ledger: offline signing for segwit inputs

related: #3302

plugins/ledger/ledger.py

@@ -356,10 +356,17 @@ class Ledger_KeyStore(Hardware_KeyStore):
                 self.give_error("No matching x_key for sign_transaction") # should never happen
 
             redeemScript = Transaction.get_preimage_script(txin)
-            if txin.get('prev_tx') is None:  # and not Transaction.is_segwit_input(txin):
+            txin_prev_tx = txin.get('prev_tx')
-                # note: offline signing does not work atm even with segwit inputs for ledger
+            if txin_prev_tx is None and not Transaction.is_segwit_input(txin):
-                raise Exception(_('Offline signing with {} is not supported.').format(self.device))
+                raise Exception(_('Offline signing with {} is not supported for legacy inputs.').format(self.device))
-            inputs.append([txin['prev_tx'].raw, txin['prevout_n'], redeemScript, txin['prevout_hash'], signingPos, txin.get('sequence', 0xffffffff - 1) ])
+            txin_prev_tx_raw = txin_prev_tx.raw if txin_prev_tx else None
+            inputs.append([txin_prev_tx_raw,
+                           txin['prevout_n'],
+                           redeemScript,
+                           txin['prevout_hash'],
+                           signingPos,
+                           txin.get('sequence', 0xffffffff - 1),
+                           txin.get('value')])
             inputsPaths.append(hwAddress)
             pubKeys.append(pubkeys)
 
@@ -401,10 +408,9 @@ class Ledger_KeyStore(Hardware_KeyStore):
             for utxo in inputs:
                 sequence = int_to_hex(utxo[5], 4)
                 if segwitTransaction:
-                    txtmp = bitcoinTransaction(bfh(utxo[0]))
                     tmp = bfh(utxo[3])[::-1]
                     tmp += bfh(int_to_hex(utxo[1], 4))
-                    tmp += txtmp.outputs[utxo[1]].amount
+                    tmp += bfh(int_to_hex(utxo[6], 8))  # txin['value']
                     chipInputs.append({'value' : tmp, 'witness' : True, 'sequence' : sequence})
                     redeemScripts.append(bfh(utxo[2]))
                 elif not p2shTransaction: