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Password Security The Right Way

stormpath.com

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Re: Password Security The Right Way

#11

Post by MattRogish »

tptacek wrote: post #3

No. http://codahale.com/how-to-safely-store-a-password/ It's really not more complicated than this. You can use scrypt instead of bcrypt if that makes you happy. The secret crypto keys in separate storage locations stuff is silly. Get the basics right.

Indeed. Encrypting your bcrypt'd hashes is... massively complex and doesn't provide any additional meaningful security relative to the complexity.

A properly bcrypt'd password table is functionally useless in the hands of a non nation-state. Yeah, it's not something you'd prefer to have a BadGuy(TM) get, but other than embarrassment, it's not a big deal.

Here's my bcrypt with salt. Please, waste your time trying to crack this.

"$2a$19$xZrwzkut/fj2gToExgw8qevT9DtevnuKLEVj.kNiSMclzfFqQq9z."

Re: Password Security The Right Way

#13

Post by strictfp »

While compromized passwords are one problem, leaking your data is bad in so many other ways as well. Yet almost all focus lies in obfuscating passwords to prevent extraction in the case of a breach. We don't talk as much about securing addresses and SSNs and other sensitive data.

Well guess what, if the attacker has access to your system he can just install a password logger and all your obfuscation would be in vain.

All extra security is added value, sure, but focus on other areas wouldn't hurt.

Re: Password Security The Right Way

#14

Post by lhazlewood »

tptacek wrote: post #3

No. http://codahale.com/how-to-safely-store-a-password/ It's really not more complicated than this. You can use scrypt instead of bcrypt if that makes you happy. The secret crypto keys in separate storage locations stuff is silly. Get the basics right.

BCrypt (level 3) is getting the basics right. Levels 4 and 5 are techniques beyond the basics used to minimize potential brute force attacks, which _are_ an issue, depending on the attack target (read the Verizon report referenced by another post on this page).

Don't think for a second that certain government agencies can't brute force a BCrypt-based password hash, especially given they will know the cost factor and salt. If the hash is encrypted, and then chunked, if an attacker doesn't have the constituent encrypted chunks and/or the encryption key _for a valid time frame_, the possibility of a brute force attack with modern computing power is almost impossible.

While you may not care about such concerns, some of Stormpath's government agency customers do, and so we provide these additional safety measures. That an average website can benefit from them is icing on the cake.

Re: Password Security The Right Way

#16

Post by tptacek »

lhazlewood wrote: post #14
tptacek wrote: post #3

No. http://codahale.com/how-to-safely-store-a-password/ It's really not more complicated than this. You can use scrypt instead of bcrypt if that makes you happy. The secret crypto keys in separate storage locations stuff is silly. Get the basics right.

BCrypt (level 3) is getting the basics right. Levels 4 and 5 are techniques beyond the basics used to minimize potential brute force attacks, which _are_ an issue, depending on the attack target (read the Verizon report referenced by another post on this page). Don't think for a second that certain government agencies can't brute force a BCrypt-based password hash, especially given they will know the cost factor and…

You feel that you're protecting password hashes from government sponsored attackers, and yet you're iterating SHA2 as your password hash?

Re: Password Security The Right Way

#17

Post by tptacek »

MattRogish wrote: post #11
tptacek wrote: post #3

No. http://codahale.com/how-to-safely-store-a-password/ It's really not more complicated than this. You can use scrypt instead of bcrypt if that makes you happy. The secret crypto keys in separate storage locations stuff is silly. Get the basics right.

Indeed. Encrypting your bcrypt'd hashes is... massively complex and doesn't provide any additional meaningful security relative to the complexity. A properly bcrypt'd password table is functionally useless in the hands of a non nation-state. Yeah, it's not something you'd prefer to have a BadGuy(TM) get, but other than embarrassment, it's not a big deal. Here's my bcrypt with salt. Please, waste your time trying to c…

I'm pretty sure your actual bcrypted password doesn't have that cost factor on it.

Re: Password Security The Right Way

#18

Post by asalazar »

Something the article didn't cover but should is the upkeep over time of whatever algorithm you use. We can argue about todays algorithms. But what do we do when those algorithm are superseded? Or when the minimum complexity factor needs to go up. If you're an app dev or devops, will you know when that happens and how will you update?

Re: Password Security The Right Way

#19

Post by MattRogish »

tptacek wrote: post #17
MattRogish wrote: post #11

Earlier quoted context omitted.

Indeed. Encrypting your bcrypt'd hashes is... massively complex and doesn't provide any additional meaningful security relative to the complexity. A properly bcrypt'd password table is functionally useless in the hands of a non nation-state. Yeah, it's not something you'd prefer to have a BadGuy(TM) get, but other than embarrassment, it's not a big deal. Here's my bcrypt with salt. Please, waste your time trying to c…

I'm pretty sure your actual bcrypted password doesn't have that cost factor on it.

That's how rails stores it in the database, so trying to be as transparent as possible.

Re: Password Security The Right Way

#20

Post by mikeash »

chunsaker wrote: post #7
tptacek wrote: post #5

Earlier quoted context omitted.

Iterated SHA2 is inferior to bcrypt and far inferior to scrypt, and yet both these Stormpath.com articles recommend it. The advice in these articles is worse that Coda's articles; developers should read Coda's post and implement it.

You're talking about Bcrypt like its some magical golden unicorn that will cover your ass from all attack vectors. Sure, its awesome. But modern security requires more than just an awesome encryption algorithm.

At what point does he attribute any unicorn-like properties to bcrypt? All he says is that SHA2 is worse, which is completely true.
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