| Message ID | xmqqed82cgmj.fsf@gitster.g (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 4f5822076f41d13258f82bd2ff7bde2630a611a0 |
| Headers | show |
| Series | [PATCH/RFC] http.c: cookie file tightening | expand |
On Tue, Jul 09, 2024 at 04:03:48PM -0700, Junio C Hamano wrote: > The manual pages https://curl.se/libcurl/c/CURLOPT_COOKIEFILE.html > and https://curl.se/libcurl/c/CURLOPT_COOKIEJAR.html talk about two > interesting special values. > > * "" (an empty string) given to CURLOPT_COOKIEFILE means not to > read cookies from any file upon startup. > > * It is not specified what "" (an empty string) given to > CURLOPT_COOKIEJAR does; presumably open a file whose name is an > empty string and write cookies to it? In any case, that is not > what we want to see happen, ever. > > * "-" (a dash) given to CURLOPT_COOKIEFILE makes cURL read cookies > from the standard input, and given to CURLOPT_COOKIEJAR makes > cURL write cookies to the standard output. Neither of which we > want ever to happen. > > So, let's make sure we avoid these nonsense cases. Specifically, > when http.cookies is set to "-", ignore it with a warning, and when > it is set to "" and http.savecookies is set, ignore http.savecookies > with a warning. > > [...] > > * I have no confidence in me doing http correctly, so I am asking > from folks who have touched http.c in the past 6 months for help. I don't have any experience with any of the cookie options, but your explanation here all makes sense. It might be worth including a test, though the interesting part is probably how things broke _before_ this patch. After it, it's pretty obvious what should happen. So I'll try to comment from the general http.c perspective. > diff --git c/http.c w/http.c > index 13fa94bef3..86ccca49f0 100644 > --- c/http.c > +++ w/http.c > @@ -1466,7 +1466,16 @@ struct active_request_slot *get_active_slot(void) > slot->finished = NULL; > slot->callback_data = NULL; > slot->callback_func = NULL; > + > + if (curl_cookie_file && !strcmp(curl_cookie_file, "-")) { > + warning(_("refusing to read cookies from http.cookiefile '-'")); > + FREE_AND_NULL(curl_cookie_file); > + } > curl_easy_setopt(slot->curl, CURLOPT_COOKIEFILE, curl_cookie_file); > + if (curl_save_cookies && (!curl_cookie_file || !curl_cookie_file[0])) { > + curl_save_cookies = 0; > + warning(_("ignoring http.savecookies for empty http.cookiefile")); > + } > if (curl_save_cookies) > curl_easy_setopt(slot->curl, CURLOPT_COOKIEJAR, curl_cookie_file); This all looks OK to me. A few things I wondered while reading: - is curl_cookie_file always an allocated string? The answer is yes, because it comes from git_config_pathname(). Good. - get_active_slot() will be called a lot of times, as we reuse the curl handles over and over (the "slot" terminology is due to the parallelism for dumb-http fetch; smart-http just reuses the one handle each time). So is this the best place to put the check? You actually unset the options when issuing the warning, so we'd never see the warning multiple times, even if this code is run repeatedly. Good. I do suspect these curl_easy_setopt() calls for cookies could just go into get_curl_handle(), which sets up the handle initially. But it's possible there's some subtle reason why they're here, and certainly moving them is orthogonal to your goal. And in the meantime, putting your new checks alongside the use of the variables makes sense. -Peff
On 10.07.2024 01:49, Jeff King wrote: > On Tue, Jul 09, 2024 at 04:03:48PM -0700, Junio C Hamano wrote: > >> The manual pages https://curl.se/libcurl/c/CURLOPT_COOKIEFILE.html >> and https://curl.se/libcurl/c/CURLOPT_COOKIEJAR.html talk about two >> interesting special values. >> >> * "" (an empty string) given to CURLOPT_COOKIEFILE means not to >> read cookies from any file upon startup. >> >> * It is not specified what "" (an empty string) given to >> CURLOPT_COOKIEJAR does; presumably open a file whose name is an >> empty string and write cookies to it? In any case, that is not >> what we want to see happen, ever. >> >> * "-" (a dash) given to CURLOPT_COOKIEFILE makes cURL read cookies >> from the standard input, and given to CURLOPT_COOKIEJAR makes >> cURL write cookies to the standard output. Neither of which we >> want ever to happen. >> >> So, let's make sure we avoid these nonsense cases. Specifically, >> when http.cookies is set to "-", ignore it with a warning, and when >> it is set to "" and http.savecookies is set, ignore http.savecookies >> with a warning. >> >> [...] >> >> * I have no confidence in me doing http correctly, so I am asking >> from folks who have touched http.c in the past 6 months for help. > I don't have any experience with any of the cookie options, but your > explanation here all makes sense. It might be worth including a test, > though the interesting part is probably how things broke _before_ this > patch. After it, it's pretty obvious what should happen. > > So I'll try to comment from the general http.c perspective. Hello! I'm able to perform some checks as I have Git repository behind HAProxy load balancer which sets HTTP cookie to record which backend should process consecutive requests. Indeed, if http.cookieFile='-' is used, git stops and waits for input. It does *not* work even if I do: $ echo '/path/to/file' | git -c http.cookieFile='-' ... On the other hand there is no problem if http.cookieFile='' and http.saveCookies=true is used together. Git operation is successful. But if GIT_TRACE_CURL=1 GIT_TRACE_CURL_NO_DATA=1 is enabled, I can see following warning it the output: > 12:19:56.280263 http.c:820 == Info: WARNING: failed to save cookies in It comes from: https://github.com/curl/curl/blob/master/lib/cookie.c#L1758 But cookies were accepted by the client and sent back to the server. PS. I'm using Git 2.42.0. Regards!
Piotr Szlazak <piotr.szlazak@gmail.com> writes: > On the other hand there is no problem if http.cookieFile='' and > http.saveCookies=true is used together. Git operation is > successful. But if GIT_TRACE_CURL=1 GIT_TRACE_CURL_NO_DATA=1 is > enabled, I can see following warning it the output: >> 12:19:56.280263 http.c:820 == Info: WARNING: failed to save cookies in > It comes from: > https://github.com/curl/curl/blob/master/lib/cookie.c#L1758 > But cookies were accepted by the client and sent back to the server. Thanks for your experiments. I do not know if it is safe to call the above observed sympotom "there is no problem". What does it even mean to set cookieFile to an empty string and ask the cookies to be saved? What does the user who makes such a pair of requests [http] saveCookies = yes cookieFile = "" expect to happen? The session begins with an empty set of cookies, cookies that come from the other side are maintained in-core during the session, and then at the very end of the session what do they want to happen to their cookies? "The system will try to save them but without finding a sensible place to save, it gives a warning without molesting the main goal of the process (which is to interact with the other side)" sounds like a rather strange wish. I'd consider "The system notices that there is no sensible place to store, so it warns about the conflicting request and ignores http.saveCookies" a bit more sensible behaviour in such a situation, but obviously I am biased.
diff --git c/http.c w/http.c index 13fa94bef3..86ccca49f0 100644 --- c/http.c +++ w/http.c @@ -1466,7 +1466,16 @@ struct active_request_slot *get_active_slot(void) slot->finished = NULL; slot->callback_data = NULL; slot->callback_func = NULL; + + if (curl_cookie_file && !strcmp(curl_cookie_file, "-")) { + warning(_("refusing to read cookies from http.cookiefile '-'")); + FREE_AND_NULL(curl_cookie_file); + } curl_easy_setopt(slot->curl, CURLOPT_COOKIEFILE, curl_cookie_file); + if (curl_save_cookies && (!curl_cookie_file || !curl_cookie_file[0])) { + curl_save_cookies = 0; + warning(_("ignoring http.savecookies for empty http.cookiefile")); + } if (curl_save_cookies) curl_easy_setopt(slot->curl, CURLOPT_COOKIEJAR, curl_cookie_file); curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, pragma_header);
The http.cookiefile configuration variable is used to call curl_easy_setopt() to set CURLOPT_COOKIEFILE and if http.savecookies is set, the same value is used for CURLOPT_COOKIEJAR. The former is used only to read cookies at startup, the latter is used to write cookies at the end. The manual pages https://curl.se/libcurl/c/CURLOPT_COOKIEFILE.html and https://curl.se/libcurl/c/CURLOPT_COOKIEJAR.html talk about two interesting special values. * "" (an empty string) given to CURLOPT_COOKIEFILE means not to read cookies from any file upon startup. * It is not specified what "" (an empty string) given to CURLOPT_COOKIEJAR does; presumably open a file whose name is an empty string and write cookies to it? In any case, that is not what we want to see happen, ever. * "-" (a dash) given to CURLOPT_COOKIEFILE makes cURL read cookies from the standard input, and given to CURLOPT_COOKIEJAR makes cURL write cookies to the standard output. Neither of which we want ever to happen. So, let's make sure we avoid these nonsense cases. Specifically, when http.cookies is set to "-", ignore it with a warning, and when it is set to "" and http.savecookies is set, ignore http.savecookies with a warning. Signed-off-by: Junio C Hamano <gitster@pobox.com> --- * I have no confidence in me doing http correctly, so I am asking from folks who have touched http.c in the past 6 months for help. A proposed documentation update to talk about an empty string by Piotr, who is also on CC:, triggered this update. http.c | 9 +++++++++ 1 file changed, 9 insertions(+)