nixos-installer/lib/setup-scripts/keys.sh
Niklas Gollenstede f56db19b5e improve installation, add support for:
ZFS, encryption (keys, keystore, LUKS), bootFS, ephemeral root (tmpfs, ZFS, F2FS, ...), testing in qemu, options & debugging, ... and many small things
2022-05-31 03:41:28 +02:00

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## Prompts for the password of every user that uses a »passwordFile«, to later use that password for home encryption and/or save it in the »passwordFile«.
function prompt-for-user-passwords { # (void)
declare -g -A userPasswords=( ) # (this ends up in the caller's scope)
for user in "@{!config.users.users!catAttrSets.password[@]}" ; do # Also grab any plaintext passwords for testing setups.
userPasswords[$user]=@{config.users.users!catAttrSets.password[$user]}
done
for user in "@{!config.users.users!catAttrSets.passwordFile[@]}" ; do
if ! userPasswords[$user]=$(prompt-new-password "for the user account »$user«") ; then exit 1 ; fi
done
}
## Mounts a ramfs as the host's keystore and populates it with keys as requested by »config.wip.fs.keystore.keys«.
# Depending on the specified key types/sources, this may prompt for user input.
function populate-keystore { { # (void)
local keystore=/run/keystore-@{config.networking.hostName!hashString.sha256:0:8}
mkdir -p $keystore && chmod 750 $keystore && prepend_trap "rmdir $keystore" EXIT
mount ramfs -t ramfs $keystore && prepend_trap "umount $keystore" EXIT
} && ( set -eu
declare -A methods=( ) ; declare -A options=( )
for usage in "@{!config.wip.fs.keystore.keys[@]}" ; do
methodAndOptions="@{config.wip.fs.keystore.keys[$usage]}"
method=$(<<<"$methodAndOptions" cut -d= -f1)
methods[$usage]=$method ; options[$usage]=${methodAndOptions/$method=/} # TODO: if no options are provided, this passes the method string as options (use something like ${methodAndOptions:(- $(( ${#method} + 1 ))})
done
for usage in "${!methods[@]}" ; do
if [[ "${methods[$usage]}" != inherit ]] ; then continue ; fi
from=${options[$usage]}
methods[$usage]=${methods[$from]} ; options[$usage]=${options[$from]}
done
for usage in "${!methods[@]}" ; do
if [[ "${methods[$usage]}" == home-pw || "${methods[$usage]}" == copy ]] ; then continue ; fi
add-key-"${methods[$usage]}" "$usage" "${options[$usage]}"
done
for usage in "${!methods[@]}" ; do
if [[ "${methods[$usage]}" != home-pw ]] ; then continue ; fi
add-key-"${methods[$usage]}" "$usage" "${options[$usage]}"
done
for usage in "${!methods[@]}" ; do
if [[ "${methods[$usage]}" != copy ]] ; then continue ; fi
add-key-"${methods[$usage]}" "$usage" "${options[$usage]}"
done
)}
## Creates the LUKS devices specified by the host using the keys created by »populate-keystore«.
function create-luks-layers {( set -eu # (void)
keystore=/run/keystore-@{config.networking.hostName!hashString.sha256:0:8}
for luksName in "@{!config.boot.initrd.luks.devices!catAttrSets.device[@]}" ; do
rawDev=@{config.boot.initrd.luks.devices!catAttrSets.device[$luksName]}
if ! is-partition-on-disks "$rawDev" "${blockDevs[@]}" ; then echo "Partition alias $rawDev used by LUKS device $luksName does not point at one of the target disks ${blockDevs[@]}" ; exit 1 ; fi
primaryKey="$keystore"/luks/"$luksName"/0.key
keyOptions=( --pbkdf=pbkdf2 --pbkdf-force-iterations=1000 )
( PATH=@{native.cryptsetup}/bin ; set -x ; cryptsetup --batch-mode luksFormat --key-file="$primaryKey" "${keyOptions[@]}" -c aes-xts-plain64 -s 512 -h sha256 "$rawDev" )
for index in 1 2 3 4 5 6 7 ; do
if [[ -e "$keystore"/luks/"$luksName"/"$index".key ]] ; then
( PATH=@{native.cryptsetup}/bin ; set -x ; cryptsetup luksAddKey --key-file="$primaryKey" "${keyOptions[@]}" "$rawDev" "$keystore"/luks/"$luksName"/"$index".key )
fi
done
done
)}
## Opens the LUKS devices specified by the host, using the opened host's keystore.
function open-luks-layers { # (void)
keystore=/run/keystore-@{config.networking.hostName!hashString.sha256:0:8}
for luksName in "@{!config.boot.initrd.luks.devices!catAttrSets.device[@]}" ; do
rawDev=@{config.boot.initrd.luks.devices!catAttrSets.device[$luksName]}
primaryKey="$keystore"/luks/"$luksName"/0.key
( PATH=@{native.cryptsetup}/bin ; set -x ; cryptsetup --batch-mode luksOpen --key-file="$primaryKey" "$rawDev" "$luksName" ) &&
prepend_trap "@{native.cryptsetup}/bin/cryptsetup close $luksName" EXIT
done
}