Add logic for decrypting, applying results to doc

See #33

lib/src/encryption.dart

@@ -0,0 +1,24 @@
+import 'package:dart_pg/dart_pg.dart';
+import 'package:org_flutter/org_flutter.dart';
+import 'package:orgro/src/debug.dart';
+
+Future<List<String?>> decrypt(
+    (List<OrgPgpBlock> blocks, String password) args) async {
+  final (blocks, password) = args;
+  final result = <String?>[];
+
+  for (final block in blocks) {
+    try {
+      final message = await OpenPGP.readMessage(block.toRfc4880());
+      final decrypted = await OpenPGP.decrypt(
+        message,
+        passwords: [password],
+      );
+      result.add(decrypted.literalData?.text);
+    } catch (e, s) {
+      result.add(null);
+      logError(e, s);
+    }
+  }
+  return result;
+}

lib/src/pages/document.dart

@@ -1,5 +1,6 @@
 import 'dart:async';
 
+import 'package:flutter/foundation.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter/services.dart';
 import 'package:flutter_gen/gen_l10n/app_localizations.dart';
@@ -16,6 +17,7 @@ import 'package:orgro/src/components/slidable_action.dart';
 import 'package:orgro/src/components/view_settings.dart';
 import 'package:orgro/src/data_source.dart';
 import 'package:orgro/src/debug.dart';
+import 'package:orgro/src/encryption.dart';
 import 'package:orgro/src/file_picker.dart';
 import 'package:orgro/src/navigation.dart';
 import 'package:orgro/src/preferences.dart';
@@ -300,6 +302,11 @@ class _DocumentPageState extends State<DocumentPage> {
             if (_dirty.value) _onDocChanged(_doc);
           },
         ),
+        DecryptContentBanner(
+          visible: _askToDecrypt,
+          onAccept: _decryptContent,
+          onDeny: viewSettings.setDecryptPolicy,
+        ),
         _maybeConstrainWidth(
           context,
           child: SelectionArea(
@@ -314,7 +321,8 @@ class _DocumentPageState extends State<DocumentPage> {
               child: switch (doc) {
                 OrgDocument() => OrgDocumentWidget(doc, shrinkWrap: true),
                 OrgSection() =>
-                  OrgSectionWidget(doc, root: true, shrinkWrap: true)
+                  OrgSectionWidget(doc, root: true, shrinkWrap: true),
+                _ => throw Exception('Unexpected document type: $doc'),
               },
             ),
           ),
@@ -622,6 +630,60 @@ class _DocumentPageState extends State<DocumentPage> {
 
     if (result == true) navigator.pop();
   }
+
+  bool? get _hasEncryptedContent =>
+      DocumentProvider.of(context).analysis.hasEncryptedContent;
+
+  bool get _askToDecrypt =>
+      _viewSettings.decryptPolicy == DecryptPolicy.ask &&
+      _hasEncryptedContent == true &&
+      !_askForDirectoryPermissions &&
+      !_askPermissionToLoadRemoteImages &&
+      !_askPermissionToSaveChanges;
+
+  Future<void> _decryptContent() async {
+    final blocks = <OrgPgpBlock>[];
+    _doc.visit<OrgPgpBlock>((block) {
+      blocks.add(block);
+      return true;
+    });
+    final password = await showDialog<String>(
+      context: context,
+      builder: (context) => const InputPasswordDialog(),
+    );
+    if (password == null) return;
+    if (!mounted) return;
+    time('decrypt', () => compute(decrypt, (blocks, password)))
+        .then((decrypted) => Navigator.pop(context, decrypted));
+    final result = await showDialog<List<String?>>(
+      context: context,
+      builder: (context) => const ProgressIndicatorDialog(),
+    );
+    if (!mounted) return;
+    if (result == null) {
+      showErrorSnackBar(context, 'Decryption failed');
+      return;
+    }
+    OrgTree newDoc = _doc;
+    for (final (i, plaintext) in result.indexed) {
+      if (plaintext == null) {
+        showErrorSnackBar(context, 'Decryption failed');
+        continue;
+      }
+      final block = blocks[i];
+      try {
+        final replacement =
+            OrgDecryptedContent.fromDecryptedResult(block, plaintext);
+        newDoc =
+            newDoc.editNode(block)!.replace(replacement).commit() as OrgTree;
+      } catch (e, s) {
+        logError(e, s);
+        showErrorSnackBar(context, 'Failed to parse plaintext');
+        continue;
+      }
+    }
+    await _updateDocument(newDoc);
+  }
 }
 
