[TREZOR] Added Segwit support.

Following changes were necessary outside the TREZOR plugin.
- transaction.py: update_transaction handles segwit transactions.
- keystore.py: added a segwit parameter to bip44_derivation,
  use m/49' instead of m/44' for segwit.

lib/base_wizard.py

@@ -227,7 +227,7 @@ class BaseWizard(object):
             self.derivation_dialog(f)
 
     def derivation_dialog(self, f):
-        default = bip44_derivation(0)
+        default = bip44_derivation(0, self.config.get('segwit'))
         message = '\n'.join([
             _('Enter your wallet derivation here.'),
             _('If you are not sure what this is, leave this field unchanged.')

lib/keystore.py

@@ -684,11 +684,10 @@ is_private_key = lambda x: is_xprv(x) or is_private_key_list(x)
 is_bip32_key = lambda x: is_xprv(x) or is_xpub(x)
 
 
-def bip44_derivation(account_id):
-    if bitcoin.TESTNET:
-        return "m/44'/1'/%d'"% int(account_id)
-    else:
-        return "m/44'/0'/%d'"% int(account_id)
+def bip44_derivation(account_id, segwit=False):
+    bip  = 49 if segwit else 44
+    coin = 1 if bitcoin.TESTNET else 0
+    return "m/%d'/%d'/%d'" % (bip, coin, int(account_id))
 
 def from_seed(seed, passphrase):
     t = seed_type(seed)

lib/transaction.py

@@ -421,8 +421,7 @@ def parse_input(vds):
 
 def parse_witness(vds):
     n = vds.read_compact_size()
-    for i in range(n):
-        x = vds.read_bytes(vds.read_compact_size())
+    return list(vds.read_bytes(vds.read_compact_size()).encode('hex') for i in xrange(n))
 
 def parse_output(vds, i):
     d = {}
@@ -548,7 +547,12 @@ class Transaction:
         for i, txin in enumerate(self.inputs()):
             pubkeys, x_pubkeys = self.get_sorted_pubkeys(txin)
             sigs1 = txin.get('signatures')
-            sigs2 = d['inputs'][i].get('signatures')
+            if d.get('witness') is None:
+                sigs2 = d['inputs'][i].get('signatures')
+            else:
+                # signatures are in the witnesses.  But the last item is
+                # the pubkey or the multisig script, so skip that.
+                sigs2 = d['witness'][i][:-1]
             for sig in sigs2:
                 if sig in sigs1:
                     continue