fixup! feat(core): add Zcash shielded transactions

core/src/apps/bitcoin/sign_tx/helpers.py

@@ -402,6 +402,15 @@ def sanitize_sign_tx(tx: SignTx, coin: CoinInfo) -> SignTx:
         if tx.branch_id is not None:
             raise wire.DataError("Branch ID not enabled on this coin.")
 
+    if tx.orchard_params is not None:
+        if not utils.ZCASH_SHIELDED:
+            raise wire.DataError("Shielded transaction disabled.")
+        elif tx.orchard_params.inputs_count + tx.orchard_params.outputs_count == 0:
+            raise wire.DataError("Orchard bundle must not be empty.")
+        elif tx.orchard_params.inputs_count > 0 and tx.inputs_count > 0:
+            raise wire.DataError(
+                "Spending transparent and Orchard inputs simultaneously is not supported."
+            )
     return tx
 
 

core/src/apps/zcash/orchard/signer.py

@@ -35,21 +35,6 @@ FLAGS = const(0b0000_0011)  # spends enbled and output enabled
 MAX_SILENT_ORCHARD_INPUTS = const(8)
 
 
-def skip_if_empty(func):
-    """
-    A function decorated by this will not be evaluated,
-    if the Orchard bundle is impty.
-    """
-
-    async def wrapper(self):
-        if self.actions_count == 0:
-            return
-        else:
-            await func(self)
-
-    return wrapper
-
-
 class OrchardSigner:
     def __init__(
         self,
@@ -59,26 +44,13 @@ class OrchardSigner:
         coin: CoinInfo,
         tx_req: TxRequest,
     ) -> None:
-        assert tx_req.serialized is not None  # typing
         params = tx_info.tx.orchard_params
-        if params is None:
-            self.inputs_count = 0
-            self.outputs_count = 0
-        else:
-            self.inputs_count = params.inputs_count
-            self.outputs_count = params.outputs_count
-
-        if self.inputs_count + self.outputs_count > 0:
-            self.actions_count = max(
-                2,  # minimal required amount of actions
-                self.inputs_count,
-                self.outputs_count,
-            )
-        else:
-            self.actions_count = 0
-
-        if self.actions_count == 0:
-            return  # no need to initialize other attributes
+        assert params is not None  # checked in sanitize_sign_tx
+        self.actions_count = max(
+            2,  # minimal required amount of actions
+            self.inputs_count,
+            self.outputs_count,
+        )
 
         self.tx_info = tx_info
         self.keychain = OrchardKeychain.from_seed_and_coin(seed, coin)
@@ -87,7 +59,6 @@ class OrchardSigner:
         self.tx_req = tx_req
         assert isinstance(tx_info.sig_hasher, ZcashHasher)
         self.sig_hasher: ZcashHasher = tx_info.sig_hasher
-        assert params is not None
         self.anchor = params.anchor
         self.key_node = self.keychain.derive(params.address_n)
 
@@ -99,7 +70,6 @@ class OrchardSigner:
 
         self.rng = None
 
-    @skip_if_empty
     async def process_inputs(self) -> None:
         await self.check_orchard_inputs_count()
         for i in range(self.inputs_count):
@@ -111,7 +81,6 @@ class OrchardSigner:
         if self.inputs_count > MAX_SILENT_ORCHARD_INPUTS:
             yield ConfirmOrchardInputsCountOverThreshold(self.inputs_count)
 
-    @skip_if_empty
     async def approve_outputs(self) -> None:
         for i in range(self.outputs_count):
             txo = await self.get_output(i)
@@ -121,7 +90,6 @@ class OrchardSigner:
             else:
                 await self.approver.add_orchard_external_output(txo)
 
-    @skip_if_empty
     async def compute_digest(self) -> None:
         # derive shielding seed
         shielding_seed = self.derive_shielding_seed()
@@ -233,7 +201,6 @@ class OrchardSigner:
         ovk = fvk.outgoing_viewing_key()
         return builder.OutputInfo(ovk, address, txo.amount, txo.memo)
 
-    @skip_if_empty
     @watch_gc_async
     async def sign_inputs(self) -> None:
         sighash = self.sig_hasher.signature_digest()

core/src/apps/zcash/signer.py

@@ -55,7 +55,7 @@ class Zcash(Bitcoinlike):
 
         super().__init__(tx, keychain, coin, approver)
 
-        if ZCASH_SHIELDED:
+        if ZCASH_SHIELDED and tx.orchard_params is not None:
             self.orchard = OrchardSigner(
                 self.tx_info,
                 keychain.seed,
@@ -63,10 +63,8 @@ class Zcash(Bitcoinlike):
                 coin,
                 self.tx_req,
             )
-            if self.orchard.inputs_count > 0 and tx.inputs_count > 0:
-                raise DataError(
-                    "Cannot spending transparent and Orchard inputs simultaneously is not supported."
-                )
+        else:
+            self.orchard = None
 
     def create_sig_hasher(self, tx: SignTx | PrevTx) -> ZcashHasher:
         return ZcashHasher(tx)
@@ -78,12 +76,12 @@ class Zcash(Bitcoinlike):
 
     async def step1_process_inputs(self):
         await super().step1_process_inputs()
-        if ZCASH_SHIELDED:
+        if ZCASH_SHIELDED and self.orchard is not None:
             await self.orchard.process_inputs()
 
     async def step2_approve_outputs(self):
         await super().step2_approve_outputs()
-        if ZCASH_SHIELDED:
+        if ZCASH_SHIELDED and self.orchard is not None:
             await self.orchard.approve_outputs()
 
     async def step3_verify_inputs(self) -> None:
@@ -97,7 +95,7 @@ class Zcash(Bitcoinlike):
         self.taproot_only = False  # turn off taproot behavior
 
     async def step4_serialize_inputs(self):
-        if ZCASH_SHIELDED:
+        if ZCASH_SHIELDED and self.orchard is not None:
             # shield actions first to get a sighash
             await self.orchard.compute_digest()
         await super().step4_serialize_inputs()
@@ -111,14 +109,14 @@ class Zcash(Bitcoinlike):
         write_compact_size(self.serialized_tx, 0)  # nOutputsSapling
 
         # nActionsOrchard
-        if ZCASH_SHIELDED:
+        if ZCASH_SHIELDED and self.orchard is not None::
             write_compact_size(self.serialized_tx, self.orchard.actions_count)
         else:
             write_compact_size(self.serialized_tx, 0)
 
     async def step6_sign_segwit_inputs(self):
         # transparent inputs were signed in step 4
-        if ZCASH_SHIELDED:
+        if ZCASH_SHIELDED and self.orchard is not None:
             await self.orchard.sign_inputs()
 
     async def sign_nonsegwit_input(self, i_sign: int) -> None:
@@ -186,5 +184,5 @@ class Zcash(Bitcoinlike):
     def set_serialized_signature(self, i: int, signature: bytes) -> None:
         super().set_serialized_signature(i, signature)
         assert self.tx_req.serialized is not None
-        if ZCASH_SHIELDED:
+        if ZCASH_SHIELDED and self.orchard is not None:
             self.tx_req.serialized.signature_type = ZcashSignatureType.TRANSPARENT