From ae79c41cd7a0f7b7a08dd6749dacfe4c41fca87d Mon Sep 17 00:00:00 2001
From: Arc Wang <arcwang@google.com>
Date: Wed, 12 Aug 2020 13:57:05 +0800
Subject: [PATCH] [Wi-Fi] Fix crash after editing invalid hotspot password

From Android 11, Wi-Fi framework only supports ASCII encoding
for hotspot password, APP should check if password character is
valid.

This change checks if SoftApConfiguration accepts the password
and disable the OK button if the password is invalid.

Bug: 163353576
Test: make RunSettingsRoboTests ROBOTEST_FILTER=WifiUtilsTest
Change-Id: Ief3c6c1f08f8fcdf128768cde3ab8eef91f19fbe
---
 src/com/android/settings/wifi/WifiUtils.java    | 17 ++++++++++-------
 .../WifiTetherPasswordPreferenceController.java |  2 +-
 .../android/settings/wifi/WifiUtilsTest.java    | 11 ++++++-----
 3 files changed, 17 insertions(+), 13 deletions(-)

diff --git a/src/com/android/settings/wifi/WifiUtils.java b/src/com/android/settings/wifi/WifiUtils.java
index 244fe48c8be..06f74d54e55 100644
--- a/src/com/android/settings/wifi/WifiUtils.java
+++ b/src/com/android/settings/wifi/WifiUtils.java
@@ -23,6 +23,7 @@ import android.content.Context;
 import android.content.pm.PackageManager;
 import android.net.NetworkCapabilities;
 import android.net.wifi.ScanResult;
+import android.net.wifi.SoftApConfiguration;
 import android.net.wifi.WifiConfiguration;
 import android.os.UserHandle;
 import android.os.UserManager;
@@ -38,8 +39,6 @@ public class WifiUtils {
 
     private static final int SSID_ASCII_MIN_LENGTH = 1;
     private static final int SSID_ASCII_MAX_LENGTH = 32;
-    private static final int PASSWORD_MIN_LENGTH = 8;
-    private static final int PASSWORD_MAX_LENGTH = 63;
 
 
     public static boolean isSSIDTooLong(String ssid) {
@@ -56,13 +55,17 @@ public class WifiUtils {
         return ssid.length() < SSID_ASCII_MIN_LENGTH;
     }
 
-    public static boolean isHotspotPasswordValid(String password) {
-        if (TextUtils.isEmpty(password)) {
+    /**
+     * Check if the WPA2-PSK hotspot password is valid.
+     */
+    public static boolean isHotspotWpa2PasswordValid(String password) {
+        final SoftApConfiguration.Builder configBuilder = new SoftApConfiguration.Builder();
+        try {
+            configBuilder.setPassphrase(password, SoftApConfiguration.SECURITY_TYPE_WPA2_PSK);
+        } catch (IllegalArgumentException e) {
             return false;
         }
-
-        final int length = password.length();
-        return length >= PASSWORD_MIN_LENGTH && length <= PASSWORD_MAX_LENGTH;
+        return true;
     }
 
     /**
diff --git a/src/com/android/settings/wifi/tether/WifiTetherPasswordPreferenceController.java b/src/com/android/settings/wifi/tether/WifiTetherPasswordPreferenceController.java
index a4a51dc0e72..be67d22d966 100644
--- a/src/com/android/settings/wifi/tether/WifiTetherPasswordPreferenceController.java
+++ b/src/com/android/settings/wifi/tether/WifiTetherPasswordPreferenceController.java
@@ -118,7 +118,7 @@ public class WifiTetherPasswordPreferenceController extends WifiTetherBasePrefer
 
     @Override
     public boolean isTextValid(String value) {
-        return WifiUtils.isHotspotPasswordValid(value);
+        return WifiUtils.isHotspotWpa2PasswordValid(value);
     }
 
     private static String generateRandomPassword() {
diff --git a/tests/robotests/src/com/android/settings/wifi/WifiUtilsTest.java b/tests/robotests/src/com/android/settings/wifi/WifiUtilsTest.java
index a3609f7eede..630b31939d7 100644
--- a/tests/robotests/src/com/android/settings/wifi/WifiUtilsTest.java
+++ b/tests/robotests/src/com/android/settings/wifi/WifiUtilsTest.java
@@ -45,11 +45,12 @@ public class WifiUtilsTest {
     public void testPassword() {
         final String longPassword = "123456789012345678901234567890"
                 + "1234567890123456789012345678901234567890";
-        assertThat(WifiUtils.isHotspotPasswordValid("123")).isFalse();
-        assertThat(WifiUtils.isHotspotPasswordValid("12345678")).isTrue();
-        assertThat(WifiUtils.isHotspotPasswordValid("1234567890")).isTrue();
-        assertThat(WifiUtils.isHotspotPasswordValid(longPassword)).isFalse();
-        assertThat(WifiUtils.isHotspotPasswordValid("")).isFalse();
+        assertThat(WifiUtils.isHotspotWpa2PasswordValid("123")).isFalse();
+        assertThat(WifiUtils.isHotspotWpa2PasswordValid("12345678")).isTrue();
+        assertThat(WifiUtils.isHotspotWpa2PasswordValid("1234567890")).isTrue();
+        assertThat(WifiUtils.isHotspotWpa2PasswordValid(longPassword)).isFalse();
+        assertThat(WifiUtils.isHotspotWpa2PasswordValid("")).isFalse();
+        assertThat(WifiUtils.isHotspotWpa2PasswordValid("€¥£")).isFalse();
     }
 
     @Test