Filter/block reports sent to ACRA

.idea/dictionaries/usernames.xml

@@ -83,6 +83,7 @@
       <w>quiro91</w>
       <w>tarekkma</w>
       <w>vianey</w>
+      <w>voczi</w>
       <w>zanki</w>
     </words>
   </dictionary>

AnkiDroid/src/main/java/com/ichi2/anki/CrashReportService.kt

@@ -18,6 +18,8 @@ package com.ichi2.anki
 import android.app.Application
 import android.content.Context
 import android.content.SharedPreferences
+import android.util.Patterns
+import androidx.annotation.CheckResult
 import androidx.annotation.StringRes
 import androidx.annotation.VisibleForTesting
 import androidx.core.content.edit
@@ -28,9 +30,11 @@ import com.ichi2.anki.analytics.UsageAnalytics
 import com.ichi2.anki.analytics.UsageAnalytics.sendAnalyticsException
 import com.ichi2.anki.exception.ManuallyReportedException
 import com.ichi2.anki.exception.UserSubmittedException
+import com.ichi2.anki.preferences.get
 import com.ichi2.anki.preferences.sharedPrefs
 import com.ichi2.libanki.utils.TimeManager
 import com.ichi2.utils.WebViewDebugging.setDataDirectorySuffix
+import net.ankiweb.rsdroid.exceptions.BackendSyncException.BackendSyncServerMessageException
 import org.acra.ACRA
 import org.acra.ReportField
 import org.acra.config.CoreConfigurationBuilder
@@ -281,12 +285,50 @@ object CrashReportService {
             }
         }
         if (FEEDBACK_REPORT_NEVER != reportMode) {
+            if (e.removePII() == null) {
+                return
+            }
             ACRA.errorReporter.putCustomData("origin", origin ?: "")
             ACRA.errorReporter.putCustomData("additionalInfo", additionalInfo ?: "")
             ACRA.errorReporter.handleException(e)
         }
     }
 
+    private fun Throwable.replaceMessage(newMessage: String?): Throwable =
+        Exception(newMessage, this.cause)
+
+    private val emailRegex = Patterns.EMAIL_ADDRESS.toRegex()
+    private val throwableRules: List<(Throwable) -> Throwable?> = listOf(
+        { e ->
+            // BackendSyncServerMessage may contain PII and we do not want this leaked to ACRA.
+            // If the exception is of a cause deemed to be associated with a message containing PII,
+            // then do not send it at all to retain user privacy.
+            // Related: https://github.com/ankidroid/Anki-Android/issues/17392
+            // and also https://github.com/ankitects/anki/commit/ba1f5f4
+            if (e.cause is BackendSyncServerMessageException) null else e
+        },
+        { e ->
+            // Make sure we filter out any email addresses which may be leaked by the sync server.
+            e.replaceMessage(emailRegex.replace(e.message.orEmpty(), "-EMAIL-"))
+        },
+        { e ->
+            // Filter out the current username in the message (if it exists) as it is considered PII.
+            e.replaceMessage(
+                e.message.orEmpty().replace(
+                    mApplication.sharedPrefs().get(SyncPreferences.USERNAME).toString(),
+                    "-USERNAME-"
+                )
+            )
+        }
+    )
+
+    // Strip Personally Identifiable Information (PII) from Exception.message
+    // or return null if we should discard completely.
+    @VisibleForTesting(otherwise = VisibleForTesting.PRIVATE)
+    @CheckResult
+    fun Throwable.removePII(): Throwable? =
+        throwableRules.fold(this) { nextThrowable, rule -> rule.invoke(nextThrowable) ?: return null }
+
     fun isProperServiceProcess(): Boolean {
         return ACRA.isACRASenderServiceProcess()
     }

AnkiDroid/src/test/java/com/ichi2/anki/CrashReportServiceTest.kt

@@ -0,0 +1,65 @@
+/*
+ *  Copyright (c) 2024 voczi <dev@voczi.com>
+ *
+ *  This program is free software; you can redistribute it and/or modify it under
+ *  the terms of the GNU General Public License as published by the Free Software
+ *  Foundation; either version 3 of the License, or (at your option) any later
+ *  version.
+ *
+ *  This program is distributed in the hope that it will be useful, but WITHOUT ANY
+ *  WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
+ *  PARTICULAR PURPOSE. See the GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License along with
+ *  this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package com.ichi2.anki
+
+import androidx.core.content.edit
+import androidx.test.ext.junit.runners.AndroidJUnit4
+import anki.backend.BackendError
+import com.ichi2.anki.CrashReportService.removePII
+import com.ichi2.anki.preferences.sharedPrefs
+import net.ankiweb.rsdroid.exceptions.BackendDeckIsFilteredException
+import net.ankiweb.rsdroid.exceptions.BackendSyncException.BackendSyncServerMessageException
+import org.hamcrest.MatcherAssert.assertThat
+import org.junit.Test
+import org.junit.runner.RunWith
+import org.mockito.Mockito.mock
+import kotlin.Throwable
+import kotlin.test.assertEquals
+import kotlin.test.assertNotNull
+import kotlin.test.assertNull
+
+@RunWith(AndroidJUnit4::class)
+class CrashReportServiceTest : RobolectricTest() {
+    @Test
+    fun `Normal exceptions are untouched`() {
+        val message = "This is a test message which should not be filtered nor blocked"
+        val processed = BackendDeckIsFilteredException(BackendError.newBuilder().setMessage(message).build()).removePII()
+
+        assertNotNull(processed, "Returned exception should not be null")
+        assertEquals(processed.message!!, message, "Returned exception's message should stay the same")
+    }
+
+    @Test
+    fun `Backend sync server messages are blocked`() {
+        assertNull(mock(BackendSyncServerMessageException::class.java).removePII(), "Returned exception is null")
+    }
+
+    @Test
+    fun `Emails are filtered out`() {
+        val msg = Throwable("Lorem ipsum 123 email@domain.tld Lorem ipsum.").removePII()!!.message!!
+        assertThat("Exception message does not contain the email", !msg.contains("email@domain.tld"))
+    }
+
+    @Test
+    fun `Username is filtered out`() {
+        val preferences = targetContext.sharedPrefs()
+        preferences.edit() { putString(SyncPreferences.USERNAME, "MyUser") }
+
+        val msg = Throwable("Lorem ipsum 123 MyUser Lorem ipsum.").removePII()!!.message!!
+        assertThat("Exception message not contain the username", !msg.contains("MyUser"))
+    }
+}