Apache .htaccess Configurations

HTTP Strict Transport Security (HSTS)

HTTP Strict Transport Security (HSTS) is a web security policy mechanism that helps protect websites against man-in-the-middle attacks, such as protocol downgrade attacks and cookie hijacking. Here's why enabling HSTS is crucial for web security:

Forced Secure Connections: HSTS ensures that browsers connect to a website only using a secure HTTPS connection. Even if a user attempts to connect through an insecure HTTP link or if an attacker tries to downgrade the connection to HTTP, the browser will automatically switch to HTTPS.
Protection Against Downgrade Attacks: Without HSTS, attackers can exploit vulnerabilities to strip out the 'S' in HTTPS, forcing users to connect via HTTP. This attack, known as SSL stripping, makes it easier for attackers to intercept and alter web traffic. HSTS eliminates this risk by insisting on secure connections.
Prevents Cookie Hijacking: Many websites use cookies to store session information. If an attacker can intercept these cookies (especially over insecure connections), they can impersonate a user. HSTS ensures the connection remains secure, safeguarding these cookies from potential interception.
Promotes Trust with Visitors: Modern web users are becoming increasingly aware of online security practices. Websites employing HSTS communicate a commitment to security, bolstering user trust.
Search Engine Optimization (SEO) Benefits: Search engines, like Google, consider website security when ranking search results. Having a secure, HTTPS-only website can potentially boost SEO rankings, leading to increased visibility and traffic.
Ease of Maintenance: While the initial setup of HTTPS and HSTS requires effort, it simplifies future security measures. With HSTS in place, there's no need to worry about insecure HTTP references or mixed content issues, as all content will be loaded over HTTPS.

In Conclusion: HSTS is an essential tool in the modern web developer's security arsenal. By ensuring that web traffic remains encrypted and secure, it not only protects sensitive data but also instills confidence in visitors who recognize the commitment to a safer web experience. Always consider enabling HSTS when deploying a new website or when enhancing the security features of an existing one.

# ----------------------------------------------------------------------
# | HTTP Strict Transport Security (HSTS)                              |
# ----------------------------------------------------------------------

# Force client-side TLS (Transport Layer Security) redirection.
#
# If a user types `example.com` in their browser, even if the server redirects
# them to the secure version of the website, that still leaves a window of
# opportunity (the initial HTTP connection) for an attacker to downgrade or
# redirect the request.
#
# The following header ensures that a browser only connects to your server
# via HTTPS, regardless of what the users type in the browser's address bar.
#
# (!) Be aware that Strict Transport Security is not revokable and you
#     must ensure being able to serve the site over HTTPS for the duration
#     you've specified in the `max-age` directive. When you don't have a
#     valid TLS connection anymore (e.g. due to an expired TLS certificate)
#     your visitors will see a nasty error message even when attempting to
#     connect over HTTP.
#
# (1) Preloading Strict Transport Security.
#     To submit your site for HSTS preloading, it is required that:
#     * the `includeSubDomains` directive is specified
#     * the `preload` directive is specified
#     * the `max-age` is specified with a value of at least 31536000 seconds
#       (1 year).
#     https://hstspreload.org/#deployment-recommendations
#
# https://tools.ietf.org/html/rfc6797#section-6.1
# https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Strict-Transport-Security
# https://www.html5rocks.com/en/tutorials/security/transport-layer-security/
# https://blogs.msdn.microsoft.com/ieinternals/2014/08/18/strict-transport-security/
# https://hstspreload.org/

<IfModule mod_headers.c>
    Header always set Strict-Transport-Security "max-age=16070400; includeSubDomains" "expr=%{HTTPS} == 'on'"
    # (1) Enable your site for HSTS preload inclusion.
    # Header always set Strict-Transport-Security "max-age=31536000; includeSubDomains; preload" "expr=%{HTTPS} == 'on'"
</IfModule>

Setting X-Frame-Options

The X-Frame-Options HTTP header is a security feature that web developers can use to dictate whether a browser should be allowed to render a page in a <frame>, <iframe>, <embed>, or <object>. Its primary purpose is to protect users from certain types of attacks, most notably clickjacking. Here's a deep dive into the importance of enabling X-Frame-Options:

Protection Against Clickjacking: Clickjacking, also known as a UI redress attack, occurs when an attacker tricks a user into clicking something different from what the user perceives. They achieve this by loading a transparent frame over a legitimate page. With X-Frame-Options in place, it becomes challenging for attackers to embed your website within a malicious site using an iframe, effectively thwarting most clickjacking attempts.
Control Over Content Display: By setting the X-Frame-Options header, website owners can have precise control over how their content is framed and who can frame it. This ensures that the content is displayed only in contexts that the website owner has explicitly approved.
Preservation of Website Reputation: If your site is embedded maliciously on disreputable or inappropriate sites, it can inadvertently harm your brand's reputation. X-Frame-Options can prevent such unintended associations by restricting where your content can be framed.
Enhancement of Website Security: Besides clickjacking, there are other potential security threats associated with allowing your content to be embedded in iframes on external sites. For instance, if your site is framed within another site, it might be used in phishing attacks, misleading users into thinking they're interacting solely with your site. X-Frame-Options helps prevent such misuse.
Boost in User Trust: Security-conscious users and organizations look for sites that employ best security practices. Implementing headers like X-Frame-Options signals to users that you take their security seriously, which can increase trust and user retention.
Compliance with Security Standards: For businesses that adhere to specific security standards or undergo regular security audits, implementing X-Frame-Options might be a requirement or a recommended best practice to ensure a robust security posture.

While there are several potential values you can set for the X-Frame-Options header, the DENY value is often the safest and most recommended, especially if there's no specific need for your content to be embedded in frames or iframes on any external site.

Why Use the DENY Value?

Maximum Security: By setting X-Frame-Options to DENY, you are ensuring that your content cannot be embedded in a frame or iframe, regardless of where the request comes from. This offers the most comprehensive protection against clickjacking and other iframe-related threats.
Simplicity: The DENY value is straightforward. There's no need to specify or maintain a list of allowed sources. This makes your security configuration simpler and less prone to potential errors or oversights.
Widest Compatibility: While there are other values like SAMEORIGIN which can be used to allow framing only from the same origin, the DENY directive is widely recognized and understood by all major browsers, ensuring consistent behavior.

Enabling the X-Frame-Options header is a simple yet effective measure to bolster a website's security. By preventing your site from being embedded in potentially malicious contexts, you not only protect your users but also maintain the integrity and reputation of your website. As with any security feature, it's essential to understand its usage and implications fully, ensuring it's implemented correctly for maximum effectiveness.

If there's no compelling reason for your site's content to be displayed in frames or iframes on other websites, setting the X-Frame-Options header value to DENY is a robust and straightforward security enhancement.

# ----------------------------------------------------------------------
# | Frame Options                                                      |
# ----------------------------------------------------------------------

# Protect website against clickjacking.
#
# The example below sends the `X-Frame-Options` response header with the value
# `DENY`, informing browsers not to display the content of the web page in any
# frame.
#
# This might not be the best setting for everyone. You should read about the
# other two possible values the `X-Frame-Options` header field can have:
# `SAMEORIGIN` and `ALLOW-FROM`.
# https://tools.ietf.org/html/rfc7034#section-2.1.
#
# Keep in mind that while you could send the `X-Frame-Options` header for all
# of your website's pages, this has the potential downside that it forbids even
# non-malicious framing of your content (e.g.: when users visit your website
# using a Google Image Search results page).
#
# Nonetheless, you should ensure that you send the `X-Frame-Options` header for
# all pages that allow a user to make a state-changing operation (e.g: pages
# that contain one-click purchase links, checkout or bank-transfer confirmation
# pages, pages that make permanent configuration changes, etc.).
#
# Sending the `X-Frame-Options` header can also protect your website against
# more than just clickjacking attacks.
# https://cure53.de/xfo-clickjacking.pdf.
#
# https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/X-Frame-Options
# https://tools.ietf.org/html/rfc7034
# https://blogs.msdn.microsoft.com/ieinternals/2010/03/30/combating-clickjacking-with-x-frame-options/
# https://www.owasp.org/index.php/Clickjacking

<IfModule mod_headers.c>
    Header always set X-Frame-Options "DENY" "expr=%{CONTENT_TYPE} =~ m#text/html#i"
</IfModule>

Content Security Policy (CSP)

Starting from this base, you should add your own rules on top of these and adjust it according to your specific needs. It is important to always set the "frame-ancestors" parameter to prevent Clickjacking.

