Handle user:pass in URLs

Fixes "nonnumeric port" errors when youtube-dl is given URLs with
usernames and passwords such as:

    http://username:password@example.com/myvideo.mp4

Refs:
- https://en.wikipedia.org/wiki/Basic_access_authentication
- https://tools.ietf.org/html/rfc1738#section-3.1
- https://docs.python.org/3.8/library/urllib.parse.html#urllib.parse.urlsplit

Fixes ytdl-org#18276 (point 4)
Fixes ytdl-org#20258
Fixes ytdl-org#26211 (see comment)

test/test_utils.py

@@ -65,6 +65,8 @@
     sanitize_filename,
     sanitize_path,
     sanitize_url,
+    extract_user_pass,
+    sanitized_Request,
     expand_path,
     prepend_extension,
     replace_extension,
@@ -237,6 +239,26 @@ def test_sanitize_url(self):
         self.assertEqual(sanitize_url('rmtps://foo.bar'), 'rtmps://foo.bar')
         self.assertEqual(sanitize_url('https://foo.bar'), 'https://foo.bar')
 
+    def test_extract_user_pass(self):
+        self.assertEqual(extract_user_pass('http://foo.bar'), ('http://foo.bar', None, None))
+        self.assertEqual(extract_user_pass('http://:foo.bar'), ('http://:foo.bar', None, None))
+        self.assertEqual(extract_user_pass('http://@foo.bar'), ('http://foo.bar', '', ''))
+        self.assertEqual(extract_user_pass('http://:pass@foo.bar'), ('http://foo.bar', '', 'pass'))
+        self.assertEqual(extract_user_pass('http://user:@foo.bar'), ('http://foo.bar', 'user', ''))
+        self.assertEqual(extract_user_pass('http://user:pass@foo.bar'), ('http://foo.bar', 'user', 'pass'))
+
+    def test_sanitized_Request(self):
+        self.assertFalse(sanitized_Request('http://foo.bar').has_header('Authorization'))
+        self.assertFalse(sanitized_Request('http://:foo.bar').has_header('Authorization'))
+        self.assertEqual(sanitized_Request('http://@foo.bar').get_header('Authorization'),
+                         'Basic Og==')
+        self.assertEqual(sanitized_Request('http://:pass@foo.bar').get_header('Authorization'),
+                         'Basic OnBhc3M=')
+        self.assertEqual(sanitized_Request('http://user:@foo.bar').get_header('Authorization'),
+                         'Basic dXNlcjo=')
+        self.assertEqual(sanitized_Request('http://user:pass@foo.bar').get_header('Authorization'),
+                         'Basic dXNlcjpwYXNz')
+
     def test_expand_path(self):
         def env(var):
             return '%{0}%'.format(var) if sys.platform == 'win32' else '${0}'.format(var)

youtube_dl/utils.py

@@ -2154,8 +2154,32 @@ def sanitize_url(url):
     return url
 
 
+def extract_user_pass(url):
+    parts = compat_urlparse.urlsplit(url)
+    username = parts.username
+    password = parts.password
+    if username is not None:
+        if password is None:
+            password = ''
+        netloc = parts.hostname
+        if parts.port is not None:
+            netloc = parts.hostname + ':' + parts.port
+        parts = parts._replace(netloc=netloc)
+        url = compat_urlparse.urlunsplit(parts)
+    return url, username, password
+
+
 def sanitized_Request(url, *args, **kwargs):
-    return compat_urllib_request.Request(sanitize_url(url), *args, **kwargs)
+    url = sanitize_url(url)
+    url, username, password = extract_user_pass(url)
+    if username is not None:
+        # password is not None
+        auth_payload = username + ':' + password
+        auth_payload = base64.b64encode(auth_payload.encode('utf-8')).decode('utf-8')
+        auth_header = 'Basic ' + auth_payload
+        headers = args[1] if len(args) >= 2 else kwargs.setdefault('headers', {})
+        headers['Authorization'] = auth_header
+    return compat_urllib_request.Request(url, *args, **kwargs)
 
 
 def expand_path(s):