Thanks to everyone who has contributed feedback. This approach is what we are going to take. Alex will be making this change shortly. I will update this thread when there is timeframe to share.
Thanks, Doug On Mon, Jul 27, 2009 at 7:52 AM, TinBlue <[email protected]> wrote: > > What is happening? > > This rollback is taking far too long for something that has affected a > lot of people! > > On Jul 25, 2:32 pm, Dewald Pretorius <[email protected]> wrote: > > Doug, > > > > I would prefer to adopt OAuth instead of writing code for Basic Auth. > > > > So, you guys need to move OAuth out of public beta into full > > production sooner rather than later. :-) > > > > I manage 100,000+ Twitter accounts, and I simply cannot take on the > > support workload of answering user tickets when there's a snag with > > OAuth beta. > > > > I monitor these forums and the API Issues and still see too many OAuth > > issues being reported to give me a level of comfort that I can safely > > switch over to OAuth. > > > > On Jul 24, 5:46 pm, Doug Williams <[email protected]> wrote: > > > > > > > > > Well said Joshua. > > > > > Dewald, you have identified the risk of using basic authentication. If > > > your users being locked out due to malicious behavior, you should > > > either implement further user-level rate limiting on your side or > > > adopt OAuth. > > > > > Are there any other glaring omissions in our thinking or should we > > > proceed with this as our solution? > > > > > Thanks, > > > Doug > > > > > On Fri, Jul 24, 2009 at 11:08 AM, Joshua Perry<[email protected]> wrote: > > > > > > Jim's concern is valid, fortunately OAuth is immune to brute-force > attacks > > > > once the access key has been issued to an application. For this > reason alone > > > > I would urge people to switch to OAuth if at all possible. I would > hope > > > > (and assume) that if login attempts for an account are locked out > that a > > > > user would still be able to successfully use an already authorized > OAuth > > > > driven application. > > > > > > Unfortunately allowing a successful un/pw login while an account is > locked > > > > out even when the correct password is presented effectively bypasses > the > > > > whole reason for a lockout in the first place, preventing brute-force > > > > password attempts. If an attacker used a dictionary or brute-force > attack > > > > and the account was locked out after 15 attempts, then they could > continue > > > > trying even though the system replied "locked out"; if they > eventually sent > > > > the correct password it would just bypass the lockout and they would > then > > > > know the correct password. > > > > > > Perhaps Twitter could implement a selective captcha, I know they are > > > > annoying but if executed properly it could be effective protection > against > > > > brute-force and dictionary attacks. Say after 3 or 4 failed attempts > without > > > > a captch the API would then include a captcha image URL in it's > response > > > > that the application would then need to show to the person and > include the > > > > user's response with the next authentication attempt as a header or > POST > > > > variable. The site stackoverflow.com does this to great effect, if > you > > > > create posts quicker than a certain threshold which a person would > not > > > > exceed then they pop a captcha up, in the normal use of the site you > will > > > > never see one; I've only hit two captchas in the last in the last 8 > months > > > > using the site. > > > > > > Josh > > > > > > Dewald Pretorius wrote: > > > > > >> Jim raised a huge weakness with the authentication rate limiting > that > > > >> could essentially break third-party apps. > > > > > >> Anybody can try to add anybody else's Twitter account to a > third-party > > > >> app using an invalid password. If they do that 15 times with a > Twitter > > > >> account, the real owner of that Twitter account, who may have added > > > >> his account a long time ago with the correct password, is locked out > > > >> from using that app for an hour. > > > > > >> I believe you will absolutely have to reset / remove the lock as > soon > > > >> as the Twitter account uses the correct password. > > > > > >> On Jul 22, 4:58 pm, "jim.renkel" <[email protected]> wrote: > > > > > >>> My concern with this proposal is that it opens up denials of > service, > > > >>> not to twitter.com, but to "associated" sites such as twitpic, or > my > > > >>> site twxlate, among others > > > > > >>> For example, Lance Armstrong is a heavy user of twitpic. It is very > > > >>> easy for anyone to find Lance's twitter ID (@lancearmstrong), view > his > > > >>> status updates, and see that he is a frequent user of twitpic. Now, > > > >>> someone that is "unhappy" with Lance, say one of George Hincapie's > > > >>> ardent fans that really believes that Lance was a significant > > > >>> contributor to George not winning the maillot jeune last Sunday, > > > >>> could go to twitpic, fail to login as Lance the requisite number of > > > >>> times, and deny Lance access to twitpic. > > > > > >>> Not only celebrities would or could be subject to such denials of > > > >>> service. I notice that @dougw occasionally uses twitpic! :-) > > > > > >>> One solution to this problem is to add to each twitter account > another > > > >>> "private" ID. By default this private ID would be equal to the > > > >>> existing (public) ID (If not equal to the account's public ID, it > > > >>> would have to be unique among all twitter IDs, both public and > > > >>> private.). > > > > > >>> The public ID would be used just as the existing twitter ID is now: > > > >>> others would use it to follow, mention, DM, etc., the user. > > > > > >>> But the user MUST use their private ID for authenticated requests > > > >>> through the API, and CAN also use it for non-authenticated > requests. > > > >>> In either case, twitter would treat a request from a private ID as > if > > > >>> it came from the corresponding public ID. > > > > > >>> Blocking the public ID because of excessive authentication failures > > > >>> would NOT block the associated private ID unless they were equal. > > > >>> Changing your public ID would also change your private ID if the > two > > > >>> were the same before the change, i.e., they would remain the same > > > >>> after the change. > > > > > >>> It may seem onerous to require all users to also have a private ID, > > > >>> but since it defaults to be the same as their public ID, only those > > > >>> concerned about their service being denied would change it and > > > >>> subsequently use it instead of their public ID to access associated > > > >>> sites such as twitpic or twxlate. > > > > > >>> In fact, I think this change, though potentially large on the > twitter > > > >>> side, could be implemented without any changes to users or > associated > > > >>> sites, with one small, obscure exception: now, if I attempt to > create > > > >>> a new twitter account or change the ID of an existing account, and > > > >>> find that the ID I want is in use, I can view that account; if this > > > >>> were implemented and I attempted to use a private ID that was not > the > > > >>> same as its associated public ID, I could not view the account > using > > > >>> the denied ID. > > > > > >>> Comments expected and welcome. > > > > > >>> Jim Renkel > > > > > >>> On Jul 21, 6:00 pm, Doug Williams <[email protected]> wrote: > > > > > >>>> Devs --A change shipped last week that limited the number of times > a > > > >>>> user > > > >>>> could access the account/verify_credentials method [1] in a given > hour. > > > >>>> This > > > >>>> change proved hasty and short-sighted as pointed out by the > subsequent > > > >>>> discussion [2]. We apologize to any developer that was adversely > > > >>>> affected. Given the problems, we want to fix this in a > > > >>>> public and transparent manner. > > > >>>> Like most web services, we limit the number of attempts users can > make > > > >>>> to > > > >>>> login to > > > >>>> their accounts on Twitter.com to prevent brute force dictionary > > > >>>> attacks. This same security is not extended to the platform > > > >>>> and leaves accounts vulnerable to the same method of attack > through the > > > >>>> API. > > > >>>> The change we shipped to limit user accounts to 15 calls an > hour to > > > >>>> the > > > >>>> account/verify_credentials method [1] was intended to mitigate > this > > > >>>> risk. It > > > >>>> was thought to limit the number of tests a potential attack could > run in > > > >>>> the > > > >>>> hour, even in a distributed fashion. However, we only protected a > single > > > >>>> resource which still leaves all other authenticated methods > exposed as a > > > >>>> vector of attack (limited only by the API rate limit). > > > >>>> Our thinking is now that we will limit the total number of > > > >>>> unsuccessful > > > >>>> attempts to access authenticated resources to 15 an hour per user > per IP > > > >>>> address. If a single IP address makes 15 attempts to access a > protected > > > >>>> resource unsuccessfully for a given user (as indicated by an HTTP > 401), > > > >>>> then > > > >>>> the user will be locked out of authenticated resources from that > IP > > > >>>> address > > > >>>> for 1 hour. > > > >>>> This scheme has all of the positive effects that we need, > however > > > >>>> we want to > > > >>>> make sure that we have thought through all of the potential > problems on > > > >>>> the > > > >>>> developer's side before we proceed with this change. Please > contribute > > > >>>> to > > > >>>> the subsequent discussion if you have an opinion or concern. Once > we > > > >>>> come to > > > >>>> an agreement, we will update with details and a timeline for > shipping > > > >>>> this > > > >>>> update. > > > > > >>>> 1. > http://apiwiki.twitter.com/Twitter-REST-API-Method%3A-account%C2%A0ve... > > > > > >>>> 2. > http://groups.google.com/group/twitter-development-talk/browse_thread... > > > >>>> Regards, > > > >>>> Doug >