To make your CSP implementation easier, you can use an online CSP header generator

It is encouraged that you validate your CSP header using a CSP validator

# ----------------------------------------------------------------------
# | Content Security Policy (CSP)                                      |
# ----------------------------------------------------------------------

# Mitigate the risk of cross-site scripting and other content-injection
# attacks.
#
# This can be done by setting a `Content Security Policy` which whitelists
# trusted sources of content for your website.
#
# There is no policy that fits all websites, you will have to modify the
# `Content-Security-Policy` directives in the example depending on your needs.
#
# The example policy below aims to:
#
#  (1) Restrict all fetches by default to the origin of the current website by
#      setting the `default-src` directive to `'self'` - which acts as a
#      fallback to all "Fetch directives" (https://developer.mozilla.org/en-US/docs/Glossary/Fetch_directive).
#
#      This is convenient as you do not have to specify all Fetch directives
#      that apply to your site, for example:
#      `connect-src 'self'; font-src 'self'; script-src 'self'; style-src 'self'`, etc.
#
#      This restriction also means that you must explicitly define from which
#      site(s) your website is allowed to load resources from.
#
#  (2) The `<base>` element is not allowed on the website. This is to prevent
#      attackers from changing the locations of resources loaded from relative
#      URLs.
#
#      If you want to use the `<base>` element, then `base-uri 'self'` can be
#      used instead.
#
#  (3) Form submissions are only allowed from the current website by setting:
#      `form-action 'self'`.
#
#  (4) Prevents all websites (including your own) from embedding your webpages
#      within e.g. the `<iframe>` or `<object>` element by setting:
#      `frame-ancestors 'none'`.
#
#      The `frame-ancestors` directive helps avoid "Clickjacking" attacks and
#      is similar to the `X-Frame-Options` header.
#
#      Browsers that support the CSP header will ignore `X-Frame-Options` if
#      `frame-ancestors` is also specified.
#
#  (5) Forces the browser to treat all the resources that are served over HTTP
#      as if they were loaded securely over HTTPS by setting the
#      `upgrade-insecure-requests` directive.
#
#      Please note that `upgrade-insecure-requests` does not ensure HTTPS for
#      the top-level navigation. If you want to force the website itself to be
#      loaded over HTTPS you must include the `Strict-Transport-Security`
#      header.
#
#  (6) The `Content-Security-Policy` header is included in all responses
#      that are able to execute scripting. This includes the commonly used
#      file types: HTML, XML and PDF documents. Although Javascript files
#      can not execute script in a "browsing context", they are still included
#      to target workers:
#      https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Content-Security-Policy#CSP_in_workers
#
# To make your CSP implementation easier, you can use an online CSP header
# generator such as:
# https://report-uri.com/home/generate/
#
# It is encouraged that you validate your CSP header using a CSP validator
# such as:
# https://csp-evaluator.withgoogle.com
#
# https://csp.withgoogle.com/docs/
# https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Content-Security-Policy
# https://www.html5rocks.com/en/tutorials/security/content-security-policy/
# https://www.w3.org/TR/CSP/

<IfModule mod_headers.c>
    #                                   (1)                 (2)              (3)                 (4)                     (5)                         (6)
    Header always set Content-Security-Policy "default-src 'self'; base-uri 'none'; form-action 'self'; frame-ancestors 'none'; upgrade-insecure-requests" "expr=%{CONTENT_TYPE} =~ m#text\/(html|javascript)|application\/pdf|xml#i"
</IfModule>

For more information, please refer yourself to these useful links below:

Disabling Server Signature

The ServerSignature directive in Apache allows the server to include detailed information about itself in error messages. When set to On, it displays the server version and other details in error documents (like 404 Not Found pages). While this might seem benign or even helpful, it poses potential security risks. Here's why setting ServerSignature Off is crucial:

Server Version Exposure: Displaying the server version can provide malicious actors with valuable information. Knowing the exact version allows attackers to look for known vulnerabilities specific to that version, making targeted attacks easier.
Unnecessary Detail Exposure: Besides the server version, the signature can also include other information about your server setup. In general, it's a security best practice to disclose as little as possible about your infrastructure.
Reduces Attack Efficiency: By keeping the server version and other details hidden, attackers won't have immediate insight into potential vulnerabilities, making their task more challenging and less efficient.
General Security Principle: One of the foundational principles of security is the principle of least privilege, which can be applied here as the principle of least information. It's always better to provide the least amount of information necessary.
Cleaner Error Pages: Having verbose server information on error pages can seem unprofessional or cluttered to end-users. A concise error page without technical details provides a cleaner user experience.
Branding Control: Without server details crowding error pages, businesses have more control over branding and messaging they want to convey in these scenarios.
Security Audits & Standards: Depending on the industry and the specific security standards a business adheres to, displaying server information might be discouraged or even prohibited.

To disable the server signature in Apache, you'd typically add or modify the following directive in your server's configuration or within an .htaccess file:

# ----------------------------------------------------------------------
# | Server software information                                        |
# ----------------------------------------------------------------------

# Prevent Apache from adding a trailing footer line containing information
# about the server to the server-generated documents (e.g.: error messages,
# directory listings, etc.).
#
# https://httpd.apache.org/docs/current/mod/core.html#serversignature

ServerSignature Off

Disabling Directory Listing

Directory listing, when enabled, displays the contents of web directories in a browser when there isn't an index file (like index.html or index.php). This can expose sensitive files, structure of your directories, and other vital information to anyone who accesses the directory via a web browser. Here's why it's crucial to disable directory listing using Options -Indexes:

Sensitive File Exposure: Without an index file, the server might list files that are not intended for public view. This could include configuration files, backup files, or other files with sensitive information.
Directory Structure Exposure: Attackers can get insights into the server's directory structure, potentially revealing the locations of important files or scripts.
Better User Experience: A directory listing doesn't provide any meaningful content or design to users. It may confuse visitors who stumble upon it, leading to a poor user experience.
Avoiding Unintended Content Display: You might not want to show every file or sub-directory in a given directory, especially if some of them are works-in-progress, backups, or test files.
Preventing Enumeration: Automated bots and scanners often look for open directory listings to enumerate and identify files that can be exploited.
Mitigating Potential Attacks: By hiding the directory structure, you make it harder for attackers to find potential targets, thus reducing the attack surface.
Adherence to Security Standards: Disabling directory listing might be a requirement in certain security standards or best practices guidelines.
Reducing Attack Vectors: It's a fundamental principle in security to reduce unnecessary exposure, and directory listings are typically an unnecessary exposure.

In Conclusion: Disabling directory listing using Options -Indexes is a straightforward yet effective measure to enhance the security and professionalism of your website. It's a recommended best practice that minimizes risks and potential exposures, ensuring your server only displays content you intend for public viewing.

# ----------------------------------------------------------------------
# | File access                                                        |
# ----------------------------------------------------------------------

# Block access to directories without a default document.
#
# You should leave the following uncommented, as you shouldn't allow anyone to
# surf through every directory on your server (which may include rather
# private places such as the CMS's directories).

<IfModule mod_autoindex.c>
    Options -Indexes
</IfModule>

This directive tells the server not to list the contents of a directory even if no default index file is present.

Suppressing the `www.`

The www. prefix, historically a standard for web domains, often serves little practical purpose for modern websites, especially when dealing with subdomains. Here's why suppressing the www. for subdomains is a recommended practice:

Simplified Structure: Subdomains are used to distinguish different sections or services of a website (e.g., blog.example.com). Adding www. (like www.blog.example.com) adds unnecessary complexity and can be redundant.
Memorability: URLs without the www. prefix for subdomains are shorter, making them easier for users to remember and type.
DNS Lookups: Suppressing www. can lead to slightly faster DNS resolutions, as there's one less subdomain level to resolve.
SSL Certificates: Certificates might not cover nested subdomains by default. For example, a wildcard certificate for *.example.com would cover blog.example.com but not www.blog.example.com.
Clear Hierarchy: In web architecture, www. is technically a subdomain itself. Having a subdomain of a subdomain (like www.blog.example.com) can confuse users and developers alike, breaking the intuitive hierarchy.
Uniformity in Links: It's essential for branding and link sharing to have a consistent URL structure. Mixing www. with subdomains can lead to inconsistency and potential dead links if not properly managed.
Avoiding Duplicate Content: Search engines might view www.sub.example.com and sub.example.com as two separate sites with duplicate content, potentially affecting search rankings. Although this can be managed with canonical tags, it's simpler to maintain a single version.

To suppress the www. for subdomains, proper server configuration (e.g., using .htaccess redirects) is essential to ensure that any traffic to www.sub.example.com is automatically redirected to sub.example.com.

