 Terms Used to Describe Modules................................... 350 10.2 Terms Used to Describe Directives.................................. 351 10.3 Apache Module core.......................................... 354 10.4 Apache Module mod access compat................................. 409 10.5 Apache Module mod actions..................................... 414 10.6 Apache Module mod alias....................................... 416 10.7 Apache Module mod allowmethods.................................. 422 10.8 Apache Module mod asis....................................... 423 10.9 Apache Module mod auth basic................................... 425 10.10 Apache Module mod auth digest................................... 429 10.11 Apache Module mod auth form.................................... 433 10.12 Apache Module mod authn anon................................... 444 10.13 Apache Module mod authn core................................... 447 10.14 Apache Module mod authn dbd.................................... 451 10.15 Apache Module mod authn dbm................................... 454 10.16 Apache Module mod authn file.................................... 456 10.17 Apache Module mod authn socache................................. 458 10.18 Apache Module mod authnz fcgi................................... 461 10.19 Apache Module mod authnz ldap..................................