Match any path component in StrictDomain FilterMode

2 files changed, 82 insertions, 16 deletions

diff --git a/app/src/androidTest/java/com/zeapo/pwdstore/StrictDomainRegexTest.kt b/app/src/androidTest/java/com/zeapo/pwdstore/StrictDomainRegexTest.kt
new file mode 100644
index 00000000..c6fa1051
--- /dev/null
+++ b/app/src/androidTest/java/com/zeapo/pwdstore/StrictDomainRegexTest.kt
@@ -0,0 +1,48 @@
+/*
+ * Copyright © 2014-2020 The Android Password Store Authors. All Rights Reserved.
+ * SPDX-License-Identifier: GPL-3.0-only
+ */
+package com.zeapo.pwdstore
+
+import kotlin.test.assertFalse
+import kotlin.test.assertNull
+import kotlin.test.assertTrue
+import org.junit.Test as test
+
+private infix fun String.matchedForDomain(domain: String) =
+    SearchableRepositoryViewModel.generateStrictDomainRegex(domain)?.containsMatchIn(this) == true
+
+class StrictDomainRegexTest {
+    @test fun acceptsLiteralDomain() {
+        assertTrue("work/example.org/john.doe@example.org.gpg" matchedForDomain "example.org")
+        assertTrue("example.org/john.doe@example.org.gpg" matchedForDomain "example.org")
+        assertTrue("example.org.gpg" matchedForDomain "example.org")
+    }
+
+    @test fun acceptsSubdomains() {
+        assertTrue("work/www.example.org/john.doe@example.org.gpg" matchedForDomain "example.org")
+        assertTrue("www2.example.org/john.doe@example.org.gpg" matchedForDomain "example.org")
+        assertTrue("www.login.example.org.gpg" matchedForDomain "example.org")
+    }
+
+    @test fun rejectsPhishingAttempts() {
+        assertFalse("example.org.gpg" matchedForDomain "xample.org")
+        assertFalse("login.example.org.gpg" matchedForDomain "xample.org")
+        assertFalse("example.org/john.doe@exmple.org.gpg" matchedForDomain "xample.org")
+        assertFalse("example.org.gpg" matchedForDomain "e/xample.org")
+    }
+
+    @test fun rejectNonGpgComponentMatches() {
+        assertFalse("work/example.org" matchedForDomain "example.org")
+    }
+
+    @test fun rejectsEmailAddresses() {
+        assertFalse("work/notexample.org/john.doe@example.org.gpg" matchedForDomain "example.org")
+        assertFalse("work/notexample.org/john.doe@www.example.org.gpg" matchedForDomain "example.org")
+        assertFalse("work/john.doe@www.example.org/foo.org" matchedForDomain "example.org")
+    }
+
+    @test fun rejectsPathSeparators() {
+        assertNull(SearchableRepositoryViewModel.generateStrictDomainRegex("ex/ample.org"))
+    }
+}
diff --git a/app/src/main/java/com/zeapo/pwdstore/SearchableRepositoryViewModel.kt b/app/src/main/java/com/zeapo/pwdstore/SearchableRepositoryViewModel.kt
index 992a5f79..47170717 100644
--- a/app/src/main/java/com/zeapo/pwdstore/SearchableRepositoryViewModel.kt
+++ b/app/src/main/java/com/zeapo/pwdstore/SearchableRepositoryViewModel.kt
@@ -126,6 +126,28 @@ enum class ListMode {
 @FlowPreview
 class SearchableRepositoryViewModel(application: Application) : AndroidViewModel(application) {
 
+    companion object {
+
+        fun generateStrictDomainRegex(domain: String): Regex? {
+            // Valid domains do not contain path separators.
+            if (domain.contains('/'))
+                return null
+            // Matches the start of a path component, which is either the start of the
+            // string or a path separator.
+            val prefix = """(?:^|/)"""
+            val escapedFilter = Regex.escape(domain.replace("/", ""))
+            // Matches either the filter literally or a strict subdomain of the filter term.
+            // We allow a lot of freedom in what a subdomain is, as long as it is not an
+            // email address.
+            val subdomain = """(?:(?:[^/@]+\.)?$escapedFilter)"""
+            // Matches the end of a path component, which is either the literal ".gpg" or a
+            // path separator.
+            val suffix = """(?:\.gpg|/)"""
+            // Match any relative path with a component that is a subdomain of the filter.
+            return Regex(prefix + subdomain + suffix)
+        }
+    }
+
     private var _updateCounter = 0
     private val updateCounter: Int
         get() = _updateCounter
@@ -219,22 +241,18 @@ class SearchableRepositoryViewModel(application: Application) : AndroidViewModel
                 }
                 FilterMode.StrictDomain -> {
                     check(searchAction.listMode == ListMode.FilesOnly) { "Searches with StrictDomain search mode can only list files" }
-                    prefilteredResultFlow
-                        .filter { absoluteFile ->
-                            val file = absoluteFile.relativeTo(root)
-                            val toMatch =
-                                directoryStructure.getIdentifierFor(file) ?: return@filter false
-                            // In strict domain mode, we match
-                            // * the search term exactly,
-                            // * subdomains of the search term,
-                            // * or the search term plus an arbitrary protocol.
-                            toMatch == searchAction.filter ||
-                                toMatch.endsWith(".${searchAction.filter}") ||
-                                toMatch.endsWith("://${searchAction.filter}")
-                        }
-                        .map { it.toPasswordItem(root) }
-                        .toList()
-                        .sortedWith(itemComparator)
+                    val regex = generateStrictDomainRegex(searchAction.filter)
+                    if (regex != null) {
+                        prefilteredResultFlow
+                            .filter { absoluteFile ->
+                                regex.containsMatchIn(absoluteFile.relativeTo(root).path)
+                            }
+                            .map { it.toPasswordItem(root) }
+                            .toList()
+                            .sortedWith(itemComparator)
+                    } else {
+                        emptyList()
+                    }
                 }
                 FilterMode.Fuzzy -> {
                     prefilteredResultFlow