~ "git: github.com/Garklein/md5ua" ~ Md₅
⊙◌⍢(+₁|<₅/+\↧=@0Md₅utf₈˜⊂°⋕)1 &fras"i/04.in"

Yes, I implemented MD5 in Uiua just for this. Yes, it takes 7m 14s for part 1. Yes, I didn't try part 2 because it would be too slow.

~/aoc15ua/04