Fix UR2 decoding/encoding to work with crypto-psbt type

Two issues:
- The UR2 sampler function was expecting the '1-3' indicator, and this is not included if there is a single UR fragment. Changed code to try to parse instead of relying on a complex regex.
- Fixed a similar issue with the UR1 sampler, but it can be simpler since we've already ruled out UR2.
- When sending the UR2 response, it always used "bytes" as the prefix.  Now if it receives 'crypto-psbt', it responds with 'crypto-psbt'.
- Fixed is_ut_type() utility function which was incorrect
- All these fixes allow the code to work with BlueWallet's new UR2 support, but also stay compatible with older BlueWallet versions that only support UR1.

ports/stm32/boards/Passport/modules/auth.py

@@ -905,7 +905,7 @@ async def sign_psbt_buf(psbt_buf):
 
     # Create a new BytesIO() to hold the result
     async def done(psbt):
-        from common import system, last_scanned_qr_type
+        from common import system, last_scanned_qr_type, last_scanned_ur_prefix
         system.hide_busy_bar()
         signed_bytes = None
         with BytesIO() as bfd:
@@ -928,7 +928,9 @@ async def sign_psbt_buf(psbt_buf):
         # print('last_scanned_qr_type={}'.format(last_scanned_qr_type))
 
         # Text format for UR1, but binary for UR2
-        o = DisplayURCode('Signed Txn', signed_bytes if last_scanned_qr_type == QRType.UR2 else signed_hex, last_scanned_qr_type or QRType.UR2, None, is_binary=True)
+        #     def __init__(self, title, qr_text, qr_type, qr_args=None, msg=None, left_btn='DONE', right_btn='RESIZE', is_binary=False):
+
+        o = DisplayURCode('Signed Txn', signed_bytes if last_scanned_qr_type == QRType.UR2 else signed_hex, last_scanned_qr_type or QRType.UR2, {'prefix': last_scanned_ur_prefix }, is_binary=True)
         result = await o.interact_bare()
         UserAuthorizedAction.cleanup()
 

ports/stm32/boards/Passport/modules/common.py

@@ -66,3 +66,4 @@ is_new_wallet_a_duplicate = False
 
 # The QRTYpe of the last QR code that was scanned
 last_scanned_qr_type = None
+last_scanned_ur_prefix = None

ports/stm32/boards/Passport/modules/data_codecs/data_decoder.py

@@ -29,7 +29,7 @@ class DataDecoder:
     def get_error(self):
         return None
 
-    def get_type(self):
+    def get_ur_prefix(self):
         return None
 
     def decode(self):

ports/stm32/boards/Passport/modules/data_codecs/qr_codec.py

@@ -30,6 +30,9 @@ class QRDecoder(DataDecoder):
     def get_error(self):
         return None
 
+    def get_ur_prefix(self):
+        return None
+
     def decode(self):
         return self.data
 

ports/stm32/boards/Passport/modules/data_codecs/ur1_codec.py

@@ -44,8 +44,8 @@ class UR1Decoder(DataDecoder):
     def get_error(self):
         return self.error
 
-    def get_type(self):
-        return self.decoder.expected_type()
+    def get_ur_prefix(self):
+        return 'bytes'  # TODO: Get the type from the UR1 decoder
 
     def decode(self):
         from common import system
@@ -112,7 +112,7 @@ class UR1Sampler(DataSampler):
     # Return True if it matches or False if not
     @classmethod
     def sample(cls, data):
-        r = re.compile('^ur:bytes/(\d)+of(\d)+/')
+        r = re.compile('^ur:bytes/')  # Don't look for the n of m count anymore
         m = r.match(data.lower())
         return m != None
 

ports/stm32/boards/Passport/modules/data_codecs/ur2_codec.py

@@ -49,7 +49,7 @@ class UR2Decoder(DataDecoder):
         else:
             return None
 
