Re: hash_hkdf() signature
| From: | Andrey Andreev | Date: | Thu, 09 Feb 2017 10:59:39 +0000 |
| Subject: | Re: hash_hkdf() signature | ||
| References: | 1 2 3 4 5 | Groups: | php.internals |
| Request: | Send a blank email to internals+get-98270@lists.php.net to get a copy of this message | ||
Hi Yasuo,
The fact that you continue to talk about passwords and other low-entropy
data as IKM shows, yet again, that you don't understand HKDF.
It is simply not a password-based KDF; if you want that - use PBKDF2.
Please read Section 4* of the spec:
https://tools.ietf.org/html/rfc5869.html#section-4
In fact, at one point I suggested the function be named just 'hkdf()' as a
way of discouraging such misuse, because a lot of people associate the word
"hash" with password handling.
And this ...
> I suppose most developers will use 'length' for shorter length.
> i.e. Weaker output keys. If it's not too short, shorter key length works.
>
>
Shows that you shouldn't be trusted with anything related to cryptography
either.
I may be no cryptographer myself, but one thing I know for sure is that
shorter than required key lengths are *never* ok, and most encryption
algorithms have a *fixed* key length.
Also, this is the last time I reply to you on this topic. You're just
impossible to reason with.
Cheers,
Andrey.