bug#14128: web/http.scm: bad-header date check (UTC?)
Hi, I was doing a test using gnutls and connecting to twitter api services. Example attached. I successfully passed the TLS/SSL part, but then I got this HTTP bad header issue. I am running Guile 2.0.5 from Debian/unstable but current stable-2.0 branch also suffers from the safe problem (I think). = 184: 1 [read-header #input-output: gnutls-session-port 2e94c30] 754: 0 [parse-asctime-date Wed, 03 Apr 2013 07:29:49 UTC] web/http.scm:754:6: In procedure parse-asctime-date: web/http.scm:754:6: Throw to key `bad-header' with args `(date Wed, 03 Apr 2013 07:29:49 UTC)'. = Basically, the problem is that web/http.scm only accepts a GMT suffix and the twitter server sends UTC. I think the RFC 822 standard accepts UT instead of UTC, so it would be wrong as well. Really, not sure what's the right way to fix this considering that even the twitter server does not send a correct day (as far as I understood the RFC). Thanks, Aleix twitter-user-timeline.scm Description: Binary data
bug#14128: web/http.scm: bad-header date check (UTC?)
On 3 April 2013 15:59, Aleix Conchillo Flaqué aconchi...@gmail.com wrote: Hi, I was doing a test using gnutls and connecting to twitter api services. Example attached. I successfully passed the TLS/SSL part, but then I got this HTTP bad header issue. I am running Guile 2.0.5 from Debian/unstable but current stable-2.0 branch also suffers from the safe problem (I think). = 184: 1 [read-header #input-output: gnutls-session-port 2e94c30] 754: 0 [parse-asctime-date Wed, 03 Apr 2013 07:29:49 UTC] web/http.scm:754:6: In procedure parse-asctime-date: web/http.scm:754:6: Throw to key `bad-header' with args `(date Wed, 03 Apr 2013 07:29:49 UTC)'. = Basically, the problem is that web/http.scm only accepts a GMT suffix and the twitter server sends UTC. I think the RFC 822 standard accepts UT instead of UTC, so it would be wrong as well. RFC 2616 _requires_ http date values have a suffix of GMT, other time zone values are not valid. RFC 822 has no relevance. Some times you see these “API” or “web services” breaking HTTP spec. in various ways and claiming “well we are not HTTP just very-HTTP-like” but that is not useful for people trying to interact. Turns out there are a few broken http servers around. 2616 recommends to convert non-GMT date values to GMT where such conversion is unambiguous, and in Guile we have done this a bit. Apparently we are supposed to do this a bit more and accomodate yet another non-compliant service? Erk. What is the point of defining protocols and standards then?
bug#14128: web/http.scm: bad-header date check (UTC?)
() Daniel Hartwig mand...@gmail.com () Wed, 3 Apr 2013 17:47:01 +0800 Apparently we are supposed to do this a bit more and accomodate yet another non-compliant service? Maybe that stuff should be exposed to the user. Do a best effort conversion and if not successful, return a pair ‘(raw-string . STRING)’ or whatever -- it's enough that it has a different type and that the type is documented. This way, you avoid carrying forward lots of cruft. Do it now before it's too late! Erk. What is the point of defining protocols and standards then? One purpose is to challenge programmers to learn how and when to say no. -- Thien-Thi Nguyen GPG key: 4C807502 pgp8YeIY0NhOd.pgp Description: PGP signature
bug#14128: web/http.scm: bad-header date check (UTC?)
On 3 April 2013 18:33, Thien-Thi Nguyen t...@gnuvola.org wrote: () Daniel Hartwig mand...@gmail.com () Wed, 3 Apr 2013 17:47:01 +0800 Apparently we are supposed to do this a bit more and accomodate yet another non-compliant service? Maybe that stuff should be exposed to the user. Do a best effort conversion and if not successful, return a pair ‘(raw-string . STRING)’ or whatever -- it's enough that it has a different type and that the type is documented. This way, you avoid carrying forward lots of cruft. Do it now before it's too late! Interesting. Though this does gradually erode the type barrier erected by the web module. I am reluctant to cede this territory. Instead of this cruft accumulating in a few places (the web modules), it becomes gratutiously spread around and duplicated in other programs. It was previously suggested to implement a permissive flag that, while not passing unparsed data to the users, will at least not raise errors and stop. Erk. What is the point of defining protocols and standards then? One purpose is to challenge programmers to learn how and when to say no. :-)
bug#14128: web/http.scm: bad-header date check (UTC?)
Daniel Hartwig mand...@gmail.com skribis: RFC 2616 _requires_ http date values have a suffix of GMT What about adding an exception for “UTC”? :-) It’s the same timezone, only with a different name, so it shouldn’t cost us much. WDYT? Ludo’.
bug#14128: web/http.scm: bad-header date check (UTC?)
On Wed, Apr 3, 2013 at 5:34 AM, Ludovic Courtès l...@gnu.org wrote: Daniel Hartwig mand...@gmail.com skribis: RFC 2616 _requires_ http date values have a suffix of GMT What about adding an exception for “UTC”? :-) It’s the same timezone, only with a different name, so it shouldn’t cost us much. WDYT? This is what I did locally so I could continue testing. But unfortunately, it's is very likely that there are more broken servers around. The permissive flag seems like an all-or-nothing, so I think Thien-Thi's suggestion sounds pretty reasonable: for all headers checks, give a default but let user specify their owns (if I understood that correctly). In my case I would just provide a #t for the date check. Best, Aleix
bug#14128: web/http.scm: bad-header date check (UTC?)
On Wed, Apr 3, 2013 at 7:57 AM, Aleix Conchillo Flaqué aconchi...@gmail.com wrote: This is what I did locally so I could continue testing. But unfortunately, it's is very likely that there are more broken servers around. The permissive flag seems like an all-or-nothing, so I think Thien-Thi's suggestion sounds pretty reasonable: for all headers checks, give a default but let user specify their owns (if I understood that correctly). In my case I would just provide a #t for the date check. I have to add, that it might be also true that you end up with all checks returning true, to make every server happy. So, all in all, I am a bit confused, may be the permissive flag is not that bad. The user could still read the headers after that, right? And decide whether they are good or bad. Aleix
