From 3762ada110e11b051badb6ff2f4109083721d627 Mon Sep 17 00:00:00 2001
From: Eric Biggers <ebiggers@google.com>
Date: Wed, 26 Jan 2022 05:22:38 +0000
Subject: [PATCH] Stop trying to update FDE password from LockSettingsService

Since FDE is no longer supported, updating the FDE password never does
anything.  Stop trying to do so.  Remove updateEncryptionPassword() from
ILockSettings, since its only caller outside of LockSettingsService
itself was in LockPatternUtils, and the previous CL removed that caller.

Bug: 208476087
Change-Id: I46c2a472177836f0c9084e4c3b4ed2e6c0ab61d5
---
 .../internal/widget/ILockSettings.aidl        |  1 -
 .../locksettings/LockSettingsService.java     | 53 ++-----------------
 2 files changed, 4 insertions(+), 50 deletions(-)

diff --git a/core/java/com/android/internal/widget/ILockSettings.aidl b/core/java/com/android/internal/widget/ILockSettings.aidl
index e64d2783f88ac..3494c9e05b4a7 100644
--- a/core/java/com/android/internal/widget/ILockSettings.aidl
+++ b/core/java/com/android/internal/widget/ILockSettings.aidl
@@ -96,7 +96,6 @@ interface ILockSettings {
     boolean hasSecureLockScreen();
     boolean tryUnlockWithCachedUnifiedChallenge(int userId);
     void removeCachedUnifiedChallenge(int userId);
-    void updateEncryptionPassword(int type, in byte[] password);
     boolean registerWeakEscrowTokenRemovedListener(in IWeakEscrowTokenRemovedListener listener);
     boolean unregisterWeakEscrowTokenRemovedListener(in IWeakEscrowTokenRemovedListener listener);
     long addWeakEscrowToken(in byte[] token, int userId, in IWeakEscrowTokenActivatedListener callback);
diff --git a/services/core/java/com/android/server/locksettings/LockSettingsService.java b/services/core/java/com/android/server/locksettings/LockSettingsService.java
index 906910a8fb9b7..89c2be735002d 100644
--- a/services/core/java/com/android/server/locksettings/LockSettingsService.java
+++ b/services/core/java/com/android/server/locksettings/LockSettingsService.java
@@ -1796,7 +1796,10 @@ public class LockSettingsService extends ILockSettings.Stub {
     }
 
     private void onPostPasswordChanged(LockscreenCredential newCredential, int userHandle) {
-        updateEncryptionPasswordIfNeeded(newCredential, userHandle);
+        if (userHandle == UserHandle.USER_SYSTEM && isDeviceEncryptionEnabled() &&
+            shouldEncryptWithCredentials() && newCredential.isNone()) {
+            setCredentialRequiredToDecrypt(false);
+        }
         if (newCredential.isPattern()) {
             setBoolean(LockPatternUtils.PATTERN_EVER_CHOSEN_KEY, true, userHandle);
         }
@@ -1804,26 +1807,6 @@ public class LockSettingsService extends ILockSettings.Stub {
         mContext.getSystemService(TrustManager.class).reportEnabledTrustAgentsChanged(userHandle);
     }
 
-    /**
-     * Update device encryption password if calling user is USER_SYSTEM and device supports
-     * encryption.
-     */
-    private void updateEncryptionPasswordIfNeeded(LockscreenCredential credential, int userHandle) {
-        // Update the device encryption password.
-        if (userHandle != UserHandle.USER_SYSTEM || !isDeviceEncryptionEnabled()) {
-            return;
-        }
-        if (!shouldEncryptWithCredentials()) {
-            updateEncryptionPassword(StorageManager.CRYPT_TYPE_DEFAULT, null);
-            return;
-        }
-        if (credential.isNone()) {
-            // Set the encryption password to default.
-            setCredentialRequiredToDecrypt(false);
-        }
-        updateEncryptionPassword(credential.getStorageCryptType(), credential.getCredential());
-    }
-
     /**
      * Store the hash of the *current* password in the password history list, if device policy
      * enforces password history requirement.
@@ -1938,34 +1921,6 @@ public class LockSettingsService extends ILockSettings.Stub {
         }
     }
 
-    /** Update the encryption password if it is enabled **/
-    @Override
-    public void updateEncryptionPassword(final int type, final byte[] password) {
-        if (!hasSecureLockScreen() && password != null && password.length != 0) {
-            throw new UnsupportedOperationException(
-                    "This operation requires the lock screen feature.");
-        }
-        if (!isDeviceEncryptionEnabled()) {
-            return;
-        }
-        final IBinder service = ServiceManager.getService("mount");
-        if (service == null) {
-            Slog.e(TAG, "Could not find the mount service to update the encryption password");
-            return;
-        }
-
-        // TODO(b/120484642): This is a location where we still use a String for vold
-        String passwordString = password != null ? new String(password) : null;
-        mHandler.post(() -> {
-            IStorageManager storageManager = mInjector.getStorageManager();
-            try {
-                storageManager.changeEncryptionPassword(type, passwordString);
-            } catch (RemoteException e) {
-                Slog.e(TAG, "Error changing encryption password", e);
-            }
-        });
-    }
-
     /** Register the given WeakEscrowTokenRemovedListener. */
     @Override
     public boolean registerWeakEscrowTokenRemovedListener(