Handle text payloads in encrypted QR decoding

src/seedsigner/models/decode_qr.py

@@ -224,6 +224,10 @@ def get_seed_phrase(self):
         if self.is_seed:
             return self.decoder.get_seed_phrase()
 
+    def get_decrypted_text(self):
+        if self.is_encrypted_seedqr:
+            return self.decoder.get_decrypted_text()
+
     def get_slip39_share(self):
         if self.is_slip39_share:
             return self.decoder.get_share()
@@ -1399,6 +1403,7 @@ def __init__(self):
         super().__init__()
         self.public_data = None
         self.seed_phrase = []
+        self.decrypted_text = None
 
 
     def add(self, segment, qr_type=QRType.SEED__ENCRYPTEDQR, encryption_key=None):
@@ -1434,9 +1439,21 @@ def add(self, segment, qr_type=QRType.SEED__ENCRYPTEDQR, encryption_key=None):
                     word_bytes = encrypted_qr.decrypt(encryption_key)
                     if not word_bytes:
                         return DecodeQRStatus.WRONG_KEY
-                    self.seed_phrase = bip39.mnemonic_from_bytes(word_bytes).split()
+                    self.decrypted_text = None
+                    try:
+                        self.seed_phrase = bip39.mnemonic_from_bytes(word_bytes).split()
+                    except Exception:
+                        self.seed_phrase = []
+                        try:
+                            decoded_text = word_bytes.decode("utf-8")
+                        except UnicodeDecodeError:
+                            decoded_text = word_bytes.decode("utf-8", errors="replace")
+                        self.decrypted_text = decoded_text
+                    else:
+                        self.decrypted_text = None
                 else:
                     self.seed_phrase = []
+                    self.decrypted_text = None
 
                 self.complete = True
                 self.collected_segments = 1
@@ -1456,6 +1473,9 @@ def get_seed_phrase(self):
         return self.seed_phrase[:]
 
 
+    def get_decrypted_text(self):
+        return self.decrypted_text
+
 
 class TextQrDecoder(BaseSingleFrameQrDecoder):
     def __init__(self):

src/seedsigner/views/scan_views.py

@@ -5,6 +5,7 @@
 
 #from embit.descriptor import Descriptor
 
+from seedsigner.gui.components import GUIConstants
 from seedsigner.gui.screens.screen import RET_CODE__BACK_BUTTON, ButtonListScreen, WarningScreen, DireWarningScreen
 from seedsigner.gui.screens.scan_screens import ScanEncryptedQRScreen, ScanTypeEncryptionKeyScreen, ScanReviewEncryptionKeyScreen
 from seedsigner.gui.screens import LargeIconStatusScreen
@@ -638,15 +639,44 @@ def run(self):
 
         if status == DecodeQRStatus.COMPLETE:
             self.controller.storage2.clear_encryptedqr()
-            self.controller.storage.set_pending_seed(
-                Seed(mnemonic=decoder.get_seed_phrase(), wordlist_language_code=self.wordlist_language_code)
-            )
-            if self.settings.get_value(SettingsConstants.SETTING__PASSPHRASE) == SettingsConstants.OPTION__REQUIRED:
-                from seedsigner.views.seed_views import SeedAddPassphraseView
-                return Destination(SeedAddPassphraseView, skip_current_view=True)
-            else:
-                from .seed_views import SeedFinalizeView
-                return Destination(SeedFinalizeView, skip_current_view=True)
+            seed_phrase = decoder.get_seed_phrase()
+
+            if seed_phrase:
+                try:
+                    self.controller.storage.set_pending_seed(
+                        Seed(mnemonic=seed_phrase, wordlist_language_code=self.wordlist_language_code)
+                    )
+                except InvalidSeedException:
+                    seed_phrase = []
+                else:
+                    if self.settings.get_value(SettingsConstants.SETTING__PASSPHRASE) == SettingsConstants.OPTION__REQUIRED:
+                        from seedsigner.views.seed_views import SeedAddPassphraseView
+                        return Destination(SeedAddPassphraseView, skip_current_view=True)
+                    else:
+                        from .seed_views import SeedFinalizeView
+                        return Destination(SeedFinalizeView, skip_current_view=True)
+
+            decrypted_text = decoder.get_decrypted_text()
+            if decrypted_text is not None:
+                self.run_screen(
+                    LargeIconStatusScreen,
+                    title=_("Decrypted Text"),
+                    status_headline=None,
+                    text=decrypted_text,
+                    show_back_button=False,
+                    button_data=[ButtonOption(_("Done"))],
+                    status_icon_size=0,
+                    status_color=GUIConstants.BODY_FONT_COLOR,
+                )
+                return Destination(MainMenuView, skip_current_view=True)
+
+            WarningScreen(
+                title="Error",
+                show_back_button=False,
+                status_headline="decryption failure",
+                text="Unknown error",
+            ).display()
+            return Destination(BackStackView)
 
         elif status == DecodeQRStatus.WRONG_KEY:
             WarningScreen(

tests/test_seedqr.py

@@ -1,7 +1,10 @@
 import os
+from types import SimpleNamespace
+
 from embit import bip39
-from seedsigner.models.decode_qr import DecodeQR, DecodeQRStatus
+from seedsigner.models.decode_qr import DecodeQR, DecodeQRStatus, EncryptedQrDecoder
 from seedsigner.models.encode_qr import SeedQrEncoder, CompactSeedQrEncoder
+from seedsigner.models.encryptedqr import EncryptedQR
 from seedsigner.models.qr_type import QRType
 from seedsigner.helpers.qr import QR
 
@@ -161,3 +164,43 @@ def test_compact_seedqr_bytes_interpretable_as_str():
         entropy_bytes.decode()  # should not raise an exception
         mnemonic_length = 12 if len(entropy_bytes) == 16 else 24
         run_encode_decode_test(entropy_bytes, mnemonic_length=mnemonic_length, qr_type=QRType.SEED__COMPACTSEEDQR)
+
+
+def test_encrypted_qr_falls_back_to_text(monkeypatch):
+    class DummyStorage:
+        def __init__(self):
+            self._encryptedqr = None
+
+        @property
+        def encryptedqr(self):
+            return self._encryptedqr
+
+        def set_encryptedqr(self, encryptedqr):
+            self._encryptedqr = encryptedqr
+
+        def clear_encryptedqr(self):
+            self._encryptedqr = None
+
+    dummy_storage = DummyStorage()
+    dummy_controller = SimpleNamespace(storage2=dummy_storage)
+
+    monkeypatch.setattr(
+        "seedsigner.controller.Controller.get_instance",
+        lambda: dummy_controller,
+    )
+
+    class DummyEncryptedQRCode:
+        def decrypt(self, key):
+            assert key == "test-key"
+            return b"hello world"
+
+    dummy_storage.set_encryptedqr(EncryptedQR(encrypted_qr=DummyEncryptedQRCode(), public_data="info"))
+
+    decoder = EncryptedQrDecoder()
+    status = decoder.add(None, qr_type=QRType.SEED__ENCRYPTEDQR, encryption_key="test-key")
+
+    assert status == DecodeQRStatus.COMPLETE
+    assert decoder.get_seed_phrase() == []
+    assert decoder.get_decrypted_text() == "hello world"
+
+    dummy_storage.clear_encryptedqr()