Merge "Added changes for storing PIN length in PasswordData" into udc-dev

6 files changed, 207 insertions, 35 deletions

diff --git a/core/java/com/android/internal/widget/ILockSettings.aidl b/core/java/com/android/internal/widget/ILockSettings.aidl
index a78145407b9f..dfcde3dbee89 100644
--- a/core/java/com/android/internal/widget/ILockSettings.aidl
+++ b/core/java/com/android/internal/widget/ILockSettings.aidl
@@ -56,6 +56,7 @@ interface ILockSettings {
     VerifyCredentialResponse verifyGatekeeperPasswordHandle(long gatekeeperPasswordHandle, long challenge, int userId);
     void removeGatekeeperPasswordHandle(long gatekeeperPasswordHandle);
     int getCredentialType(int userId);
+    int getPinLength(int userId);
     byte[] getHashFactor(in LockscreenCredential currentCredential, int userId);
     void setSeparateProfileChallengeEnabled(int userId, boolean enabled, in LockscreenCredential managedUserPassword);
     boolean getSeparateProfileChallengeEnabled(int userId);
diff --git a/core/java/com/android/internal/widget/LockPatternChecker.java b/core/java/com/android/internal/widget/LockPatternChecker.java
index 5c3759f96764..5adbc583140f 100644
--- a/core/java/com/android/internal/widget/LockPatternChecker.java
+++ b/core/java/com/android/internal/widget/LockPatternChecker.java
@@ -117,9 +117,6 @@ public final class LockPatternChecker {
             @Override
             protected void onPostExecute(Boolean result) {
                 callback.onChecked(result, mThrottleTimeout);
-                if (LockPatternUtils.isAutoPinConfirmFeatureAvailable()) {
-                    utils.setPinLength(userId, credentialCopy.size());
-                }
                 credentialCopy.zeroize();
             }
 
diff --git a/core/java/com/android/internal/widget/LockPatternUtils.java b/core/java/com/android/internal/widget/LockPatternUtils.java
index 4d9141052c49..38632d15e857 100644
--- a/core/java/com/android/internal/widget/LockPatternUtils.java
+++ b/core/java/com/android/internal/widget/LockPatternUtils.java
@@ -116,6 +116,12 @@ public class LockPatternUtils {
     public static final int CREDENTIAL_TYPE_PIN = 3;
     public static final int CREDENTIAL_TYPE_PASSWORD = 4;
 
+    // This is the value of pin length whenever pin length is not available
+    public static final int PIN_LENGTH_UNAVAILABLE = -1;
+
+    // This is the minimum pin length at which auto confirmation is supported
+    public static final int MIN_AUTO_PIN_REQUIREMENT_LENGTH = 6;
+
     /**
      * Header used for the encryption and decryption of the device credential for
      * remote device lockscreen validation.
@@ -177,8 +183,6 @@ public class LockPatternUtils {
     @Deprecated
     public final static String LOCKSCREEN_WIDGETS_ENABLED = "lockscreen.widgets_enabled";
 
-    public static final String PIN_LENGTH = "lockscreen.pin_length";
-
     public final static String PASSWORD_HISTORY_KEY = "lockscreen.passwordhistory";
 
     private static final String LOCK_SCREEN_OWNER_INFO = Settings.Secure.LOCK_SCREEN_OWNER_INFO;
@@ -193,7 +197,7 @@ public class LockPatternUtils {
     private static final String KNOWN_TRUST_AGENTS = "lockscreen.knowntrustagents";
     private static final String IS_TRUST_USUALLY_MANAGED = "lockscreen.istrustusuallymanaged";
 
-    private static final String AUTO_PIN_CONFIRM = "lockscreen.auto_pin_confirm";
+    public static final String AUTO_PIN_CONFIRM = "lockscreen.auto_pin_confirm";
 
     public static final String CURRENT_LSKF_BASED_PROTECTOR_ID_KEY = "sp-handle";
     public static final String PASSWORD_HISTORY_DELIMITER = ",";
@@ -604,23 +608,20 @@ public class LockPatternUtils {
     }
 
