Programmatically changing a cryptsetup LUKS key

lukspass.sh

#!/bin/bash

luksobject='crypto.dat'

read -r -s -p 'Old passphrase: ' old
printf "\n"
read -r -s -p 'New passphrase: ' new
printf "\n"
read -r -s -p 'New passphrase again: ' new2
printf "\n"

if [[ "${new}" != "${new2}" ]]
then
        printf "New passphrase mismatch. Aborting.\n"
        exit 1
fi

if command -v pwscore >/dev/null && ! pwscore >/dev/null <<< "${new}"
then
        printf "Weak passphrase. Aborting.\n"
        exit 2
fi

printf "Passing control to cryptsetup:\n"
exec cryptsetup luksChangeKey --verbose \
        --key-file <(tr -d '\n' <<< "${old}") "${luksobject}" <<< "${new}"

# Further Reading:
#
# pwscore(1)
# cryptsetup(8) "Notes on passphrase processing" (regarding the \n substition)
# bash(1) "Process Substitution" (regarding the <())
# bash(1) "Here Strings" (regarding the <<<)