version 2.9.4

This is mostly a manual copy of parts of multiple commits from the master branch.

RELEASE-NOTES

@@ -1,3 +1,7 @@
+# Release 2.9.4 (security update)
+  * Backport security fixes from 3.0.5 after vulnerability was
+    discovered in JSONRPC interface.
+
 # Release 2.9.3
   * fix configuration file issue #2719
   * fix ledger signing of non-RBF transactions

electrum

@@ -372,7 +372,7 @@ if __name__ == '__main__':
         fd, server = daemon.get_fd_or_server(config)
         if fd is not None:
             plugins = init_plugins(config, config.get('gui', 'qt'))
-            d = daemon.Daemon(config, fd)
+            d = daemon.Daemon(config, fd, True)
             d.start()
             d.init_gui(config, plugins)
             sys.exit(0)
@@ -393,7 +393,7 @@ if __name__ == '__main__':
                         print_stderr("starting daemon (PID %d)" % pid)
                         sys.exit(0)
                 init_plugins(config, 'cmdline')
-                d = daemon.Daemon(config, fd)
+                d = daemon.Daemon(config, fd, False)
                 d.start()
                 if config.get('websocket_server'):
                     from electrum import websockets

gui/qt/__init__.py

@@ -168,7 +168,12 @@ class ElectrumGui:
                 w.bring_to_top()
                 break
         else:
-            wallet = self.daemon.load_wallet(path, None)
+            try:
+                wallet = self.daemon.load_wallet(path, None)
+            except  BaseException as e:
+                d = QMessageBox(QMessageBox.Warning, _('Error'), 'Cannot load wallet:\n' + str(e))
+                d.exec_()
+                return
             if not wallet:
                 storage = WalletStorage(path)
                 wizard = InstallWizard(self.config, self.app, self.plugins, storage)

lib/daemon.py

@@ -29,12 +29,12 @@ import sys
 import time
 
 import jsonrpclib
-from jsonrpclib.SimpleJSONRPCServer import SimpleJSONRPCServer, SimpleJSONRPCRequestHandler
+from .jsonrpc import VerifyingJSONRPCServer
 
 from version import ELECTRUM_VERSION
 from network import Network
-from util import json_decode, DaemonThread
-from util import print_msg, print_error, print_stderr, UserCancelled
+from util import (json_decode, DaemonThread, print_msg, print_error,
+                  print_stderr, UserCancelled, to_string, int_to_bytes)
 from wallet import Wallet
 from storage import WalletStorage
 from commands import known_commands, Commands
@@ -73,7 +73,14 @@ def get_server(config):
         try:
             with open(lockfile) as f:
                 (host, port), create_time = ast.literal_eval(f.read())
-                server = jsonrpclib.Server('http://%s:%d' % (host, port))
+                rpc_user, rpc_password = get_rpc_credentials(config)
+                if rpc_password == '':
+                    # authentication disabled
+                    server_url = 'http://%s:%d' % (host, port)
+                else:
+                    server_url = 'http://%s:%s@%s:%d' % (
+                        rpc_user, rpc_password, host, port)
+                server = jsonrpclib.Server(server_url)
             # Test daemon is running
             server.ping()
             return server
@@ -85,23 +92,29 @@ def get_server(config):
         time.sleep(1.0)
 
 
-
-class RequestHandler(SimpleJSONRPCRequestHandler):
-
-    def do_OPTIONS(self):
-        self.send_response(200)
-        self.end_headers()
-
-    def end_headers(self):
-        self.send_header("Access-Control-Allow-Headers",
-                         "Origin, X-Requested-With, Content-Type, Accept")
-        self.send_header("Access-Control-Allow-Origin", "*")
-        SimpleJSONRPCRequestHandler.end_headers(self)
+def get_rpc_credentials(config):
+    rpc_user = config.get('rpcuser', None)
+    rpc_password = config.get('rpcpassword', None)
+    if rpc_user is None or rpc_password is None:
+        rpc_user = 'user'
+        import ecdsa, base64
+        bits = 128
+        nbytes = bits // 8 + (bits % 8 > 0)
+        pw_int = ecdsa.util.randrange(pow(2, bits))
+        pw_b64 = base64.b64encode(
+            int_to_bytes(pw_int, nbytes, 'big'), b'-_')
+        rpc_password = to_string(pw_b64, 'ascii')
+        config.set_key('rpcuser', rpc_user)
+        config.set_key('rpcpassword', rpc_password, save=True)
+    elif rpc_password == '':
+        from .util import print_stderr
+        print_stderr('WARNING: RPC authentication is disabled.')
+    return rpc_user, rpc_password
 
 
 class Daemon(DaemonThread):
 
-    def __init__(self, config, fd):
+    def __init__(self, config, fd, is_gui):
         DaemonThread.__init__(self)
         self.config = config
         if config.get('offline'):
@@ -116,30 +129,34 @@ class Daemon(DaemonThread):
         self.gui = None
         self.wallets = {}
         # Setup JSONRPC server
-        self.cmd_runner = Commands(self.config, None, self.network)
-        self.init_server(config, fd)
+        self.init_server(config, fd, is_gui)
 
-    def init_server(self, config, fd):
+    def init_server(self, config, fd, is_gui):
         host = config.get('rpchost', '127.0.0.1')
         port = config.get('rpcport', 0)
+
+        rpc_user, rpc_password = get_rpc_credentials(config)
         try:
-            server = SimpleJSONRPCServer((host, port), logRequests=False,
-                                         requestHandler=RequestHandler)
-        except:
-            self.print_error('Warning: cannot initialize RPC server on host', host)
+            server = VerifyingJSONRPCServer((host, port), logRequests=False,
+                                            rpc_user=rpc_user, rpc_password=rpc_password)
+        except Exception as e:
+            self.print_error('Warning: cannot initialize RPC server on host', host, e)
             self.server = None
             os.close(fd)
             return
         os.write(fd, repr((server.socket.getsockname(), time.time())))
         os.close(fd)
-        server.timeout = 0.1
-        for cmdname in known_commands:
-            server.register_function(getattr(self.cmd_runner, cmdname), cmdname)
-        server.register_function(self.run_cmdline, 'run_cmdline')
-        server.register_function(self.ping, 'ping')
-        server.register_function(self.run_daemon, 'daemon')
-        server.register_function(self.run_gui, 'gui')
         self.server = server
+        server.timeout = 0.1
+        server.register_function(self.ping, 'ping')
+        if is_gui:
+            server.register_function(self.run_gui, 'gui')
+        else:
+            self.cmd_runner = Commands(self.config, None, self.network)
+            for cmdname in known_commands:
+                server.register_function(getattr(self.cmd_runner, cmdname), cmdname)
+            server.register_function(self.run_cmdline, 'run_cmdline')
+            server.register_function(self.run_daemon, 'daemon')
 
