Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Show HN: Forgiva – Never saves your passwords but regenerates them

forgiva.com

Post reply on HN
Print view View original

61–70 of 98 posts

Re: Show HN: Forgiva – Never saves your passwords but regenerates them

#61

Post by tptacek »

I'm reading the open source code and this thing is... odd. For instance: it has a "simple", "intermediate", and "advanced" password complexity, and depending on which you choose, it uses SHA1, SHA2-256, and SHA2-512 for the PBKDF2 hash. What does password complexity have to do with the strength of the algorithm used to generate passwords?

Also: it's 2016. Why is this using PBKDF2? If PBKDF2 is what you've got and you're protecting a website, that's fine, but this is a password manager.

Is the "commercial" version of this also Ruby code wrapping OpenSSL?

Re: Show HN: Forgiva – Never saves your passwords but regenerates them

#62

Post by gliptic »

marcusfrex wrote: post #53
SloopJon wrote: post #49

As I see it, the main benefit of deterministic password generation is the convenience of not needing a password database. Indeed, if the scheme is simple and/or portable enough (e.g., PBKDF2) you can implement it from scratch in a minute or two, depending on what software you have handy. The convenience breaks down as you need to maintain additional state: password rotation, site-specific password rules, etc. Forgiva…

>> Spamming the input with an array of whatever OpenSSL algorithms Ruby happens to make available, rather than using a memory hard KDF like scrypt, is a bad smell. Sooner or later key-derivation schemes gets outdated and requires a better version as happened to bcrypt [1] and will happen to scrypt [2]. It is not "whatever OpenSSL provides" but just combining strong algorithms over to spread the "getting outdated" ris…

What evidence do you have that your scheme is any more future proof than, say, Argon2? No, just using a bunch of different primitives is not going to guard against the kind of breaks found in bcrypt or scrypt, which aren't really breaks at all.

Re: Show HN: Forgiva – Never saves your passwords but regenerates them

#63

Post by Cyph0n »

tptacek wrote: post #61

I'm reading the open source code and this thing is... odd. For instance: it has a "simple", "intermediate", and "advanced" password complexity, and depending on which you choose, it uses SHA1, SHA2-256, and SHA2-512 for the PBKDF2 hash. What does password complexity have to do with the strength of the algorithm used to generate passwords? Also: it's 2016. Why is this using PBKDF2? If PBKDF2 is what you've got and you…

It would be better to use more hashing rounds as changing the algorithm itself doesn't require more computational effort from the attacker.

Re: Show HN: Forgiva – Never saves your passwords but regenerates them

#64

Post by cyphar »

dom96 wrote: post #37
mynameislegion wrote: post #34

Earlier quoted context omitted.

NC licenses aren't considered "Open Source": http://www.opensource.org/docs/osd

Interesting, but then what do you call something who's source is available to be viewed?

I'd call it proprietary. It's closer to free software, but it's not all the way there.

Re: Show HN: Forgiva – Never saves your passwords but regenerates them

#65

Post by jjnoakes »

RubyPinch wrote: post #32
cauterized wrote: post #24

Earlier quoted context omitted.

What happens then if you want/need to rotate your password? How does it deal with stupid password format restrictions?

the salt gets changed so, either password database + master password gets stolen, or salt database + master password gets stolen

Except if the master db is stolen without the master password, one can throw guessed passwords at it and know when one worked (i.e. the db becomes readable).

Throwing passwords at a salt db gets you... what?

Re: Show HN: Forgiva – Never saves your passwords but regenerates them

#66

Post by Canada »

How does this handle situations where the generated password isn't accepted by the site? eg. Is too long, absolutely must have at least one symbol and one number, etc.

How does this handle changing passwords? How can I know from the master secret that xyz.com is on the 4th password?

Re: Show HN: Forgiva – Never saves your passwords but regenerates them

#67

Post by nickpsecurity »

Cyph0n wrote: post #63
tptacek wrote: post #61

I'm reading the open source code and this thing is... odd. For instance: it has a "simple", "intermediate", and "advanced" password complexity, and depending on which you choose, it uses SHA1, SHA2-256, and SHA2-512 for the PBKDF2 hash. What does password complexity have to do with the strength of the algorithm used to generate passwords? Also: it's 2016. Why is this using PBKDF2? If PBKDF2 is what you've got and you…

It would be better to use more hashing rounds as changing the algorithm itself doesn't require more computational effort from the attacker.

I argued with that since cryptographers first told me about it. Ludicrous concept. The goal is to eliminate brute force attacks by making the process inherently slow. That technique starts with something inherently ultra-fast that everyone is trying to speed up and hardware accelerate then iterates it a bit. Better concept to get a slow process is design an algorithm that is inherently slow and hard to speed up, esp requiring many memory accesses. My hack, aimed at defeating FPGA's, was putting a random stream into no less than 16MB of RAM (SRAM limit at time) that I iterated through randomly with a hash function. All inherently sequential, random, and large. Accelerate that!

Fortunately, Colin Percival came up with a much better solution in scrypt. It's a nice default if you want something battle-tested for a long time. Nobody should be using SHA-1, etc with solutions like scrypt available.

Re: Show HN: Forgiva – Never saves your passwords but regenerates them

#68

Post by kevhito »

marcusfrex wrote: post #54
kevhito wrote: post #28

Earlier quoted context omitted.

And if you go that path, "theoretically" an attacker might simply guess your password on the first try when attempting to log in as you, so password "storages" and "brute-force" has nothing to do it.

You are mistaken on one think: it is not just being it "theoretically" possible but likeliness -or hardness- of it. If the possibility of an attacker guessing my password at first try is one in a billion -or trillion- chance, then we can say it pretty secure. But hacking a cloud with a possible zero-day flaw and cracking a password database is not that hard if we compare it with your example.

I was responding to this assertion:

> all encryption methods prone to brute-force attacks

The chance of succeeding within our lifetime with a brute-force attack against modern encryption is far less than one in a trillion. So in your words, it is far better than "pretty secure".

Re: Show HN: Forgiva – Never saves your passwords but regenerates them

#70

Post by tptacek »

nickpsecurity wrote: post #67
Cyph0n wrote: post #63

Earlier quoted context omitted.

It would be better to use more hashing rounds as changing the algorithm itself doesn't require more computational effort from the attacker.

I argued with that since cryptographers first told me about it. Ludicrous concept. The goal is to eliminate brute force attacks by making the process inherently slow. That technique starts with something inherently ultra-fast that everyone is trying to speed up and hardware accelerate then iterates it a bit. Better concept to get a slow process is design an algorithm that is inherently slow and hard to speed up, esp…

Just pick a real password hash and dial up the hardness as high as you reasonably can for your environment. Don't do anything more complicated than that.
Post reply on HN