# ----------------------------------------------------------------------
# | Suppressing the `www.` at the beginning of URLs                    |
# ----------------------------------------------------------------------

# Rewrite www.example.com → example.com

# The same content should never be available under two different URLs,
# especially not with and without `www.` at the beginning.
# This can cause SEO problems (duplicate content), and therefore, you should
# choose one of the alternatives and redirect the other one.
#
# (!) NEVER USE BOTH WWW-RELATED RULES AT THE SAME TIME!

# (1) Set %{ENV:PROTO} variable, to allow rewrites to redirect with the
#     appropriate schema automatically (http or https).
#
# (2) The rule assumes by default that both HTTP and HTTPS environments are
#     available for redirection.
#     If your SSL certificate could not handle one of the domains used during
#     redirection, you should turn the condition on.
#
#     https://github.com/h5bp/server-configs-apache/issues/52

<IfModule mod_rewrite.c>

    RewriteEngine On

    # (1)
    RewriteCond %{HTTPS} =on
    RewriteRule ^ - [E=PROTO:https]
    RewriteCond %{HTTPS} !=on
    RewriteRule ^ - [E=PROTO:http]

    # (2)
    # RewriteCond %{HTTPS} !=on

    RewriteCond %{HTTP_HOST} ^www\.(.+)$ [NC]
    RewriteRule ^ %{ENV:PROTO}://%1%{REQUEST_URI} [R=301,L]

</IfModule>

Removing the www. prefix for subdomains offers a cleaner, more intuitive, and efficient URL structure. This practice not only aligns with modern web standards but also offers technical and SEO benefits, making it a recommended approach when setting up new websites on subdomains.

Note: The example above also work for main domains if you want to suppress the www.. Keep in mind that it is instead recommended forcing the www. for the main domain.

Forcing the `www.`

While there are arguments for both using and omitting the www. prefix for main domains, there are specific reasons to favor its enforcement. Here's why enforcing the www. prefix for main domains is a recommended practice:

CNAME Records: With the www. prefix, it's easier to change the infrastructure behind your website without changing the main domain's A record. The www. subdomain can have a CNAME record pointing to a CDN or other service, while the apex domain remains pointing to the original server.
Load Balancing: The www. subdomain allows for easier distribution of traffic across multiple servers or locations, providing scalability and redundancy benefits.
Cookie Scope: Cookies set on a domain without www. will be sent to all subdomains as well, potentially leading to unintended data exposure or increased traffic overhead. Enforcing www. can help to isolate cookies to just the main site.
Historical Familiarity: For many users, the www. prefix still signifies a website, providing immediate recognition of a web address.
Explicit Web Context: The www. makes it clear that the address leads to a website, differentiating it from other subdomains that might cater to different services (like ftp.example.com for FTP or mail.example.com for email).
Avoiding Duplicate Content Issues: Just as with subdomains, search engines could potentially view www.example.com and example.com as separate entities with duplicate content. Enforcing one version ensures consistency for search engine indexing.
To enforce the www. prefix for main domains, you'll typically use server configuration (e.g., .htaccess redirects) to ensure any traffic to example.com is automatically redirected to www.example.com.

# ----------------------------------------------------------------------
# | Forcing the `www.` at the beginning of URLs                        |
# ----------------------------------------------------------------------

# Rewrite example.com → www.example.com

# The same content should never be available under two different URLs,
# especially not with and without `www.` at the beginning.
# This can cause SEO problems (duplicate content), and therefore, you should
# choose one of the alternatives and redirect the other one.
#
# (!) NEVER USE BOTH WWW-RELATED RULES AT THE SAME TIME!

# (1) Set %{ENV:PROTO} variable, to allow rewrites to redirect with the
#     appropriate schema automatically (http or https).
#
# (2) The rule assumes by default that both HTTP and HTTPS environments are
#     available for redirection.
#     If your SSL certificate could not handle one of the domains used during
#     redirection, you should turn the condition on.
#
#     https://github.com/h5bp/server-configs-apache/issues/52

# Be aware that the following might not be a good idea if you use "real"
# subdomains for certain parts of your website.

<IfModule mod_rewrite.c>

    RewriteEngine On

    # (1)
    RewriteCond %{HTTPS} =on
    RewriteRule ^ - [E=PROTO:https]
    RewriteCond %{HTTPS} !=on
    RewriteRule ^ - [E=PROTO:http]

    # (2)
    # RewriteCond %{HTTPS} !=on

    RewriteCond %{HTTP_HOST} !^www\. [NC]
    RewriteCond %{SERVER_ADDR} !=127.0.0.1
    RewriteCond %{SERVER_ADDR} !=::1
    RewriteRule ^ %{ENV:PROTO}://www.%{HTTP_HOST}%{REQUEST_URI} [R=301,L]

</IfModule>

In Conclusion: While the choice to enforce www. largely depends on individual needs and preferences, the reasons outlined above highlight the technical, clarity, and SEO benefits of the practice. By ensuring consistency with the www. prefix for main domains, website administrators can harness these benefits while providing a recognizable web experience for users.

Note: The example above also work for sub-domains if you want to force the www.. Keep in mind that it is instead recommended forcing the www. for the sub-domains.

Forcing the `https://`

Transitioning from HTTP to HTTPS is not just a trend but a pivotal shift towards enhanced security and trustworthiness of web content. Here's why setting up an HTTP to HTTPS redirection is imperative for websites:

Encrypted Transmissions: HTTPS encrypts the data exchanged between a user's browser and the server. This means sensitive information, such as login credentials and credit card details, is protected from eavesdropping and potential interception by malicious actors.
Visible Assurance for Users: The padlock icon and the 'https' prefix in the browser's address bar reassure visitors that their data is secure. This can be especially crucial for e-commerce websites, where users need to feel safe before making transactions.
Ranking Boost: Search engines like Google give a ranking boost to secure HTTPS websites, making it an essential factor for SEO optimization.
HTTP/2 Support: Many modern browsers only support the newer, faster HTTP/2 protocol over HTTPS. Transitioning to HTTPS can lead to performance improvements due to this protocol.
Secure Browsing: With HTTPS, it's challenging for malicious entities to impersonate the website or tamper with the content that users receive. This protects users from potential man-in-the-middle attacks.
Analytics Accuracy: When traffic passes from an HTTPS site to an HTTP site, referrer data is often lost. This can skew analytics and hinder understanding of traffic sources. With an HTTPS setup, referrer data is preserved, ensuring accurate analytics.

To transition from HTTP to HTTPS, obtain a trusted SSL/TLS certificate and configure it on your server. Subsequently, set up server-side redirects to ensure all HTTP requests are automatically redirected to their HTTPS equivalents.

# ----------------------------------------------------------------------
# | Forcing `https://`                                                 |
# ----------------------------------------------------------------------

# Redirect from the `http://` to the `https://` version of the URL.
#
# https://wiki.apache.org/httpd/RewriteHTTPToHTTPS

# (1) If you're using cPanel AutoSSL or the Let's Encrypt webroot method it
#     will fail to validate the certificate if validation requests are
#     redirected to HTTPS. Turn on the condition(s) you need.
#
#     https://www.iana.org/assignments/well-known-uris/well-known-uris.xhtml
#     https://tools.ietf.org/html/draft-ietf-acme-acme-12

<IfModule mod_rewrite.c>
   RewriteEngine On
   RewriteCond %{HTTPS} !=on

   # (1)
   RewriteCond %{REQUEST_URI} !^/\.well-known/acme-challenge/
   RewriteCond %{REQUEST_URI} !^/\.well-known/cpanel-dcv/[\w-]+$
   RewriteCond %{REQUEST_URI} !^/\.well-known/pki-validation/[A-F0-9]{32}\.txt(?:\ Comodo\ DCV)?$

   RewriteRule ^ https://%{HTTP_HOST}%{REQUEST_URI} [R=301,L]
</IfModule>

In Conclusion: Migrating from HTTP to HTTPS and ensuring redirection is not just a best practice, it's a fundamental step to safeguard user data, enhance trustworthiness, and reap ancillary benefits like SEO boosts. Given today's heightened focus on web security, making this move is both prudent and essential.

HTML5 Boilerplate

Based on the official HTML5 Boilerplate 8.0.0 .htaccess example.

