Merge branch 'sighash-improvements'

riemann/tests/tx/test_tx.py

@@ -735,13 +735,3 @@ def test_sighash_forkid_all_anyone_can_pay(self):
         self.assertEqual(
             sighash,
             helpers.SIGHASH_FORKID['all_anyone_can_pay'])
-
-    def test_get_script_code(self):
-        tx_ins = [tx.TxIn.from_bytes(
-            helpers.P2SH['ser']['ins'][0]['input'])]
-        t = tx.Tx(self.version, self.none_flag, tx_ins, self.tx_outs,
-                  self.none_witnesses, self.lock_time)
-
-        self.assertEqual(
-            t._get_script_code(0),
-            helpers.P2SH['ser']['ins'][0]['redeem_script'])

riemann/tx/decred.py

@@ -304,25 +304,14 @@ def copy(self, version=None, tx_ins=None, tx_outs=None,
             tx_witnesses=(tx_witnesses if tx_witnesses is not None
                           else self.tx_witnesses))
 
-    def _get_script_code(self, index):
-        if len(self.tx_witnesses[index].redeem_script) != 0:
-            script = DecredByteData()
-            # redeemScript in case of P2SH
-            script += self.tx_witnesses[index].redeem_script
-            return script.to_bytes()
-        return b''
-
     def sighash_none(self):
         raise NotImplementedError('SIGHASH_NONE is a bad idea.')
 
     def _sighash_prep(self, index, script=None):
-        sub_script = self._get_script_code(index)
-        if sub_script == b'':
-            sub_script = script
         copy_tx_witnesses = [w.copy(stack_script=b'', redeem_script=b'')
                              for w in self.tx_witnesses]
         copy_tx_witnesses[index] = \
-            copy_tx_witnesses[index].copy(stack_script=sub_script,
+            copy_tx_witnesses[index].copy(stack_script=script,
                                           redeem_script=b'')
 
         return self.copy(tx_witnesses=copy_tx_witnesses)

riemann/tx/sprout.py

@@ -216,17 +216,6 @@ def copy(self, version=None, tx_ins=None, tx_outs=None, lock_time=None,
             joinsplit_sig=(joinsplit_sig if joinsplit_sig is not None
                            else self.joinsplit_sig))
 
-    def _get_script_code(self, index):
-        '''
-        SproutTx, int -> bytes
-        '''
-        if len(self.tx_ins) > 0 and len(self.tx_ins[index].redeem_script) > 0:
-            script = z.ZcashByteData()
-            # redeemScript in case of P2SH
-            script += self.tx_ins[index].redeem_script
-            return script.to_bytes()
-        return b''
-
     def _sighash_prep(self, index, script):
         '''
         SproutTx, int, byte-like -> SproutTx
@@ -236,9 +225,6 @@ def _sighash_prep(self, index, script):
         https://bitcoin.stackexchange.com/questions/3374/how-to-redeem-a-basic-tx
         We save on complexity by refusing to support OP_CODESEPARATOR
         '''
-        sub_script = self._get_script_code(index=index)
-        if sub_script == b'':
-            sub_script = script
 
         if len(self.tx_ins) == 0:
             return self.copy(joinsplit_sig=b'')
@@ -249,7 +235,7 @@ def _sighash_prep(self, index, script):
         # NB: The script for the current transaction input in txCopy is set to
         #     subScript (lead in by its length as a var-integer encoded!)
         copy_tx_ins[index] = \
-            copy_tx_ins[index].copy(stack_script=b'', redeem_script=sub_script)
+            copy_tx_ins[index].copy(stack_script=b'', redeem_script=script)
 
         return self.copy(tx_ins=copy_tx_ins, joinsplit_sig=b'')
 

riemann/tx/tx.py

@@ -410,7 +410,7 @@ def no_witness(self):
         return bytes(tx)
 
     def is_witness(self):
-        return self.flag is not None
+        return self.flag is not None or self.tx_witnesses is not None
 
     def calculate_fee(self, input_values):
         '''
@@ -450,17 +450,14 @@ def _sighash_prep(self, index, script):
         https://bitcoin.stackexchange.com/questions/3374/how-to-redeem-a-basic-tx
         We save on complexity by refusing to support OP_CODESEPARATOR
         '''
-        sub_script = self._get_script_code(index=index)
-        if sub_script == b'':
-            sub_script = script
         # 0 out scripts in tx_ins
         copy_tx_ins = [tx_in.copy(stack_script=b'', redeem_script=b'')
                        for tx_in in self.tx_ins]
 
