2014-04-14 14:26:48 +00:00
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{ config, lib, pkgs, ... }:
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2010-10-25 00:57:30 +00:00
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2014-04-14 14:26:48 +00:00
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with lib;
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2010-10-25 00:57:30 +00:00
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let
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2012-03-03 16:07:18 +00:00
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luks = config.boot.initrd.luks;
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2020-01-17 09:39:22 +00:00
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kernelPackages = config.boot.kernelPackages;
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2012-03-03 16:07:18 +00:00
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2017-09-15 21:47:36 +00:00
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commonFunctions = ''
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die() {
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2018-10-11 19:52:11 +00:00
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echo "$@" >&2
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exit 1
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2017-09-15 21:47:36 +00:00
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}
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2017-04-04 19:19:38 +00:00
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2018-09-03 17:45:54 +00:00
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dev_exist() {
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2018-10-11 19:52:11 +00:00
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local target="$1"
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if [ -e $target ]; then
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return 0
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else
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local uuid=$(echo -n $target | sed -e 's,UUID=\(.*\),\1,g')
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2018-10-11 19:52:46 +00:00
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blkid --uuid $uuid >/dev/null
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2018-10-11 19:52:11 +00:00
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return $?
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fi
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2018-09-03 17:45:54 +00:00
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}
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2017-04-04 19:19:38 +00:00
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wait_target() {
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local name="$1"
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local target="$2"
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2017-09-15 21:47:36 +00:00
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local secs="''${3:-10}"
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local desc="''${4:-$name $target to appear}"
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2017-04-04 19:19:38 +00:00
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2018-09-03 17:45:54 +00:00
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if ! dev_exist $target; then
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2017-09-15 21:47:36 +00:00
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echo -n "Waiting $secs seconds for $desc..."
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2017-04-04 19:19:38 +00:00
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local success=false;
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2017-09-15 21:47:36 +00:00
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for try in $(seq $secs); do
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2017-04-04 19:19:38 +00:00
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echo -n "."
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sleep 1
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2018-09-03 17:45:54 +00:00
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if dev_exist $target; then
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2017-09-15 21:47:36 +00:00
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success=true
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break
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fi
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2017-04-04 19:19:38 +00:00
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done
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2017-09-15 21:47:36 +00:00
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if [ $success == true ]; then
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2017-04-04 19:19:38 +00:00
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echo " - success";
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2017-09-15 21:47:36 +00:00
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return 0
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2017-04-04 19:19:38 +00:00
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else
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echo " - failure";
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2017-09-15 21:47:36 +00:00
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return 1
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2017-04-04 19:19:38 +00:00
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fi
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fi
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2017-09-15 21:47:36 +00:00
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return 0
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2017-04-04 19:19:38 +00:00
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}
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2017-09-15 21:47:36 +00:00
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wait_yubikey() {
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2018-10-11 19:52:11 +00:00
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local secs="''${1:-10}"
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2017-09-15 21:47:36 +00:00
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2018-10-11 19:52:11 +00:00
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ykinfo -v 1>/dev/null 2>&1
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if [ $? != 0 ]; then
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2020-12-20 21:35:59 +00:00
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echo -n "Waiting $secs seconds for YubiKey to appear..."
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2018-10-11 19:52:11 +00:00
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local success=false
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for try in $(seq $secs); do
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echo -n .
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sleep 1
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ykinfo -v 1>/dev/null 2>&1
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if [ $? == 0 ]; then
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success=true
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break
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fi
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done
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if [ $success == true ]; then
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echo " - success";
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return 0
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else
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echo " - failure";
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return 1
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fi
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fi
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return 0
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2017-09-15 21:47:36 +00:00
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}
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2019-05-09 18:15:35 +00:00
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wait_gpgcard() {
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local secs="''${1:-10}"
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gpg --card-status > /dev/null 2> /dev/null
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if [ $? != 0 ]; then
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echo -n "Waiting $secs seconds for GPG Card to appear"
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local success=false
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for try in $(seq $secs); do
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echo -n .