# Apache Server Configs v4.0.0 | MIT License
# https://github.com/h5bp/server-configs-apache

# (!) Using `.htaccess` files slows down Apache, therefore, if you have
# access to the main server configuration file (which is usually called
# `httpd.conf`), you should add this logic there.
#
# https://httpd.apache.org/docs/current/howto/htaccess.html

# ######################################################################
# # CROSS-ORIGIN                                                       #
# ######################################################################

# ----------------------------------------------------------------------
# | Cross-origin requests                                              |
# ----------------------------------------------------------------------

# Allow cross-origin requests.
#
# https://developer.mozilla.org/en-US/docs/Web/HTTP/Access_control_CORS
# https://enable-cors.org/
# https://www.w3.org/TR/cors/

# (!) Do not use this without understanding the consequences.
#     This will permit access from any other website.
#     Instead of using this file, consider using a specific rule such as
#     allowing access based on (sub)domain:
#
#         Header set Access-Control-Allow-Origin "subdomain.example.com"

# <IfModule mod_headers.c>
#     Header set Access-Control-Allow-Origin "*"
# </IfModule>

# ----------------------------------------------------------------------
# | Cross-origin images                                                |
# ----------------------------------------------------------------------

# Send the CORS header for images when browsers request it.
#
# https://developer.mozilla.org/en-US/docs/Web/HTML/CORS_enabled_image
# https://blog.chromium.org/2011/07/using-cross-domain-images-in-webgl-and.html

<IfModule mod_setenvif.c>
    <IfModule mod_headers.c>
        <FilesMatch "\.(bmp|cur|gif|ico|jpe?g|a?png|svgz?|webp)$">
            SetEnvIf Origin ":" IS_CORS
            Header set Access-Control-Allow-Origin "*" env=IS_CORS
        </FilesMatch>
    </IfModule>
</IfModule>

# ----------------------------------------------------------------------
# | Cross-origin web fonts                                             |
# ----------------------------------------------------------------------

# Allow cross-origin access to web fonts.
#
# https://developers.google.com/fonts/docs/troubleshooting

<IfModule mod_headers.c>
    <FilesMatch "\.(eot|otf|tt[cf]|woff2?)$">
        Header set Access-Control-Allow-Origin "*"
    </FilesMatch>
</IfModule>

# ----------------------------------------------------------------------
# | Cross-origin resource timing                                       |
# ----------------------------------------------------------------------

# Allow cross-origin access to the timing information for all resources.
#
# If a resource isn't served with a `Timing-Allow-Origin` header that would
# allow its timing information to be shared with the document, some of the
# attributes of the `PerformanceResourceTiming` object will be set to zero.
#
# https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Timing-Allow-Origin
# https://www.w3.org/TR/resource-timing/
# https://www.stevesouders.com/blog/2014/08/21/resource-timing-practical-tips/

# <IfModule mod_headers.c>
#     Header set Timing-Allow-Origin: "*"
# </IfModule>

# ######################################################################
# # ERRORS                                                             #
# ######################################################################

# ----------------------------------------------------------------------
# | Custom error messages/pages                                        |
# ----------------------------------------------------------------------

# Customize what Apache returns to the client in case of an error.
#
# https://httpd.apache.org/docs/current/mod/core.html#errordocument

ErrorDocument 404 /404.html

# ----------------------------------------------------------------------
# | Error prevention                                                   |
# ----------------------------------------------------------------------

# Disable the pattern matching based on filenames.
#
# This setting prevents Apache from returning a 404 error as the result of a
# rewrite when the directory with the same name does not exist.
#
# https://httpd.apache.org/docs/current/content-negotiation.html#multiviews

Options -MultiViews

# ######################################################################
# # INTERNET EXPLORER                                                  #
# ######################################################################

# ----------------------------------------------------------------------
# | Document modes                                                     |
# ----------------------------------------------------------------------

# Force Internet Explorer 8/9/10 to render pages in the highest mode
# available in various cases when it may not.
#
# https://hsivonen.fi/doctype/#ie8
#
# (!) Starting with Internet Explorer 11, document modes are deprecated.
#     If your business still relies on older web apps and services that were
#     designed for older versions of Internet Explorer, you might want to
#     consider enabling `Enterprise Mode` throughout your company.
#
# https://msdn.microsoft.com/en-us/library/ie/bg182625.aspx#docmode
# https://blogs.msdn.microsoft.com/ie/2014/04/02/stay-up-to-date-with-enterprise-mode-for-internet-explorer-11/
# https://msdn.microsoft.com/en-us/library/ff955275.aspx

<IfModule mod_headers.c>
    Header always set X-UA-Compatible "IE=edge" "expr=%{CONTENT_TYPE} =~ m#text/html#i"
</IfModule>

# ######################################################################
# # MEDIA TYPES AND CHARACTER ENCODINGS                                #
# ######################################################################

# ----------------------------------------------------------------------
# | Media types                                                        |
# ----------------------------------------------------------------------

# Serve resources with the proper media types (f.k.a. MIME types).
#
# https://www.iana.org/assignments/media-types/media-types.xhtml
# https://httpd.apache.org/docs/current/mod/mod_mime.html#addtype

<IfModule mod_mime.c>

  # Data interchange

    AddType application/atom+xml                        atom
    AddType application/json                            json map topojson
    AddType application/ld+json                         jsonld
    AddType application/rss+xml                         rss
    AddType application/geo+json                        geojson
    AddType application/rdf+xml                         rdf
    AddType application/xml                             xml


  # JavaScript

    # Servers should use text/javascript for JavaScript resources.
    # https://html.spec.whatwg.org/multipage/scripting.html#scriptingLanguages

    AddType text/javascript                             js mjs


  # Manifest files

    AddType application/manifest+json                   webmanifest
    AddType application/x-web-app-manifest+json         webapp
    AddType text/cache-manifest                         appcache


  # Media files

    AddType audio/mp4                                   f4a f4b m4a
    AddType audio/ogg                                   oga ogg opus
    AddType image/bmp                                   bmp
    AddType image/svg+xml                               svg svgz
    AddType image/webp                                  webp
    AddType video/mp4                                   f4v f4p m4v mp4
    AddType video/ogg                                   ogv
    AddType video/webm                                  webm
    AddType video/x-flv                                 flv

    # Serving `.ico` image files with a different media type prevents
    # Internet Explorer from displaying them as images:
    # https://github.com/h5bp/html5-boilerplate/commit/37b5fec090d00f38de64b591bcddcb205aadf8ee

    AddType image/x-icon                                cur ico


  # WebAssembly

    AddType application/wasm                            wasm


  # Web fonts

    AddType font/woff                                   woff
    AddType font/woff2                                  woff2
    AddType application/vnd.ms-fontobject               eot
    AddType font/ttf                                    ttf
    AddType font/collection                             ttc
    AddType font/otf                                    otf


  # Other

    AddType application/octet-stream                    safariextz
    AddType application/x-bb-appworld                   bbaw
    AddType application/x-chrome-extension              crx
    AddType application/x-opera-extension               oex
    AddType application/x-xpinstall                     xpi
    AddType text/calendar                               ics
    AddType text/markdown                               markdown md
    AddType text/vcard                                  vcard vcf
    AddType text/vnd.rim.location.xloc                  xloc
    AddType text/vtt                                    vtt
    AddType text/x-component                            htc

</IfModule>

# ----------------------------------------------------------------------
# | Character encodings                                                |
# ----------------------------------------------------------------------

# Serve all resources labeled as `text/html` or `text/plain` with the media type
# `charset` parameter set to `UTF-8`.
#
# https://httpd.apache.org/docs/current/mod/core.html#adddefaultcharset

AddDefaultCharset utf-8

# - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

# Serve the following file types with the media type `charset` parameter set to
# `UTF-8`.
#
# https://httpd.apache.org/docs/current/mod/mod_mime.html#addcharset

<IfModule mod_mime.c>
    AddCharset utf-8 .appcache \
                     .bbaw \
                     .css \
                     .htc \
                     .ics \
                     .js \
                     .json \
                     .manifest \
                     .map \
                     .markdown \
                     .md \
                     .mjs \
                     .topojson \
                     .vtt \
                     .vcard \
                     .vcf \
                     .webmanifest \
                     .xloc
</IfModule>

# ######################################################################
# # REWRITES                                                           #
# ######################################################################

# ----------------------------------------------------------------------
# | Rewrite engine                                                     |
# ----------------------------------------------------------------------

# (1) Turn on the rewrite engine (this is necessary in order for the
#     `RewriteRule` directives to work).
#
#     https://httpd.apache.org/docs/current/mod/mod_rewrite.html#RewriteEngine
#
# (2) Enable the `FollowSymLinks` option if it isn't already.
#
#     https://httpd.apache.org/docs/current/mod/core.html#options
#
# (3) If your web host doesn't allow the `FollowSymlinks` option, you need to
#     comment it out or remove it, and then uncomment the
#     `Options +SymLinksIfOwnerMatch` line (4), but be aware of the performance
#     impact.
#
#     https://httpd.apache.org/docs/current/misc/perf-tuning.html#symlinks
#
# (4) Some cloud hosting services will require you set `RewriteBase`.
#
#     https://www.rackspace.com/knowledge_center/frequently-asked-question/why-is-modrewrite-not-working-on-my-site
#     https://httpd.apache.org/docs/current/mod/mod_rewrite.html#rewritebase
#
# (5) Depending on how your server is set up, you may also need to use the
#     `RewriteOptions` directive to enable some options for the rewrite engine.
#
#     https://httpd.apache.org/docs/current/mod/mod_rewrite.html#rewriteoptions

<IfModule mod_rewrite.c>

    # (1)
    RewriteEngine On

    # (2)
    Options +FollowSymlinks

    # (3)
    # Options +SymLinksIfOwnerMatch

    # (4)
    # RewriteBase /

    # (5)
    # RewriteOptions <options>

</IfModule>

# ----------------------------------------------------------------------
# | Forcing `https://`                                                 |
# ----------------------------------------------------------------------

# Redirect from the `http://` to the `https://` version of the URL.
#
# https://wiki.apache.org/httpd/RewriteHTTPToHTTPS

# (1) If you're using cPanel AutoSSL or the Let's Encrypt webroot method it
#     will fail to validate the certificate if validation requests are
#     redirected to HTTPS. Turn on the condition(s) you need.
#
#     https://www.iana.org/assignments/well-known-uris/well-known-uris.xhtml
#     https://tools.ietf.org/html/draft-ietf-acme-acme-12

# <IfModule mod_rewrite.c>
#    RewriteEngine On
#    RewriteCond %{HTTPS} !=on
#    # (1)
#    # RewriteCond %{REQUEST_URI} !^/\.well-known/acme-challenge/
#    # RewriteCond %{REQUEST_URI} !^/\.well-known/cpanel-dcv/[\w-]+$
#    # RewriteCond %{REQUEST_URI} !^/\.well-known/pki-validation/[A-F0-9]{32}\.txt(?:\ Comodo\ DCV)?$
#    RewriteRule ^ https://%{HTTP_HOST}%{REQUEST_URI} [R=301,L]
# </IfModule>

# ----------------------------------------------------------------------
# | Suppressing the `www.` at the beginning of URLs                    |
# ----------------------------------------------------------------------

# Rewrite www.example.com → example.com

# The same content should never be available under two different URLs,
# especially not with and without `www.` at the beginning.
# This can cause SEO problems (duplicate content), and therefore, you should
# choose one of the alternatives and redirect the other one.
#
# (!) NEVER USE BOTH WWW-RELATED RULES AT THE SAME TIME!

# (1) Set %{ENV:PROTO} variable, to allow rewrites to redirect with the
#     appropriate schema automatically (http or https).
#
# (2) The rule assumes by default that both HTTP and HTTPS environments are
#     available for redirection.
#     If your SSL certificate could not handle one of the domains used during
#     redirection, you should turn the condition on.
#
#     https://github.com/h5bp/server-configs-apache/issues/52

<IfModule mod_rewrite.c>

    RewriteEngine On

    # (1)
    RewriteCond %{HTTPS} =on
    RewriteRule ^ - [E=PROTO:https]
    RewriteCond %{HTTPS} !=on
    RewriteRule ^ - [E=PROTO:http]

    # (2)
    # RewriteCond %{HTTPS} !=on

    RewriteCond %{HTTP_HOST} ^www\.(.+)$ [NC]
    RewriteRule ^ %{ENV:PROTO}://%1%{REQUEST_URI} [R=301,L]

</IfModule>

# ----------------------------------------------------------------------
# | Forcing the `www.` at the beginning of URLs                        |
# ----------------------------------------------------------------------

# Rewrite example.com → www.example.com

# The same content should never be available under two different URLs,
# especially not with and without `www.` at the beginning.
# This can cause SEO problems (duplicate content), and therefore, you should
# choose one of the alternatives and redirect the other one.
#
# (!) NEVER USE BOTH WWW-RELATED RULES AT THE SAME TIME!

# (1) Set %{ENV:PROTO} variable, to allow rewrites to redirect with the
#     appropriate schema automatically (http or https).
#
# (2) The rule assumes by default that both HTTP and HTTPS environments are
#     available for redirection.
#     If your SSL certificate could not handle one of the domains used during
#     redirection, you should turn the condition on.
#
#     https://github.com/h5bp/server-configs-apache/issues/52

# Be aware that the following might not be a good idea if you use "real"
# subdomains for certain parts of your website.

# <IfModule mod_rewrite.c>

#     RewriteEngine On

#     # (1)
#     RewriteCond %{HTTPS} =on
#     RewriteRule ^ - [E=PROTO:https]
#     RewriteCond %{HTTPS} !=on
#     RewriteRule ^ - [E=PROTO:http]

#     # (2)
#     # RewriteCond %{HTTPS} !=on

#     RewriteCond %{HTTP_HOST} !^www\. [NC]
#     RewriteCond %{SERVER_ADDR} !=127.0.0.1
#     RewriteCond %{SERVER_ADDR} !=::1
#     RewriteRule ^ %{ENV:PROTO}://www.%{HTTP_HOST}%{REQUEST_URI} [R=301,L]

# </IfModule>

# ######################################################################
# # SECURITY                                                           #
# ######################################################################

# ----------------------------------------------------------------------
# | Frame Options                                                      |
# ----------------------------------------------------------------------

# Protect website against clickjacking.
#
# The example below sends the `X-Frame-Options` response header with the value
# `DENY`, informing browsers not to display the content of the web page in any
# frame.
#
# This might not be the best setting for everyone. You should read about the
# other two possible values the `X-Frame-Options` header field can have:
# `SAMEORIGIN` and `ALLOW-FROM`.
# https://tools.ietf.org/html/rfc7034#section-2.1.
#
# Keep in mind that while you could send the `X-Frame-Options` header for all
# of your website's pages, this has the potential downside that it forbids even
# non-malicious framing of your content (e.g.: when users visit your website
# using a Google Image Search results page).
#
# Nonetheless, you should ensure that you send the `X-Frame-Options` header for
# all pages that allow a user to make a state-changing operation (e.g: pages
# that contain one-click purchase links, checkout or bank-transfer confirmation
# pages, pages that make permanent configuration changes, etc.).
#
# Sending the `X-Frame-Options` header can also protect your website against
# more than just clickjacking attacks.
# https://cure53.de/xfo-clickjacking.pdf.
#
# https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/X-Frame-Options
# https://tools.ietf.org/html/rfc7034
# https://blogs.msdn.microsoft.com/ieinternals/2010/03/30/combating-clickjacking-with-x-frame-options/
# https://www.owasp.org/index.php/Clickjacking

# <IfModule mod_headers.c>
#     Header always set X-Frame-Options "DENY" "expr=%{CONTENT_TYPE} =~ m#text/html#i"
# </IfModule>

# ----------------------------------------------------------------------
# | Content Security Policy (CSP)                                      |
# ----------------------------------------------------------------------

