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1. This is not about being perfect, this is about being trustworthy or secure. Right now this is very dangerous to be promoting as even remotely private, as you

1. This is not about being perfect, this is about being trustworthy or secure. Right now this is very dangerous to be promoting as even remotely private, as you claim on both your website and twitter. This is no more secure than chatting over facebook. There is no 'clever solution' to get around crypto in the browser, it's always bad. 2. There is absolutely no point to using end-to-end crypto in this setup because it can all be intercepted. Not to mention there is no key verification, so even if you're JS wasn't interceptable it's still trivial to intercept messages. It's a red herring at best and at worst deceptive . 3. I stand corrected, although JS (regardless of whether it's in the browser or not) is usually considered terrible for crypto implementations because of it's math bugs. 4. You might want to check yourself, https://www.ssllabs.com/ssltest/analyze.html?d=www.cyph.com&s=104.28.19.46 https://www.ssllabs.com/ssltest/analyze.html?d=www.cyph.com&... you're pointed to cloudflare's SNI server. I think what you fail to understand is you're relying entirely on TLS for all of your security, which means a LOT of different people are able to read these messages. It's not just your CA that could be compromised to hack you, its ANY CA. So for example the chinese government decides they want to read everyone's messages, all they need to do is publish a cert with your domain. Or any of your staff. Or anyone at cloudflare. Or anyone with access to your server. Or access to your home computers which have login credentials.

buu700 12y ago
4) We're using CloudFlare to redirect our naked domain to www.cyph.com. Re: the rest, assuming the user trusts that we haven't served up malicious code (which, again, I acknowledge isn't completely trustless for now), I disagree that JS crypto is bad/useless. It definitely was bad/useless at one point in time, but with the introduction of the Web Crypto API I haven't seen a convincing argument that it's still strictly inferior to C/C++ crypto. (And, to be clear, Cyph will refuse to run in a browser without Web Crypto API support, e.g. any version of IE before 11.) I'd argue that a safe language like JavaScript running in as well-vetted a sandbox as in modern browsers has a lot of pretty favourable security properties (entire classes of exploits are impossible here, as opposed to in Pidgin/OTR whose implementation is known to be less than ideal for security[1]). 1: http://motherboard.vice.com/en_ca/read/secure-messaging-might-not-be-so-secure-otr-libpurple http://motherboard.vice.com/en_ca/read/secure-messaging-migh...
- upperechelon 12y ago
  4) So they can redirect all users to a non-HTTPS site. That's interesting. What youre saying is ridiculous, it's nothing to do with "completely" trustless, you're not trustworthy at all. The "we promise we wont serve malicious code" is the same securi Basically your users have to trust: -You -Your staff -Cloudflare -Google -Any computer used to design, build or login to your web app -Anyone with access to any of these computers -Every single CA in existence (including the US and Chinese government) -Anyone with resources to spoof a CA SHA-1 signature (anyone with ~$700,000 [0]) -The authors of the JS OTR library and any other code you use Do you see the problem here? There are literally millions of people in your trust chain. Libpurple sucks, but browsers are the #1 target for exploit writers, not to mention the HUGE attack surface they pose. There are just so many angles of attack for your service. Anything hosted on a shared server is not secure. The word cloud and security should not be in the same sentence. No offense, but you guys really do not seem like cryptography experts and there are so many pitfalls here that I would not recommend trying to promote this until you completely re-design everything. As far as WebCrypto.. I'm just going to leave this here: http://tonyarcieri.com/whats-wrong-with-webcrypto http://tonyarcieri.com/whats-wrong-with-webcrypto http://matasano.com/articles/javascript-cryptography/ http://matasano.com/articles/javascript-cryptography/ [0] https://www.schneier.com/blog/archives/2012/10/when_will_we_se.html https://www.schneier.com/blog/archives/2012/10/when_will_we_...
  - williamcotton 12y ago
    Oh, so an argument to authority? First off, that Matasano article was written before the Web Crypto API and is out of date. Second, Tony's article does make a good point... can you trust that the web site is going to be serving up code that won't spy on you? Well, can you trust that ANY code on any platform won't spy on you? People offer that Javascript doesn't have code-signing. Well, that's fucking bullshit. All that needs to happen is someone needs to just, sign all the checksums of the code served to the browser and publish it somewhere. You can then have a third-party site verify that the code is still what it says it is. Personally, I use this pattern internally. I run my server-side APIs on a different host than my static front-end code. My server-side API then checksums the front-end code and makes sure it is legit before proceeding in certain situations. Your arguments are weak and out of date.
wernerb 12y ago
Totally novice to security here, but curious to the answer. What if they keep cyph as it is with a warning that this is in browser javascript insecure. They can demo the functionality, then if people want to continue using it (more securely?) they provide a chrome extension to be installed which is sandboxed and maybe also the client-side code is published/signed with (for example) keybase by the developers for additional security improvements? On Cyph: Really dig the look and feel of the app, gorgeous! [0]: https://keybase.io/warp/warp_1.0.6_SHA256_e68d4587b0e2ec34a7b554fbd1ed2d0fedfaeacf3e47fbb6c5403e252348cbfc.html https://keybase.io/warp/warp_1.0.6_SHA256_e68d4587b0e2ec34a7...
- buu700 12y ago
  Thanks! This is our first step, but we have a lot more interesting things in the pipeline in terms of security features.

buu700 12y ago

4) We're using CloudFlare to redirect our naked domain to www.cyph.com. Re: the rest, assuming the user trusts that we haven't served up malicious code (which, again, I acknowledge isn't completely trustless for now), I disagree that JS crypto is bad/useless. It definitely was bad/useless at one point in time, but with the introduction of the Web Crypto API I haven't seen a convincing argument that it's still strictly inferior to C/C++ crypto. (And, to be clear, Cyph will refuse to run in a browser without Web Crypto API support, e.g. any version of IE before 11.) I'd argue that a safe language like JavaScript running in as well-vetted a sandbox as in modern browsers has a lot of pretty favourable security properties (entire classes of exploits are impossible here, as opposed to in Pidgin/OTR whose implementation is known to be less than ideal for security[1]). 1: http://motherboard.vice.com/en_ca/read/secure-messaging-might-not-be-so-secure-otr-libpurple http://motherboard.vice.com/en_ca/read/secure-messaging-migh...

upperechelon 12y ago
4) So they can redirect all users to a non-HTTPS site. That's interesting. What youre saying is ridiculous, it's nothing to do with "completely" trustless, you're not trustworthy at all. The "we promise we wont serve malicious code" is the same securi Basically your users have to trust: -You -Your staff -Cloudflare -Google -Any computer used to design, build or login to your web app -Anyone with access to any of these computers -Every single CA in existence (including the US and Chinese government) -Anyone with resources to spoof a CA SHA-1 signature (anyone with ~$700,000 [0]) -The authors of the JS OTR library and any other code you use Do you see the problem here? There are literally millions of people in your trust chain. Libpurple sucks, but browsers are the #1 target for exploit writers, not to mention the HUGE attack surface they pose. There are just so many angles of attack for your service. Anything hosted on a shared server is not secure. The word cloud and security should not be in the same sentence. No offense, but you guys really do not seem like cryptography experts and there are so many pitfalls here that I would not recommend trying to promote this until you completely re-design everything. As far as WebCrypto.. I'm just going to leave this here: http://tonyarcieri.com/whats-wrong-with-webcrypto http://tonyarcieri.com/whats-wrong-with-webcrypto http://matasano.com/articles/javascript-cryptography/ http://matasano.com/articles/javascript-cryptography/ [0] https://www.schneier.com/blog/archives/2012/10/when_will_we_se.html https://www.schneier.com/blog/archives/2012/10/when_will_we_...
- williamcotton 12y ago
  Oh, so an argument to authority? First off, that Matasano article was written before the Web Crypto API and is out of date. Second, Tony's article does make a good point... can you trust that the web site is going to be serving up code that won't spy on you? Well, can you trust that ANY code on any platform won't spy on you? People offer that Javascript doesn't have code-signing. Well, that's fucking bullshit. All that needs to happen is someone needs to just, sign all the checksums of the code served to the browser and publish it somewhere. You can then have a third-party site verify that the code is still what it says it is. Personally, I use this pattern internally. I run my server-side APIs on a different host than my static front-end code. My server-side API then checksums the front-end code and makes sure it is legit before proceeding in certain situations. Your arguments are weak and out of date.

wernerb 12y ago

Totally novice to security here, but curious to the answer. What if they keep cyph as it is with a warning that this is in browser javascript insecure. They can demo the functionality, then if people want to continue using it (more securely?) they provide a chrome extension to be installed which is sandboxed and maybe also the client-side code is published/signed with (for example) keybase by the developers for additional security improvements? On Cyph: Really dig the look and feel of the app, gorgeous! [0]: https://keybase.io/warp/warp_1.0.6_SHA256_e68d4587b0e2ec34a7b554fbd1ed2d0fedfaeacf3e47fbb6c5403e252348cbfc.html https://keybase.io/warp/warp_1.0.6_SHA256_e68d4587b0e2ec34a7...

buu700 12y ago
Thanks! This is our first step, but we have a lot more interesting things in the pipeline in terms of security features.