     /**
-     * Used for setting the length of the PIN set by a particular user.
-     * @param userId user id of the user whose pin length we save
-     * @param val value of length of pin
-     */
-    public void setPinLength(int userId, long val) {
-        setLong(PIN_LENGTH, val, userId);
-    }
-
-    /**
      * Returns the length of the PIN set by a particular user.
      * @param userId user id of the user whose pin length we have to return
-     * @return the length of the pin set by user and -1 if nothing
+     * @return
+     *       A. the length of the pin set by user if it is currently available
+     *       B. PIN_LENGTH_UNAVAILABLE if it is not available or if an exception occurs
      */
-    public long getPinLength(int userId) {
-        return getLong(PIN_LENGTH, -1, userId);
+    public int getPinLength(int userId) {
+        try {
+            return getLockSettings().getPinLength(userId);
+        } catch (RemoteException e) {
+            Log.e(TAG, "Could not fetch PIN length " + e);
+            return PIN_LENGTH_UNAVAILABLE;
+        }
     }
-
     /**
      * Records that the user has chosen a pattern at some time, even if the pattern is
      * currently cleared.
diff --git a/services/core/java/com/android/server/locksettings/LockSettingsService.java b/services/core/java/com/android/server/locksettings/LockSettingsService.java
index 2b5f874156ee..0da94ff6aa0f 100644
--- a/services/core/java/com/android/server/locksettings/LockSettingsService.java
+++ b/services/core/java/com/android/server/locksettings/LockSettingsService.java
@@ -36,6 +36,7 @@ import static com.android.internal.widget.LockPatternUtils.CREDENTIAL_TYPE_PASSW
 import static com.android.internal.widget.LockPatternUtils.CREDENTIAL_TYPE_PIN;
 import static com.android.internal.widget.LockPatternUtils.CURRENT_LSKF_BASED_PROTECTOR_ID_KEY;
 import static com.android.internal.widget.LockPatternUtils.EscrowTokenStateChangeCallback;
+import static com.android.internal.widget.LockPatternUtils.PIN_LENGTH_UNAVAILABLE;
 import static com.android.internal.widget.LockPatternUtils.StrongAuthTracker.STRONG_AUTH_REQUIRED_AFTER_LOCKOUT;
 import static com.android.internal.widget.LockPatternUtils.StrongAuthTracker.STRONG_AUTH_REQUIRED_FOR_UNATTENDED_UPDATE;
 import static com.android.internal.widget.LockPatternUtils.USER_FRP;
@@ -1202,6 +1203,31 @@ public class LockSettingsService extends ILockSettings.Stub {
                 DevicePolicyManager.PASSWORD_QUALITY_UNSPECIFIED, userId);
     }
 
+    /*
+     * Gets the PIN length for the given user if it is currently available.
+     * Can only be invoked by process/activity that have the right permission.
+     * Returns:
+     *      A. Actual PIN length if credential type PIN and auto confirm feature is enabled
+     *         for the user or user's PIN has been successfully verified since the device booted
+     *      B. PIN_LENGTH_UNAVAILABLE if pin length is not stored/available
+     */
+    @Override
+    public int getPinLength(int userId) {
+        checkPasswordHavePermission();
+        PasswordMetrics passwordMetrics = getUserPasswordMetrics(userId);
+        if (passwordMetrics != null && passwordMetrics.credType == CREDENTIAL_TYPE_PIN) {
+            return passwordMetrics.length;
+        }
+        synchronized (mSpManager) {
+            final long protectorId = getCurrentLskfBasedProtectorId(userId);
+            if (protectorId == SyntheticPasswordManager.NULL_PROTECTOR_ID) {
+                // Only possible for new users during early boot (before onThirdPartyAppsStarted())
+                return PIN_LENGTH_UNAVAILABLE;
+            }
+            return mSpManager.getPinLength(protectorId, userId);
+        }
+    }
+
     /**
      * This API is cached; whenever the result would change,
      * {@link com.android.internal.widget.LockPatternUtils#invalidateCredentialTypeCache}
@@ -1683,11 +1709,6 @@ public class LockSettingsService extends ILockSettings.Stub {
         if (newCredential.isPattern()) {
             setBoolean(LockPatternUtils.PATTERN_EVER_CHOSEN_KEY, true, userHandle);
         }
-        if (LockPatternUtils.isAutoPinConfirmFeatureAvailable()) {
-            if (newCredential.isPin()) {
-                setLong(LockPatternUtils.PIN_LENGTH, newCredential.size(), userHandle);
-            }
-        }
 
         updatePasswordHistory(newCredential, userHandle);
         mContext.getSystemService(TrustManager.class).reportEnabledTrustAgentsChanged(userHandle);
@@ -2229,6 +2250,11 @@ public class LockSettingsService extends ILockSettings.Stub {
         }
     }
 
