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NIST proposes barring some of the most nonsensical password rules (arstechnica.com)
submitted 2 years ago by to c/technology@lemmy.world
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Here is the text of the NIST sp800-63b Digital Identity Guidelines.

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[–] 6 points 2 years ago (1 child)

You should accept Unicode; if doing so, you must count each code as one char.

Hmm. I wonder about this one. Different ways to encode the same character. Different ways to calculate the length. No obvious max byte size.

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  • [–] 10 points 2 years ago (2 children)

    Who cares? It's going to be hashed anyway. If the same user can generate the same input, it will result in the same hash. If another user can't generate the same input, well, that's really rather the point. And I can't think of a single backend, language, or framework that doesn't treat a single Unicode character as one character. Byte length of the character is irrelevant as long as you're not doing something ridiculous like intentionally parsing your input in binary and blithely assuming that every character must be 8 bits in length.

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  • [–] 5 points 2 years ago

    It matters for bcrypt/scrypt. They have a 72 byte limit. Not characters, bytes.

    That said, I also think it doesn't matter much. Reasonable length passphrases that could be covered by the old Latin-1 charset can easily fit in that. If you're talking about KJC languages, then each character is actually a whole word, and you're packing a lot of entropy into one character. 72 bytes is already beyond what's needed for security; it's diminishing returns at that point.

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  • [–] 1 point 2 years ago

    If the same user can generate the same input, it will result in the same hash.

    Yes, if. I don't know if you can guarantee that. It's all fun and games as long as you're doing English. In other languages, you get characters that can be encoded in more than 1 way. User at home has a localized keyboard with a dedicated key for such a character. User travels across the border and has a different language keyboard and uses a different way to create the character. Euro problems.

    https://en.wikipedia.org/wiki/Unicode_equivalence

    Byte length of the character is irrelevant as long as you’re not doing something ridiculous like intentionally parsing your input in binary and blithely assuming that every character must be 8 bits in length.

    There is always some son-of-a-bitch who doesn’t get the word.

    • John F. Kennedy
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