aiorpcx: pin certificates

electrum/__init__.py

@@ -4,7 +4,7 @@ from .wallet import Wallet
 from .storage import WalletStorage
 from .coinchooser import COIN_CHOOSERS
 from .network import Network, pick_random_server
-from .interface import Connection, Interface
+from .interface import Interface
 from .simple_config import SimpleConfig, get_config, set_config
 from . import bitcoin
 from . import transaction

electrum/interface.py

@@ -28,343 +28,131 @@ import socket
 import ssl
 import sys
 import threading
-import time
 import traceback
+import aiorpcx
+import asyncio
 
 import requests
 
-from .util import print_error
+from .util import PrintError
 
 ca_path = requests.certs.where()
 
 from . import util
 from . import x509
 from . import pem
+from .version import ELECTRUM_VERSION, PROTOCOL_VERSION
 
+class Interface(PrintError):
 
-def Connection(server, queue, config_path):
+    def __init__(self, server, config_path, connecting):
-    """Makes asynchronous connections to a remote Electrum server.
+        self.connecting = connecting
-    Returns the running thread that is making the connection.
-
-    Once the thread has connected, it finishes, placing a tuple on the
-    queue of the form (server, socket), where socket is None if
-    connection failed.
-    """
-    host, port, protocol = server.rsplit(':', 2)
-    if not protocol in 'st':
-        raise Exception('Unknown protocol: %s' % protocol)
-    c = TcpConnection(server, queue, config_path)
-    c.start()
-    return c
-
-
-class TcpConnection(threading.Thread, util.PrintError):
-    verbosity_filter = 'i'
-
-    def __init__(self, server, queue, config_path):
-        threading.Thread.__init__(self)
-        self.config_path = config_path
-        self.queue = queue
         self.server = server
-        self.host, self.port, self.protocol = self.server.rsplit(':', 2)
+        self.host, self.port, self.protocol = self.server.split(':')
-        self.host = str(self.host)
+        self.config_path = config_path
-        self.port = int(self.port)
+        self.cert_path = os.path.join(self.config_path, 'certs', self.host)
-        self.use_ssl = (self.protocol == 's')
+        self.fut = asyncio.get_event_loop().create_task(self.run())
-        self.daemon = True
 
     def diagnostic_name(self):
         return self.host
 
-    def check_host_name(self, peercert, name):
+    async def is_server_ca_signed(self, sslc):
-        """Simple certificate/host name checker.  Returns True if the
+        try:
-        certificate matches, False otherwise.  Does not support
+            await self.open_session(sslc, do_sleep=False)
-        wildcards."""
+        except ssl.SSLError as e:
-        # Check that the peer has supplied a certificate.
+            assert e.reason == 'CERTIFICATE_VERIFY_FAILED'
-        # None/{} is not acceptable.
-        if not peercert:
             return False
-        if 'subjectAltName' in peercert:
-            for typ, val in peercert["subjectAltName"]:
-                if typ == "DNS" and val == name:
         return True
-        else:
-            # Only check the subject DN if there is no subject alternative
-            # name.
-            cn = None
-            for attr, val in peercert["subject"]:
-                # Use most-specific (last) commonName attribute.
-                if attr == "commonName":
-                    cn = val
-            if cn is not None:
-                return cn == name
-        return False
 
-    def get_simple_socket(self):
+    @util.aiosafe
-        try:
+    async def run(self):
-            l = socket.getaddrinfo(self.host, self.port, socket.AF_UNSPEC, socket.SOCK_STREAM)
+        if self.protocol != 's':
-        except socket.gaierror:
+            await self.open_session(None, execute_after_connect=lambda: self.connecting.remove(self.server))
-            self.print_error("cannot resolve hostname")
             return
-        e = None
-        for res in l:
-            try:
-                s = socket.socket(res[0], socket.SOCK_STREAM)
-                s.settimeout(10)
-                s.connect(res[4])
-                s.settimeout(2)
-                s.setsockopt(socket.SOL_SOCKET, socket.SO_KEEPALIVE, 1)
-                return s
-            except BaseException as _e:
-                e = _e
-                continue
-        else:
-            self.print_error("failed to connect", str(e))
-
-    @staticmethod
-    def get_ssl_context(cert_reqs, ca_certs):
-        context = ssl.create_default_context(purpose=ssl.Purpose.SERVER_AUTH, cafile=ca_certs)
-        context.check_hostname = False
-        context.verify_mode = cert_reqs
-
-        context.options |= ssl.OP_NO_SSLv2
-        context.options |= ssl.OP_NO_SSLv3
-        context.options |= ssl.OP_NO_TLSv1
 
-        return context
+        ca_sslc = ssl.create_default_context(ssl.Purpose.SERVER_AUTH)
-
+        exists = os.path.exists(self.cert_path)
-    def get_socket(self):
+        if exists:
-        if self.use_ssl:
+            with open(self.cert_path, 'r') as f:
-            cert_path = os.path.join(self.config_path, 'certs', self.host)
+                contents = f.read()
-            if not os.path.exists(cert_path):
+                if contents != '': # if not CA signed
-                is_new = True
-                s = self.get_simple_socket()
-                if s is None:
-                    return
-                # try with CA first
                     try:
-                    context = self.get_ssl_context(cert_reqs=ssl.CERT_REQUIRED, ca_certs=ca_path)
+                        b = pem.dePem(contents, 'CERTIFICATE')
-                    s = context.wrap_socket(s, do_handshake_on_connect=True)
+                    except SyntaxError:
-                except ssl.SSLError as e:
+                        exists = False
-                    self.print_error(e)
-                except:
-                    return
                     else:
+                        x = x509.X509(b)
                         try:
-                        peer_cert = s.getpeercert()
+                            x.check_date()
-                    except OSError:
+                        except x509.CertificateError:
-                        return
+                            self.print_error("certificate has expired:", self.cert_path)
-                    if self.check_host_name(peer_cert, self.host):
+                            os.unlink(self.cert_path)
-                        self.print_error("SSL certificate signed by CA")
+                            exists = False
-                        return s
+        if not exists:
-                # get server certificate.
+            ca_signed = await self.is_server_ca_signed(ca_sslc)
-                # Do not use ssl.get_server_certificate because it does not work with proxy
+            if ca_signed:
-                s = self.get_simple_socket()
+                with open(self.cert_path, 'w') as f:
-                if s is None:
+                    # empty file means this is CA signed, not self-signed
-                    return
+                    f.write('')
-                try:
+            else:
-                    context = self.get_ssl_context(cert_reqs=ssl.CERT_NONE, ca_certs=None)
+                await self.save_certificate()
-                    s = context.wrap_socket(s)
+        siz = os.stat(self.cert_path).st_size
-                except ssl.SSLError as e:
+        if siz == 0: # if CA signed
-                    self.print_error("SSL error retrieving SSL certificate:", e)
+            sslc = ca_sslc
-                    return
+        else:
-                except:
+            sslc = ssl.create_default_context(ssl.Purpose.SERVER_AUTH, cafile=self.cert_path)
-                    return
+            sslc.check_hostname = 0
-
+        await self.open_session(sslc, execute_after_connect=lambda: self.connecting.remove(self.server))
-                try:
+
-                    dercert = s.getpeercert(True)
+    async def save_certificate(self):
-                except OSError:
+        if not os.path.exists(self.cert_path):
-                    return
+            # we may need to retry this a few times, in case the handshake hasn't completed
-                s.close()
+            for _ in range(10):
+                dercert = await self.get_certificate()
+                if dercert:
+                    self.print_error("succeeded in getting cert")
+                    with open(self.cert_path, 'w') as f:
                         cert = ssl.DER_cert_to_PEM_cert(dercert)
                         # workaround android bug
                         cert = re.sub("([^\n])-----END CERTIFICATE-----","\\1\n-----END CERTIFICATE-----",cert)
-                temporary_path = cert_path + '.temp'
-                util.assert_datadir_available(self.config_path)
-                with open(temporary_path, "w", encoding='utf-8') as f:
                         f.write(cert)
+                        # even though close flushes we can't fsync when closed.
+                        # and we must flush before fsyncing, cause flush flushes to OS buffer
+                        # fsync writes to OS buffer to disk
                         f.flush()
                         os.fsync(f.fileno())
-            else:
+                    break
-                is_new = False
+                await asyncio.sleep(1)
-
+            assert False, "could not get certificate"
-        s = self.get_simple_socket()
-        if s is None:
-            return
-
-        if self.use_ssl:
-            try:
-                context = self.get_ssl_context(cert_reqs=ssl.CERT_REQUIRED,
-                                               ca_certs=(temporary_path if is_new else cert_path))
-                s = context.wrap_socket(s, do_handshake_on_connect=True)
-            except socket.timeout:
-                self.print_error('timeout')
-                return
-            except ssl.SSLError as e:
-                self.print_error("SSL error:", e)
-                if e.errno != 1:
-                    return
-                if is_new:
-                    rej = cert_path + '.rej'
-                    if os.path.exists(rej):
-                        os.unlink(rej)
-                    os.rename(temporary_path, rej)
-                else:
-                    util.assert_datadir_available(self.config_path)
-                    with open(cert_path, encoding='utf-8') as f:
-                        cert = f.read()
-                    try:
-                        b = pem.dePem(cert, 'CERTIFICATE')
-                        x = x509.X509(b)
-                    except:
-                        traceback.print_exc(file=sys.stderr)
-                        self.print_error("wrong certificate")
-                        return
-                    try:
-                        x.check_date()
-                    except:
-                        self.print_error("certificate has expired:", cert_path)
-                        os.unlink(cert_path)
-                        return
-                    self.print_error("wrong certificate")
-                if e.errno == 104:
-                    return
-                return
-            except BaseException as e:
-                self.print_error(e)
-                traceback.print_exc(file=sys.stderr)
-                return
-
-            if is_new:
-                self.print_error("saving certificate")
-                os.rename(temporary_path, cert_path)
-
-        return s
-
-    def run(self):
-        socket = self.get_socket()
-        if socket:
-            self.print_error("connected")
-        self.queue.put((self.server, socket))
-
-
-class Interface(util.PrintError):
-    """The Interface class handles a socket connected to a single remote
-    Electrum server.  Its exposed API is:
-
-    - Member functions close(), fileno(), get_responses(), has_timed_out(),
-      ping_required(), queue_request(), send_requests()
-    - Member variable server.
-    """
-
-    def __init__(self, server, socket):
-        self.server = server
-        self.host, _, _ = server.rsplit(':', 2)
-        self.socket = socket
-
-        self.pipe = util.SocketPipe(socket)
-        self.pipe.set_timeout(0.0)  # Don't wait for data
-        # Dump network messages.  Set at runtime from the console.
-        self.debug = False
-        self.unsent_requests = []
-        self.unanswered_requests = {}
-        self.last_send = time.time()
-        self.closed_remotely = False
-
-    def diagnostic_name(self):
-        return self.host
-
-    def fileno(self):
-        # Needed for select
-        return self.socket.fileno()
-
-    def close(self):
-        if not self.closed_remotely:
-            try:
-                self.socket.shutdown(socket.SHUT_RDWR)
-            except socket.error:
-                pass
-        self.socket.close()
-
-    def queue_request(self, *args):  # method, params, _id
-        '''Queue a request, later to be send with send_requests when the
-        socket is available for writing.
-        '''
-        self.request_time = time.time()
-        self.unsent_requests.append(args)
-
-    def num_requests(self):
-        '''Keep unanswered requests below 100'''
-        n = 100 - len(self.unanswered_requests)
-        return min(n, len(self.unsent_requests))
 
-    def send_requests(self):
+    async def get_certificate(self):
-        '''Sends queued requests.  Returns False on failure.'''
+        sslc = ssl.SSLContext()
-        self.last_send = time.time()
-        make_dict = lambda m, p, i: {'method': m, 'params': p, 'id': i}
-        n = self.num_requests()
-        wire_requests = self.unsent_requests[0:n]
         try:
-            self.pipe.send_all([make_dict(*r) for r in wire_requests])
+            async with aiorpcx.ClientSession(self.host, self.port, ssl=sslc) as session:
-        except BaseException as e:
+                return session.transport._ssl_protocol._sslpipe._sslobj.getpeercert(True)
-            self.print_error("pipe send error:", e)
+        except ValueError:
-            return False
+            return None
-        self.unsent_requests = self.unsent_requests[n:]
+
-        for request in wire_requests:
+    async def open_session(self, sslc, do_sleep=True, execute_after_connect=lambda: None):
-            if self.debug:
+        async with aiorpcx.ClientSession(self.host, self.port, ssl=sslc) as session:
-                self.print_error("-->", request)
+            ver = await session.send_request('server.version', [ELECTRUM_VERSION, PROTOCOL_VERSION])
-            self.unanswered_requests[request[2]] = request
+            print(ver)
-        return True
+            connect_hook_executed = False
-
+            while do_sleep:
-    def ping_required(self):
+                if not connect_hook_executed:
-        '''Returns True if a ping should be sent.'''
+                    connect_hook_executed = True
-        return time.time() - self.last_send > 300
+                    execute_after_connect()
+                await asyncio.wait_for(session.send_request('server.ping'), 5)
+                await asyncio.sleep(300)
 
     def has_timed_out(self):
-        '''Returns True if the interface has timed out.'''
+        return self.fut.done()
-        if (self.unanswered_requests and time.time() - self.request_time > 10
-            and self.pipe.idle_time() > 10):
-            self.print_error("timeout", len(self.unanswered_requests))
-            return True
 
