Implement http://bugs.python.org/issue10155 using And Clover's patch, w/added
docs and support for more client-generated CGI variables. (This should
complete the WSGI 1.0.1 compliance changes for Python 3.x.)
diff --git a/Lib/wsgiref/handlers.py b/Lib/wsgiref/handlers.py
index 3e11219..6d6f80f 100644
--- a/Lib/wsgiref/handlers.py
+++ b/Lib/wsgiref/handlers.py
@@ -5,7 +5,10 @@
import sys, os, time
-__all__ = ['BaseHandler', 'SimpleHandler', 'BaseCGIHandler', 'CGIHandler']
+__all__ = [
+ 'BaseHandler', 'SimpleHandler', 'BaseCGIHandler', 'CGIHandler',
+ 'IISCGIHandler', 'read_environ'
+]
# Weekday and month names for HTTP date/time formatting; always English!
_weekdayname = ["Mon", "Tue", "Wed", "Thu", "Fri", "Sat", "Sun"]
@@ -19,6 +22,74 @@
_weekdayname[wd], day, _monthname[month], year, hh, mm, ss
)
+_is_request = {
+ 'SCRIPT_NAME', 'PATH_INFO', 'QUERY_STRING', 'REQUEST_METHOD', 'AUTH_TYPE',
+ 'CONTENT_TYPE', 'CONTENT_LENGTH', 'HTTPS', 'REMOTE_USER', 'REMOTE_IDENT',
+}.__contains__
+
+def _needs_transcode(k):
+ return _is_request(k) or k.startswith('HTTP_') or k.startswith('SSL_') \
+ or (k.startswith('REDIRECT_') and _needs_transcode(k[9:]))
+
+def read_environ():
+ """Read environment, fixing HTTP variables"""
+ enc = sys.getfilesystemencoding()
+ esc = 'surrogateescape'
+ try:
+ ''.encode('utf-8', esc)
+ except LookupError:
+ esc = 'replace'
+ environ = {}
+
+ # Take the basic environment from native-unicode os.environ. Attempt to
+ # fix up the variables that come from the HTTP request to compensate for
+ # the bytes->unicode decoding step that will already have taken place.
+ for k, v in os.environ.items():
+ if _needs_transcode(k):
+
+ # On win32, the os.environ is natively Unicode. Different servers
+ # decode the request bytes using different encodings.
+ if sys.platform == 'win32':
+ software = os.environ.get('SERVER_SOFTWARE', '').lower()
+
+ # On IIS, the HTTP request will be decoded as UTF-8 as long
+ # as the input is a valid UTF-8 sequence. Otherwise it is
+ # decoded using the system code page (mbcs), with no way to
+ # detect this has happened. Because UTF-8 is the more likely
+ # encoding, and mbcs is inherently unreliable (an mbcs string
+ # that happens to be valid UTF-8 will not be decoded as mbcs)
+ # always recreate the original bytes as UTF-8.
+ if software.startswith('microsoft-iis/'):
+ v = v.encode('utf-8').decode('iso-8859-1')
+
+ # Apache mod_cgi writes bytes-as-unicode (as if ISO-8859-1) direct
+ # to the Unicode environ. No modification needed.
+ elif software.startswith('apache/'):
+ pass
+
+ # Python 3's http.server.CGIHTTPRequestHandler decodes
+ # using the urllib.unquote default of UTF-8, amongst other
+ # issues.
+ elif (
+ software.startswith('simplehttp/')
+ and 'python/3' in software
+ ):
+ v = v.encode('utf-8').decode('iso-8859-1')
+
+ # For other servers, guess that they have written bytes to
+ # the environ using stdio byte-oriented interfaces, ending up
+ # with the system code page.
+ else:
+ v = v.encode(enc, 'replace').decode('iso-8859-1')
+
+ # Recover bytes from unicode environ, using surrogate escapes
+ # where available (Python 3.1+).
+ else:
+ v = v.encode(enc, esc).decode('iso-8859-1')
+
+ environ[k] = v
+ return environ
+
class BaseHandler:
"""Manage the invocation of a WSGI application"""
@@ -36,7 +107,7 @@
# os_environ is used to supply configuration from the OS environment:
# by default it's a copy of 'os.environ' as of import time, but you can
# override this in e.g. your __init__ method.
- os_environ = dict(os.environ.items())
+ os_environ= read_environ()
# Collaborator classes
wsgi_file_wrapper = FileWrapper # set to None to disable
@@ -431,6 +502,42 @@
def __init__(self):
BaseCGIHandler.__init__(
- self, sys.stdin, sys.stdout, sys.stderr, dict(os.environ.items()),
- multithread=False, multiprocess=True
+ self, sys.stdin.buffer, sys.stdout.buffer, sys.stderr,
+ read_environ(), multithread=False, multiprocess=True
+ )
+
+
+class IISCGIHandler(BaseCGIHandler):
+ """CGI-based invocation with workaround for IIS path bug
+
+ This handler should be used in preference to CGIHandler when deploying on
+ Microsoft IIS without having set the config allowPathInfo option (IIS>=7)
+ or metabase allowPathInfoForScriptMappings (IIS<7).
+ """
+ wsgi_run_once = True
+ os_environ = {}
+
+ # By default, IIS gives a PATH_INFO that duplicates the SCRIPT_NAME at
+ # the front, causing problems for WSGI applications that wish to implement
+ # routing. This handler strips any such duplicated path.
+
+ # IIS can be configured to pass the correct PATH_INFO, but this causes
+ # another bug where PATH_TRANSLATED is wrong. Luckily this variable is
+ # rarely used and is not guaranteed by WSGI. On IIS<7, though, the
+ # setting can only be made on a vhost level, affecting all other script
+ # mappings, many of which break when exposed to the PATH_TRANSLATED bug.
+ # For this reason IIS<7 is almost never deployed with the fix. (Even IIS7
+ # rarely uses it because there is still no UI for it.)
+
+ # There is no way for CGI code to tell whether the option was set, so a
+ # separate handler class is provided.
+ def __init__(self):
+ environ= read_environ()
+ path = environ.get('PATH_INFO', '')
+ script = environ.get('SCRIPT_NAME', '')
+ if (path+'/').startswith(script+'/'):
+ environ['PATH_INFO'] = path[len(script):]
+ BaseCGIHandler.__init__(
+ self, sys.stdin.buffer, sys.stdout.buffer, sys.stderr,
+ environ, multithread=False, multiprocess=True
)