cvs commit: httpd-python/Doc modpython4.tex

[gr...@apache.org]

grisha      2003/07/24 13:51:08

  Modified:    lib/python/mod_python Cookie.py
               Doc      modpython4.tex
  Log:
  The SignedCookie and MarshalCookie will now downgrade to plain
  Cookie if signature or unmarshal errors are encountered (intead of
  raising an exception). This is necessary because the browser may
  return "outside" cookies (e.g. set by mod_usertrack). As a side
  effect, it is important to check the type of object returned, which
  has been noted in the docs.
  
  Revision  Changes    Path
  1.7       +18 -8     httpd-python/lib/python/mod_python/Cookie.py
  
  Index: Cookie.py
  ===================================================================
  RCS file: /home/cvs/httpd-python/lib/python/mod_python/Cookie.py,v
  retrieving revision 1.6
  retrieving revision 1.7
  diff -u -r1.6 -r1.7
  --- Cookie.py	24 Jul 2003 19:00:46 -0000	1.6
  +++ Cookie.py	24 Jul 2003 20:51:08 -0000	1.7
  @@ -210,12 +210,17 @@
       is still plainly visible as part of the cookie.
       """
   
  -    def parse(Class, secret, str):
  +    def parse(Class, secret, s):
   
  -        dict = _parseCookie(str, Class)
  +        dict = _parseCookie(s, Class)
   
           for k in dict:
  -            dict[k].unsign(secret)
  +            c = dict[k]
  +            try:
  +                c.unsign(secret)
  +            except CookieError:
  +                # downgrade to Cookie
  +                dict[k] = Cookie.parse(Cookie.__str__(c))[k]
           
           return dict
   
  @@ -276,13 +281,18 @@
       http://groups.google.com/groups?hl=en&lr=&ie=UTF-8&selm=7xn0hcugmy.fsf%40ruckus.brouhaha.com
       """
   
  -    def parse(Class, secret, str):
  +    def parse(Class, secret, s):
   
  -        dict = _parseCookie(str, Class)
  +        dict = _parseCookie(s, Class)
   
           for k in dict:
  -            dict[k].unmarshal(secret)
  -        
  +            c = dict[k]
  +            try:
  +                c.unmarshal(secret)
  +            except (CookieError, ValueError):
  +                # downgrade to Cookie
  +                dict[k] = Cookie.parse(Cookie.__str__(c))[k]
  +
           return dict
   
       parse = classmethod(parse)
  
  
  
  1.40      +27 -16    httpd-python/Doc/modpython4.tex
  
  Index: modpython4.tex
  ===================================================================
  RCS file: /home/cvs/httpd-python/Doc/modpython4.tex,v
  retrieving revision 1.39
  retrieving revision 1.40
  diff -u -r1.39 -r1.40
  --- modpython4.tex	24 Jul 2003 19:00:46 -0000	1.39
  +++ modpython4.tex	24 Jul 2003 20:51:08 -0000	1.40
  @@ -1575,16 +1575,27 @@
   
   \begin{classdesc}{SignedCookie}{name, value, secret\optional{, attributes}}
   
  -  This is a subclass of \class{Cookie}.
  +  This is a subclass of \class{Cookie}. This class creates cookies
  +  whose name and value are automatically signed using HMAC (md5) with
  +  a provided secret \var{secret}, which must be a non-empty string.
   
  -  This class creates cookies whose name and value are automatically
  -  signed using HMAC (md5) with a provided secret \var{secret}, which must be
  -  a non-empty string.
  -
  -  \begin{methoddesc}[Cookie]{parse}{string}{secret}
  +  \begin{methoddesc}[SignedCookie]{parse}{string, secret}
       This method acts the same way as \class{Cookie.parse()}, but also
       verifies that the cookie is correctly signed. If the signature
  -    cannot be verified, a \exception{CookieError} is raised.
  +    cannot be verified, the object returned will be of class
  +    \class{Cookie}.
  +
  +    \begin{notice}
  +      Always check the type of the object returned by
  +      \method{SignedCookie.parse()} is an instance of \class{Cookie}
  +      (as oppsed to \class{SignedCookie}), the signature verification
  +      failed:
  +      \begin{verbatim}
  +# assume spam is supposed to be a signed cookie
  +if type(spam) is not Cookie.SignedCookie:
  +    # do something that indicates cookie isn't signed correctly
  +      \end{verbatim}
  +    \end{notice}
     \end{methoddesc}
   
   \end{classdesc}
  @@ -1647,7 +1658,7 @@
   
   \end{verbatim}
   
  -This example checks for incoming marshal cookie and displays it the
  +This example checks for incoming marshal cookie and displays it to the
   client. If no incoming cookie is present a new marshal cookie is set.
   This example uses \samp{secret007} as the secret for HMAC signature.
   
  @@ -1656,19 +1667,19 @@
   
   def handler(req):
       
  -    try:
  -        cookies = Cookie.getCookie(req, Cookie.MarshalCookie, \
  +    cookies = Cookie.getCookie(req, Cookie.MarshalCookie, \
                                      'secret007')
  -    except Cookie.CookieError:
  -        req.write('Cookie parsing error!\n')
  -	return apache.OK
  -
       if cookies.has_key('spam'):
           spamcookie = cookies['spam']
  +
           req.write('Great, a spam cookie was found: %s\n' \
                                         % str(spamcookie))
  -        req.write('Here is what it looks like decoded: %s=%s\n'
  -                  % (spamcookie.name, spamcookie.value))
  +        if type(spamcookie) is Cookie.MarshalCookie:
  +            req.write('Here is what it looks like decoded: %s=%s\n'
  +                      % (spamcookie.name, spamcookie.value))
  +	else:
  +            req.write('WARNING: The cookie found is not a \
  +                       MarshalCookie, it may have been tapered with!')
   
       else: