5 ms·

+1. If he's paying $1000 so he can personally witness how something like this works, rather than reading about it, it's a fine learning experience. I'll total

+1. If he's paying $1000 so he can personally witness how something like this works, rather than reading about it, it's a fine learning experience. I'll totally back away if he tries to make this into a product.

tptacek 13y ago
He's not paying. He contacted Moxie Marlinspike privately, and then Moxie posted on Twitter saying he wasn't paying. So he's not only wrong, but also a weasel. A WEASEL. I said it!
- danielweber 13y ago
  There is an extreme lack of detail here for me to come to that conclusion about another human being. Did Moxie think that his description of what he would do was sufficient? Adam offered to enter whatever environment was offered. Has Adam now refused to participate in that? Has he participated in that and Moxie broke it? If either of those has happened, I've seen nothing written about that on this HN page, on Moxie's blog, on Moxie's twitter feed, or on TFA. Maybe there is some big part of the discussion I'm not seeing. Maybe it's not worth Moxie's time. That is perfectly fine. There's lot of things that I could do but don't because they're not worth my time, but I don't get to say I did them.
  - absherwin 13y ago
    I truly appreciate your attitude. As you can imagine, having my integrity questioned is quite hurtful. So before I address, your point, thank you. Your comment means a lot to me. Moxie did provide a more detailed attack description. I had to correct an iptables command and modify sslstrip to alter the JS but otherwise his instructions were complete and correct. Per the original instructions, he should have had to configure the proxy but that's purely a function of who does that labor so I happily did the small amount of extra work. Once I completed the attack, I learned as I suspected from reading about sslstrip, the SSL certificate was removed. I thanked Moxie for his efforts and praised his work but informed him that it didn't meet the initial requirements. He argued that it works in the wild and that I could acquire appspot.cc and a certificate for that. I replied that if he wanted to conduct a convincing enough demo that I would be fooled into clicking, I'd consider that sufficiently close to being valid. Alternatively, he could produce an SSL certificat e that the browser would accept as valid for that domain. I agreed that a user in the wild might not be as cautious but that in agreeing to route my traffic through a malicious proxy, I recognized I was giving an attacker a significant advantage and that's why I made a valid SSL certificate a requirement in the initial post. He replied back that any LAN can be malicious so he disagrees with my assessment and that he didn't trust I wouldn't throw up more unreasonable objections and that I should pay. I replied outlining exactly how I would evaluate any alterations to the MITM he's proposing. It was at this time he posted to twitter. I heard about that and emailed him and he denied he was accusing of of dishonesty but only noting that I had declined to pay the reward tptacek thought he was owed. I remained concerned that it wouldn't be taken that way and unfortunately tptacek has proven my fears correct. In any event, I asked him if he believed his approach genuinely met the valid certificate requirement at this point because I wanted to assess whether he was he felt my rules were unfair or that I wasn't abiding by them. He declined to reply to that question.
    - tptacek 13y ago
      If it helps you understand the objection I have to this whole exercise: I think the whole contest was weaselly. You designed a challenge that stipulated away the simplest and most reasonable attacks on the system, and created an objective for the contest that would have been equally annoying to achieve had you used repeated-key XOR as your cipher instead of AES, and suggested in your promotion for the contest that its intent was to demonstrate something about cryptography. I think the commenter who parodied the exercise with a contest about a post-it on his computer hit the nail on the head. But, since I didn't take the contest seriously, I didn't take the time to verify that you'd actually set up your server properly. Moxie, on the other hand, did. If I put $1000 on the line, I might have taken the time to ensure that the SSL connectivity I had set up for my server actually worked. You didn't; you left a vulnerability on your server that any security audit of any SSL-only service would have flagged as "MUST FIX". Moxie not only flagged the vulnerability but explained it to you and provided exact steps to reproduce it for you. Here is is worth noting that $1000 probably does not buy enough of Moxie Marlinspike's time to compose the emails he seems to have sent you. Instead of conceding the point --- that, in setting up a contest that obviously depended on your SSL/TLS connectivity actually working, you had made a material error that made the