improved uri parsing

2026-02-27 08:31:19 +01:00
parent d24675094d
commit d25229cb95
19 changed files with 1132 additions and 95 deletions
@@ -0,0 +1,198 @@
+/*
+ * Copyright (c) 2024-2026 Fabian Freund.
+ *
+ * This file is part of WebLibre
+ * (see https://weblibre.eu).
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero 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 Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+import 'dart:io';
+
+import 'package:weblibre/utils/uri_input_parser.dart';
+import 'package:weblibre/utils/uri_policy.dart';
+
+enum NavigationReason {
+  explicitScheme,
+  schemelessHost,
+  localhost,
+  ipLiteral,
+  aboutLike,
+}
+
+enum SearchReason {
+  containsWhitespace,
+  notHostCandidate,
+  invalidHostChars,
+  fallback,
+}
+
+enum InvalidReason {
+  unsupportedScheme,
+  malformedUri,
+  containsControlChars,
+  emptyInput,
+  tooLong,
+}
+
+sealed class InputClassification {
+  const InputClassification();
+
+  const factory InputClassification.navigate(Uri uri, NavigationReason reason) =
+      NavigateInputClassification;
+  const factory InputClassification.search(String query, SearchReason reason) =
+      SearchInputClassification;
+  const factory InputClassification.invalid(String raw, InvalidReason reason) =
+      InvalidInputClassification;
+}
+
+final class NavigateInputClassification extends InputClassification {
+  final Uri uri;
+  final NavigationReason reason;
+
+  const NavigateInputClassification(this.uri, this.reason);
+}
+
+final class SearchInputClassification extends InputClassification {
+  final String query;
+  final SearchReason reason;
+
+  const SearchInputClassification(this.query, this.reason);
+}
+
+final class InvalidInputClassification extends InputClassification {
+  final String raw;
+  final InvalidReason reason;
+
+  const InvalidInputClassification(this.raw, this.reason);
+}
+
+InputClassification classifyAddressBarInput(
+  String input, {
+  SchemePolicy policy = SchemePolicy.addressBarTyped,
+}) {
+  final normalizedInput = normalizeInput(input);
+
+  if (normalizedInput.isEmpty) {
+    return InputClassification.invalid(
+      normalizedInput,
+      InvalidReason.emptyInput,
+    );
+  }
+
+  if (exceedsMaxInputLength(normalizedInput)) {
+    return InputClassification.invalid(normalizedInput, InvalidReason.tooLong);
+  }
+
+  if (containsControlChars(normalizedInput)) {
+    return InputClassification.invalid(
+      normalizedInput,
+      InvalidReason.containsControlChars,
+    );
+  }
+
+  if (hasExplicitScheme(normalizedInput)) {
+    final explicitUri = parseExplicitUri(normalizedInput, policy: policy);
+    if (explicitUri != null) {
+      final reason = explicitUri.isScheme('about')
+          ? NavigationReason.aboutLike
+          : NavigationReason.explicitScheme;
+
+      return InputClassification.navigate(explicitUri, reason);
+    }
+
+    if (hasAllowedScheme(normalizedInput, policy.allowedSchemes)) {
+      return InputClassification.invalid(
+        normalizedInput,
+        InvalidReason.malformedUri,
+      );
+    }
+
+    return InputClassification.invalid(
+      normalizedInput,
+      InvalidReason.unsupportedScheme,
+    );
+  }
+
+  if (normalizedInput.contains(whitespaceRegex)) {
+    return InputClassification.search(
+      normalizedInput,
+      SearchReason.containsWhitespace,
+    );
+  }
+
+  final schemelessUri = parseSchemelessWebHost(
+    normalizedInput,
+    allowedSchemes: policy.allowedSchemes,
+  );
+
+  if (schemelessUri != null) {
+    if (schemelessUri.host.toLowerCase() == 'localhost') {
+      return InputClassification.navigate(
+        schemelessUri,
+        NavigationReason.localhost,
+      );
+    }
+
+    if (InternetAddress.tryParse(schemelessUri.host) != null) {
+      return InputClassification.navigate(
+        schemelessUri,
+        NavigationReason.ipLiteral,
+      );
+    }
+
+    return InputClassification.navigate(
+      schemelessUri,
+      NavigationReason.schemelessHost,
+    );
+  }
+
+  if (looksLikeHostExpression(normalizedInput) &&
+      hasInvalidHostLikeChars(normalizedInput)) {
+    return InputClassification.search(
+      normalizedInput,
+      SearchReason.invalidHostChars,
+    );
+  }
+
+  return InputClassification.search(
+    normalizedInput,
+    SearchReason.notHostCandidate,
+  );
+}
+
+Uri? parseSharedIntentUrl(
+  String input, {
+  SchemePolicy policy = SchemePolicy.sharedIntent,
+}) {
+  final normalizedInput = normalizeInput(input);
+  if (normalizedInput.isEmpty ||
+      exceedsMaxInputLength(normalizedInput) ||
+      containsControlChars(normalizedInput)) {
+    return null;
+  }
+
+  if (hasExplicitScheme(normalizedInput)) {
+    return parseExplicitUri(normalizedInput, policy: policy);
+  }
+
+  if (normalizedInput.contains(whitespaceRegex)) {
+    return null;
+  }
+
+  return parseSchemelessWebHost(
+    normalizedInput,
+    allowedSchemes: policy.allowedSchemes,
+  );
+}