Add docs

Author: joefarebrother

java/ql/src/Security/CWE/CWE-524/Example.xml

@@ -0,0 +1,15 @@
+<?xml version="1.0" encoding="utf-8"?>
+<LinearLayout
+    xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto">
+
+    <!-- BAD: This password field uses the `text` input type, which allows the input to be saved to the keyboard cache. -->
+    <EditText
+        android:id="@+id/password_bad"
+        android:inputType="text"/> 
+
+    <!-- GOOD: This password field uses the `textPassword` input type, which ensures that the input is not saved to the keyboard cache. -->
+    <EditText
+        android:id="@+id/password_good"
+        android:inputType="textPassword"/>  
+</LinearLayout>

java/ql/src/Security/CWE/CWE-524/SensitiveKeyboardCache.qhelp

@@ -1 +1,36 @@
-todo
+<!DOCTYPE qhelp PUBLIC
+  "-//Semmle//qhelp//EN"
+  "qhelp.dtd">
+<qhelp>
+
+<overview>
+<p>When a user enters information to a text input field on an Android application, then by default their input is saved to a keyboard cache, 
+which provides autocomplete suggestions and predictions. If the input field is expected to contain sensitive information, such as a password or banking details, 
+this sensitive data may be leaked to other applications via the keyboard cache.</p>
+
+</overview>
+<recommendation>
+
+<p>For input fields expected to accept sensitive information, an input type such as <code>"textNoSuggestions"</code> (or <code>"textPassword"</code> for a password) 
+should be used to ensure that the input does not get stored in the keyboard cache.</p>
+
+</recommendation>
+<example>
+
+<p>In the following example, the field labeled BAD could allow the password to be saved to the keyboard cache;
+ whereas the field labeled GOOD uses the <code>"textPassword"</code> input type, which ensures that it is not.</p>
+
+<sample src="Example.xml" />
+
+</example>
+<references>
+
+<li>
+  OWASP Mobile Application Security Testing Guie: <a href="https://github.com/OWASP/owasp-mastg/blob/b7a93a2e5e0557cc9a12e55fc3f6675f6986bb86/Document/0x05d-Testing-Data-Storage.md#determining-whether-the-keyboard-cache-is-disabled-for-text-input-fields-mstg-storage-5">Determining Whether the Keyboard Cache Is Disabled for Text Input Fields</a>.
+</li>
+<li>
+  Android Developers: <a href="https://developer.android.com/reference/android/widget/TextView#attr_android:inputType"> <code>android:inputType</code> attribute documentation.
+<li>
+
+</references>
+</qhelp>

java/ql/src/Security/CWE/CWE-524/SensitiveKeyboardCache.ql

@@ -3,9 +3,9 @@
  * @description Sensitive information should not be saved to the keyboard cache.
  * @kind problem
  * @problem.severity warning
- * @id java/android/debuggable-attribute-enabled
+ * @id java/android/sensetive-keyboard-cache
  * @tags security
- *       external/cwe/cwe-489
+ *       external/cwe/cwe-524
  * @precision high
  */