     def ping(self):
         return True

lib/jsonrpc.py

@@ -0,0 +1,97 @@
+#!/usr/bin/env python2
+#
+# Electrum - lightweight Bitcoin client
+# Copyright (C) 2018 Thomas Voegtlin
+#
+# Permission is hereby granted, free of charge, to any person
+# obtaining a copy of this software and associated documentation files
+# (the "Software"), to deal in the Software without restriction,
+# including without limitation the rights to use, copy, modify, merge,
+# publish, distribute, sublicense, and/or sell copies of the Software,
+# and to permit persons to whom the Software is furnished to do so,
+# subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be
+# included in all copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+# BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+# ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+# CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+# SOFTWARE.
+
+from jsonrpclib.SimpleJSONRPCServer import SimpleJSONRPCServer, SimpleJSONRPCRequestHandler
+from base64 import b64decode
+import time
+
+from . import util
+
+
+class RPCAuthCredentialsInvalid(Exception):
+    def __str__(self):
+        return 'Authentication failed (bad credentials)'
+
+
+class RPCAuthCredentialsMissing(Exception):
+    def __str__(self):
+        return 'Authentication failed (missing credentials)'
+
+
+class RPCAuthUnsupportedType(Exception):
+    def __str__(self):
+        return 'Authentication failed (only basic auth is supported)'
+
+
+# based on http://acooke.org/cute/BasicHTTPA0.html by andrew cooke
+class VerifyingJSONRPCServer(SimpleJSONRPCServer):
+
+    def __init__(self, *args, **kargs):
+
+        self.rpc_user = kargs['rpc_user']
+        self.rpc_password = kargs['rpc_password']
+        del kargs['rpc_user']
+        del kargs['rpc_password']
+
+        class VerifyingRequestHandler(SimpleJSONRPCRequestHandler):
+            def parse_request(myself):
+                # first, call the original implementation which returns
+                # True if all OK so far
+                if SimpleJSONRPCRequestHandler.parse_request(myself):
+                    try:
+                        self.authenticate(myself.headers)
+                        return True
+                    except (RPCAuthCredentialsInvalid, RPCAuthCredentialsMissing,
+                            RPCAuthUnsupportedType) as e:
+                        myself.send_error(401, str(e))
+                    except BaseException as e:
+                        import traceback, sys
+                        traceback.print_exc(file=sys.stderr)
+                        myself.send_error(500, str(e))
+                return False
+
+        SimpleJSONRPCServer.__init__(
+            self, requestHandler=VerifyingRequestHandler, *args, **kargs)
+
+    def authenticate(self, headers):
+        if self.rpc_password == '':
+            # RPC authentication is disabled
+            return
+
+        auth_string = headers.get('Authorization', None)
+        if auth_string is None:
+            raise RPCAuthCredentialsMissing()
+
+        (basic, _, encoded) = auth_string.partition(' ')
+        if basic != 'Basic':
+            raise RPCAuthUnsupportedType()
+
+        encoded = util.to_bytes(encoded, 'utf8')
+        credentials = util.to_string(b64decode(encoded), 'utf8')
+        (username, _, password) = credentials.partition(':')
+        if not (util.constant_time_compare(username, self.rpc_user)
+                and util.constant_time_compare(password, self.rpc_password)):
+            time.sleep(0.050)
+            raise RPCAuthCredentialsInvalid()

lib/storage.py

@@ -75,6 +75,9 @@ class WalletStorage(PrintError):
                 self.raw = f.read()
             if not self.is_encrypted():
                 self.load_data(self.raw)
+        else:
+            # avoid new wallets getting 'upgraded'
+            self.put('seed_version', FINAL_SEED_VERSION)
 
     def load_data(self, s):
         try:
@@ -161,8 +164,6 @@ class WalletStorage(PrintError):
 
     @profiler
     def write(self):
-        # this ensures that previous versions of electrum won't open the wallet
-        self.put('seed_version', FINAL_SEED_VERSION)
         with self.lock:
             self._write()
 
@@ -244,12 +245,14 @@ class WalletStorage(PrintError):
         return result
 
     def requires_upgrade(self):
-        return self.file_exists() and self.get_seed_version() != FINAL_SEED_VERSION
+        return self.file_exists() and self.get_seed_version() < FINAL_SEED_VERSION
 
     def upgrade(self):
         self.convert_imported()
         self.convert_wallet_type()
         self.convert_account()
+
+        self.put('seed_version', FINAL_SEED_VERSION)
         self.write()
 
     def convert_wallet_type(self):
@@ -379,6 +382,8 @@ class WalletStorage(PrintError):
         seed_version = self.get('seed_version')
         if not seed_version:
             seed_version = OLD_SEED_VERSION if len(self.get('master_public_key','')) == 128 else NEW_SEED_VERSION
+        if seed_version > FINAL_SEED_VERSION:
+            raise BaseException('This version of Electrum is too old to open this wallet')
         if seed_version >=12:
             return seed_version
         if seed_version not in [OLD_SEED_VERSION, NEW_SEED_VERSION]:

lib/util.py

@@ -34,6 +34,8 @@ import urlparse
 import urllib
 import threading
 from i18n import _
+import hmac
+
 
 base_units = {'BTC':8, 'mBTC':5, 'uBTC':2}
 fee_levels = [_('Within 25 blocks'), _('Within 10 blocks'), _('Within 5 blocks'), _('Within 2 blocks'), _('In the next block')]
@@ -191,6 +193,13 @@ def json_decode(x):
     except:
         return x
 
