Remove restrictions PIN functionality

Bug: 20852231
Change-Id: I5666ee28ff1341ead9b258bc0852d8ba6d313c5e

1 files changed, 0 insertions, 189 deletions

diff --git a/services/core/java/com/android/server/pm/UserManagerService.java b/services/core/java/com/android/server/pm/UserManagerService.java
index e79a206..e4495f6 100644
--- a/services/core/java/com/android/server/pm/UserManagerService.java
+++ b/services/core/java/com/android/server/pm/UserManagerService.java
@@ -68,9 +68,6 @@ import java.io.FileNotFoundException;
 import java.io.FileOutputStream;
 import java.io.IOException;
 import java.io.PrintWriter;
-import java.security.MessageDigest;
-import java.security.NoSuchAlgorithmException;
-import java.security.SecureRandom;
 import java.util.ArrayList;
 import java.util.List;
 
@@ -88,10 +85,6 @@ public class UserManagerService extends IUserManager.Stub {
     private static final String ATTR_ID = "id";
     private static final String ATTR_CREATION_TIME = "created";
     private static final String ATTR_LAST_LOGGED_IN_TIME = "lastLoggedIn";
-    private static final String ATTR_SALT = "salt";
-    private static final String ATTR_PIN_HASH = "pinHash";
-    private static final String ATTR_FAILED_ATTEMPTS = "failedAttempts";
-    private static final String ATTR_LAST_RETRY_MS = "lastAttemptMs";
     private static final String ATTR_SERIAL_NO = "serialNumber";
     private static final String ATTR_NEXT_SERIAL_NO = "nextSerialNumber";
     private static final String ATTR_PARTIAL = "partial";
@@ -129,17 +122,10 @@ public class UserManagerService extends IUserManager.Stub {
 
     private static final long EPOCH_PLUS_30_YEARS = 30L * 365 * 24 * 60 * 60 * 1000L; // ms
 
-    // Number of attempts before jumping to the next BACKOFF_TIMES slot
-    private static final int BACKOFF_INC_INTERVAL = 5;
-
     // Maximum number of managed profiles permitted is 1. This cannot be increased
     // without first making sure that the rest of the framework is prepared for it.
     private static final int MAX_MANAGED_PROFILES = 1;
 
-    // Amount of time to force the user to wait before entering the PIN again, after failing
-    // BACKOFF_INC_INTERVAL times.
-    private static final int[] BACKOFF_TIMES = { 0, 30*1000, 60*1000, 5*60*1000, 30*60*1000 };
-
     static final int WRITE_USER_MSG = 1;
     static final int WRITE_USER_DELAY = 2*1000;  // 2 seconds
 
@@ -158,16 +144,6 @@ public class UserManagerService extends IUserManager.Stub {
     private final SparseArray<Bundle> mUserRestrictions = new SparseArray<Bundle>();
     private final Bundle mGuestRestrictions = new Bundle();
 
-    class RestrictionsPinState {
-        long salt;
-        String pinHash;
-        int failedAttempts;
-        long lastAttemptTime;
-    }
-
-    private final SparseArray<RestrictionsPinState> mRestrictionsPinStates =
-            new SparseArray<RestrictionsPinState>();
-
     /**
      * Set of user IDs being actively removed. Removed IDs linger in this set
      * for several seconds to work around a VFS caching issue.
@@ -806,21 +782,6 @@ public class UserManagerService extends IUserManager.Stub {
             serializer.attribute(null, ATTR_CREATION_TIME, Long.toString(userInfo.creationTime));
             serializer.attribute(null, ATTR_LAST_LOGGED_IN_TIME,
                     Long.toString(userInfo.lastLoggedInTime));
-            RestrictionsPinState pinState = mRestrictionsPinStates.get(userInfo.id);
-            if (pinState != null) {
-                if (pinState.salt != 0) {
-                    serializer.attribute(null, ATTR_SALT, Long.toString(pinState.salt));
-                }
-                if (pinState.pinHash != null) {
-                    serializer.attribute(null, ATTR_PIN_HASH, pinState.pinHash);
-                }
-                if (pinState.failedAttempts != 0) {
-                    serializer.attribute(null, ATTR_FAILED_ATTEMPTS,
-                            Integer.toString(pinState.failedAttempts));
-                    serializer.attribute(null, ATTR_LAST_RETRY_MS,
-                            Long.toString(pinState.lastAttemptTime));
-                }
-            }
             if (userInfo.iconPath != null) {
                 serializer.attribute(null,  ATTR_ICON_PATH, userInfo.iconPath);
             }
@@ -940,11 +901,7 @@ public class UserManagerService extends IUserManager.Stub {
         String iconPath = null;
         long creationTime = 0L;
         long lastLoggedInTime = 0L;
-        long salt = 0L;
-        String pinHash = null;
-        int failedAttempts = 0;
         int profileGroupId = UserInfo.NO_PROFILE_GROUP_ID;
-        long lastAttemptTime = 0L;
         boolean partial = false;
         boolean guestToRemove = false;
         Bundle restrictions = new Bundle();
@@ -978,10 +935,6 @@ public class UserManagerService extends IUserManager.Stub {
                 iconPath = parser.getAttributeValue(null, ATTR_ICON_PATH);
                 creationTime = readLongAttribute(parser, ATTR_CREATION_TIME, 0);
                 lastLoggedInTime = readLongAttribute(parser, ATTR_LAST_LOGGED_IN_TIME, 0);
-                salt = readLongAttribute(parser, ATTR_SALT, 0L);
-                pinHash = parser.getAttributeValue(null, ATTR_PIN_HASH);
-                failedAttempts = readIntAttribute(parser, ATTR_FAILED_ATTEMPTS, 0);
-                lastAttemptTime = readLongAttribute(parser, ATTR_LAST_RETRY_MS, 0L);
                 profileGroupId = readIntAttribute(parser, ATTR_PROFILE_GROUP_ID,
                         UserInfo.NO_PROFILE_GROUP_ID);
                 String valueString = parser.getAttributeValue(null, ATTR_PARTIAL);
@@ -1019,17 +972,6 @@ public class UserManagerService extends IUserManager.Stub {
             userInfo.guestToRemove = guestToRemove;
             userInfo.profileGroupId = profileGroupId;
             mUserRestrictions.append(id, restrictions);
-            if (salt != 0L) {
-                RestrictionsPinState pinState = mRestrictionsPinStates.get(id);
-                if (pinState == null) {
-                    pinState = new RestrictionsPinState();
-                    mRestrictionsPinStates.put(id, pinState);
-                }
-                pinState.salt = salt;
-                pinState.pinHash = pinHash;
-                pinState.failedAttempts = failedAttempts;
-                pinState.lastAttemptTime = lastAttemptTime;
-            }
             return userInfo;
 
         } catch (IOException ioe) {
@@ -1431,8 +1373,6 @@ public class UserManagerService extends IUserManager.Stub {
 
         // Remove this user from the list
         mUsers.remove(userHandle);
-
-        mRestrictionsPinStates.remove(userHandle);
         // Remove user file
         AtomicFile userFile = new AtomicFile(new File(mUsersDir, userHandle + XML_SUFFIX));
         userFile.delete();
@@ -1504,92 +1444,6 @@ public class UserManagerService extends IUserManager.Stub {
     }
 
     @Override
-    public boolean setRestrictionsChallenge(String newPin) {
-        checkManageUsersPermission("Only system can modify the restrictions pin");
-        int userId = UserHandle.getCallingUserId();
-        synchronized (mPackagesLock) {
-            RestrictionsPinState pinState = mRestrictionsPinStates.get(userId);
-            if (pinState == null) {
-                pinState = new RestrictionsPinState();
-            }
-            if (newPin == null) {
-                pinState.salt = 0;
-                pinState.pinHash = null;
-            } else {
-                try {
-                    pinState.salt = SecureRandom.getInstance("SHA1PRNG").nextLong();
-                } catch (NoSuchAlgorithmException e) {
-                    pinState.salt = (long) (Math.random() * Long.MAX_VALUE);
-                }
-                pinState.pinHash = passwordToHash(newPin, pinState.salt);
-                pinState.failedAttempts = 0;
-            }
-            mRestrictionsPinStates.put(userId, pinState);
-            writeUserLocked(mUsers.get(userId));
-        }
-        return true;
-    }
-
-    @Override
-    public int checkRestrictionsChallenge(String pin) {
-        checkManageUsersPermission("Only system can verify the restrictions pin");
-        int userId = UserHandle.getCallingUserId();
-        synchronized (mPackagesLock) {
-            RestrictionsPinState pinState = mRestrictionsPinStates.get(userId);
-            // If there's no pin set, return error code
-            if (pinState == null || pinState.salt == 0 || pinState.pinHash == null) {
-                return UserManager.PIN_VERIFICATION_FAILED_NOT_SET;
-            } else if (pin == null) {
-                // If just checking if user can be prompted, return remaining time
-                int waitTime = getRemainingTimeForPinAttempt(pinState);
-                Slog.d(LOG_TAG, "Remaining waittime peek=" + waitTime);
-                return waitTime;
-            } else {
-                int waitTime = getRemainingTimeForPinAttempt(pinState);
-                Slog.d(LOG_TAG, "Remaining waittime=" + waitTime);
-                if (waitTime > 0) {
-                    return waitTime;
-                }
-                if (passwordToHash(pin, pinState.salt).equals(pinState.pinHash)) {
-                    pinState.failedAttempts = 0;
-                    scheduleWriteUserLocked(mUsers.get(userId));
-                    return UserManager.PIN_VERIFICATION_SUCCESS;
-                } else {
-                    pinState.failedAttempts++;
-                    pinState.lastAttemptTime = System.currentTimeMillis();
-                    scheduleWriteUserLocked(mUsers.get(userId));
-                    return waitTime;
-                }
-            }
-        }
-    }
-
-    private int getRemainingTimeForPinAttempt(RestrictionsPinState pinState) {
-        int backoffIndex = Math.min(pinState.failedAttempts / BACKOFF_INC_INTERVAL,
-                BACKOFF_TIMES.length - 1);
-        int backoffTime = (pinState.failedAttempts % BACKOFF_INC_INTERVAL) == 0 ?
-                BACKOFF_TIMES[backoffIndex] : 0;
-        return (int) Math.max(backoffTime + pinState.lastAttemptTime - System.currentTimeMillis(),
-                0);
-    }
-
-    @Override
-    public boolean hasRestrictionsChallenge() {
-        int userId = UserHandle.getCallingUserId();
-        synchronized (mPackagesLock) {
-            return hasRestrictionsPinLocked(userId);
-        }
-    }
-
-    private boolean hasRestrictionsPinLocked(int userId) {
-        RestrictionsPinState pinState = mRestrictionsPinStates.get(userId);
-        if (pinState == null || pinState.salt == 0 || pinState.pinHash == null) {
-            return false;
-        }
-        return true;
-    }
-
-    @Override
     public void removeRestrictions() {
         checkManageUsersPermission("Only system can remove restrictions");
         final int userHandle = UserHandle.getCallingUserId();
@@ -1600,8 +1454,6 @@ public class UserManagerService extends IUserManager.Stub {
         synchronized (mPackagesLock) {
             // Remove all user restrictions
             setUserRestrictions(new Bundle(), userHandle);
-            // Remove restrictions pin
-            setRestrictionsChallenge(null);
             // Remove any app restrictions
             cleanAppRestrictions(userHandle);
         }
@@ -1633,42 +1485,6 @@ public class UserManagerService extends IUserManager.Stub {
             }
         });
     }
-
-    /*
-     * Generate a hash for the given password. To avoid brute force attacks, we use a salted hash.
-     * Not the most secure, but it is at least a second level of protection. First level is that
-     * the file is in a location only readable by the system process.
-     * @param password the password.
-     * @param salt the randomly generated salt
-     * @return the hash of the pattern in a String.
-     */
-    private String passwordToHash(String password, long salt) {
-        if (password == null) {
-            return null;
-        }
-        String algo = null;
-        String hashed = salt + password;
-        try {
-            byte[] saltedPassword = (password + salt).getBytes();
-            byte[] sha1 = MessageDigest.getInstance(algo = "SHA-1").digest(saltedPassword);
-            byte[] md5 = MessageDigest.getInstance(algo = "MD5").digest(saltedPassword);
-            hashed = toHex(sha1) + toHex(md5);
-        } catch (NoSuchAlgorithmException e) {
-            Log.w(LOG_TAG, "Failed to encode string because of missing algorithm: " + algo);
-        }
-        return hashed;
-    }
-
-    private static String toHex(byte[] ary) {
-        final String hex = "0123456789ABCDEF";
-        String ret = "";
-        for (int i = 0; i < ary.length; i++) {
-            ret += hex.charAt((ary[i] >> 4) & 0xf);
-            ret += hex.charAt(ary[i] & 0xf);
-        }
-        return ret;
-    }
-
     private int getUidForPackage(String packageName) {
         long ident = Binder.clearCallingIdentity();
         try {
@@ -1954,11 +1770,6 @@ public class UserManagerService extends IUserManager.Stub {
         return RESTRICTIONS_FILE_PREFIX + packageName + XML_SUFFIX;
     }
 
-    private String restrictionsFileNameToPackage(String fileName) {
-        return fileName.substring(RESTRICTIONS_FILE_PREFIX.length(),
-                (int) (fileName.length() - XML_SUFFIX.length()));
-    }
-
     @Override
     protected void dump(FileDescriptor fd, PrintWriter pw, String[] args) {
         if (mContext.checkCallingOrSelfPermission(android.Manifest.permission.DUMP)