From 7ff3ee91c4bbaee823bdb778ab2d6f4e7c67285e Mon Sep 17 00:00:00 2001
From: Rotzbua <Rotzbua@users.noreply.github.com>
Date: Fri, 8 Dec 2017 08:25:18 +0100
Subject: [PATCH] [doc] update client-secure-class.rst (#3924)

add limitations of tls connection
---
 doc/esp8266wifi/client-secure-class.rst | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)

diff --git a/doc/esp8266wifi/client-secure-class.rst b/doc/esp8266wifi/client-secure-class.rst
index cbfd24699..4a9449200 100644
--- a/doc/esp8266wifi/client-secure-class.rst
+++ b/doc/esp8266wifi/client-secure-class.rst
@@ -5,6 +5,29 @@ Client Secure Class
 
 Methods and properties described in this section are specific to ESP8266. They are not covered in `Arduino WiFi library <https://www.arduino.cc/en/Reference/WiFi>`__ documentation. Before they are fully documented please refer to information below.
 
+Supported crypto
+~~~~~~~~~~~~~~~~
+
+In the background the library `axtls <http://axtls.sourceforge.net>`_ is used. The library supports only rsa certificates and no new eliptic curve certificates. TLSv1.2 is supported since SDK 2.4.0-rc1.
+
+The following ciphers and digests are supported by `specification <http://axtls.sourceforge.net/specifications.htm>`_:
+
+* Symmetric Ciphers
+    * AES128-SHA
+    * AES256-SHA
+    * AES128-SHA256
+    * AES256-SHA256
+* Asymmetric Ciphers
+    * RSA 512/1024/2048/4096 bit encryption/decryption.
+    * RSA signing/verification
+* Digests
+    * SHA1
+    * MD5
+    * SHA256/384/512
+    * HMAC-SHA1
+    * HMAC-MD5
+    * HMAC-SHA256
+
 loadCertificate
 ~~~~~~~~~~~~~~~