Mercurial > p > roundup > code
diff roundup/cgi/client.py @ 6693:9a1f5e496e6c
issue2551203 - Add support for CORS preflight request
Add support for unauthenticated CORS preflight and fix headers for
CORS.
client.py:
pass through unauthenticated CORS preflight to rest backend. Normal
rest OPTION handlers (including tracker defined extensions) can
see and handle the request.
make some error cases return error json with crrect mime type rather
than plain text tracebacks.
create new functions to verify origin and referer that filter using
allowed origins setting.
remove tracker base url from error message is referer is not at an
allowed origin.
rest.py:
fix up OPTION methods handlers to include
Access-Control-Allow-Methods that are the same as the Allow
header.
set cache to one week for all Access-Control headers for CORS
preflight only.
remove self.client.setHeader("Access-Control-Allow-Origin", "*") and
set Access-Control-Allow-Origin to the client supplied origin if
it passes allowed origin checks. Required for CORS otherwise data
isn't available to caller. Set for all responses.
set Vary header now includes Origin as responses can differ based on
Origin for all responses.
set Access-Control-Allow-Credentials to true on all responses.
test_liveserver.py:
run server with setting to enforce origin csrf header check
run server with setting to enforce x-requested-with csrf header check
run server with setting for allowed_api_origins
requests now set required csrf headers
test preflight request on collections
check new headers and Origin is no longer '*'
rewrite all compression checks to use a single method with argument
to use different compression methods. Reduce a lot of code
duplication and makes updating for new headers easier.
test_cgi:
test new error messages in client.py
account for new headers
test preflight and new code paths
| author | John Rouillard <rouilj@ieee.org> |
|---|---|
| date | Tue, 07 Jun 2022 09:39:35 -0400 |
| parents | ab2ed11c021e |
| children | 6b636fb29740 |
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--- a/roundup/cgi/client.py Mon Jun 06 15:15:31 2022 -0400 +++ b/roundup/cgi/client.py Tue Jun 07 09:39:35 2022 -0400 @@ -620,7 +620,32 @@ self.write(output) return - if not self.db.security.hasPermission('Rest Access', self.userid): + # allow preflight request even if unauthenticated + if ( self.env['REQUEST_METHOD'] == "OPTIONS" + and self.request.headers.get ("Access-Control-Request-Headers") + and self.request.headers.get ("Access-Control-Request-Method") + and self.request.headers.get ("Origin") + ): + # verify Origin is allowed + if not self.is_origin_header_ok(api=True): + # Use code 400 as 401 and 403 imply that authentication + # is needed or authenticates person is not authorized. + # Preflight doesn't do authentication. + self.response_code = 400 + msg = self._("Client is not allowed to use Rest Interface.") + output = s2b( + '{ "error": { "status": 400, "msg": "%s" } }'%msg ) + self.setHeader("Content-Length", str(len(output))) + self.setHeader("Content-Type", "application/json") + self.write(output) + return + + # Call rest library to handle the pre-flight request + handler = rest.RestfulInstance(self, self.db) + output = handler.dispatch(self.env['REQUEST_METHOD'], + self.path, self.form) + + elif not self.db.security.hasPermission('Rest Access', self.userid): self.response_code = 403 output = s2b('{ "error": { "status": 403, "msg": "Forbidden." } }') self.setHeader("Content-Length", str(len(output))) @@ -636,14 +661,12 @@ # raises exception on check failure. csrf_ok = self.handle_csrf(api=True) except (Unauthorised, UsageError) as msg: - # report exception back to server - exc_type, exc_value, exc_tb = sys.exc_info() # FIXME should return what the client requests # via accept header. - output = s2b("%s: %s\n"%(exc_type, exc_value)) + output = s2b('{ "error": { "status": 400, "msg": "%s"}}'% str(msg)) self.response_code = 400 self.setHeader("Content-Length", str(len(output))) - self.setHeader("Content-Type", "text/plain") + self.setHeader("Content-Type", "application/json") self.write(output) csrf_ok = False # we had an error, failed check return @@ -1223,9 +1246,39 @@ # Original spec says origin is case sensitive match. # Living spec doesn't address Origin value's case or # how to compare it. So implement case sensitive.... - if allowed_origins[0] == '*' or origin in allowed_origins: + if allowed_origins: + if allowed_origins[0] == '*' or origin in allowed_origins: + return True + + return False + + def is_referer_header_ok(self, api=False): + referer = self.env['HTTP_REFERER'] + # parse referer and create an origin + referer_comp = urllib_.urlparse(referer) + + # self.base always has trailing /, so add trailing / to referer_origin + referer_origin = "%s://%s/"%(referer_comp[0], referer_comp[1]) + foundat = self.base.find(referer_origin) + if foundat == 0: return True + if not api: + return False + + allowed_origins = self.db.config['WEB_ALLOWED_API_ORIGINS'] + if allowed_origins[0] == '*': + return True + + # For referer, loop over allowed_api_origins and + # see if any of them are a prefix to referer, case sensitive. + # Append / to each origin so that: + # an allowed_origin of https://my.host does not match + # a referer of https://my.host.com/my/path + for allowed_origin in allowed_origins: + foundat = referer_origin.find(allowed_origin + '/') + if foundat == 0: + return True return False def handle_csrf(self, api=False): @@ -1335,13 +1388,11 @@ # self.base always matches: ^https?://hostname enforce=config['WEB_CSRF_ENFORCE_HEADER_REFERER'] if 'HTTP_REFERER' in self.env and enforce != "no": - referer = self.env['HTTP_REFERER'] - # self.base always has trailing / - foundat = referer.find(self.base) - if foundat != 0: + if not self.is_referer_header_ok(api=api): + referer = self.env['HTTP_REFERER'] if enforce in ('required', 'yes'): logger.error(self._("csrf Referer header check failed for user%s. Value=%s"), current_user, referer) - raise Unauthorised(self._("Invalid Referer %s, %s")%(referer,self.base)) + raise Unauthorised(self._("Invalid Referer: %s")%(referer)) elif enforce == 'logfailure': logger.warning(self._("csrf Referer header check failed for user%s. Value=%s"), current_user, referer) else: