PyLint cleanups; implement connection_willSendRequestForAuthenticationChallenge_ delegate method since it replaces two other method depreacted in 10.10 (connection_canAuthenticateAgainstProtectionSpace_, connection_didReceiveAuthenticationChallenge_)

2026-05-05 03:49:22 -05:00 · 2014-10-26 08:37:27 -07:00
parent a3f137da33
commit c80b9a1041
1 changed files with 168 additions and 59 deletions
@@ -23,23 +23,25 @@ curl replacement using NSURLConnection and friends
 """

 import os
-import sys
 import xattr

+# PyLint cannot properly find names inside Cocoa libraries, so issues bogus
+# No name 'Foo' in module 'Bar' warnings. Disable them.
+# pylint: disable=E0611
 from Foundation import NSRunLoop, NSDate
 from Foundation import NSObject, NSURL, NSURLConnection
 from Foundation import NSMutableURLRequest
 from Foundation import NSURLRequestReloadIgnoringLocalCacheData
 from Foundation import NSURLResponseUnknownLength
 from Foundation import NSLog
-from Foundation import NSString, NSUTF8StringEncoding
 from Foundation import NSURLCredential, NSURLCredentialPersistenceNone
+from Foundation import NSPropertyListSerialization
+from Foundation import NSPropertyListMutableContainersAndLeaves
+from Foundation import NSPropertyListXMLFormat_v1_0
+# pylint: enable=E0611

-from Foundation import NSData, \
-                       NSPropertyListSerialization, \
-                       NSPropertyListMutableContainersAndLeaves, \
-                       NSPropertyListXMLFormat_v1_0
-
+# Disable PyLint complaining about 'invalid' names
+# pylint: disable=C0103

 ssl_error_codes = {
    -9800: u'SSL protocol error',
@@ -98,9 +100,17 @@ class Gurl(NSObject):
    '''A class for getting content from a URL
       using NSURLConnection and friends'''

+    # since we inherit from NSObject, PyLint issues a few bogus warnings
+    # pylint: disable=W0232,E1002
+
+    # Don't want to define the attributes twice that are initialized in
+    # initWithOptions_(), so:
+    # pylint: disable=E1101,W0201
+
    GURL_XATTR = 'com.googlecode.munki.downloadData'

    def initWithOptions_(self, options):
+        '''Set up our Gurl object'''
        self = super(Gurl, self).init()
        if not self:
            return
@@ -113,10 +123,10 @@ class Gurl(NSObject):
        self.username = options.get('username')
        self.password = options.get('password')
        self.download_only_if_changed = options.get(
-                                            'download_only_if_changed', False)
+            'download_only_if_changed', False)
        self.cache_data = options.get('cache_data')
        self.connection_timeout = options.get('connection_timeout', 10)
-        
+
        self.log = options.get('logging_function', NSLog)

        self.resume = False
@@ -135,6 +145,7 @@ class Gurl(NSObject):
        return self

    def start(self):
+        '''Start the connection'''
        if not self.destination_path:
            self.log('No output file specified.')
            self.done = True
@@ -142,7 +153,7 @@ class Gurl(NSObject):
        url = NSURL.URLWithString_(self.url)
        request = (
            NSMutableURLRequest.requestWithURL_cachePolicy_timeoutInterval_(
-                url, NSURLRequestReloadIgnoringLocalCacheData, 
+                url, NSURLRequestReloadIgnoringLocalCacheData,
                self.connection_timeout))
        if self.additional_headers:
            for header, value in self.additional_headers.items():
@@ -150,8 +161,8 @@ class Gurl(NSObject):
        # does the file already exist? See if we can resume a partial download
        if os.path.isfile(self.destination_path):
            stored_data = self.get_stored_headers()
-            if (self.can_resume and 'expected-length' in stored_data
-                and ('last-modified' in stored_data or 'etag' in stored_data)):
+            if (self.can_resume and 'expected-length' in stored_data and
+                    ('last-modified' in stored_data or 'etag' in stored_data)):
                # we have a partial file and we're allowed to resume
                self.resume = True
                local_filesize = os.path.getsize(self.destination_path)
@@ -166,14 +177,17 @@ class Gurl(NSObject):
                request.setValue_forHTTPHeaderField_(
                    stored_data['etag'], 'if-none-match')
        self.connection = NSURLConnection.alloc().initWithRequest_delegate_(
-                            request, self)
+            request, self)

    def cancel(self):
+        '''Cancel the connection'''
        if self.connection:
            self.connection.cancel()
            self.done = True

    def isDone(self):
+        '''Check if the connection request is complete. As a side effect,
+        allow the delegates to work my letting the run loop run for a bit'''
        if self.done:
            return self.done
        # let the delegates do their thing
@@ -192,8 +206,8 @@ class Gurl(NSObject):
        data = buffer(stored_plist_str)
        dataObject, plistFormat, error = (
            NSPropertyListSerialization.
-                propertyListFromData_mutabilityOption_format_errorDescription_(
-                    data, NSPropertyListMutableContainersAndLeaves, None, None))
+            propertyListFromData_mutabilityOption_format_errorDescription_(
+                data, NSPropertyListMutableContainersAndLeaves, None, None))
        if error:
            return {}
        else:
@@ -203,8 +217,8 @@ class Gurl(NSObject):
        '''Store dictionary data as an xattr for self.destination_path'''
        plistData, error = (
            NSPropertyListSerialization.
-                dataFromPropertyList_format_errorDescription_(
-                    headers, NSPropertyListXMLFormat_v1_0, None))
+            dataFromPropertyList_format_errorDescription_(
+                headers, NSPropertyListXMLFormat_v1_0, None))
        if error:
            string = ''
        else:
@@ -212,20 +226,29 @@ class Gurl(NSObject):
        try:
            xattr.setxattr(self.destination_path, self.GURL_XATTR, string)
        except IOError, err:
-            self.log('Could not store metadata to %s: %s' % 
-                (self.destination_path, err))
-            pass
+            self.log('Could not store metadata to %s: %s'
+                     % (self.destination_path, err))

    def normalize_header_dict(self, a_dict):
        '''Since HTTP header names are not case-sensitive, we normalize a
        dictionary of HTTP headers by converting all the key names to
        lower case'''
+
+        # yes, we don't use 'self'!
+        # pylint: disable=R0201
+
        new_dict = {}
        for key, value in a_dict.items():
            new_dict[key.lower()] = value
        return new_dict

    def connection_didFailWithError_(self, connection, error):
+        '''NSURLConnection delegate method
+        Sent when a connection fails to load its request successfully.'''
+
+        # we don't actually use the connection argument, so
+        # pylint: disable=W0613
+
        self.error = error
        # If this was an SSL error, try to extract the SSL error code.
        if 'NSUnderlyingError' in error.userInfo():
@@ -240,6 +263,12 @@ class Gurl(NSObject):
            # delete it? Might not want to...

    def connectionDidFinishLoading_(self, connection):
+        '''NSURLConnectionDataDelegat delegate method
+        Sent when a connection has finished loading successfully.'''
+
+        # we don't actually use the connection argument, so
+        # pylint: disable=W0613
+
        self.done = True
        if self.destination and self.destination_path:
            self.destination.close()
@@ -251,6 +280,10 @@ class Gurl(NSObject):
                self.store_headers(headers)

    def connection_didReceiveResponse_(self, connection, response):
+        '''NSURLConnectionDataDelegate delegate method
+        Sent when the connection has received sufficient data to construct the
+        URL response for its request.'''
+
        self.response = response
        self.bytesReceived = 0
        self.percentComplete = -1
@@ -264,20 +297,23 @@ class Gurl(NSObject):
            normalized_headers = self.normalize_header_dict(self.headers)
            if 'last-modified' in normalized_headers:
                download_data['last-modified'] = normalized_headers[
-                                                            'last-modified']
+                    'last-modified']
            if 'etag' in normalized_headers:
                download_data['etag'] = normalized_headers['etag']
            download_data['expected-length'] = self.expectedLength

+        # self.destination is defined in initWithOptions_
+        # pylint: disable=E0203
+
        if not self.destination and self.destination_path:
            if self.status == 206 and self.resume:
                # 206 is Partial Content response
                stored_data = self.get_stored_headers()
-                if (not stored_data
-                    or stored_data.get('etag') != download_data.get('etag')
-                    or stored_data.get('last-modified') != download_data.get(
-                                                            'last-modified')):
-                    # file on server is different than the one 
+                if (not stored_data or
+                        stored_data.get('etag') != download_data.get('etag') or
+                        stored_data.get('last-modified') != download_data.get(
+                            'last-modified')):
+                    # file on server is different than the one
                    # we have a partial for
                    self.log(
                        'Can\'t resume download; file on server has changed.')
@@ -298,7 +334,7 @@ class Gurl(NSObject):
                self.expectedLength += local_filesize
                # open file for append
                self.destination = open(self.destination_path, 'a')
-                
+
            elif str(self.status).startswith('2'):
                # not resuming, just open the file for writing
                self.destination = open(self.destination_path, 'w')
@@ -308,7 +344,14 @@ class Gurl(NSObject):
                self.store_headers(download_data)

    def connection_willSendRequest_redirectResponse_(
-                                        self, connection, request, response):
+            self, connection, request, response):
+        '''NSURLConnectionDataDelegate delegate method
+        Sent when the connection determines that it must change URLs in order to
+        continue loading a request.'''
+
+        # we don't actually use the connection argument, so
+        # pylint: disable=W0613
+
        if response == None:
            # This isn't a real redirect, this is without talking to a server.
            # Pass it back as-is
@@ -328,29 +371,17 @@ class Gurl(NSObject):
            self.log('Denying redirect to: %s' % newURL)
            return None

-    def connection_canAuthenticateAgainstProtectionSpace_(
-                                            self, connection, protectionSpace):
-        # this is not called in 10.5.x.
-        self.log('connection_canAuthenticateAgainstProtectionSpace_')
-        if protectionSpace:
-            host = protectionSpace.host()
-            realm = protectionSpace.realm()
-            authenticationMethod = protectionSpace.authenticationMethod()
-            self.log('Protection space found. Host: %s Realm: %s AuthMethod: %s'
-                  % (host, realm, authenticationMethod))
-            if self.username and self.password and authenticationMethod in [
-                'NSURLAuthenticationMethodDefault', 
-                'NSURLAuthenticationMethodHTTPBasic', 
-                'NSURLAuthenticationMethodHTTPDigest']:
-                # we know how to handle this
-                self.log('Can handle this authentication request')
-                return True
-        # we don't know how to handle this; let the OS try
-        self.log('Allowing OS to handle authentication request')
-        return False
+    def connection_willSendRequestForAuthenticationChallenge_(
+            self, connection, challenge):
+        '''NSURLConnection delegate method
+        Tells the delegate that the connection will send a request for an
+        authentication challenge.
+        New in 10.7.'''

-    def connection_didReceiveAuthenticationChallenge_(
-                                                self, connection, challenge):
+        # we don't actually use the connection argument, so
+        # pylint: disable=W0613
+
+        self.log('connection_willSendRequestForAuthenticationChallenge_')
        protectionSpace = challenge.protectionSpace()
        host = protectionSpace.host()
        realm = protectionSpace.realm()
@@ -363,25 +394,103 @@ class Gurl(NSObject):
            self.log('Previous authentication attempt failed.')
            challenge.sender().cancelAuthenticationChallenge_(challenge)
        if self.username and self.password and authenticationMethod in [
-            'NSURLAuthenticationMethodDefault',
-            'NSURLAuthenticationMethodHTTPBasic',
-            'NSURLAuthenticationMethodHTTPDigest']:
+                'NSURLAuthenticationMethodDefault',
+                'NSURLAuthenticationMethodHTTPBasic',
+                'NSURLAuthenticationMethodHTTPDigest']:
            self.log('Will attempt to authenticate.')
-            self.log('Username: %s Password: %s' 
-                  % (self.username, ('*' * len(self.password or ''))))
+            self.log('Username: %s Password: %s'
+                     % (self.username, ('*' * len(self.password or ''))))
            credential = (
                NSURLCredential.credentialWithUser_password_persistence_(
-                self.username, self.password, NSURLCredentialPersistenceNone))
+                    self.username, self.password,
+                    NSURLCredentialPersistenceNone))
            challenge.sender().useCredential_forAuthenticationChallenge_(
-                                                        credential, challenge)
+                credential, challenge)
+        else:
+            # fall back to system-provided default behavior
+            self.log('Allowing OS to handle authentication request')
+            challenge.sender(
+                ).performDefaultHandlingForAuthenticationChallenge_(
+                    challenge)
+
+    def connection_canAuthenticateAgainstProtectionSpace_(
+            self, connection, protectionSpace):
+        '''NSURLConnection delegate method
+        Sent to determine whether the delegate is able to respond to a
+        protection space’s form of authentication.
+        Deprecated in 10.10'''
+
+        # we don't actually use the connection argument, so
+        # pylint: disable=W0613
+
+        # this is not called in 10.5.x.
+        self.log('connection_canAuthenticateAgainstProtectionSpace_')
+        if protectionSpace:
+            host = protectionSpace.host()
+            realm = protectionSpace.realm()
+            authenticationMethod = protectionSpace.authenticationMethod()
+            self.log('Protection space found. Host: %s Realm: %s AuthMethod: %s'
+                     % (host, realm, authenticationMethod))
+            if self.username and self.password and authenticationMethod in [
+                    'NSURLAuthenticationMethodDefault',
+                    'NSURLAuthenticationMethodHTTPBasic',
+                    'NSURLAuthenticationMethodHTTPDigest']:
+                # we know how to handle this
+                self.log('Can handle this authentication request')
+                return True
+        # we don't know how to handle this; let the OS try
+        self.log('Allowing OS to handle authentication request')
+        return False
+
+    def connection_didReceiveAuthenticationChallenge_(
+            self, connection, challenge):
+        '''NSURLConnection delegate method
+        Sent when a connection must authenticate a challenge in order to
+        download its request.
+        Deprecated in 10.10'''
+
+        # we don't actually use the connection argument, so
+        # pylint: disable=W0613
+
+        self.log('connection_didReceiveAuthenticationChallenge_')
+        protectionSpace = challenge.protectionSpace()
+        host = protectionSpace.host()
+        realm = protectionSpace.realm()
+        authenticationMethod = protectionSpace.authenticationMethod()
+        self.log(
+            'Authentication challenge for Host: %s Realm: %s AuthMethod: %s'
+            % (host, realm, authenticationMethod))
+        if challenge.previousFailureCount() > 0:
+            # we have the wrong credentials. just fail
+            self.log('Previous authentication attempt failed.')
+            challenge.sender().cancelAuthenticationChallenge_(challenge)
+        if self.username and self.password and authenticationMethod in [
+                'NSURLAuthenticationMethodDefault',
+                'NSURLAuthenticationMethodHTTPBasic',
+                'NSURLAuthenticationMethodHTTPDigest']:
+            self.log('Will attempt to authenticate.')
+            self.log('Username: %s Password: %s'
+                     % (self.username, ('*' * len(self.password or ''))))
+            credential = (
+                NSURLCredential.credentialWithUser_password_persistence_(
+                    self.username, self.password,
+                    NSURLCredentialPersistenceNone))
+            challenge.sender().useCredential_forAuthenticationChallenge_(
+                credential, challenge)
        else:
            # fall back to system-provided default behavior
            self.log('Continuing without credential.')
            challenge.sender(
                ).continueWithoutCredentialForAuthenticationChallenge_(
-                                                                    challenge)
+                    challenge)

    def connection_didReceiveData_(self, connection, data):
+        '''NSURLConnectionDataDelegate method
+        Sent as a connection loads data incrementally'''
+
+        # we don't actually use the connection argument, so
+        # pylint: disable=W0613
+
        if self.destination:
            self.destination.write(str(data))
        else:
@@ -389,4 +498,4 @@ class Gurl(NSObject):
        self.bytesReceived += len(data)
        if self.expectedLength != NSURLResponseUnknownLength:
            self.percentComplete = int(
-                float(self.bytesReceived)/float(self.expectedLength) * 100.0)
+                float(self.bytesReceived)/float(self.expectedLength) * 100.0)