split up interface.run

electrum/interface.py

@@ -122,49 +122,67 @@ class Interface(PrintError):
             return False
         return True
 
-    @aiosafe
+    async def _try_saving_ssl_cert_for_first_time(self, ca_ssl_context):
-    async def run(self):
+        try:
-        if self.protocol != 's':
+            ca_signed = await self.is_server_ca_signed(ca_ssl_context)
-            await self.open_session(None, exit_early=False)
+        except (ConnectionRefusedError, socket.gaierror, aiorpcx.socks.SOCKSFailure) as e:
-            assert False
+            self.print_error('disconnecting due to: {}'.format(e))
+            self.exception = e
+            return False
+        if ca_signed:
+            with open(self.cert_path, 'w') as f:
+                # empty file means this is CA signed, not self-signed
+                f.write('')
+        else:
+            await self.save_certificate()
+        return True
 
-        ca_sslc = ssl.create_default_context(ssl.Purpose.SERVER_AUTH)
+    def _is_saved_ssl_cert_available(self):
-        exists = os.path.exists(self.cert_path)
+        if not os.path.exists(self.cert_path):
-        if exists:
+            return False
         with open(self.cert_path, 'r') as f:
             contents = f.read()
-            if contents != '': # if not CA signed
+        if contents == '':  # CA signed
+            return True
+        # pinned self-signed cert
         try:
             b = pem.dePem(contents, 'CERTIFICATE')
         except SyntaxError:
-                    exists = False
+            self.print_error("error parsing already saved cert:", e)
-                else:
+            return False
+        try:
             x = x509.X509(b)
+        except Exception as e:
+            self.print_error("error parsing already saved cert:", e)
+            return False
         try:
             x.check_date()
+            return True
         except x509.CertificateError as e:
-                        self.print_error("certificate problem", e)
+            self.print_error("certificate has expired:", e)
             os.unlink(self.cert_path)
-                        exists = False
+            return False
-        if not exists:
+
-            try:
+    @aiosafe
-                ca_signed = await self.is_server_ca_signed(ca_sslc)
+    async def run(self):
-            except (ConnectionRefusedError, socket.gaierror, aiorpcx.socks.SOCKSFailure) as e:
+        if self.protocol != 's':
-                self.print_error('disconnecting due to: {}'.format(e))
+            await self.open_session(None, exit_early=False)
-                self.exception = e
+            assert False
+
+        ca_sslc = ssl.create_default_context(ssl.Purpose.SERVER_AUTH)
+        if not self._is_saved_ssl_cert_available():
+            done_saving_cert = await self._try_saving_ssl_cert_for_first_time(ca_sslc)
+            if not done_saving_cert:
                 return
-            if ca_signed:
-                with open(self.cert_path, 'w') as f:
-                    # empty file means this is CA signed, not self-signed
-                    f.write('')
-            else:
-                await self.save_certificate()
         siz = os.stat(self.cert_path).st_size
-        if siz == 0: # if CA signed
+        if siz == 0:
+            # CA signed cert
             sslc = ca_sslc
         else:
+            # pinned self-signed cert
             sslc = ssl.create_default_context(ssl.Purpose.SERVER_AUTH, cafile=self.cert_path)
             sslc.check_hostname = 0
+        # start main connection
         try:
             await self.open_session(sslc, exit_early=False)
         except (asyncio.CancelledError, ConnectionRefusedError, socket.gaierror,