contest easy to win --- you raised an arbitrary objection: the judge of the contest was permitted to take arbitrary steps to verify in exacting detail which SSL certificate was presented, at least on the first connection if not on subsequent connections (as you note, Moxie didn't get that far with you). The same objection would have worked if you'd used a self-signed certificate; Moxie would have said, "any MITM could interpose a new certificate" and you'd have said "oh, but I would check the fingerprint of the certificate against the certificate pinning list I maintain in my head". Here, for obvious reasons, Moxie gave up. Nobody cares about your money. The problem is that in "staking" $1000 on this contest, you've created a perception, exclusively among people who don't know much about cryptography, I'd add, that SJCL stapled to a web form is a viable mechanism for building a secure system (or at least, something more secure than just HTTPS). This perception is wrong, and it's aggravating that the $1000 gimmick reinforces it among precisely the people who most need to be made aware of how wrong it is. I don't think you're a dishonest person, in the sense of, "I would avoid doing business with you". I don't know you at all, and certainly not well enough to judge your character. I do think you've fallen victim to message- board- lawyering, something (uh) many of us have problems with, and are reluctant to concede any point that harms your argument. That, sorry to say, is weaselly behavior. If it helps you any to hear it, I'm sure someone could find someplace on HN where I too have been weaselly in debates.
- absherwin 13y ago
  I haven't paid anyone yet because no attack has yet met the conditions. As others have noted, a valid SSL certificate is required for this to work. Moxie suggested that I acquire a certificate for a similar domain to meet that requirement but that doesn't meet either the normal definition of valid (If a show requires a valid ticket to be shown at the entrance, will one from last night do?). He did claim that producing a forged certificate is possible and I have no reason to doubt him. However, he noted that he nor anyone else would produce one for a reward of this amount. We were still corresponding when he made the tweet in question. I ultimately asked him if he believed that a certificate to another domain was a valid certificate and his reply didn't address that point but discussed instead why he and tptacek are frustrated by these kind of contests. I'm sorry I seem to have offended you.
  - tptacek 13y ago
    You haven't offended me. You did however launch a "contest" to demonstrate the soundness of using browser Javascript cryptography to protect user secrets, and made exactly the kind of slip-up that trivially demonstrates what a bad idea browser JS crypto is: to wit, your application couldn't even protect its own pages, let alone use them to safely deliver crypto code; you provided an ambiguous address and didn't properly lock the server down to SSL, so you couldn't even rely on users getting to your app under SSL. Your app wouldn't have demonstrated any of the security value (largely nonexistent) of browser JS crypto even if it had been careful about SSL hygiene. But you spared Moxie the trouble of making that case. Somehow I doubt Moxie cares too much about the $1000, but: you screwed up, lost the contest, and then (from what I can see) weaseled. The real point isn't "pay Moxie $1000"; it's, "don't try to run contests like this".
    - lawnchair_larry 13y ago
      You can say it's a dumb contest, just like I will, but you can't say he weaseled. Unless you would like to first admit to a reading disability. It says, plainly, he wouldn't click unless there was a valid SSL cert. Do you know what sslstrip does? I know you do, so stop playing dumb. "I won't promise to log in if you can't provide a valid SSL certificate :)" Apologize to absherwin and admit you were wrong, or it is you who is the weasel.
- chetanahuja 13y ago
  Boy you need to calm down tptacek. Personal attacks on the OP based on a highly disputable claim (it's just a description of a possible attack that doesn't fulfill the original conditions in the first place) is a bit unseemly and makes you sound desperate to an extent.
  - tptacek 13y ago
    YOU'RE ALL WEASELS.
    - chetanahuja 13y ago
      Great. Keep it classy.
absherwin 13y ago
Thanks. This is an attempt at doing three things: 1. Learning more about the security risks of JavaScript 2. Facilitating a more create and nuanced discussion of its pros and cons 3. Learning about interacting with HN I failed at my second goal and while I've succeeded in the third it was in different way than anticipated. I also to reiterate that this isn't some backhanded attempt at a product launch. I would have hoped that my statements, using an appspot domain, no design and limited functionality would have made that clear.
- tptacek 13y ago
  For the record: at no point have I believed this contest was a surreptitious effort to market a product.

tptacek 13y ago

He's not paying. He contacted Moxie Marlinspike privately, and then Moxie posted on Twitter saying he wasn't paying. So he's not only wrong, but also a weasel. A WEASEL. I said it!

danielweber 13y ago
There is an extreme lack of detail here for me to come to that conclusion about another human being. Did Moxie think that his description of what he would do was sufficient? Adam offered to enter whatever environment was offered. Has Adam now refused to participate in that? Has he participated in that and Moxie broke it? If either of those has happened, I've seen nothing written about that on this HN page, on Moxie's blog, on Moxie's twitter feed, or on TFA. Maybe there is some big part of the discussion I'm not seeing. Maybe it's not worth Moxie's time. That is perfectly fine. There's lot of things that I could do but don't because they're not worth my time, but I don't get to say I did them.
- absherwin 13y ago
  I truly appreciate your attitude. As you can imagine, having my integrity questioned is quite hurtful. So before I address, your point, thank you. Your comment means a lot to me. Moxie did provide a more detailed attack description. I had to correct an iptables command and modify sslstrip to alter the JS but otherwise his instructions were complete and correct. Per the original instructions, he should have had to configure the proxy but that's purely a function of who does that labor so I happily did the small amount of extra work. Once I completed the attack, I learned as I suspected from reading about sslstrip, the SSL certificate was removed. I thanked Moxie for his efforts and praised his work but informed him that it didn't meet the initial requirements. He argued that it works in the wild and that I could acquire appspot.cc and a certificate for that. I replied that if he wanted to conduct a convincing enough demo that I would be fooled into clicking, I'd consider that sufficiently close to being valid. Alternatively, he could produce an SSL certificat e that the browser would accept as valid for that domain. I agreed that a user in the wild might not be as cautious but that in agreeing to route my traffic through a malicious proxy, I recognized I was giving an attacker a significant advantage and that's why I made a valid SSL certificate a requirement in the initial post. He replied back that any LAN can be malicious so he disagrees with my assessment and that he didn't trust I wouldn't throw up more unreasonable objections and that I should pay. I replied outlining exactly how I would evaluate any alterations to the MITM he's proposing. It was at this time he posted to twitter. I heard about that and emailed him and he denied he was accusing of of dishonesty but only noting that I had declined to pay the reward tptacek thought he was owed. I remained concerned that it wouldn't be taken that way and unfortunately tptacek has proven my fears correct. In any event, I asked him if he believed his approach genuinely met the valid certificate requirement at this point because I wanted to assess whether he was he felt my rules were unfair or that I wasn't abiding by them. He declined to reply to that question.
  - tptacek 13y ago
    If it helps you understand the objection I have to this whole exercise: I think the whole contest was weaselly. You designed a challenge that stipulated away the simplest and most reasonable attacks on the system, and created an objective for the contest that would have been equally annoying to achieve had you used repeated-key XOR as your cipher instead of AES, and suggested in your promotion for the contest that its intent was to demonstrate something about cryptography. I think the commenter who parodied the exercise with a contest about a post-it on his computer hit the nail on the head. But, since I didn't take the contest seriously, I didn't take the time to verify that you'd actually set up your server properly. Moxie, on the other hand, did. If I put $1000 on the line, I might have taken the time to ensure that the SSL connectivity I had set up for my server actually worked. You didn't; you left a vulnerability on your server that any security audit of any SSL-only service would have flagged as "MUST FIX". Moxie not only flagged the vulnerability but explained it to you and provided exact steps to reproduce it for you. Here is is worth noting that $1000 probably does not buy enough of Moxie Marlinspike's time to compose the emails he seems to have sent you. Instead of conceding the point --- that, in setting up a contest that obviously depended on your SSL/TLS connectivity actually working, you had made a material error that made the contest easy to win --- you raised an arbitrary objection: the judge of the contest was permitted to take arbitrary steps to verify in exacting detail which SSL certificate was presented, at least on the first connection if not on subsequent connections (as you note, Moxie didn't get that far with you). The same objection would have worked if you'd used a self-signed certificate; Moxie would have said, "any MITM could interpose a new certificate" and you'd have said "oh, but I would check the fingerprint of the certificate against the certificate pinning list I maintain in my head". Here, for obvious reasons, Moxie gave up. Nobody cares about your money. The problem is that in "staking" $1000 on this contest, you've created a perception, exclusively among people who don't know much about cryptography, I'd add, that SJCL stapled to a web form is a viable mechanism for building a secure system (or at least, something more secure than just HTTPS). This perception is wrong, and it's aggravating that the $1000 gimmick reinforces it among precisely the people who most need to be made aware of how wrong it is. I don't think you're a dishonest person, in the sense of, "I would avoid doing business with you". I don't know you at all, and certainly not well enough to judge your character. I do think you've fallen victim to message- board- lawyering, something (uh) many of us have problems with, and are reluctant to concede any point that harms your argument. That, sorry to say, is weaselly behavior. If it helps you any to hear it, I'm sure someone could find someplace on HN where I too have been weaselly in debates.
absherwin 13y ago
I haven't paid anyone yet because no attack has yet met the conditions. As others have noted, a valid SSL certificate is required for this to work. Moxie suggested that I acquire a certificate for a similar domain to meet that requirement but that doesn't meet either the normal definition of valid (If a show requires a valid ticket to be shown at the entrance, will one from last night do?). He did claim that producing a forged certificate is possible and I have no reason to doubt him. However, he noted that he nor anyone else would produce one for a reward of this amount. We were still corresponding when he made the tweet in question. I ultimately asked him if he believed that a certificate to another domain was a valid certificate and his reply didn't address that point but discussed instead why he and tptacek are frustrated by these kind of contests. I'm sorry I seem to have offended you.
- tptacek 13y ago
  You haven't offended me. You did however launch a "contest" to demonstrate the soundness of using browser Javascript cryptography to protect user secrets, and made exactly the kind of slip-up that trivially demonstrates what a bad idea browser JS crypto is: to wit, your application couldn't even protect its own pages, let alone use them to safely deliver crypto code; you provided an ambiguous address and didn't properly lock the server down to SSL, so you couldn't even rely on users getting to your app under SSL. Your app wouldn't have demonstrated any of the security value (largely nonexistent) of browser JS crypto even if it had been careful about SSL hygiene. But you spared Moxie the trouble of making that case. Somehow I doubt Moxie cares too much about the $1000, but: you screwed up, lost the contest, and then (from what I can see) weaseled. The real point isn't "pay Moxie $1000"; it's, "don't try to run contests like this".
  - lawnchair_larry 13y ago
    You can say it's a dumb contest, just like I will, but you can't say he weaseled. Unless you would like to first admit to a reading disability. It says, plainly, he wouldn't click unless there was a valid SSL cert. Do you know what sslstrip does? I know you do, so stop playing dumb. "I won't promise to log in if you can't provide a valid SSL certificate :)" Apologize to absherwin and admit you were wrong, or it is you who is the weasel.
chetanahuja 13y ago
Boy you need to calm down tptacek. Personal attacks on the OP based on a highly disputable claim (it's just a description of a possible attack that doesn't fulfill the original conditions in the first place) is a bit unseemly and makes you sound desperate to an extent.
- tptacek 13y ago
  YOU'RE ALL WEASELS.
  - chetanahuja 13y ago
    Great. Keep it classy.

absherwin 13y ago

Thanks. This is an attempt at doing three things: 1. Learning more about the security risks of JavaScript 2. Facilitating a more create and nuanced discussion of its pros and cons 3. Learning about interacting with HN I failed at my second goal and while I've succeeded in the third it was in different way than anticipated. I also to reiterate that this isn't some backhanded attempt at a product launch. I would have hoped that my statements, using an appspot domain, no design and limited functionality would have made that clear.

tptacek 13y ago
For the record: at no point have I believed this contest was a surreptitious effort to market a product.