From 18be93533372da3558f664312612dd462b3cc27c Mon Sep 17 00:00:00 2001
From: Wukong <wukong1971@protonmail.com>
Date: Tue, 10 May 2022 23:55:07 -0700
Subject: [PATCH] Enable importing joinmarket wallet as watch-only

---
 jmclient/jmclient/__init__.py     |  2 +-
 jmclient/jmclient/configure.py    |  8 ++++++++
 jmclient/jmclient/cryptoengine.py | 22 +++++++++++++++++++++-
 scripts/joinmarket-qt.py          |  6 +++---
 4 files changed, 33 insertions(+), 5 deletions(-)

diff --git a/jmclient/jmclient/__init__.py b/jmclient/jmclient/__init__.py
index 3495c8d7d..2d862a4e1 100644
--- a/jmclient/jmclient/__init__.py
+++ b/jmclient/jmclient/__init__.py
@@ -22,7 +22,7 @@
                       StoragePasswordError, VolatileStorage)
 from .cryptoengine import (BTCEngine, BTC_P2PKH, BTC_P2SH_P2WPKH, BTC_P2WPKH, EngineError,
                            TYPE_P2PKH, TYPE_P2SH_P2WPKH, TYPE_P2WPKH, detect_script_type,
-                           is_extended_public_key)
+                           is_extended_public_key, convert_xpub_if_needed)
 from .configure import (load_test_config, process_shutdown,
     load_program_config, jm_single, get_network, update_persist_config,
     validate_address, is_burn_destination, get_mchannels,
diff --git a/jmclient/jmclient/configure.py b/jmclient/jmclient/configure.py
index daef3b50a..676ce018b 100644
--- a/jmclient/jmclient/configure.py
+++ b/jmclient/jmclient/configure.py
@@ -262,6 +262,11 @@ def jm_single():
 #        2. You cannot change the type of a pre-existing wallet.
 native = true
 
+# Display zpub for native segwit wallet, and ypub for non-native segwit wallet.
+# If set to false, the extended public key will always display in the xpub
+# format.
+display_ypub_zpub = true
+
 # for dust sweeping, try merge_algorithm = gradual
 # for more rapid dust sweeping, try merge_algorithm = greedy
 # for most rapid dust sweeping, try merge_algorithm = greediest
@@ -986,6 +991,9 @@ def is_native_segwit_mode():
         return False
     return jm_single().config.get('POLICY', 'native') != 'false'
 
+def display_ypub_zpub():
+    return jm_single().config.get('POLICY', 'display_ypub_zpub') != 'false'
+
 def process_shutdown(mode="command-line"):
     if mode=="command-line":
         from twisted.internet import reactor
diff --git a/jmclient/jmclient/cryptoengine.py b/jmclient/jmclient/cryptoengine.py
index 70f35f799..cc4afe70c 100644
--- a/jmclient/jmclient/cryptoengine.py
+++ b/jmclient/jmclient/cryptoengine.py
@@ -1,10 +1,11 @@
 
 from collections import OrderedDict
+from bitcointx import base58
 import struct
 
 import jmbitcoin as btc
 from jmbase import bintohex
-from .configure import get_network, jm_single
+from .configure import get_network, jm_single, is_segwit_mode, is_native_segwit_mode, display_ypub_zpub
 
 
 #NOTE: before fidelity bonds and watchonly wallet, each of these types corresponded
@@ -25,7 +26,9 @@
 
 BIP32_PUB_PREFIX = "xpub"
 BIP49_PUB_PREFIX = "ypub"
+BIP49_PUB_PREFIX_BYTES = b"\x04\x9d\x7c\xb2"
 BIP84_PUB_PREFIX = "zpub"
+BIP84_PUB_PREFIX_BYTES = b"\x04\xb2\x47\x46"
 TESTNET_PUB_PREFIX = "tpub"
 
 def detect_script_type(script_str):
@@ -61,6 +64,23 @@ def is_extended_public_key(key_str):
         BIP32_PUB_PREFIX, BIP49_PUB_PREFIX, BIP84_PUB_PREFIX, TESTNET_PUB_PREFIX]])
 
 
+def convert_xpub_if_needed(xpub):
+    if not xpub.startswith(BIP32_PUB_PREFIX):
+        return xpub
+    if not display_ypub_zpub():
+        return xpub
+
+    # Convert xpub to ypub or zpub for display
+    if is_segwit_mode():
+        if is_native_segwit_mode():
+            # BIP84 format
+            xpub = base58.encode(BIP84_PUB_PREFIX_BYTES + base58.decode(xpub)[4:])
+        else:
+            # BIP49 format
+            xpub = base58.encode(BIP49_PUB_PREFIX_BYTES + base58.decode(xpub)[4:])
+    return xpub
+
+
 class classproperty(object):
     """
     from https://stackoverflow.com/a/5192374
diff --git a/scripts/joinmarket-qt.py b/scripts/joinmarket-qt.py
index 416bce94d..8bc699182 100755
--- a/scripts/joinmarket-qt.py
+++ b/scripts/joinmarket-qt.py
@@ -73,7 +73,7 @@
     parse_payjoin_setup, send_payjoin, JMBIP78ReceiverManager, \
     detect_script_type, general_custom_change_warning, \
     nonwallet_custom_change_warning, sweep_custom_change_warning, EngineError,\
-    TYPE_P2WPKH, check_and_start_tor, is_extended_public_key
+    TYPE_P2WPKH, check_and_start_tor, is_extended_public_key, convert_xpub_if_needed
 from jmclient.wallet import BaseWallet
 
 from qtsupport import ScheduleWizard, TumbleRestartWizard, config_tips,\
@@ -1573,7 +1573,7 @@ def updateWalletInfo(self, walletinfo=None):
                     continue
 
                 if address_type == BaseWallet.ADDRESS_TYPE_EXTERNAL:
-                    heading = "EXTERNAL " + xpubs[mixdepth][address_type]
+                    heading = "EXTERNAL " + convert_xpub_if_needed(xpubs[mixdepth][address_type])
                 elif address_type == BaseWallet.ADDRESS_TYPE_INTERNAL:
                     heading = "INTERNAL"
                 elif address_type == FidelityBondMixin.BIP32_TIMELOCK_ID:
@@ -2339,7 +2339,7 @@ def get_wallet_printout(wallet_service):
         account_xpub = acct.xpub
         if account_xpub.startswith(FBONDS_PUBKEY_PREFIX):
             account_xpub = account_xpub[len(FBONDS_PUBKEY_PREFIX):]
-        xpubs[j].append(account_xpub)
+        xpubs[j].append(convert_xpub_if_needed(account_xpub))
     # in case the wallet is not yet synced, don't return an incorrect
     # 0 balance, but signal incompleteness:
     total_bal = walletview.get_fmt_balance() if wallet_service.synced else None