[1.4.x] Rewrote security.txt SSL docs, noting SECURE_PROXY_SSL_HEADER.

attackers -- to alter data that is sent in either direction.

If you want the protection that HTTPS provides, and have enabled it on your

server, there are some additional steps to consider to ensure that sensitive

information is not leaked:

server, there are some additional steps you may need:

* If necessary, set :setting:`SECURE_PROXY_SSL_HEADER`, ensuring that you have

  understood the warnings there thoroughly. Failure to do this can result

  in CSRF vulnerabilities, and failure to do it correctly can also be

  dangerous!

* Set up redirection so that requests over HTTP are redirected to HTTPS.

  It is possible to do this with a piece of Django middleware. However, this has

  problems for the common case of a Django app running behind a reverse

  proxy. Often, reverse proxies are configured to set the ``X-Forwarded-SSL``

  header (or equivalent) if the incoming connection was HTTPS, and the absence

  of this header could be used to detect a request that was not HTTPS. However,

  this method usually cannot be relied on, as a client, or a malicious active

  network attacker, could also set this header.

  So, for the case of a reverse proxy, it is recommended that the main Web

  server should be configured to do the redirect to HTTPS, or configured to send

  HTTP requests to an app that unconditionally redirects to HTTPS.

  This could be done using a custom middleware. Please note the caveats under

  :setting:`SECURE_PROXY_SSL_HEADER`. For the case of a reverse proxy, it may be

  easier or more secure to configure the main Web server to do the redirect to

  HTTPS.

* Use 'secure' cookies.