-        return False
+    def queue_request(self, method, params, msg_id):
-
+        pass
-    def get_responses(self):
-        '''Call if there is data available on the socket.  Returns a list of
-        (request, response) pairs.  Notifications are singleton
-        unsolicited responses presumably as a result of prior
-        subscriptions, so request is None and there is no 'id' member.
-        Otherwise it is a response, which has an 'id' member and a
-        corresponding request.  If the connection was closed remotely
-        or the remote server is misbehaving, a (None, None) will appear.
-        '''
-        responses = []
-        while True:
-            try:
-                response = self.pipe.get()
-            except util.timeout:
-                break
-            if not type(response) is dict:
-                responses.append((None, None))
-                if response is None:
-                    self.closed_remotely = True
-                    self.print_error("connection closed remotely")
-                break
-            if self.debug:
-                self.print_error("<--", response)
-            wire_id = response.get('id', None)
-            if wire_id is None:  # Notification
-                responses.append((None, response))
-            else:
-                request = self.unanswered_requests.pop(wire_id, None)
-                if request:
-                    responses.append((request, response))
-                else:
-                    self.print_error("unknown wire ID", wire_id)
-                    responses.append((None, None)) # Signal
-                    break
-
-        return responses
 
+    def close(self):
+        self.fut.cancel()
 
 def check_cert(host, cert):
     try:

electrum/network.py

@@ -47,38 +47,14 @@ from . import blockchain
 from .version import ELECTRUM_VERSION, PROTOCOL_VERSION
 from .i18n import _
 from .blockchain import InvalidHeader
+from .interface import Interface
 
-import aiorpcx, asyncio, ssl
+import asyncio
 import concurrent.futures
 
 NODES_RETRY_INTERVAL = 60
 SERVER_RETRY_INTERVAL = 10
 
-class Interface(PrintError):
-    @util.aiosafe
-    async def run(self):
-        self.host, self.port, self.protocol = self.server.split(':')
-        sslc = ssl.SSLContext(ssl.PROTOCOL_TLS) if self.protocol == 's' else None
-        async with aiorpcx.ClientSession(self.host, self.port, ssl=sslc) as session:
-            ver = await session.send_request('server.version', [ELECTRUM_VERSION, PROTOCOL_VERSION])
-            print(ver)
-            while True:
-                print("sleeping")
-                await asyncio.sleep(1)
-
-    def __init__(self, server):
-        self.exception = None
-        self.server = server
-        self.fut = asyncio.get_event_loop().create_task(self.run())
-
-    def has_timed_out(self):
-        return self.fut.done()
-
-    def queue_request(self, method, params, msg_id):
-        pass
-
-    def close(self):
-        self.fut.cancel()
 
 def parse_servers(result):
     """ parse servers list into dict format"""
@@ -539,7 +515,7 @@ class Network(PrintError):
             self.close_interface(self.interface)
         assert self.interface is None
         assert not self.interfaces
-        self.connecting = set()
+        self.connecting.clear()
         # Get a new queue - no old pending connections thanks!
         self.socket_queue = queue.Queue()
 
@@ -810,7 +786,7 @@ class Network(PrintError):
     def new_interface(self, server):
         # todo: get tip first, then decide which checkpoint to use.
         self.add_recent_server(server)
-        interface = Interface(server)
+        interface = Interface(server, self.config.path, self.connecting)
         interface.blockchain = None
         interface.tip_header = None
         interface.tip = 0
@@ -1368,9 +1344,12 @@ class Network(PrintError):
             for k, i in self.interfaces.items():
                 if i.has_timed_out():
                     remove.append(k)
+            changed = False
             for k in remove:
                 self.connection_down(k)
+                changed = True
             for i in range(self.num_server - len(self.interfaces)):
                 self.start_random_interface()
-            self.notify('updated')
+                changed = True
+            if changed: self.notify('updated')
             await asyncio.sleep(1)