For the justifiably paranoid, a web service is not going to cut it (lack of https is just the start - relying on any web service is a _lot_ of trust to put in such an Important Thing). Even if you are as trustworthy as I'd hope, it's foolish to even allow the possibility of you (or your service) being compromised to affect the safety of my passwords.
Personally, I use a command-line implementation of SuperGenPass that a friend of mine wrote (and I host at github:gfxmonk/supergenpass). It avoids all sorts of spoofing / browser vulnerabilities, and is reasonably convenient with something like Guake.
I'm not trying to diss the concept at all - I love this kind of thing, and honestly can't understand why it isn't more widely used / encouraged. But It's worth pointing out what already exists in the space.
NullPass isn't a Web service, it's a one-page Javascript app like mine and SuperGenPass. But it loads a bunch of libraries, so it can't as easily be copied for safe offline or local use.
I never realised there were so many implementations of this floating around. It might be a neat idea to inline/reduce the libraries I used to more easily distribute for offline. Although I have to say that I don't feel this is any less safe because it can't run locally :)
The problems with these master password implementations comes when you want to change the password for one site only. Sure, I can add a token in addition to the domain. But what token did I add to which domain? If I have to remember individual tokens I might as well remember the entire password.
A solution could be to generate a “salt” for each domain, but then we're no longer stateless…
One solution is to use a separate storage for salts (or hints, really - it doesn't need to be a complex scheme, since we're hashing it anyway).
I do this myself with supergenpass, for when a site's password DB gets compromised (a common enough occurrence these days).
Importantly, this augmented state is a convenience - it's not irreplaceable. If I find myself _without_ my list of hints, I am not completely screwed - I'll just have a harder time logging into those few sites, and it's quite likely I'll remember the right hint after a few tries from memory if I really need to.
Basically the same idea but seeds a random number generator with the master password and the service name to have an infinite supply of passwords. Technically no state is needed because Python's random module is deterministic, but I will end up saving the state with the service name and the index of the random number so that I don't have to try each and every one (not that I change passwords that often, for better or worse).
And, for convenience, since I won't be saving the master password, I'm looking into adding a credential cache like sudo has.
I use the HMAC hash of the username, the site, and a ‘key’ generated at random. However, this does mean that I'm screwed if I cannot access the keys [and cannot remember the password].
Hi all, this is the first side project I've had that I've been happy enough to share with the world at large. I hope someone finds it useful and would be very eager for some feedback :) (Especially negative!)
I've been using PassHash "http://passhash.connorhd.co.uk/" for a while now and I really like it. If I understand your application correctly, PassHash does essentially the same thing as NullPass. I run PassHash using a local copy of PassHash so I don't have to worry about MITM attacks.
Is there a reason why you are using straight sha512 with concatenated elements instead of using a sha512 HMAC with the local password as the key to the HMAC?
No, not really. I do like having the length concatenated inside as well, as this provides a unique password for different lengths (useful to quickly visually identify if a password looks 'right').
Is there any reason why HMAC would be better than my current implementation? I have had a read over the article and it seems that straight SHA512 should have similar cryptographic strength.
I am concerned about changing the algorithm at this point in case anyone has already used it. I don't think there are any serious concerns but will report back if I find any (after taking some more time). Of course if anyone knows this stuff very well I'd be very eager for some feedback!
http://supergenpass.com/
For the justifiably paranoid, a web service is not going to cut it (lack of https is just the start - relying on any web service is a _lot_ of trust to put in such an Important Thing). Even if you are as trustworthy as I'd hope, it's foolish to even allow the possibility of you (or your service) being compromised to affect the safety of my passwords.
Personally, I use a command-line implementation of SuperGenPass that a friend of mine wrote (and I host at github:gfxmonk/supergenpass). It avoids all sorts of spoofing / browser vulnerabilities, and is reasonably convenient with something like Guake.
I'm not trying to diss the concept at all - I love this kind of thing, and honestly can't understand why it isn't more widely used / encouraged. But It's worth pointing out what already exists in the space.