AmicitasNIST proposes barring some of the most nonsensical password rules
At roughly 35,000 words and filled with jargon and bureaucratic terms, the document is nearly impossible to read all the way through and just as hard to understand fully.
A section devoted to passwords injects a large helping of badly needed common sense practices that challenge common policies. An example: The new rules bar the requirement that end users periodically change their passwords. This requirement came into being decades ago when password security was poorly understood, and it was common for people to choose common names, dictionary words, and other secrets that were easily guessed.
Since then, most services require the use of stronger passwords made up of randomly generated characters or phrases. When passwords are chosen properly, the requirement to periodically change them, typically every one to three months, can actually diminish security because the added burden incentivizes weaker passwords that are easier for people to set and remember.
A.k.a use a password manager for most things and a couple of long complex passwords for things that a password manager wouldn’t work for (the password manager’s password, encrypted system partitions, etc). I’m assuming In just summed up 35,000 words.
Please ban all the stupid password rules. I would rather just get hacked than come up with an impossible to remember password once a month.
darklamerPlease ban all the stupid password rules.
Yes.
I would rather just get hacked […]
Eh, no.
the document is nearly impossible to read all the way through and just as hard to understand fully
It is a boring document but it not impossible to read through, nor understand. The is what compliances officer need to read through and understand. I have a (useless) cybersecurity degree and reading NIST publications is part of my lecture.
ToriborMy career as a sysadmin consistently has me veering toward security and compliance and my brain is absolutely fried on trying to figure out what these huge docs actually mean, how they apply to the things I’m responsible for and what we’re supposed to do about it.
Props to all the folks that can do it without losing their mind.
You break it down into chunks and delegate. They’re not expecting any one person to implement the whole thing.
They’re not expecting any one person to implement the whole thing.
Hahaha, tell that to leadership! 😩
You need to first understand the grand sturcture of the doc, then cherry pick the content to action points. At least that’s how I do it.
ISOmorphUseless??? Ever since the pandemic and the need for a robust remote work infrastructure, the amount of cybersecurity related job offers has exploded. And they’re very well paid where I live.
The knowledge is useful, but I can’t say the same for the degree
GoofSchmooferIt sets both the technical requirements and recommended best practices for determining the validity of methods used to authenticate digital identities online. Organizations that interact with the federal government online are required to be in compliance
My argument is that if this document (and others) are requirements for companies shouldn’t there also be a more approachable document for people to use?
Sure, have the jargon filled document that those in the know can access, but without an additional not so jargon-y document you’ve just added a barrier to change. Maybe just an abstract of the rule changes on the front page without the jargon?
I don’t know, maybe it’s not a big deal to compliance officers but just seems to me (someone that isn’t a compliance officer) that obfuscating the required changes behind jargon and acronyms is going to slow adoption of the changes.
0xDIt needs to be specific to be clear for its purposes. You can express everything in simpler terms but then you risk leaving things out of definitions. It’s basically legal speak.
Normally, you’d read the scope of such a document to see whether it fits your purpose, then cherry-pick the chapters necessary. If something’s unclear, you can google pretty much everything.
Doing that a few times will make it infinitely easier! You especially get to understand those broad, inaccessible definitions a lot easier.
Any password length (within reason) and any character should be allowed. It’s going to be hashed and only the hash will be stored right? Length and character limits make me suspect it’s being stored in plain text.
Then you’re vulnerable to simple brute force attacks, which if paired with a dumped hash table, can severely cut the time it takes to solve the hash and reveal all passwords.
By any length I meant no maximum length. Obviously you don’t want to use a super short password.
MelodiousFunk“What’s your password?”
“The letter A.”
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Mine is the null string. They’ll never guess it!
Some kind of upper bound is usually sensible. You can open a potential DoS vector by accepting anything. The 72 byte bcrypt/scrypt limit is generally sensible, but going for 255 would be fine. There’s very little security to be gained at those lengths.
I do 256 so I hopefully never need to update it, but most of my passwords are 20-30 characters or something, and generated by my password manager. I don’t care if you choose to write a poem or enter a ton of unicode, I just need a bunch of bytes to hash.
I don’t know about a min length; setting a lenient lower bound means that any passwords in that space are going to be absolutely brutal force-able (and because humans are lazy, there are almost certainly be passwords clustered around the minimum).
I very much agree with the rest though, it’s unnerving when sites have a low max length. It almost feels like advertising that passwords aren’t being hashed and if that’s the case there’s a snowball’s chance in hell that they’re also salted. Really restrictive character sets also tell me that said site / company either has super old infra or doesn’t know how to sanitize strings (or entirely likely both)…
The only justifiable reason I can see to have a length limit is because longer passwords would take more time to process and they don’t want to deal with that.
