diff --git a/CHANGELOG.md b/CHANGELOG.md
index 906c1fc..335d0fc 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,9 @@
 # Changelog
 
+## 2.5.0
+
+- Feature #56: add support for X.509 client certificate based authentication
+
 ## 2.4.1
 
 - Fixed #296: multipart requests are not serialized on browser platform
diff --git a/README.md b/README.md
index b7458e0..4135de8 100644
--- a/README.md
+++ b/README.md
@@ -16,6 +16,7 @@ This is a fork of [Wymsee's Cordova-HTTP plugin](https://github.com/wymsee/cordo
 
  - SSL / TLS Pinning
  - CORS restrictions do not apply
+ - X.509 client certificate based authentication
  - Handling of HTTP code 401 - read more at [Issue CB-2415](https://issues.apache.org/jira/browse/CB-2415)
 
 ## Updates
@@ -186,6 +187,29 @@ cordova.plugin.http.setServerTrustMode('nocheck', function() {
 });
 ```
 
+### setClientAuthMode<a name="setClientAuthMode"></a>
+Configure X.509 client certificate authentication. Takes mode and options. `mode` being one of following values:
+
+* `none`: disable client certificate authentication
+* `systemstore` (only on Android): use client certificate installed in the Android system store; user will be presented with a list of all installed certificates
+* `buffer`: use given client certificate; you will need to provide an options object:
+  * `rawPkcs`: ArrayBuffer containing raw PKCS12 container with client certificate and private key
+  * `pkcsPassword`: password of the PKCS container
+
+```js
+  // enable client auth using PKCS12 container given in ArrayBuffer `myPkcs12ArrayBuffer`
+  cordova.plugin.http.setClientAuthMode('buffer', {
+    rawPkcs: myPkcs12ArrayBuffer,
+    pkcsPassword: 'mySecretPassword'
+  }, success, fail);
+
+  // enable client auth using certificate in system store (only on Android)
+  cordova.plugin.http.setClientAuthMode('systemstore', {}, success, fail);
+
+  // disable client auth
+  cordova.plugin.http.setClientAuthMode('none', {}, success, fail);
+```
+
 ### disableRedirect (deprecated)
 This function was deprecated in 2.0.9. Use ["setFollowRedirect"](#setFollowRedirect) instead.
 
diff --git a/package.json b/package.json
index 8548a50..c29ce3d 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "cordova-plugin-advanced-http",
-  "version": "2.4.1",
+  "version": "2.5.0",
   "description": "Cordova / Phonegap plugin for communicating with HTTP servers using SSL pinning",
   "scripts": {
     "updatecert": "node ./scripts/update-e2e-server-cert.js && node ./scripts/update-e2e-client-cert.js",
@@ -69,4 +69,4 @@
     "wd": "1.4.1",
     "xml2js": "0.4.19"
   }
-}
+}
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