Unsupported Bitwarden export (kdfType: 1)

Ah, PBKDF2 wasn't completely broken, you're right, it just requires a huge number of iterations now.  

As discovered in 2023, LastPass was doing 100,000 iterations on thier PBKDF2-HMAC-SHA256 hashing. Bitwarden at the time was found to have implemented thier hashing iterations of the same algorithm incorrectly and instead of doing 200,000 iterations, they effectively were also doing only 100,000. Only 100,000 iterations at the time was found to be reversible on modern hardware and therefore not even close to secure (where threats have include current encrypted content capture and future hardware cracking).

At that time, 350,000 became the absolute minimum number of iterations for PBKDF2-HMAC-SHA256, and OWASP changed thier recommendation to be an absolute minimum of 600,000. Bitwarden discovered this makes the hashing very slow and added Argon2id support as a far more efficient alternative, as well as switching thier default PBKDF2 iterations to 600,000 for new accounts (or when re-keying), along with a configurable value for higher numbers of iterations. The PBKDF2-HMAC-SHA512 iterations also went up to an absolute minimum of 210,000 as well.

Ultimately though PBKDF2 has become like RSA keys where it's a forever chase on increasing the number of bits (iterations) at progressively higher and higher usage cost (key size/iteration processing) versus switching to a more efficient algorithm (e.g ed25519/Argon2id). 

Understandably this does cause a bit of an issue if you're trying to sell FIPS compliance, since the latest FIPS 140-3 was already partially out of date with modern technology before it even released, and FIPS certified algorithms require certification by the US government specifically, something Argon2id has explicitly declined to do. It leaves the unfortunate situation that FIPS is actively known to be less secure than average industry standards (across the board actually, not just specific to this), yet still has pull in marketing materials. I'm not surprised 1Password has opted to use the single non-configurable algorithm for the hashing and picked something that fits with FIPS so they can check that box in the marketing materials for customers that care about it. I'm hoping they've picked an iteration count much much higher than the OWASP minimum though

I would hope 1Password has high priority plans to add support for accounts to re-key, since their entire selling point is that they shouldn't be able to do it for you (otherwise it's not zero-knowledge as claimed) and they also provide strong security (which is a moving target and therefore requires the ability to update the cryptographic algorithms uses).

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I do see there's a small note after all the step by step instructions for importing from Bitwarden included for some of the mostly duplicate official instructions (I'm seeing at least 3 different sets of official instructions), that you need to use PBKDF2 or re-ley to it in Bitwarden before export, otherwise 1Password won't be able to import. This could probably be noted at the top, when it matters, rather than the end of the instructions, and also included on all versions of the instructions scattered around the 1Password site.