Mercurial > p > roundup > code
view roundup/cgi/exceptions.py @ 5201:a9ace22e0a2f
issue 2550690 - Adding anti-csrf measures to roundup following
https://www.owasp.org/index.php/Cross-Site_Request_Forgery_(CSRF)_Prevention_Cheat_Sheet
and
https://seclab.stanford.edu/websec/csrf/csrf.pdf
Basically implement Synchronizer (CSRF) Tokens per form on a page.
Single use (destroyed once used). Random input data for the token
includes:
system random implementation in python using /dev/urandom
(fallback to random based on timestamp as the seed. Not
as good, but should be ok for the short lifetime of the
token??)
the id (in cpython it's the memory address) of the object
requesting a token. In theory this depends on memory layout, the
history of the process (how many previous objects have been
allocated from the heap etc.) I claim without any proof that for
long running processes this is another source of randomness. For
short running processes with little activity it could be guessed.
last the floating point time.time() value is added. This may
only have 1 second resolution so may be guessable.
Hopefully for a short lived (2 week by default) token this is
sufficient. Also in the current implementation the user is notified when
validation fails and is told why. This allows the roundup admin to find
the log entry (at error level) and try to resolve the issue. In the
future user notification may change but for now this is probably best.
| author | John Rouillard <rouilj@ieee.org> |
|---|---|
| date | Sat, 18 Mar 2017 16:59:01 -0400 |
| parents | 65fef7858606 |
| children | 32f95ec6bd8e |
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"""Exceptions for use in Roundup's web interface. """ __docformat__ = 'restructuredtext' from roundup.exceptions import LoginError, Unauthorised import cgi class HTTPException(Exception): pass class Redirect(HTTPException): pass class NotFound(HTTPException): pass class NotModified(HTTPException): pass class DetectorError(Exception): """Raised when a detector throws an exception. Contains details of the exception.""" def __init__(self, subject, html, txt): self.subject = subject self.html = html self.txt = txt class FormError(ValueError): """An 'expected' exception occurred during form parsing. That is, something we know can go wrong, and don't want to alarm the user with. We trap this at the user interface level and feed back a nice error to the user. """ pass class SendFile(Exception): """Send a file from the database.""" class SendStaticFile(Exception): """Send a static file from the instance html directory.""" class SeriousError(Exception): """Raised when we can't reasonably display an error message on a templated page. The exception value will be displayed in the error page, HTML escaped. """ def __str__(self): return """ <html><head><title>Roundup issue tracker: An error has occurred</title> <link rel="stylesheet" type="text/css" href="@@file/style.css"> </head> <body class="body" marginwidth="0" marginheight="0"> <p class="error-message">%s</p> </body></html> """%cgi.escape(self.args[0]) # vim: set filetype=python sts=4 sw=4 et si :