Although it would only be on the order of a couple of extra microseconds and I’m not sure how much difference it would really make. But even on cyber security forums the max password length is 64 characters.
But it really doesn’t, unless you’re sending megabytes of text or something. Industry standard password algorithms run the hash a lot of times, and your entry will only impact the first iteration.
I usually set mine to 256 characters to prevent DOS attacks, and also so I don’t need to update it ever. Most of my passwords are actually around 20-30 characters in length (I pick a random length in the slider on my password manager), because I don’t want to be there all day if I ever need to manually enter it (looking at you stupid smart TV…).
unless you’re sending megabytes of text or something
That’s exactly what someone malicious would do though, either in a single password submission or DOS via the password maximum repeatedly. IMO there is no functional security difference between a 64 and a 256 character password, so the NIST 64 character max is reasonable.
Rules here are 64 as a reasonable maximum. A lot of programmers don’t realize that bcrypt and scrypt max at 72 bytes (which may or may not be the same as 72 characters). You can get around it by prehashing, but meh. This is long enough even for a reasonable passphrase scheme.
Minor note: 64 unicode characters is potentially much more than 72 bytes.
dual_sport_dork 🐧🗡️You should probably have some safeguard to prevent jokers from uploading 14.2 gigabytes of absolute nonsense into your system’s password field just to see if they can make it crash. But I think limiting it to, like, 8 kB ought to be quite lenient for anything with a modern internet connection.
As others have noticed, various hashing functions have an upperbound input length limit anyway. But I don’t see any pressing reason to limit your field length to exactly that, even if only not to reveal anything about what you might be feeding that value into behind the scenes.
I usually do 256 characters. That’s long enough that most password managers top out anyway (mine tops out at 128), and it shouldn’t ever present a DOS risk. Anything much beyond that and you’ll go beyond the hash length.
Lvxferre [he/him]Reworded rules for clarity:
I was expecting idiotic rules screaming “bureaucratic muppets don’t know what they’re legislating on”, but instead what I’m seeing is surprisingly sane and sensible.
NIST generally knows what they’re doing. Want to overwrite a hard drive securely? NIST 800-88 has you covered. Need a competition for a new block cipher? NIST ran that and AES came out of it. Same for a new hash with SHA3.
Didn’t know about sha3.
NIST generally knows what they’re doing
For now, at least. Could change after Inauguration Day.
I hate that anyone has to be told not to truncate passwords. Like even if you haven’t had any training at all, you’d have to be advanced stupid to even come up with that idea in the first place.
Can you elaborate further? Why would someone want to truncate passwords to begin with?
To save a few megabytes of text in a database somewhere. Likely the same database that gets hacked.
Which shouldn’t even matter because passwords are salted and hashed before storing them, so you’re not actually saving anything. At least they better be. If you’re not hashing passwords you’ve got a much bigger problem than low complexity passwords.
The place that truncates passwords is probably not the place to look for best practices when it comes to security. :-)
Hashing passwords isn’t even best practice at this point, it’s the minimally acceptable standard.
Tywèle [she|her]What is the best practice currently?
Use a library. It’s far too easy for developers or project managers to fuck up the minimum requirements for safely storing passwords.
Salt the hash with something unique to that specific user so identical passwords have different hashes
Isn’t that… the very definition of a Salt? A user-specific known string? Though my understanding is that the salt gets appended to the user-provided password, hashed and then checked against the record, so I wouldn’t say that the hash is salted, but rather the password.
Also using a pepper is good practice in addition to a salt, though the latter is more important.
Some implementers reuse the same salt for all passwords. It’s not the worst thing ever, but it does make it substantially easier to crack than if everything has its own salt.
That’s a pepper not a salt. A constant value added to the password that’s the same for every user is a pepper and prevents rainbow table attacks. A per-user value added is a salt and prevents a number of things, but the big one is being able to overwrite a users password entry with another known users password (perhaps with a SQL injection).
I remember hearing to not layer encryptions or hashes on top of themselves. It didn’t make any sense to me at the time. It was presented as if that weakened the encryption somehow, though wasn’t elaborated on (it was a security focused class, not encryption focused, so didn’t go heavy into the math).
Like my thought was, if doing more encryption weakened the encryption that was already there, couldn’t an attacker just do more encryption themselves to reduce entropy?
The class was overall good, but this was still a university level CS course and I really wish I had pressed on that bit of “advice” more. Best guess at this point is that I misunderstood what was really being said because it just never made any sense at all to me.
It’s because layering doesn’t really gain you anything so it only has downsides. It’s important to differentiate encryption and hashing from here on since the dangers are different.
With hashing, layering different hashing algorithms can lead to increased collision chance and if done wrong a reduced entropy (for instance hashing a 256 bit hash with a 16 bit hashing algorithm). Done correctly it’s probably fine and in fact rehashing a hash with the same algorithm is standard practice, but care should be taken.
With encryption things get much worse. When layering encryption algorithms a flaw in one can severely compromise them all. Presumably you’re using the same secret across them all. If the attacker has a known piece of input or can potentially control the input a variety of potential attack vectors open up. If there’s a flaw in one of the algorithms used that can make the process of extracting the encryption key much easier. Often times the key is more valuable than any single piece of input because keys are often shared across many encrypted files or data streams.
With the hash one, it doesn’t look like that could be exploited by an attacker doing the bad hashing themselves, since any collisions they do find will only be relevant to the extra hashing they do on their end.
But that encryption one still sounds like it could be exploited by an attacker applying more encryption themselves. Though I’m assuming there’s a public key the attacker has access to and if more layers of encryption make it easier to determine the associated private key, then just do that?
Though when you say they share the same secret, my assumption is that a public key for one algorithm doesn’t map to the same private key as another algorithm, so wouldn’t cracking one layer still be uncorrelated with cracking the other layers? Assuming it’s not reusing a one time pad or something like that, so I guess context matters here.
Sorta. Not really.
Key derivation algorithms are still hashes in most practical ways. Though they’re derived directly from block ciphers in most cases, so you could also say they’re encrypted. Even though people say to hash passwords, not encrypt them.
I find the whole terminology here to be unenlightening. It obscures more than it understands.
A KDF is not reversible so it’s not encryption (a bad one can be brute forced or have a collision, but that’s different from decrypting it even if the outcome is effectively the same). As long as you’re salting (and ideally peppering) your passwords and the iteration count is sufficiently high, any sufficiently long password will be effectively unrecoverable via any known means (barring a flaw being found in the KDF).
The defining characteristic that separates hashing from encryption is that for hashing there is no inverse function that can take the output and one or more extra parameters (secrets, salts, etc.) and produce the original input, unlike with encryption.
OK. How do you reconcile that with “Hashing passwords isn’t even the best practice at this point”? Key derivation functions are certainly the recommended approach these days. If they are hashes, then your earlier post is wrong, and if they aren’t hashes, then your next post was wrong.
The rest of that sentence is important. Hashing passwords is the minimum practice, not best practice. You should always be at least hashing passwords. Best practice would be salting and peppering them as well as picking a strong hashing function with as high a number of iterations as you can support. You would then pair that with 2FA (not SMS based), and a minimum password length of 16 with no maximum length.
Lots of older databases had fixed length fields, and you had to pad it if it was smaller. VARCHAR is a relatively new thing. So it’s not just saving space, but that old databases tended to force the issue.
Nobody has an excuse today. Even Cobol has variable length strings.
Microsoft used to do that. I made a password in the late 90’s for a we service and I found out that it truncated my password when they made it after it warned my my password was too long when I tried to log in. It truncated at 16 characters.
The weirdest one I found was a site that would only check to see if what you entered started with the correct password. So if your password was hunter2 and you tried hunter246, it would let you in.
Which means not only were they storing the password, but they had to go out of their way to use the wrong kind of string comparison.
Midnight WolfUSAA does this. I renentl learned that, when I updated my password a few years back to my personal standard number of characters, everything was good until someone mentioned this fuck-up in a thread. USAA only checks the first… 16? characters. I assume it just discards anything beyond that. Other users say that it warns and doesn’t let you enter more than that during password creation, but it/my pw mgr sure didn’t care, as I have a password several fold that limit. I took out a couple characters from my ‘set’ password, and it still logged in just fine. 16, just fine. 15, error.
Fucking wild.
I used to work there. I reported this bug every quarter until a VP told me to stop…
chiisanaThe LM password hash (predecessor to NTLM) was calculated in two blocks of 7 characters from that truncated 14 characters. Which meant the rainbow table for that is much smaller than necessary and if your password is not 14 characters, then technically part of the hash is much easier to brute force, because the other missing characters are just padded with null.
What kind of barbarian puts a space in their password?
Very common for pass phrases, and not dissuaded. Pass phrases are good for people to remember without using poor storage practices (post it notes, txt file, etc) and are strong enough to keep secure against brute force attacks or just guessing based off knowledge of the user.
On one hand, that’s true. On the other hand, a person should only need exactly one passphrase, which is the one used to unlock their password manager. Every other password should be randomly-generated and would only contain space characters by chance.
That’s great in theory, but you’ll have passwords for logging into OSes too which password managers do not help with and you better have it memorized or you’re going to have a bad time.
I’m waiting for backspace to be a valid character