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sleep 1
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gpg --card-status > /dev/null 2> /dev/null
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if [ $? == 0 ]; then
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success=true
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break
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fi
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done
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if [ $success == true ]; then
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echo " - success";
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return 0
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else
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echo " - failure";
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return 1
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fi
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fi
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return 0
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}
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2017-09-15 21:47:36 +00:00
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'';
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2017-09-15 21:48:51 +00:00
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preCommands = ''
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# A place to store crypto things
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# A ramfs is used here to ensure that the file used to update
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# the key slot with cryptsetup will never get swapped out.
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# Warning: Do NOT replace with tmpfs!
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mkdir -p /crypt-ramfs
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mount -t ramfs none /crypt-ramfs
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2018-06-10 20:18:21 +00:00
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2019-04-28 17:49:32 +00:00
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# Cryptsetup locking directory
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mkdir -p /run/cryptsetup
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2020-12-20 21:35:59 +00:00
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# For YubiKey salt storage
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2018-06-10 20:18:21 +00:00
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mkdir -p /crypt-storage
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2018-06-10 20:18:27 +00:00
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2019-05-09 18:15:35 +00:00
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${optionalString luks.gpgSupport ''
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export GPG_TTY=$(tty)
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export GNUPGHOME=/crypt-ramfs/.gnupg
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gpg-agent --daemon --scdaemon-program $out/bin/scdaemon > /dev/null 2> /dev/null
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''}
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2019-12-10 01:51:19 +00:00
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2018-06-10 20:18:27 +00:00
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# Disable all input echo for the whole stage. We could use read -s
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# instead but that would ocasionally leak characters between read
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# invocations.
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stty -echo
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2017-09-15 21:48:51 +00:00
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'';
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postCommands = ''
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2018-06-10 20:18:27 +00:00
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stty echo
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2018-06-10 20:18:21 +00:00
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umount /crypt-storage 2>/dev/null
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2017-09-15 21:48:51 +00:00
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umount /crypt-ramfs 2>/dev/null
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'';
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2020-06-14 10:03:00 +00:00
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openCommand = name': { name, device, header, keyFile, keyFileSize, keyFileOffset, allowDiscards, yubikey, gpgCard, fido2, fallbackToPassword, preOpenCommands, postOpenCommands,... }: assert name' == name;
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2017-09-15 21:48:51 +00:00
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let
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csopen = "cryptsetup luksOpen ${device} ${name} ${optionalString allowDiscards "--allow-discards"} ${optionalString (header != null) "--header=${header}"}";
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cschange = "cryptsetup luksChangeKey ${device} ${optionalString (header != null) "--header=${header}"}";
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in ''
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2017-04-04 19:19:38 +00:00
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# Wait for luksRoot (and optionally keyFile and/or header) to appear, e.g.
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# if on a USB drive.
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2017-09-15 21:47:36 +00:00
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wait_target "device" ${device} || die "${device} is unavailable"
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2012-03-03 16:07:18 +00:00
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2017-09-15 21:47:36 +00:00
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${optionalString (header != null) ''
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wait_target "header" ${header} || die "${header} is unavailable"
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2017-04-04 19:19:38 +00:00
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''}
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2017-09-15 21:48:51 +00:00
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do_open_passphrase() {
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local passphrase
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while true; do
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echo -n "Passphrase for ${device}: "
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passphrase=
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while true; do
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if [ -e /crypt-ramfs/passphrase ]; then
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echo "reused"
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passphrase=$(cat /crypt-ramfs/passphrase)
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break
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else
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# ask cryptsetup-askpass
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echo -n "${device}" > /crypt-ramfs/device
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2018-06-10 20:18:27 +00:00
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# and try reading it from /dev/console with a timeout
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IFS= read -t 1 -r passphrase
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2017-09-15 21:48:51 +00:00
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if [ -n "$passphrase" ]; then
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${if luks.reusePassphrases then ''
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# remember it for the next device
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echo -n "$passphrase" > /crypt-ramfs/passphrase
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'' else ''
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# Don't save it to ramfs. We are very paranoid
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''}
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echo
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break
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fi
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fi
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done
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2019-01-08 20:39:18 +00:00
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echo -n "Verifying passphrase for ${device}..."