         # NB: The script for the current transaction input in txCopy is set to
         #     subScript (lead in by its length as a var-integer encoded!)
         copy_tx_ins[index] = \
-            copy_tx_ins[index].copy(stack_script=b'', redeem_script=sub_script)
+            copy_tx_ins[index].copy(stack_script=b'', redeem_script=script)
 
         return self.copy(tx_ins=copy_tx_ins)
 
@@ -470,7 +467,7 @@ def sighash_all(self, index, script=None,
         Tx, int, byte-like, byte-like, bool -> bytearray
         Sighashes suck
         Generates the hash to be signed with shared.SIGHASH_ALL
-        https://en.bitcoin.it/wiki/OP_CHECKSIG#Hashtype_shared.SIGHASH_ALL_.28default.29
+        https://en.bitcoin.it/wiki/OP_CHECKSIG#Hashtype_SIGHASH_ALL_.28default.29
         '''
 
         if riemann.network.FORKID is not None:
@@ -572,9 +569,7 @@ def segwit_sighash(self, index, script, prevout_value=None,
         data += self.tx_ins[index].outpoint
 
         # 5. scriptCode of the input (serialized as scripts inside CTxOuts)
-        data += self._adjusted_script_code(
-            index=index,
-            script=script)
+        data += self._adjusted_script_code(script=script)
 
         # 6. value of the output spent by this input (8-byte little endian)
         data += prevout_value
@@ -636,6 +631,14 @@ def _hash_prevouts(self, anyone_can_pay):
         return hash_prevouts
 
     def _hash_sequence(self, sighash_type, anyone_can_pay):
+        '''BIP143 hashSequence implementation
+
+        Args:
+            sighash_type    (int): SIGHASH_SINGLE or SIGHASH_ALL
+            anyone_can_pay (bool): true if ANYONECANPAY should be set
+        Returns:
+            (bytes): the hashSequence, a 32 byte hash
+        '''
         if anyone_can_pay or sighash_type == shared.SIGHASH_SINGLE:
             # If any of ANYONECANPAY, SINGLE sighash type is set,
             # hashSequence is a uint256 of 0x0000......0000.
@@ -647,26 +650,34 @@ def _hash_sequence(self, sighash_type, anyone_can_pay):
                 sequences += tx_in.sequence
             return utils.hash256(sequences.to_bytes())
 
-    def _get_script_code(self, index):
-        if len(self.tx_ins[index].redeem_script) != 0:
-            script = ByteData()
-            # redeemScript in case of P2SH
-            script += self.tx_ins[index].redeem_script
-            return script.to_bytes()
-        return b''
-
-    def _adjusted_script_code(self, index, script):
+    def _adjusted_script_code(self, script):
+        '''
+        Checks if the script code pased in to the sighash function is already
+        length-prepended
+        This will break if there's a redeem script that's just a pushdata
+        That won't happen in practice
+
+        Args:
+            script (bytes): the spend script
+        Returns:
+            (bytes): the length-prepended script (if necessary)
+        '''
         script_code = ByteData()
-        tx_in_redeem_script = self._get_script_code(index=index)
-        if tx_in_redeem_script == b'':
-            script_code += VarInt(len(script))
-            script_code += script
-            return script_code
-        script_code += VarInt(len(tx_in_redeem_script))
-        script_code += tx_in_redeem_script
+        if script[0] == len(script) - 1:
+            return script
+        script_code += VarInt(len(script))
+        script_code += script
         return script_code
 
     def _hash_outputs(self, index, sighash_type):
+        '''BIP143 hashOutputs implementation
+
+        Args:
+            index        (int): index of input being signed
+            sighash_type (int): SIGHASH_SINGLE or SIGHASH_ALL
+        Returns:
+            (bytes): the hashOutputs, a 32 byte hash
+        '''
         if sighash_type == shared.SIGHASH_ALL:
             # If the sighash type is ALL,
             # hashOutputs is the double SHA256 of all output amounts
@@ -725,9 +736,7 @@ def _sighash_forkid(self, index, script, prevout_value,
         data += self.tx_ins[index].outpoint
 
         # 5. scriptCode of the input (serialized as scripts inside CTxOuts)
-        data += self._adjusted_script_code(
-            index=index,
-            script=script)
+        data += self._adjusted_script_code(script=script)
 
         # 6. value of the output spent by this input (8-byte little endian)
         data += prevout_value

setup.py

@@ -4,7 +4,7 @@
 
 setup(
     name='riemann-tx',
-    version='1.1.0',
+    version='1.1.1',
     description=('Transaction creation library for Bitcoin-like coins'),
     url='https://github.com/summa-tx/riemann',
     author='James Prestwich',