Comment by cryptonector

4 years ago

Your tool would be safer if you used CBC (with some MAC) rather than GCM as the cipher mode, so that key & IV reuse would not be as dangerous. That said, since you generate a different salt and IV every time, the likelihood of key & IV reuse is very low, and having to implement an AEAD cipher mode by generic construction would be somewhat annoying. So I think the choice of GCM is fine enough.

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cryptonector

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mprime1  4 years ago

I started with CBC (without MAC) and upgraded with GCM since it was a more convenient way to provide integrity without adding the MAC step manually.

I should really make sure IV/Salt are regenerated automatically after use. (there is a small print warning in the creator about reuse)

  • cryptonector  4 years ago

    > I should really make sure IV/Salt are regenerated automatically after use.

    Good idea.

    > I started with CBC (without MAC)

    Oof, you really didn't want to do that :) Glad you upgraded to GCM.