# Apache httpd 2.4 configuration for cgit.
#
# This is a complete httpd.conf rather than a vhost snippet, so nothing here
# is included from elsewhere and no distro base config is assumed. Check it
# and run it with
#     httpd -t -f /path/to/apache.conf     # check the syntax
#     httpd -f /path/to/apache.conf        # run it
# To use it as an ordinary vhost file instead, drop everything above the
# virtual hosts and let your distro's httpd.conf supply it.
#
# Apache runs the cgit.cgi binary directly through mod_cgid, so no FastCGI
# bridge is needed.
#
# Paths assumed below, edit them to match your install.
#   cgit CGI binary   /usr/lib/cgit/cgit.cgi
#   static assets     /usr/share/cgit  (cgit.css cgit.js cgit.png favicon.ico robots.txt)
#   cgit config       /etc/cgitrc
#   public URL        https://git.example.org/  (cgit at the domain root)
#
# cgit is one CGI executable. It learns the repository and the page from
# PATH_INFO and reads page options such as h= and id= from QUERY_STRING.
# ScriptAlias runs the binary and forwards the trailing path as PATH_INFO, so
# no extra path tuning is needed. cgit builds its own link base from
# SCRIPT_NAME. The five static assets are served straight off disk. mod_alias
# resolves Alias and ScriptAlias in order and the first match wins, so the
# static Alias lines come before the catch-all ScriptAlias to stop the two
# routes from shadowing each other.


# ServerRoot is what every relative path below resolves against, including the
# module paths. It is /etc/httpd on RHEL and Fedora and /etc/apache2 on Debian
# and Ubuntu, where the modules live in /usr/lib/apache2/modules and the
# LoadModule lines need that absolute path instead of the relative one.
ServerRoot /etc/httpd
PidFile    /var/run/httpd.pid

# Where Apache puts its runtime scratch, the mutexes and the SSL session
# cache. It is /var/run/httpd on RHEL and Fedora and /var/run/apache2 on
# Debian and Ubuntu. The directory has to exist and be writable before Apache
# starts, which is normally the packaging's job.
DefaultRuntimeDir /var/run/httpd

Listen 80
Listen 443

# Set globally so Apache does not have to guess a name at startup, which it
# warns about. Each vhost overrides it with its own.
ServerName git.example.org

# Drop the version number from the Server header and from error pages.
ServerTokens Prod
ServerSignature Off


# mod_cgid suits the threaded MPMs that ship by default. Use mod_cgi instead
# only on the old prefork MPM. mod_alias provides Alias and ScriptAlias,
# mod_env provides SetEnv, and the rest are the core pieces a standalone
# config cannot do without. On Debian and Ubuntu run
#     a2enmod cgid alias env headers expires ssl
# rather than editing these lines. The guards make double-loading harmless.
<IfModule !mpm_event_module>
    LoadModule mpm_event_module     modules/mod_mpm_event.so
</IfModule>
<IfModule !unixd_module>
    LoadModule unixd_module         modules/mod_unixd.so
</IfModule>
<IfModule !authz_core_module>
    LoadModule authz_core_module    modules/mod_authz_core.so
</IfModule>
<IfModule !log_config_module>
    LoadModule log_config_module    modules/mod_log_config.so
</IfModule>
<IfModule !mime_module>
    LoadModule mime_module          modules/mod_mime.so
</IfModule>
<IfModule !alias_module>
    LoadModule alias_module         modules/mod_alias.so
</IfModule>
<IfModule !cgid_module>
    LoadModule cgid_module          modules/mod_cgid.so
</IfModule>
<IfModule !env_module>
    LoadModule env_module           modules/mod_env.so
</IfModule>
<IfModule !headers_module>
    LoadModule headers_module       modules/mod_headers.so
</IfModule>
<IfModule !expires_module>
    LoadModule expires_module       modules/mod_expires.so
</IfModule>
# TLS. Delete these two along with the HTTPS vhost to run plain HTTP only.
# mod_socache_shmcb backs the SSL session cache and mod_ssl expects it.
<IfModule !socache_shmcb_module>
    LoadModule socache_shmcb_module modules/mod_socache_shmcb.so
</IfModule>
<IfModule !ssl_module>
    LoadModule ssl_module           modules/mod_ssl.so
</IfModule>


# The user Apache drops to after binding the ports. It is apache on RHEL and
# Fedora, www-data on Debian and Ubuntu, and http on Arch.
User  apache
Group apache


# The combined format comes from the distro config rather than from Apache
# itself, so a standalone config has to define it before any CustomLog uses it.
LogFormat "%h %l %u %t \"%r\" %>s %b \"%{Referer}i\" \"%{User-Agent}i\"" combined
ErrorLog /var/log/apache2/error.log
LogLevel warn


# The usual "TypesConfig conf/mime.types" would pull in a second file. Exactly
# five static files are served off disk, so their types are declared here
# instead. Everything else Apache returns comes from cgit, which sets its own
# Content-Type.
AddType text/css                 .css
AddType text/javascript          .js
AddType image/png                .png
AddType image/vnd.microsoft.icon .ico
AddType text/plain               .txt


# Deny the whole filesystem, then open only the two directories cgit needs.
# Without this a misplaced Alias could expose anything readable on the host.
<Directory />
    AllowOverride None
    Require all denied
</Directory>

# The static asset directory, read only.
<Directory "/usr/share/cgit">
    Options None
    AllowOverride None
    Require all granted

    # These assets rarely change, so let browsers cache them. Keep the
    # caching scoped to this directory. Ordinary cgit pages carry no caching
    # headers, so a server-wide ExpiresDefault would stamp freshness onto
    # them, fight the no-store cgit puts on the login page, and could let
    # one visitor's page be served to another from a shared cache.
    <IfModule mod_expires.c>
        ExpiresActive On
        ExpiresDefault "access plus 30 days"
    </IfModule>
</Directory>

# The cgit binary.
<Directory "/usr/lib/cgit">
    # Allow CGI execution here.
    Options +ExecCGI
    # Run cgit.cgi as a CGI even if it is ever reached through a plain Alias
    # rather than ScriptAlias.
    SetHandler cgi-script
    AllowOverride None
    Require all granted
</Directory>


# This vhost only bounces plain HTTP up to HTTPS. It serves no cgit itself.
# Every cgit directive lives in the HTTPS vhost below. To run without TLS for
# now, convert the HTTPS vhost to port 80 and delete this whole block rather
# than editing it, since deleting only the Redirect line would leave a vhost
# that serves nothing.
<VirtualHost *:80>
    ServerName git.example.org

    ErrorLog  /var/log/apache2/cgit_error.log
    CustomLog /var/log/apache2/cgit_access.log combined

    Redirect permanent / https://git.example.org/
</VirtualHost>


# The vhost that serves cgit. To run without TLS for now, change this opening
# line to port 80, delete the SSL lines, delete the Strict-Transport-Security
# line, and delete the vhost above so there is only one. Everything else stays
# as it is.
<VirtualHost *:443>
    ServerName git.example.org

    ErrorLog  /var/log/apache2/cgit_ssl_error.log
    CustomLog /var/log/apache2/cgit_ssl_access.log combined

    # Point these at your certificate.
    SSLEngine on
    SSLCertificateFile    /etc/ssl/certs/git.example.org.crt
    SSLCertificateKeyFile /etc/ssl/private/git.example.org.key
    # Subtractive rather than naming the versions to keep, since a mod_ssl
    # built before TLS 1.3 rejects the +TLSv1.3 token outright and refuses to
    # start. This form enables 1.3 wherever it exists.
    SSLProtocol           all -SSLv3 -TLSv1 -TLSv1.1

    # Which config cgit reads. It falls back to the compiled-in /etc/cgitrc,
    # the same path used here, but setting it makes the location explicit and
    # lets you point at a per-vhost file later.
    SetEnv CGIT_CONFIG /etc/cgitrc

    # The only request body cgit ever reads is the auth-filter login form, and
    # it stops after 4096 bytes. Nothing else here accepts an upload.
    LimitRequestBody 65536