 class _KeyboardShortcuts extends StatelessWidget {

pubspec.lock

@@ -97,6 +97,14 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "3.0.3"
+  dart_pg:
+    dependency: "direct main"
+    description:
+      name: dart_pg
+      sha256: "07f082f30a4ba024c181fd57906ea487d6e826d9c3281e0d6289fc17212a47c7"
+      url: "https://pub.dev"
+    source: hosted
+    version: "1.1.5"
   dynamic_fonts:
     dependency: "direct main"
     description:
@@ -146,6 +154,14 @@ packages:
       url: "https://github.com/amake/file_picker_writable.git"
     source: git
     version: "2.1.0+1"
+  fixnum:
+    dependency: transitive
+    description:
+      name: fixnum
+      sha256: "25517a4deb0c03aa0f32fd12db525856438902d9c16536311e76cdc57b31d7d1"
+      url: "https://pub.dev"
+    source: hosted
+    version: "1.1.0"
   flutter:
     dependency: "direct main"
     description: flutter
@@ -310,6 +326,14 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "0.18.1"
+  js:
+    dependency: transitive
+    description:
+      name: js
+      sha256: f2c445dce49627136094980615a031419f7f3eb393237e4ecd97ac15dea343f3
+      url: "https://pub.dev"
+    source: hosted
+    version: "0.6.7"
   leak_tracker:
     dependency: transitive
     description:
@@ -386,18 +410,18 @@ packages:
     dependency: "direct main"
     description:
       name: org_flutter
-      sha256: "0bb754da89f7528d0dd81ff61403dc61382728e470ccec0abf9fa07b440344af"
+      sha256: f99f7128594c5ddae8a345525073a8a3d6dee51f3378ae3bcac509d7db430393
       url: "https://pub.dev"
     source: hosted
-    version: "5.1.0"
+    version: "5.2.0"
   org_parser:
     dependency: transitive
     description:
       name: org_parser
-      sha256: "5745d233316b3f8cf27ff9082987c8cdcec792c7e6d138f2203aed4a30a99238"
+      sha256: d73bbf50aa9765ce3a624422dc9c37020fb83a816d983a15f846ba310064eb83
       url: "https://pub.dev"
     source: hosted
-    version: "5.3.0"
+    version: "5.4.0"
   path:
     dependency: transitive
     description:
@@ -478,6 +502,14 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "6.0.2"
+  pinenacl:
+    dependency: transitive
+    description:
+      name: pinenacl
+      sha256: "3a5503637587d635647c93ea9a8fecf48a420cc7deebe6f1fc85c2a5637ab327"
+      url: "https://pub.dev"
+    source: hosted
+    version: "0.5.1"
   platform:
     dependency: transitive
     description:
@@ -494,6 +526,14 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "2.1.7"
+  pointycastle:
+    dependency: transitive
+    description:
+      name: pointycastle
+      sha256: "7c1e5f0d23c9016c5bbd8b1473d0d3fb3fc851b876046039509e18e0c7485f2c"
+      url: "https://pub.dev"
+    source: hosted
+    version: "3.7.3"
   quiver:
     dependency: transitive
     description:

pubspec.yaml

@@ -11,6 +11,7 @@ environment:
 
 dependencies:
   cached_network_image: ^3.0.0
+  dart_pg: ^1.1.5
   dynamic_fonts: ^2.2.0
   # dynamic_fonts:
   #   path: ../dynamic-fonts-flutter
@@ -35,7 +36,7 @@ dependencies:
   google_fonts: ^6.0.0
   http: ^1.1.0
   intl: ^0.18.0
-  org_flutter: ^5.1.0
+  org_flutter: ^5.2.0
   # org_flutter:
     # path: ../org_flutter
   path_provider: ^2.0.9