-    def get_type(self):
+    def get_ur_prefix(self):
         return self.decoder.expected_type()
 
     def decode(self):
@@ -69,9 +69,13 @@ class UR2Decoder(DataDecoder):
         return QRType.UR2
 
 class UR2Encoder(DataEncoder):
-    def __init__(self, _args):
+    def __init__(self, args):
         self.qr_sizes = [280, 100, 70]
         self.type = None
+        if isinstance(args, dict):
+            self.prefix = args['prefix'] or 'bytes'
+        else:
+            self.prefix = 'bytes'
 
     def get_num_supported_sizes(self):
         return len(self.qr_sizes)
@@ -87,7 +91,7 @@ class UR2Encoder(DataEncoder):
         # print('UR2: data={}'.format(to_str(data)))
         encoder.encodeBytes(data)
         # TODO: Need to change this interface most likely to allow for different types like crypto-psbt
-        ur_obj = UR("bytes", encoder.get_bytes())
+        ur_obj = UR(self.prefix, encoder.get_bytes())
         self.ur_encoder = UREncoder(ur_obj, max_fragment_len)
 
     # UR2.0's next_part() returns the initial pieces split into max_fragment_len bytes, but then switches over to
@@ -104,9 +108,14 @@ class UR2Sampler(DataSampler):
     # Return True if it matches or False if not
     @classmethod
     def sample(cls, data):
-        r = re.compile('^ur:[a-z\d-]+\/(\d)+-(\d)+\/')
-        m = r.match(data.lower())
-        return m != None
+        try:
+            # Rather than try a complex regex here, we just let the decoder try to decode and if it fails.
+            # it must not be UR2.
+            decoder = URDecoder()
+            result = decoder.receive_part(data)
+            return result
+        except e:
+            return False
 
     # Number of bytes required to successfully recognize this format
     @classmethod

ports/stm32/boards/Passport/modules/ur2/ur_decoder.py

@@ -34,7 +34,7 @@ class InvalidFragment(Exception):
 class URDecoder:
     def __init__(self):
         self.fountain_decoder = FountainDecoder()
-        self.expected_type = None
+        self._expected_type = None
         self.result = None
 
     @staticmethod
@@ -93,13 +93,13 @@ class URDecoder:
             raise InvalidSequenceComponent()
 
     def validate_part(self, type):
-        if self.expected_type == None:
+        if self._expected_type == None:
             if not is_ur_type(type):
                 return False
-            self.expected_type = type
+            self._expected_type = type
             return True
         else:
-            return type == self.expected_type
+            return type == self._expected_type
 
     def receive_part(self, str):
         try:
@@ -148,7 +148,7 @@ class URDecoder:
             return False
 
     def expected_type(self):
-        return self.expected_type
+        return self._expected_type
 
     def expected_part_count(self):
         return self.fountain_decoder.expected_part_count()

ports/stm32/boards/Passport/modules/ur2/utils.py

@@ -33,14 +33,12 @@ def string_to_bytes(s):
     return bytes(s, 'utf8')
 
 
-def is_ur_type(ch):
-    if 'a' <= ch and ch <= 'z':
-        return True
-    if '0' <= ch and ch <= '9':
-        return True
-    if ch == '-':
-        return True
-    return False
+def is_ur_type(type):
+	for ch in type:
+		if not (ch >= 'a' and ch <= 'z') and not(ch >= '0' and ch <= '9') and ch != '-':
+			return False
+
+	return True
 
 
 def partition(s, n):

ports/stm32/boards/Passport/modules/ux.py

@@ -1180,9 +1180,9 @@ class DisplayURCode(UserInteraction):
             return 250
 
     def render_qr(self, data):
-        from utils import imported
+        from utils import imported, bytes_to_hex_str
 
-        # print('data: {}'.format(data))
+        # print('data: {}'.format(bytes_to_hex_str(data)))
 
         if self.last_render_id != self.render_id:
             self.last_render_id = self.render_id
@@ -1488,7 +1488,9 @@ async def ux_scan_qr_code(title):
 
                     # Set the last QRType so that signed transactions know what to encode as
                     common.last_scanned_qr_type = qr_decoder.get_data_format()
+                    common.last_scanned_ur_prefix = qr_decoder.get_ur_prefix()
                     # print('common.last_scanned_qr_type={}'.format(common.last_scanned_qr_type))
+                    # print('common.last_scanned_ur_prefix={}'.format(common.last_scanned_ur_prefix))
                     break
 
                 progress = '{} OF {}'.format(qr_decoder.received_parts(), qr_decoder.total_parts())