PolarSSL: deprecate support step 1. Removed from configure.

Also removed mentions from most docs.

Discussed: https://curl.haxx.se/mail/lib-2019-05/0045.html

Closes #3888

1 files changed, 29 insertions, 0 deletions

diff --git a/docs/DEPRECATE.md b/docs/DEPRECATE.md
index 4f2570ade..94a5c6256 100644
--- a/docs/DEPRECATE.md
+++ b/docs/DEPRECATE.md
@@ -19,3 +19,32 @@ version. The default remains supported for now.
 
 The support for HTTP/0.9 will be switched to disabled by default in 6 months,
 in the September 2019 release (possibly called curl 7.68.0).
+
+## PolarSSL
+
+The polarssl TLS library has not had an update in over three years. The last
+release was done on [January 7
+2016](https://tls.mbed.org/tech-updates/releases). This library has been
+superceded by the mbedTLS library, which is the current incarnation of
+PolarSSL. curl has supported mbedTLS since 2015.
+
+It seems unlikely that this library is a good choice for users to get proper
+TLS security and support today and at the same time there are plenty of good
+and updated alternatives.
+
+I consider it likely that the existing users of curl + polarssl out there are
+stuck on old curl versions and when they eventually manage to update curl they
+should also be able to update their TLS library.
+
+### State
+
+In the curl 7.66.0 release (July 17, 2019) the ability to build with this TLS
+backend is removed from the configure script. The code remains and can be
+built and used going forward, but it has to be manually enabled in a build (or
+the configure removal reverted).
+
+### Removal
+
+The support for PolarSSL and all code for it will be completely removed from
+the curl code base six months after it ships disabled in configure in a
+release. In the release on or near February 27, 2020. (Named 7.70.0?)