+
+# taken from Django Source Code
+def constant_time_compare(val1, val2):
+    """Return True if the two strings are equal, False otherwise."""
+    return hmac.compare_digest(to_bytes(val1, 'utf8'), to_bytes(val2, 'utf8'))
+
+
 # decorator that prints execution time
 def profiler(func):
     def do_profile(func, args, kw_args):
@@ -238,6 +247,38 @@ def android_check_data_dir():
 def get_headers_dir(config):
     return android_headers_dir() if 'ANDROID_DATA' in os.environ else config.path
 
+def to_string(x, enc):
+    if isinstance(x, (bytes, bytearray)):
+        return x.decode(enc)
+    if isinstance(x, str):
+        return x
+    else:
+        raise TypeError("Not a string or bytes like object")
+
+def to_bytes(something, encoding='utf8'):
+    """
+    cast string to bytes() like object, but for python2 support it's bytearray copy
+    """
+    if isinstance(something, bytes):
+        return something
+    if isinstance(something, str) or isinstance(something, unicode):
+        return something.encode(encoding)
+    elif isinstance(something, bytearray):
+        return bytes(something)
+    else:
+        raise TypeError("Not a string or bytes like object")
+
+# based on https://stackoverflow.com/questions/16022556/has-python-3-to-bytes-been-back-ported-to-python-2-7
+def int_to_bytes(n, length, endianess='big'):
+    hex_n = '%x' % n
+    hex_n2 = '0'*(len(hex_n) % 2) + hex_n
+    left_padded_hex_n = hex_n2.zfill(length*2)
+    if len(left_padded_hex_n) > length*2:
+        raise OverflowError()
+    assert len(left_padded_hex_n) == length*2
+    bytes_n = left_padded_hex_n.decode('hex')
+    return bytes_n if endianess == 'big' else bytes_n[::-1]
+
 def user_dir():
     if 'ANDROID_DATA' in os.environ:
         return android_check_data_dir()

lib/version.py

@@ -1,4 +1,4 @@
-ELECTRUM_VERSION = '2.9.3'  # version of the client package
+ELECTRUM_VERSION = '2.9.4'  # version of the client package
 PROTOCOL_VERSION = '0.10'   # protocol version requested
 
 # The hash of the mnemonic seed must begin with this

plugins/trezor/clientbase.py

@@ -229,7 +229,7 @@ class TrezorClientBase(GuiMixin, PrintError):
 
     @staticmethod
     def wrap_methods(cls):
-        for method in ['apply_settings', 'change_pin', 'decrypt_message',
+        for method in ['apply_settings', 'change_pin',
                        'get_address', 'get_public_node',
                        'load_device_by_mnemonic', 'load_device_by_xprv',
                        'recovery_device', 'reset_device', 'sign_message',

plugins/trezor/plugin.py

@@ -29,14 +29,7 @@ class TrezorCompatibleKeyStore(Hardware_KeyStore):
         return self.plugin.get_client(self, force_pair)
 
     def decrypt_message(self, sequence, message, password):
-        raise RuntimeError(_('Electrum and %s encryption and decryption are currently incompatible') % self.device)
-        client = self.get_client()
-        address_path = self.get_derivation() + "/%d/%d"%sequence
-        address_n = client.expand_path(address_path)
-        payload = base64.b64decode(message)
-        nonce, message, msg_hmac = payload[:33], payload[33:-8], payload[-8:]
-        result = client.decrypt_message(address_n, nonce, message, msg_hmac)
-        return result.message
+        raise RuntimeError(_('Encryption and decryption are not implemented by %s') % self.device)
 
     def sign_message(self, sequence, message, password):
         client = self.get_client()
@@ -55,7 +48,7 @@ class TrezorCompatibleKeyStore(Hardware_KeyStore):
         for txin in tx.inputs():
             pubkeys, x_pubkeys = tx.get_sorted_pubkeys(txin)
             tx_hash = txin['prevout_hash']
-            prev_tx[tx_hash] = txin['prev_tx'] 
+            prev_tx[tx_hash] = txin['prev_tx']
             for x_pubkey in x_pubkeys:
                 if not is_xpubkey(x_pubkey):
                     continue
@@ -96,7 +89,7 @@ class TrezorCompatiblePlugin(HW_PluginBase):
             # raise
             self.print_error("cannot connect at", device.path, str(e))
             return None
- 
+
     def _try_bridge(self, device):
         self.print_error("Trying to connect over Trezor Bridge...")
         try: