From a798817de09cc787850ee957c7326fb36dc6c5a5 Mon Sep 17 00:00:00 2001 From: Daniel Micay Date: Thu, 3 Dec 2015 14:27:34 -0500 Subject: [PATCH] support separate encryption/lockscreen passwords This adds the necessary infrastructure for allowing users to opt-in to a distinct device encryption passphrase. The passwords are still tied together by default. This makes it possible to use a complex encryption passphrase without losing the convenience of a very simple lockscreen pin. This feature can be combined with a forced reboot after a chosen number of failed unlocking attempts to prevent brute-forcing by requiring the entry of the encryption password instead. --- core/java/android/provider/Settings.java | 7 +++ .../android/internal/widget/LockPatternUtils.java | 72 +++++++++++++++++++++- .../com/android/server/LockSettingsService.java | 1 + 3 files changed, 77 insertions(+), 3 deletions(-) diff --git a/core/java/android/provider/Settings.java b/core/java/android/provider/Settings.java index e107fd1..a6be540 100644 --- a/core/java/android/provider/Settings.java +++ b/core/java/android/provider/Settings.java @@ -4850,6 +4850,13 @@ public static boolean putFloatForUser(ContentResolver cr, String name, float val "lock_screen_allow_private_notifications"; /** + * Separate password for encryption and the lockscreen. + * @hide + */ + public static final String LOCK_SEPARATE_ENCRYPTION_PASSWORD = + "lock_separate_encryption_password"; + + /** * Set by the system to track if the user needs to see the call to action for * the lockscreen notification policy. * @hide diff --git a/core/java/com/android/internal/widget/LockPatternUtils.java b/core/java/com/android/internal/widget/LockPatternUtils.java index ae22b50..25f56e7 100644 --- a/core/java/com/android/internal/widget/LockPatternUtils.java +++ b/core/java/com/android/internal/widget/LockPatternUtils.java @@ -457,7 +457,8 @@ public void clearLock(int userHandle) { // well, we tried... } - if (userHandle == UserHandle.USER_OWNER) { + if (userHandle == UserHandle.USER_OWNER + && !isSeparateEncryptionPasswordEnabled()) { // Set the encryption password to default. updateEncryptionPassword(StorageManager.CRYPT_TYPE_DEFAULT, null); } @@ -518,7 +519,8 @@ public void saveLockPattern(List pattern, String savedPatt // Update the device encryption password. if (userId == UserHandle.USER_OWNER - && LockPatternUtils.isDeviceEncryptionEnabled()) { + && LockPatternUtils.isDeviceEncryptionEnabled() + && !isSeparateEncryptionPasswordEnabled()) { if (!shouldEncryptWithCredentials(true)) { clearEncryptionPassword(); } else { @@ -727,7 +729,8 @@ public void saveLockPassword(String password, String savedPassword, int quality, // Update the device encryption password. if (userHandle == UserHandle.USER_OWNER - && LockPatternUtils.isDeviceEncryptionEnabled()) { + && LockPatternUtils.isDeviceEncryptionEnabled() + && !isSeparateEncryptionPasswordEnabled()) { if (!shouldEncryptWithCredentials(true)) { clearEncryptionPassword(); } else { @@ -1071,6 +1074,69 @@ public void setVisiblePasswordEnabled(boolean enabled, int userId) { } } + private void updateEncryptionPasswordFromPassword(String password) { + if (!TextUtils.isEmpty(password)) { + int computedQuality = computePasswordQuality(password); + boolean numeric = computedQuality + == DevicePolicyManager.PASSWORD_QUALITY_NUMERIC; + boolean numericComplex = computedQuality + == DevicePolicyManager.PASSWORD_QUALITY_NUMERIC_COMPLEX; + int type = numeric || numericComplex ? StorageManager.CRYPT_TYPE_PIN + : StorageManager.CRYPT_TYPE_PASSWORD; + updateEncryptionPassword(type, password); + } else { + clearEncryptionPassword(); + } + } + + /** + * Set the encryption password separately from the lockscreen password. + * + * @param password The password to save + */ + public void setSeparateEncryptionPassword(String password) { + updateEncryptionPasswordFromPassword(password); + setSeparateEncryptionPasswordEnabled(true); + } + + /** + * Replace the separate encryption password by tying it to the lockscreen + * password. No change will occur if the provided lockscreen password is + * incorrect. + * + * @param password The current lockscreen password + * @return Whether the lockscreen password was correct. + */ + public void replaceSeparateEncryptionPassword(String password) { + updateEncryptionPasswordFromPassword(password); + setSeparateEncryptionPasswordEnabled(false); + } + + /** + * Replace the separate encryption password by tying it to the lockscreen + * pattern. No change will occur if the provided lockscreen password is + * incorrect. + * + * @param pattern The current lockscreen pattern + * @return Whether the lockscreen pattern was correct. + */ + public void replaceSeparateEncryptionPasswordWithPattern(List pattern) { + String stringPattern = patternToString(pattern); + updateEncryptionPassword(StorageManager.CRYPT_TYPE_PATTERN, stringPattern); + setSeparateEncryptionPasswordEnabled(false); + } + + /** + * @return Whether the encryption password is separate from the lockscreen password. + */ + public boolean isSeparateEncryptionPasswordEnabled() { + return getBoolean(Settings.Secure.LOCK_SEPARATE_ENCRYPTION_PASSWORD, false, UserHandle.USER_OWNER); + } + + private void setSeparateEncryptionPasswordEnabled(boolean enabled) { + setBoolean(Settings.Secure.LOCK_SEPARATE_ENCRYPTION_PASSWORD, enabled, UserHandle.USER_OWNER); + } + /** * @return Whether tactile feedback for the pattern is enabled. */ diff --git a/services/core/java/com/android/server/LockSettingsService.java b/services/core/java/com/android/server/LockSettingsService.java index bb0615d..6e05fde 100644 --- a/services/core/java/com/android/server/LockSettingsService.java +++ b/services/core/java/com/android/server/LockSettingsService.java @@ -813,6 +813,7 @@ public void requireStrongAuth(int strongAuthReason, int userId) { Secure.LOCK_PATTERN_SIZE, Secure.LOCK_DOTS_VISIBLE, Secure.LOCK_SHOW_ERROR_PATH, + Secure.LOCK_SEPARATE_ENCRYPTION_PASSWORD }; // Reading these settings needs the contacts permission