+    /**
+     * Returns the PasswordMetrics for the current user
+     * @param userHandle The id of the user for which we return the password metrics object
+     * @return passwordmetrics for the user or null if not available
+     */
     @VisibleForTesting
     PasswordMetrics getUserPasswordMetrics(int userHandle) {
         if (!isUserSecure(userHandle)) {
diff --git a/services/core/java/com/android/server/locksettings/SyntheticPasswordManager.java b/services/core/java/com/android/server/locksettings/SyntheticPasswordManager.java
index 1663b019d769..a4dab729250d 100644
--- a/services/core/java/com/android/server/locksettings/SyntheticPasswordManager.java
+++ b/services/core/java/com/android/server/locksettings/SyntheticPasswordManager.java
@@ -17,6 +17,7 @@
 package com.android.server.locksettings;
 
 import static com.android.internal.widget.LockPatternUtils.EscrowTokenStateChangeCallback;
+import static com.android.internal.widget.LockPatternUtils.PIN_LENGTH_UNAVAILABLE;
 
 import android.annotation.IntDef;
 import android.annotation.NonNull;
@@ -150,6 +151,9 @@ class SyntheticPasswordManager {
     // The security strength of the synthetic password, in bytes
     private static final int SYNTHETIC_PASSWORD_SECURITY_STRENGTH = 256 / 8;
 
+    public static final short PASSWORD_DATA_V1 = 1;
+    public static final short PASSWORD_DATA_V2 = 2;
+
     private static final int PASSWORD_SCRYPT_LOG_N = 11;
     private static final int PASSWORD_SCRYPT_LOG_R = 3;
     private static final int PASSWORD_SCRYPT_LOG_P = 1;
@@ -351,13 +355,19 @@ class SyntheticPasswordManager {
         // When Weaver is unavailable, this is the Gatekeeper password handle that resulted from
         // enrolling the stretched LSKF.
         public byte[] passwordHandle;
+        /**
+         * Pin length field, only stored in version 2 of the password data and when auto confirm
+         * flag is enabled, otherwise this field contains PIN_LENGTH_UNAVAILABLE
+         */
+        public int pinLength;
 
-        public static PasswordData create(int credentialType) {
+        public static PasswordData create(int credentialType, int pinLength) {
             PasswordData result = new PasswordData();
             result.scryptLogN = PASSWORD_SCRYPT_LOG_N;
             result.scryptLogR = PASSWORD_SCRYPT_LOG_R;
             result.scryptLogP = PASSWORD_SCRYPT_LOG_P;
             result.credentialType = credentialType;
+            result.pinLength = pinLength;
             result.salt = SecureRandomUtils.randomBytes(PASSWORD_SALT_LENGTH);
             return result;
         }
@@ -367,7 +377,22 @@ class SyntheticPasswordManager {
             ByteBuffer buffer = ByteBuffer.allocate(data.length);
             buffer.put(data, 0, data.length);
             buffer.flip();
-            result.credentialType = buffer.getInt();
+
+          /*
+           * Originally this file did not contain a version number. However, its first field was
+           * 'credentialType' as an 'int'. Since 'credentialType' could only be in the range
+           * [-1, 4] and this file uses big endian byte order, the first two bytes were redundant,
+           * and when interpreted as a 'short' could only contain -1 or 0. Therefore, we've now
+           * reclaimed these two bytes for a 'short' version number and shrunk 'credentialType'
+           * to a 'short'.
+           */
+            short version = buffer.getShort();
+            if (version == ((short) 0) || version == (short) -1) {
+                version = PASSWORD_DATA_V1;
+            } else if (version != PASSWORD_DATA_V2) {
+                throw new IllegalArgumentException("Unknown PasswordData version: " + version);
+            }
+            result.credentialType = buffer.getShort();
             result.scryptLogN = buffer.get();
             result.scryptLogR = buffer.get();
             result.scryptLogP = buffer.get();
@@ -381,15 +406,24 @@ class SyntheticPasswordManager {
             } else {
                 result.passwordHandle = null;
             }
+            if (version == PASSWORD_DATA_V2) {
+                result.pinLength = buffer.getInt();
+            } else {
+                result.pinLength = PIN_LENGTH_UNAVAILABLE;
+            }
             return result;
         }
 
         public byte[] toBytes() {
 
-            ByteBuffer buffer = ByteBuffer.allocate(Integer.BYTES + 3 * Byte.BYTES
+            ByteBuffer buffer = ByteBuffer.allocate(2 * Short.BYTES + 3 * Byte.BYTES
                     + Integer.BYTES + salt.length + Integer.BYTES +
-                    (passwordHandle != null ? passwordHandle.length : 0));
-            buffer.putInt(credentialType);
+                    (passwordHandle != null ? passwordHandle.length : 0) + Integer.BYTES);
+            if (credentialType < Short.MIN_VALUE || credentialType > Short.MAX_VALUE) {
+                throw new IllegalArgumentException("Unknown credential type: " + credentialType);
+            }
+            buffer.putShort(PASSWORD_DATA_V2);
+            buffer.putShort((short) credentialType);
             buffer.put(scryptLogN);
             buffer.put(scryptLogR);
             buffer.put(scryptLogP);
@@ -401,6 +435,7 @@ class SyntheticPasswordManager {
             } else {
                 buffer.putInt(0);
             }
+            buffer.putInt(pinLength);
             return buffer.array();
         }
     }
@@ -649,6 +684,14 @@ class SyntheticPasswordManager {
         }
     }
 
+    int getPinLength(long protectorId, int userId) {
+        byte[] passwordData = loadState(PASSWORD_DATA_NAME, protectorId, userId);
+        if (passwordData == null) {
+            return LockPatternUtils.PIN_LENGTH_UNAVAILABLE;
+        }
+        return PasswordData.fromBytes(passwordData).pinLength;
+    }
+
     int getCredentialType(long protectorId, int userId) {
         byte[] passwordData = loadState(PASSWORD_DATA_NAME, protectorId, userId);
         if (passwordData == null) {
@@ -857,8 +900,13 @@ class SyntheticPasswordManager {
     public long createLskfBasedProtector(IGateKeeperService gatekeeper,
             LockscreenCredential credential, SyntheticPassword sp, int userId) {
         long protectorId = generateProtectorId();
+        int pinLength = PIN_LENGTH_UNAVAILABLE;
+        if (LockPatternUtils.isAutoPinConfirmFeatureAvailable()) {
+            pinLength = derivePinLength(credential, userId);
+        }
         // There's no need to store password data about an empty LSKF.
-        PasswordData pwd = credential.isNone() ? null : PasswordData.create(credential.getType());
+        PasswordData pwd = credential.isNone() ? null :
+                PasswordData.create(credential.getType(), pinLength);
         byte[] stretchedLskf = stretchLskf(credential, pwd);
         long sid = GateKeeper.INVALID_SECURE_USER_ID;
         final byte[] protectorSecret;
@@ -930,6 +978,15 @@ class SyntheticPasswordManager {
         return protectorId;
     }
 
+    private int derivePinLength(LockscreenCredential credential, int userId) {
+        if (!credential.isPin()
+                || !mStorage.getBoolean(LockPatternUtils.AUTO_PIN_CONFIRM, false, userId)
+                || credential.size() < LockPatternUtils.MIN_AUTO_PIN_REQUIREMENT_LENGTH) {
+            return PIN_LENGTH_UNAVAILABLE;
+        }
+        return credential.size();
+    }
+
     public VerifyCredentialResponse verifyFrpCredential(IGateKeeperService gatekeeper,
             LockscreenCredential userCredential,
             ICheckCredentialProgressCallback progressCallback) {
@@ -1285,11 +1342,20 @@ class SyntheticPasswordManager {
 
         // Upgrade case: store the metrics if the device did not have stored metrics before, should
         // only happen once on old protectors.
-        if (result.syntheticPassword != null && !credential.isNone() &&
-                !hasPasswordMetrics(protectorId, userId)) {
+        if (result.syntheticPassword != null && !credential.isNone()
+                && !hasPasswordMetrics(protectorId, userId)) {
             savePasswordMetrics(credential, result.syntheticPassword, protectorId, userId);
             syncState(userId); // Not strictly needed as the upgrade can be re-done, but be safe.
         }
+        if (LockPatternUtils.isAutoPinConfirmFeatureAvailable()
+                && result.syntheticPassword != null && pwd != null) {
+            int expectedPinLength = derivePinLength(credential, userId);
+            if (pwd.pinLength != expectedPinLength) {
+                pwd.pinLength = expectedPinLength;
+                saveState(PASSWORD_DATA_NAME, pwd.toBytes(), protectorId, userId);
+                syncState(userId);
+            }
+        }
         return result;
     }
 
diff --git a/services/tests/servicestests/src/com/android/server/locksettings/SyntheticPasswordTests.java b/services/tests/servicestests/src/com/android/server/locksettings/SyntheticPasswordTests.java
index 62d8a7645236..bdc5be6d3714 100644
--- a/services/tests/servicestests/src/com/android/server/locksettings/SyntheticPasswordTests.java
+++ b/services/tests/servicestests/src/com/android/server/locksettings/SyntheticPasswordTests.java
@@ -23,6 +23,7 @@ import static android.content.pm.UserInfo.FLAG_PRIMARY;
 import static com.android.internal.widget.LockPatternUtils.CREDENTIAL_TYPE_NONE;
 import static com.android.internal.widget.LockPatternUtils.CREDENTIAL_TYPE_PASSWORD;
 import static com.android.internal.widget.LockPatternUtils.CREDENTIAL_TYPE_PASSWORD_OR_PIN;
+import static com.android.internal.widget.LockPatternUtils.PIN_LENGTH_UNAVAILABLE;
 
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
@@ -579,12 +580,13 @@ public class SyntheticPasswordTests extends BaseLockSettingsServiceTests {
         data.scryptLogN = 11;
         data.scryptLogR = 3;
         data.scryptLogP = 1;
+        data.pinLength = 5;
         data.salt = "abcdefghijklmnop".getBytes();
         return data;
     }
 
     @Test
-    public void testPasswordData_serializeDeserialize() {
+    public void testPasswordDataLatestVersion_serializeDeserialize() {
         PasswordData data = new PasswordData();
         data.scryptLogN = 11;
         data.scryptLogR = 22;
@@ -592,19 +594,97 @@ public class SyntheticPasswordTests extends BaseLockSettingsServiceTests {
         data.credentialType = CREDENTIAL_TYPE_PASSWORD;
         data.salt = PAYLOAD;
         data.passwordHandle = PAYLOAD2;
+        data.pinLength = 5;
 
         PasswordData deserialized = PasswordData.fromBytes(data.toBytes());
-
         assertEquals(11, deserialized.scryptLogN);
         assertEquals(22, deserialized.scryptLogR);
         assertEquals(33, deserialized.scryptLogP);
+        assertEquals(5, deserialized.pinLength);
         assertEquals(CREDENTIAL_TYPE_PASSWORD, deserialized.credentialType);
         assertArrayEquals(PAYLOAD, deserialized.salt);
         assertArrayEquals(PAYLOAD2, deserialized.passwordHandle);
     }
 
     @Test
-    public void testPasswordData_deserialize() {
+    public void testPasswordDataV2VersionCredentialTypePin_deserialize() {
+        // Test that we can deserialize existing PasswordData and don't inadvertently change the
+        // wire format.
+        byte[] serialized = new byte[] {
+                0, 2, 0, 2, /* CREDENTIAL_TYPE_PASSWORD_OR_PIN */
+                11, /* scryptLogN */
+                22, /* scryptLogR */
+                33, /* scryptLogP */
+                0, 0, 0, 5, /* salt.length */
+                1, 2, -1, -2, 55, /* salt */
+                0, 0, 0, 6, /* passwordHandle.length */
+                2, 3, -2, -3, 44, 1, /* passwordHandle */
+                0, 0, 0, 5, /* pinLength */
+        };
+        PasswordData deserialized = PasswordData.fromBytes(serialized);
+
+        assertEquals(11, deserialized.scryptLogN);
+        assertEquals(22, deserialized.scryptLogR);
+        assertEquals(33, deserialized.scryptLogP);
+        assertEquals(5, deserialized.pinLength);
+        assertEquals(CREDENTIAL_TYPE_PASSWORD_OR_PIN, deserialized.credentialType);
+        assertArrayEquals(PAYLOAD, deserialized.salt);
+        assertArrayEquals(PAYLOAD2, deserialized.passwordHandle);
+    }
+
+    @Test
+    public void testPasswordDataV2VersionNegativePinLengthNoCredential_deserialize() {
+        // Test that we can deserialize existing PasswordData and don't inadvertently change the
+        // wire format.
+        byte[] serialized = new byte[] {
+                0, 2, -1, -1, /* CREDENTIAL_TYPE_NONE */
+                11, /* scryptLogN */
+                22, /* scryptLogR */
+                33, /* scryptLogP */
+                0, 0, 0, 5, /* salt.length */
+                1, 2, -1, -2, 55, /* salt */
+                0, 0, 0, 6, /* passwordHandle.length */
+                2, 3, -2, -3, 44, 1, /* passwordHandle */
+                -1, -1, -1, -2, /* pinLength */
+        };
+        PasswordData deserialized = PasswordData.fromBytes(serialized);
+
+        assertEquals(11, deserialized.scryptLogN);
+        assertEquals(22, deserialized.scryptLogR);
+        assertEquals(33, deserialized.scryptLogP);
+        assertEquals(-2, deserialized.pinLength);
+        assertEquals(CREDENTIAL_TYPE_NONE, deserialized.credentialType);
+        assertArrayEquals(PAYLOAD, deserialized.salt);
+        assertArrayEquals(PAYLOAD2, deserialized.passwordHandle);
+    }
+
+    @Test
+    public void testPasswordDataV1VersionNoCredential_deserialize() {
+        // Test that we can deserialize existing PasswordData and don't inadvertently change the
+        // wire format.
+        byte[] serialized = new byte[] {
+                -1, -1, -1, -1, /* CREDENTIAL_TYPE_NONE */
+                11, /* scryptLogN */
+                22, /* scryptLogR */
+                33, /* scryptLogP */
+                0, 0, 0, 5, /* salt.length */
+                1, 2, -1, -2, 55, /* salt */
+                0, 0, 0, 6, /* passwordHandle.length */
+                2, 3, -2, -3, 44, 1, /* passwordHandle */
+        };
+        PasswordData deserialized = PasswordData.fromBytes(serialized);
+
+        assertEquals(11, deserialized.scryptLogN);
+        assertEquals(22, deserialized.scryptLogR);
+        assertEquals(33, deserialized.scryptLogP);
+        assertEquals(PIN_LENGTH_UNAVAILABLE, deserialized.pinLength);
+        assertEquals(CREDENTIAL_TYPE_NONE, deserialized.credentialType);
+        assertArrayEquals(PAYLOAD, deserialized.salt);
+        assertArrayEquals(PAYLOAD2, deserialized.passwordHandle);
+    }
+
+    @Test
+    public void testPasswordDataV1VersionCredentialTypePin_deserialize() {
         // Test that we can deserialize existing PasswordData and don't inadvertently change the
         // wire format.
         byte[] serialized = new byte[] {
@@ -622,6 +702,7 @@ public class SyntheticPasswordTests extends BaseLockSettingsServiceTests {
         assertEquals(11, deserialized.scryptLogN);
         assertEquals(22, deserialized.scryptLogR);
         assertEquals(33, deserialized.scryptLogP);
+        assertEquals(PIN_LENGTH_UNAVAILABLE, deserialized.pinLength);
         assertEquals(CREDENTIAL_TYPE_PASSWORD_OR_PIN, deserialized.credentialType);
         assertArrayEquals(PAYLOAD, deserialized.salt);
         assertArrayEquals(PAYLOAD2, deserialized.passwordHandle);