Re: [Cryptography] Why is emailing me my password?
On 10/01/2013 11:36 PM, R. Hirschfeld wrote: Your objections are understandable but aren't really an issue with mailman because if you don't enter a password then mailman will choose one for you (which I always let it do) and there's no need to remember it because if you ever need it (a rare occasion!) and don't happen to have a monthly password reminder to hand, clicking the link at the bottom of each list message will take you to a page where you can have it mailed to you. Mailman choosing a random password for you is certainly better, yes. And closer to the email based OTP solution. It's still a permanent password, though. By definition, a single interception suffices for an attacker to be able to (ab)use it until you modify it. As opposed to the mail based OTP scheme. And the monthly reminder essentially makes an interception even more likely. Granted, the worst an attacker can do with an intercepted password (permanent or OTP) is just a tad annoying - given it's not used elsewhere. The real danger is that those who don't read the instructions might enter a password that they use elsewhere and want to keep secure. Agreed. It's opposed to good practice and common sense of password handling. Regards Markus Wanner ___ The cryptography mailing list cryptography@metzdowd.com http://www.metzdowd.com/mailman/listinfo/cryptography
Re: [Cryptography] Why is emailing me my password?
On 10/02/2013 12:11 AM, Joshua Marpet wrote: Low security environment, minimal ability to inflict damage, clear instructions from the beginning. Agreed. There certainly are bigger problems on earth. And I really don't mind if you move on and take care of any of those, first. :-) If the system and processes are not to your liking, that's understandable. Everyone is different. Please read my arguments, I'm not opposed to it based on personal preference. Quite the opposite, I actually like web front-ends better than email commands. But in this case, I think a mail based OTP solution is better from a security perspective. There are other choices. If you'd like to investigate them, determine an appropriate one, and advocate a move to it, that would be welcomed, I presume? I did investigate. And I'm currently using smartlist. Whether or not you or anybody else moves is entirely up to you or them. If you use mailman, your users better be aware it doesn't follow best practice regarding password handling, though. And yes, smartlist certainly has its issues as well. If you know of any, please let me know as well. No offense meant, in any way. Please forgive me if offense is given. No offense taken. And if it were, you're hereby forgiven. ;-) Regards Markus Wanner ___ The cryptography mailing list cryptography@metzdowd.com http://www.metzdowd.com/mailman/listinfo/cryptography
Re: [Cryptography] Why is emailing me my password?
On 10/02/2013 12:03 AM, Greg wrote: Running a mailing list is not hard work. There are only so many things one can fuck up. This is probably one of the biggest mistakes that can be made in running a mailing list, and on a list that's about software security. It's just ridiculous. While I agree in principle, I don't quite like the tone here. But I liked your password, though. ;-) And no: there certainly are bigger mistakes an admin of a mailing list can do. Think: members list, spam, etc.. A mailing list shouldn't have any passwords to begin with. There is no need for passwords, and it shouldn't be possible for anyone to unsubscribe anyone else. User: Unsubscribe [EMAIL] - Server Server: Are you sure? - [EMAIL] User@[EMAIL]: YES! - Server. No passwords, and no fake unsubscribes. For that to be as secure as you make it sound, you still need a password or token. Hopefully a one-time, randomly generated one, but it's still a password. And it still crosses the wires unencrypted and can thus be intercepted by a MITM. The gain of that approach really is that there's no danger of a user inadvertently revealing a valuable password. The limited life time of the OTP may also make it a tad harder for an attacker, but given the (absence of) value for an attacker, that's close to irrelevant. Regards Markus Wanner ___ The cryptography mailing list cryptography@metzdowd.com http://www.metzdowd.com/mailman/listinfo/cryptography
Re: [Cryptography] Why is emailing me my password?
On 10/02/2013 04:32 PM, Greg wrote: I agree, I apologize for the excessively negative tone. I think RL (and unrelated) agitation affected my writing and word choice. I've taken steps to prevent that from happening again (via magic of self-censoring software). Cool. :-) I don't see why a one-time-password is necessary. Just check the headers to verify that the send-path was the same as it was on the original request. Hm.. that's a nice idea, but I don't think it can work reliably. What if the send path changes in between? AFAIK there are legitimate reasons for that, like load balancers or weird greylisting setups. Plus: why should that part of the header be more trustworthy than any other part? Granted, at least the last IP is added by a trusted server. But doesn't that boil down to IP-based authentication? I'm not saying it's impossible, I just don't think it's as good as a one-time token. Do you know of a mailing list software implementing such a thing? Regards Markus Wanner signature.asc Description: OpenPGP digital signature ___ The cryptography mailing list cryptography@metzdowd.com http://www.metzdowd.com/mailman/listinfo/cryptography
Re: [Cryptography] Why is emailing me my password?
On 10/01/2013 06:56 PM, Benjamin Kreuter wrote: 2. The password is sent just in case you forgot it and want to unsubscribe. Without the password, any troll might unsubscribe you from the list by simply forging headers. Were this to be encrypted, you would wind up with the classic problem of lost private keys, leaving people who forgot their password unable to unsubscribe (at least in any automated fashion). Agreed, that's a good point against PKI in this case. However, why use a password at all? I'd also argue it gives a false sense of security. For that very reason I prefer mailing list software that works via email (rather than web interface) and authenticates by the ability to receive mails under the given email. Forging headers doesn't quite suffice there, either. Regards Markus Wanner ___ The cryptography mailing list cryptography@metzdowd.com http://www.metzdowd.com/mailman/listinfo/cryptography
Re: [Cryptography] Why is emailing me my password?
On 10/01/2013 10:26 PM, Kelly John Rose wrote: I think that's absurd to say that it gives a false sense of security. It only gives a sense of security if you didn't read the text when you entered the password in the first place. Well, that applies to at least 90% of people for 90% the cases. Yes, often enough including myself. It keeps people from doing mass unsubscribes trivially. As I pointed out, there are other ways to achieve that, without the need for a password. Or actually rather with one-time passwords, instead. If someone was targeting you, yes, they would be able to delete your subscription, Sure. That's the case either way. but that would likely be true with little effort to begin with if you are of the type that doesn't read that your password is stored insecurely and sent in plain text when you enter it. Let's compare apples to apples: even if you manage to actually read the instructions, you actually have to do so, have to come up with a throw-away-password, and remember it. For no additional safety compared to one-time tokens. The positive point I see for the web front-end is that people are more used to it. And have a hard time reading instructions on emails and hitting reply to send back a confirmation token. But your hypothesis is that people do read instructions, so... Regards Markus Wanner ___ The cryptography mailing list cryptography@metzdowd.com http://www.metzdowd.com/mailman/listinfo/cryptography