# Mitigate the risk of cross-site scripting and other content-injection
# attacks.
#
# This can be done by setting a `Content Security Policy` which whitelists
# trusted sources of content for your website.
#
# There is no policy that fits all websites, you will have to modify the
# `Content-Security-Policy` directives in the example depending on your needs.
#
# The example policy below aims to:
#
#  (1) Restrict all fetches by default to the origin of the current website by
#      setting the `default-src` directive to `'self'` - which acts as a
#      fallback to all "Fetch directives" (https://developer.mozilla.org/en-US/docs/Glossary/Fetch_directive).
#
#      This is convenient as you do not have to specify all Fetch directives
#      that apply to your site, for example:
#      `connect-src 'self'; font-src 'self'; script-src 'self'; style-src 'self'`, etc.
#
#      This restriction also means that you must explicitly define from which
#      site(s) your website is allowed to load resources from.
#
#  (2) The `<base>` element is not allowed on the website. This is to prevent
#      attackers from changing the locations of resources loaded from relative
#      URLs.
#
#      If you want to use the `<base>` element, then `base-uri 'self'` can be
#      used instead.
#
#  (3) Form submissions are only allowed from the current website by setting:
#      `form-action 'self'`.
#
#  (4) Prevents all websites (including your own) from embedding your webpages
#      within e.g. the `<iframe>` or `<object>` element by setting:
#      `frame-ancestors 'none'`.
#
#      The `frame-ancestors` directive helps avoid "Clickjacking" attacks and
#      is similar to the `X-Frame-Options` header.
#
#      Browsers that support the CSP header will ignore `X-Frame-Options` if
#      `frame-ancestors` is also specified.
#
#  (5) Forces the browser to treat all the resources that are served over HTTP
#      as if they were loaded securely over HTTPS by setting the
#      `upgrade-insecure-requests` directive.
#
#      Please note that `upgrade-insecure-requests` does not ensure HTTPS for
#      the top-level navigation. If you want to force the website itself to be
#      loaded over HTTPS you must include the `Strict-Transport-Security`
#      header.
#
#  (6) The `Content-Security-Policy` header is included in all responses
#      that are able to execute scripting. This includes the commonly used
#      file types: HTML, XML and PDF documents. Although Javascript files
#      can not execute script in a "browsing context", they are still included
#      to target workers:
#      https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Content-Security-Policy#CSP_in_workers
#
# To make your CSP implementation easier, you can use an online CSP header
# generator such as:
# https://report-uri.com/home/generate/
#
# It is encouraged that you validate your CSP header using a CSP validator
# such as:
# https://csp-evaluator.withgoogle.com
#
# https://csp.withgoogle.com/docs/
# https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Content-Security-Policy
# https://www.html5rocks.com/en/tutorials/security/content-security-policy/
# https://www.w3.org/TR/CSP/

# <IfModule mod_headers.c>
#     #                                   (1)                 (2)              (3)                 (4)                     (5)                         (6)
#     Header always set Content-Security-Policy "default-src 'self'; base-uri 'none'; form-action 'self'; frame-ancestors 'none'; upgrade-insecure-requests" "expr=%{CONTENT_TYPE} =~ m#text\/(html|javascript)|application\/pdf|xml#i"
# </IfModule>

# ----------------------------------------------------------------------
# | File access                                                        |
# ----------------------------------------------------------------------

# Block access to directories without a default document.
#
# You should leave the following uncommented, as you shouldn't allow anyone to
# surf through every directory on your server (which may include rather
# private places such as the CMS's directories).

<IfModule mod_autoindex.c>
    Options -Indexes
</IfModule>

# - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

# Block access to all hidden files and directories except for the
# visible content from within the `/.well-known/` hidden directory.
#
# These types of files usually contain user preferences or the preserved state
# of a utility, and can include rather private places like, for example, the
# `.git` or `.svn` directories.
#
# The `/.well-known/` directory represents the standard (RFC 5785) path prefix
# for "well-known locations" (e.g.: `/.well-known/manifest.json`,
# `/.well-known/keybase.txt`), and therefore, access to its visible content
# should not be blocked.
#
# https://www.mnot.net/blog/2010/04/07/well-known
# https://tools.ietf.org/html/rfc5785

<IfModule mod_rewrite.c>
    RewriteEngine On
    RewriteCond %{REQUEST_URI} "!(^|/)\.well-known/([^./]+./?)+$" [NC]
    RewriteCond %{SCRIPT_FILENAME} -d [OR]
    RewriteCond %{SCRIPT_FILENAME} -f
    RewriteRule "(^|/)\." - [F]
</IfModule>

# - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

# Block access to files that can expose sensitive information.
#
# By default, block access to backup and source files that may be left by some
# text editors and can pose a security risk when anyone has access to them.
#
# https://feross.org/cmsploit/
#
# (!) Update the `<FilesMatch>` regular expression from below to include any
#     files that might end up on your production server and can expose
#     sensitive information about your website. These files may include:
#     configuration files, files that contain metadata about the project (e.g.:
#     project dependencies, build scripts, etc.).

<IfModule mod_authz_core.c>
    <FilesMatch "(^#.*#|\.(bak|conf|dist|fla|in[ci]|log|orig|psd|sh|sql|sw[op])|~)$">
        Require all denied
    </FilesMatch>
</IfModule>

# ----------------------------------------------------------------------
# | HTTP Strict Transport Security (HSTS)                              |
# ----------------------------------------------------------------------

# Force client-side TLS (Transport Layer Security) redirection.
#
# If a user types `example.com` in their browser, even if the server redirects
# them to the secure version of the website, that still leaves a window of
# opportunity (the initial HTTP connection) for an attacker to downgrade or
# redirect the request.
#
# The following header ensures that a browser only connects to your server
# via HTTPS, regardless of what the users type in the browser's address bar.
#
# (!) Be aware that Strict Transport Security is not revokable and you
#     must ensure being able to serve the site over HTTPS for the duration
#     you've specified in the `max-age` directive. When you don't have a
#     valid TLS connection anymore (e.g. due to an expired TLS certificate)
#     your visitors will see a nasty error message even when attempting to
#     connect over HTTP.
#
# (1) Preloading Strict Transport Security.
#     To submit your site for HSTS preloading, it is required that:
#     * the `includeSubDomains` directive is specified
#     * the `preload` directive is specified
#     * the `max-age` is specified with a value of at least 31536000 seconds
#       (1 year).
#     https://hstspreload.org/#deployment-recommendations
#
# https://tools.ietf.org/html/rfc6797#section-6.1
# https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Strict-Transport-Security
# https://www.html5rocks.com/en/tutorials/security/transport-layer-security/
# https://blogs.msdn.microsoft.com/ieinternals/2014/08/18/strict-transport-security/
# https://hstspreload.org/

# <IfModule mod_headers.c>
#     Header always set Strict-Transport-Security "max-age=16070400; includeSubDomains" "expr=%{HTTPS} == 'on'"
#     # (1) Enable your site for HSTS preload inclusion.
#     # Header always set Strict-Transport-Security "max-age=31536000; includeSubDomains; preload" "expr=%{HTTPS} == 'on'"
# </IfModule>

# ----------------------------------------------------------------------
# | Content Type Options                                               |
# ----------------------------------------------------------------------

# Prevent some browsers from MIME-sniffing the response.
#
# This reduces exposure to drive-by download attacks and cross-origin data
# leaks, and should be left uncommented, especially if the server is serving
# user-uploaded content or content that could potentially be treated as
# executable by the browser.
#
# https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/X-Content-Type-Options
# https://blogs.msdn.microsoft.com/ie/2008/07/02/ie8-security-part-v-comprehensive-protection/
# https://mimesniff.spec.whatwg.org/

<IfModule mod_headers.c>
    Header always set X-Content-Type-Options "nosniff"
</IfModule>

# ----------------------------------------------------------------------
# | Cross-Site Scripting (XSS) Protection                              |
# ----------------------------------------------------------------------

# Protect website reflected Cross-Site Scripting (XSS) attacks.
#
# (1) Try to re-enable the cross-site scripting (XSS) filter built into most
#     web browsers.
#
#     The filter is usually enabled by default, but in some cases, it may be
#     disabled by the user. However, in Internet Explorer, for example, it can be
#     re-enabled just by sending the  `X-XSS-Protection` header with the value
#     of `1`.
#
# (2) Prevent web browsers from rendering the web page if a potential reflected
#     (a.k.a non-persistent) XSS attack is detected by the filter.
#
#     By default, if the filter is enabled and browsers detect a reflected XSS
#     attack, they will attempt to block the attack by making the smallest
#     possible modifications to the returned web page.
#
#     Unfortunately, in some browsers (e.g.: Internet Explorer), this default
#     behavior may allow the XSS filter to be exploited. Therefore, it's better
#     to inform browsers to prevent the rendering of the page altogether,
#     instead of attempting to modify it.
#
#     https://hackademix.net/2009/11/21/ies-xss-filter-creates-xss-vulnerabilities
#
# (!) Do not rely on the XSS filter to prevent XSS attacks! Ensure that you are
#     taking all possible measures to prevent XSS attacks, the most obvious
#     being: validating and sanitizing your website's inputs.
#
# https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/X-XSS-Protection
# https://blogs.msdn.microsoft.com/ie/2008/07/02/ie8-security-part-iv-the-xss-filter/
# https://blogs.msdn.microsoft.com/ieinternals/2011/01/31/controlling-the-xss-filter/
# https://www.owasp.org/index.php/Cross-site_Scripting_%28XSS%29

# <IfModule mod_headers.c>
#     #                           (1)    (2)
#     Header always set X-XSS-Protection "1; mode=block" "expr=%{CONTENT_TYPE} =~ m#text/html#i"
# </IfModule>

# ----------------------------------------------------------------------
# | Referrer Policy                                                    |
# ----------------------------------------------------------------------

# Set a strict Referrer Policy to mitigate information leakage.
#
# (1) The `Referrer-Policy` header is included in responses for resources
#     that are able to request (or navigate to) other resources.
#
#     This includes the commonly used resource types:
#     HTML, CSS, XML/SVG, PDF documents, scripts and workers.
#
# To prevent referrer leakage entirely, specify the `no-referrer` value
# instead. Note that the effect could impact analytics metrics negatively.
#
# To check your Referrer Policy, you can use an online service, such as:
# https://securityheaders.com/
# https://observatory.mozilla.org/
#
# https://scotthelme.co.uk/a-new-security-header-referrer-policy/
# https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Referrer-Policy

# <IfModule mod_headers.c>
#     #                                                             (1)
#     Header always set Referrer-Policy "strict-origin-when-cross-origin" "expr=%{CONTENT_TYPE} =~ m#text\/(css|html|javascript)|application\/pdf|xml#i"
# </IfModule>

# ----------------------------------------------------------------------
# | Disable TRACE HTTP Method                                          |
# ----------------------------------------------------------------------

# Prevent Apache from responding to `TRACE` HTTP request.
#
# The TRACE method, while seemingly harmless, can be successfully leveraged
# in some scenarios to steal legitimate users' credentials.
#
# Modern browsers now prevent TRACE requests being made via JavaScript,
# however, other ways of sending TRACE requests with browsers have been
# discovered, such as using Java.
#
# (!) If you have access to the main server configuration file, use the
#     `TraceEnable` directive instead.
#
# https://tools.ietf.org/html/rfc7231#section-4.3.8
# https://www.owasp.org/index.php/Cross_Site_Tracing
# https://www.owasp.org/index.php/Test_HTTP_Methods_(OTG-CONFIG-006)
# https://httpd.apache.org/docs/current/mod/core.html#traceenable

# <IfModule mod_rewrite.c>
#     RewriteEngine On
#     RewriteCond %{REQUEST_METHOD} ^TRACE [NC]
#     RewriteRule .* - [R=405,L]
# </IfModule>

# ----------------------------------------------------------------------
# | Server-side technology information                                 |
# ----------------------------------------------------------------------

# Remove the `X-Powered-By` response header that:
#
#  * is set by some frameworks and server-side languages (e.g.: ASP.NET, PHP),
#    and its value contains information about them (e.g.: their name, version
#    number)
#
#  * doesn't provide any value to users, contributes to header bloat, and in
#    some cases, the information it provides can expose vulnerabilities
#
# (!) If you can, you should disable the `X-Powered-By` header from the
#     language/framework level (e.g.: for PHP, you can do that by setting
#     `expose_php = off` in `php.ini`).
#
# https://php.net/manual/en/ini.core.php#ini.expose-php

<IfModule mod_headers.c>
    Header unset X-Powered-By
    Header always unset X-Powered-By
</IfModule>

# ----------------------------------------------------------------------
# | Server software information                                        |
# ----------------------------------------------------------------------

# Prevent Apache from adding a trailing footer line containing information
# about the server to the server-generated documents (e.g.: error messages,
# directory listings, etc.).
#
# https://httpd.apache.org/docs/current/mod/core.html#serversignature

ServerSignature Off

# ######################################################################
# # WEB PERFORMANCE                                                    #
# ######################################################################

# ----------------------------------------------------------------------
# | Compression                                                        |
# ----------------------------------------------------------------------

<IfModule mod_deflate.c>

    # Force compression for mangled `Accept-Encoding` request headers
    #
    # https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Accept-Encoding
    # https://calendar.perfplanet.com/2010/pushing-beyond-gzipping/

    <IfModule mod_setenvif.c>
        <IfModule mod_headers.c>
            SetEnvIfNoCase ^(Accept-EncodXng|X-cept-Encoding|X{15}|~{15}|-{15})$ ^((gzip|deflate)\s*,?\s*)+|[X~-]{4,13}$ HAVE_Accept-Encoding
            RequestHeader append Accept-Encoding "gzip,deflate" env=HAVE_Accept-Encoding
        </IfModule>
    </IfModule>

    # - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

    # Compress all output labeled with one of the following media types.
    #
    # https://httpd.apache.org/docs/current/mod/mod_filter.html#addoutputfilterbytype

    <IfModule mod_filter.c>
        AddOutputFilterByType DEFLATE "application/atom+xml" \
                                      "application/javascript" \
                                      "application/json" \
                                      "application/ld+json" \
                                      "application/manifest+json" \
                                      "application/rdf+xml" \
                                      "application/rss+xml" \
                                      "application/schema+json" \
                                      "application/geo+json" \
                                      "application/vnd.ms-fontobject" \
                                      "application/wasm" \
                                      "application/x-font-ttf" \
                                      "application/x-javascript" \
                                      "application/x-web-app-manifest+json" \
                                      "application/xhtml+xml" \
                                      "application/xml" \
                                      "font/eot" \
                                      "font/opentype" \
                                      "font/otf" \
                                      "font/ttf" \
                                      "image/bmp" \
                                      "image/svg+xml" \
                                      "image/vnd.microsoft.icon" \
                                      "text/cache-manifest" \
                                      "text/calendar" \
                                      "text/css" \
                                      "text/html" \
                                      "text/javascript" \
                                      "text/plain" \
                                      "text/markdown" \
                                      "text/vcard" \
                                      "text/vnd.rim.location.xloc" \
                                      "text/vtt" \
                                      "text/x-component" \
                                      "text/x-cross-domain-policy" \
                                      "text/xml"

    </IfModule>

    # - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

    # Map the following filename extensions to the specified encoding type in
    # order to make Apache serve the file types with the appropriate
    # `Content-Encoding` response header (do note that this will NOT make
    # Apache compress them!).
    #
    # If these files types would be served without an appropriate
    # `Content-Encoding` response header, client applications (e.g.: browsers)
    # wouldn't know that they first need to uncompress the response, and thus,
    # wouldn't be able to understand the content.
    #
    # https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Content-Encoding
    # https://httpd.apache.org/docs/current/mod/mod_mime.html#addencoding

    <IfModule mod_mime.c>
        AddEncoding gzip              svgz
    </IfModule>

</IfModule>

# ----------------------------------------------------------------------
# | Brotli pre-compressed content                                      |
# ----------------------------------------------------------------------

# Serve brotli compressed CSS, JS, HTML, SVG, ICS and JSON files if they exist
# and if the client accepts br encoding.
#
# (!) To make this part relevant, you need to generate encoded files by your
#     own. Enabling this part will not auto-generate brotlied files.
#
# Note that some clients (eg. browsers) require a secure connection to request
# brotli-compressed resources.
# https://www.chromestatus.com/feature/5420797577396224
#
# https://httpd.apache.org/docs/current/mod/mod_brotli.html#precompressed

# <IfModule mod_headers.c>

#     RewriteCond %{HTTP:Accept-Encoding} br
#     RewriteCond %{REQUEST_FILENAME}\.br -f
#     RewriteRule \.(css|ics|js|json|html|svg)$ %{REQUEST_URI}.br [L]

#     # Prevent mod_deflate double gzip
#     RewriteRule \.br$ - [E=no-gzip:1]

#     <FilesMatch "\.br$">

#         <IfModule mod_mime.c>
#             # Serve correct content types
#             AddType text/css              css.br
#             AddType text/calendar         ics.br
#             AddType text/javascript       js.br
#             AddType application/json      json.br
#             AddType text/html             html.br
#             AddType image/svg+xml         svg.br

#             # Serve correct content charset
#             AddCharset utf-8 .css.br \
#                              .ics.br \
#                              .js.br \
#                              .json.br
#         </IfModule>

#         # Force proxies to cache brotlied and non-brotlied files separately
#         Header append Vary Accept-Encoding

#     </FilesMatch>

#     # Serve correct encoding type
#     AddEncoding br .br

# </IfModule>

# ----------------------------------------------------------------------
# | GZip pre-compressed content                                        |
# ----------------------------------------------------------------------

# Serve gzip compressed CSS, JS, HTML, SVG, ICS, and JSON files if they exist
# and if the client accepts gzip encoding.
#
# (!) To make this part relevant, you need to generate encoded files by your
#     own. Enabling this part will not auto-generate gziped files.
#
# https://httpd.apache.org/docs/current/mod/mod_deflate.html#precompressed
#
# (1) Removing default MIME Type for .gz files allowing to add custom
#     sub-types.
#     You may prefer using less generic extensions such as .html_gz in order to
#     keep the default behavior regarding .gz files.
#     https://httpd.apache.org/docs/current/mod/mod_mime.html#removetype