    # Site-wide security headers are set here so they also cover the static
    # assets Apache serves. cgit itself sends only the headers the proxy
    # cannot supply. Those are Status, Content-Type, Content-Length and
    # Content-Disposition on downloads, Location on redirects, a no-store
    # Cache-Control on unauthenticated responses, the auth filter's
    # Set-Cookie, and on raw
    # repository bytes a nosniff of its own next to the stricter policy
    # "default-src 'none'". Everything else, this policy included, is the
    # proxy's job.
    #
    # The word setifempty is load bearing on the two headers cgit can also
    # emit. "Header always set" replaces a same-named header even when the
    # CGI sent it, which would swap the strict policy on raw repository
    # content for this looser site one. setifempty yields to whatever cgit
    # sent. Referrer-Policy stays a plain set because cgit never emits it.
    #
    # form-action self covers the login form, the only form cgit renders. If
    # you enable the gravatar or libravatar avatar filter, add its host to
    # img-src, for example https://www.gravatar.com. A head-include or
    # repo.head-content that injects a <style> block needs 'unsafe-inline'
    # added to style-src.
    Header always setifempty Content-Security-Policy "default-src 'self'; script-src 'self'; style-src 'self'; img-src 'self' data:; object-src 'none'; base-uri 'none'; frame-ancestors 'self'; form-action 'self'"
    Header always setifempty X-Content-Type-Options "nosniff"
    Header always set Referrer-Policy "no-referrer"

    # The browser features a git viewer never asks for, camera and location
    # among them, are refused outright for everything served here, repository
    # files included.
    Header always set Permissions-Policy "accelerometer=(), autoplay=(), camera=(), display-capture=(), geolocation=(), gyroscope=(), magnetometer=(), microphone=(), midi=(), payment=(), picture-in-picture=(), usb=()"

    # Cross-origin isolation. The opener policy cuts any window.opener link
    # between cgit and pages that open it, and the resource policy stops
    # other origins from embedding what cgit serves, a hotlinked raw file for
    # example. git clients are not browsers and ignore both, so clone and
    # snapshot downloads keep working. The stricter
    # Cross-Origin-Embedder-Policy is deliberately absent because it would
    # break the avatar filters mentioned above.
    Header always set Cross-Origin-Opener-Policy "same-origin"
    Header always set Cross-Origin-Resource-Policy "same-origin"

    # Two years of forced HTTPS. This config already redirects every plain
    # request to TLS, so browsers may as well stop asking. Delete this line
    # if you convert the vhost to plain HTTP, and know it is hard to undo
    # once browsers have seen it.
    Header always set Strict-Transport-Security "max-age=63072000; includeSubDomains"

    # These five files are the only things served off disk. cgit.css and
    # cgit.js are the paths cgit's HTML points at by default, so if you
    # relocate the assets update both these Alias targets and the css, js,
    # logo and favicon settings in cgitrc to agree.
    Alias /cgit.css    /usr/share/cgit/cgit.css
    Alias /cgit.js     /usr/share/cgit/cgit.js
    Alias /cgit.png    /usr/share/cgit/cgit.png
    Alias /favicon.ico /usr/share/cgit/favicon.ico
    Alias /robots.txt  /usr/share/cgit/robots.txt

    # ScriptAlias maps a URL prefix to a path, marks it executable, and
    # forwards the rest of the URL as PATH_INFO. Mapping / makes cgit the
    # handler for every URL the static Aliases above did not already claim.
    # The trailing slash on cgit.cgi/ is load bearing, telling Apache that
    # cgit.cgi is the program and the rest of the URL is PATH_INFO. cgit
    # derives its link base from SCRIPT_NAME, which at the domain root is /
    # and needs no tuning. For a sub-path install see the note below.
    ScriptAlias / /usr/lib/cgit/cgit.cgi/
</VirtualHost>


# The SSL session cache is a global mod_ssl setting, so it sits outside the
# vhosts. Resumption keeps a browser paging through a repository from redoing
# a full handshake on every connection. Delete along with the HTTPS vhost if
# you serve plain HTTP.
<IfModule mod_ssl.c>
    # Relative, so it lands in DefaultRuntimeDir and follows it across distros.
    SSLSessionCache        "shmcb:ssl_scache(512000)"
    SSLSessionCacheTimeout 300
</IfModule>


# To serve cgit at https://git.example.org/cgit/ instead of the root, change
# the ScriptAlias to
#     ScriptAlias /cgit/ /usr/lib/cgit/cgit.cgi/
# and move the static assets under the same prefix, for example
#     Alias /cgit/cgit.css /usr/share/cgit/cgit.css
# SCRIPT_NAME then becomes /cgit and cgit auto-detects it. If links come out
# wrong, pin the base in cgitrc with virtual-root=/cgit.