# <IfModule mod_headers.c>

#     RewriteCond %{HTTP:Accept-Encoding} gzip
#     RewriteCond %{REQUEST_FILENAME}\.gz -f
#     RewriteRule \.(css|ics|js|json|html|svg)$ %{REQUEST_URI}.gz [L]

#     # Prevent mod_deflate double gzip
#     RewriteRule \.gz$ - [E=no-gzip:1]

#     <FilesMatch "\.gz$">

#         # Serve correct content types
#         <IfModule mod_mime.c>
#             # (1)
#             RemoveType gz

#             # Serve correct content types
#             AddType text/css              css.gz
#             AddType text/calendar         ics.gz
#             AddType text/javascript       js.gz
#             AddType application/json      json.gz
#             AddType text/html             html.gz
#             AddType image/svg+xml         svg.gz

#             # Serve correct content charset
#             AddCharset utf-8 .css.gz \
#                              .ics.gz \
#                              .js.gz \
#                              .json.gz
#         </IfModule>

#         # Force proxies to cache gzipped and non-gzipped files separately
#         Header append Vary Accept-Encoding

#     </FilesMatch>

#     # Serve correct encoding type
#     AddEncoding gzip .gz

# </IfModule>

# ----------------------------------------------------------------------
# | Content transformation                                             |
# ----------------------------------------------------------------------

# Prevent intermediate caches or proxies (such as those used by mobile
# network providers) and browsers data-saving features from modifying
# the website's content using the `cache-control: no-transform` directive.
#
# https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Cache-Control
# https://tools.ietf.org/html/rfc7234#section-5.2.2.4
#
# (!) Carefully consider the impact on your visitors before disabling
#     content transformation. These transformations are performed to
#     improve the experience for data- and cost-constrained users
#     (e.g. users on a 2G connection).
#
#     You can test the effects of content transformation applied by
#     Google's Lite Mode by visiting: https://googleweblight.com/i?u=https://www.example.com
#
#     https://support.google.com/webmasters/answer/6211428
#
# (!) If you are using `mod_pagespeed`, note that disabling this will
#     prevent `PageSpeed` from rewriting HTML files, and, if the
#     `ModPagespeedDisableRewriteOnNoTransform` directive isn't set to
#     `off`, also from rewriting other resources.
#
#     https://developers.google.com/speed/pagespeed/module/configuration#notransform

# <IfModule mod_headers.c>
#     Header merge Cache-Control "no-transform"
# </IfModule>

# ----------------------------------------------------------------------
# | ETags                                                              |
# ----------------------------------------------------------------------

# Remove `ETags` as resources are sent with far-future expires headers.
#
# https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/ETag
# https://developer.yahoo.com/performance/rules.html#etags
# https://tools.ietf.org/html/rfc7232#section-2.3

# `FileETag None` doesn't work in all cases.
<IfModule mod_headers.c>
    Header unset ETag
</IfModule>

FileETag None

# ----------------------------------------------------------------------
# | Cache expiration                                                   |
# ----------------------------------------------------------------------

# Serve resources with a far-future expiration date.
#
# (!) If you don't control versioning with filename-based cache busting, you
# should consider lowering the cache times to something like one week.
#
# https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Cache-Control
# https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Expires
# https://httpd.apache.org/docs/current/mod/mod_expires.html

<IfModule mod_expires.c>

    ExpiresActive on
    ExpiresDefault                                      "access plus 1 month"

  # CSS

    ExpiresByType text/css                              "access plus 1 year"


  # Data interchange

    ExpiresByType application/atom+xml                  "access plus 1 hour"
    ExpiresByType application/rdf+xml                   "access plus 1 hour"
    ExpiresByType application/rss+xml                   "access plus 1 hour"

    ExpiresByType application/json                      "access plus 0 seconds"
    ExpiresByType application/ld+json                   "access plus 0 seconds"
    ExpiresByType application/schema+json               "access plus 0 seconds"
    ExpiresByType application/geo+json                  "access plus 0 seconds"
    ExpiresByType application/xml                       "access plus 0 seconds"
    ExpiresByType text/calendar                         "access plus 0 seconds"
    ExpiresByType text/xml                              "access plus 0 seconds"


  # Favicon (cannot be renamed!) and cursor images

    ExpiresByType image/vnd.microsoft.icon              "access plus 1 week"
    ExpiresByType image/x-icon                          "access plus 1 week"

  # HTML

    ExpiresByType text/html                             "access plus 0 seconds"


  # JavaScript

    ExpiresByType application/javascript                "access plus 1 year"
    ExpiresByType application/x-javascript              "access plus 1 year"
    ExpiresByType text/javascript                       "access plus 1 year"


  # Manifest files

    ExpiresByType application/manifest+json             "access plus 1 week"
    ExpiresByType application/x-web-app-manifest+json   "access plus 0 seconds"
    ExpiresByType text/cache-manifest                   "access plus 0 seconds"


  # Markdown

    ExpiresByType text/markdown                         "access plus 0 seconds"


  # Media files

    ExpiresByType audio/ogg                             "access plus 1 month"
    ExpiresByType image/apng                            "access plus 1 month"
    ExpiresByType image/bmp                             "access plus 1 month"
    ExpiresByType image/gif                             "access plus 1 month"
    ExpiresByType image/jpeg                            "access plus 1 month"
    ExpiresByType image/png                             "access plus 1 month"
    ExpiresByType image/svg+xml                         "access plus 1 month"
    ExpiresByType image/webp                            "access plus 1 month"
    ExpiresByType video/mp4                             "access plus 1 month"
    ExpiresByType video/ogg                             "access plus 1 month"
    ExpiresByType video/webm                            "access plus 1 month"


  # WebAssembly

    ExpiresByType application/wasm                      "access plus 1 year"


  # Web fonts

    # Collection
    ExpiresByType font/collection                       "access plus 1 month"

    # Embedded OpenType (EOT)
    ExpiresByType application/vnd.ms-fontobject         "access plus 1 month"
    ExpiresByType font/eot                              "access plus 1 month"

    # OpenType
    ExpiresByType font/opentype                         "access plus 1 month"
    ExpiresByType font/otf                              "access plus 1 month"

    # TrueType
    ExpiresByType application/x-font-ttf                "access plus 1 month"
    ExpiresByType font/ttf                              "access plus 1 month"

    # Web Open Font Format (WOFF) 1.0
    ExpiresByType application/font-woff                 "access plus 1 month"
    ExpiresByType application/x-font-woff               "access plus 1 month"
    ExpiresByType font/woff                             "access plus 1 month"

    # Web Open Font Format (WOFF) 2.0
    ExpiresByType application/font-woff2                "access plus 1 month"
    ExpiresByType font/woff2                            "access plus 1 month"


  # Other

    ExpiresByType text/x-cross-domain-policy            "access plus 1 week"

</IfModule>

# ----------------------------------------------------------------------
# | File concatenation                                                 |
# ----------------------------------------------------------------------

# Allow concatenation from within specific files.
#
# If you have the following lines in a file called, for example,
# `main.combined.js`:
#
#     <!--#include file="js/jquery.js" -->
#     <!--#include file="js/jquery.timer.js" -->
#
# Apache will replace those lines with the content of the specified files.

# <IfModule mod_include.c>

#     <FilesMatch "\.combined\.js$">
#         Options +Includes
#         AddOutputFilterByType INCLUDES application/javascript \
#                                        application/x-javascript \
#                                        text/javascript
#         SetOutputFilter INCLUDES
#     </FilesMatch>

#     <FilesMatch "\.combined\.css$">
#         Options +Includes
#         AddOutputFilterByType INCLUDES text/css
#         SetOutputFilter INCLUDES
#     </FilesMatch>

# </IfModule>

# ----------------------------------------------------------------------
# | Filename-based cache busting                                       |
# ----------------------------------------------------------------------

# If you're not using a build process to manage your filename version revving,
# you might want to consider enabling the following directives.
#
# To understand why this is important and even a better solution than using
# something like `*.css?v231`, please see:
# https://www.stevesouders.com/blog/2008/08/23/revving-filenames-dont-use-querystring/

# <IfModule mod_rewrite.c>
#     RewriteEngine On
#     RewriteCond %{REQUEST_FILENAME} !-f
#     RewriteRule ^(.+)\.(\w+)\.(bmp|css|cur|gif|ico|jpe?g|m?js|a?png|svgz?|webp|webmanifest)$ $1.$3 [L]
# </IfModule>