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2017-09-15 21:48:51 +00:00
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echo -n "$passphrase" | ${csopen} --key-file=-
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if [ $? == 0 ]; then
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echo " - success"
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${if luks.reusePassphrases then ''
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# we don't rm here because we might reuse it for the next device
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'' else ''
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rm -f /crypt-ramfs/passphrase
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''}
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break
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else
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echo " - failure"
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# ask for a different one
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rm -f /crypt-ramfs/passphrase
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fi
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done
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}
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2012-05-02 22:37:14 +00:00
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2017-09-15 21:48:51 +00:00
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# LUKS
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2014-01-28 03:02:51 +00:00
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open_normally() {
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2017-09-15 21:48:51 +00:00
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${if (keyFile != null) then ''
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if wait_target "key file" ${keyFile}; then
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${csopen} --key-file=${keyFile} \
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${optionalString (keyFileSize != null) "--keyfile-size=${toString keyFileSize}"} \
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${optionalString (keyFileOffset != null) "--keyfile-offset=${toString keyFileOffset}"}
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2017-10-14 16:08:25 +00:00
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else
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2017-09-15 21:48:51 +00:00
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${if fallbackToPassword then "echo" else "die"} "${keyFile} is unavailable"
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echo " - failing back to interactive password prompt"
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do_open_passphrase
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2017-10-14 16:08:25 +00:00
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fi
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2017-09-15 21:48:51 +00:00
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'' else ''
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do_open_passphrase
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2017-10-14 16:08:25 +00:00
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''}
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2014-01-28 03:02:51 +00:00
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}
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2019-05-09 18:15:35 +00:00
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${optionalString (luks.yubikeySupport && (yubikey != null)) ''
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2020-12-20 21:35:59 +00:00
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# YubiKey
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2014-01-28 03:02:51 +00:00
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rbtohex() {
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Replace the current Yubikey PBA implementation with the previous one.
Rationale:
* The main reason for choosing to implement the PBA in accordance
with the Yubico documentation was to prevent a MITM-USB-attack
successfully recovering the new LUKS key.
* However, a MITM-USB-attacker can read user id and password when
they were entered for PBA, which allows him to recover the new
challenge after the PBA is complete, with which he can challenge
the Yubikey, decrypt the new AES blob and recover the LUKS key.
* Additionally, since the Yubikey shared secret is stored in the
same AES blob, after such an attack not only is the LUKS device
compromised, the Yubikey is as well, since the shared secret
has also been recovered by the attacker.
* Furthermore, with this method an attacker could also bruteforce
the AES blob, if he has access to the unencrypted device, which
would again compromise the Yubikey, should he be successful.
* Finally, with this method, once the LUKS key has been recovered
once, the encryption is permanently broken, while with the previous
system, the LUKS key itself it changed at every successful boot,
so recovering it once will not necessarily result in a permanent
breakage and will also not compromise the Yubikey itself (since
its secret is never stored anywhere but on the Yubikey itself).
Summary:
The current implementation opens up up vulnerability to brute-forcing
the AES blob, while retaining the current MITM-USB attack, additionally
making the consequences of this attack permanent and extending it to
the Yubikey itself.
2014-02-03 21:50:17 +00:00
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( od -An -vtx1 | tr -d ' \n' )
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2014-01-28 03:02:51 +00:00
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}
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hextorb() {
|
Update to the Yubikey PBA
Security-relevant changes:
* No (salted) passphrase hash send to the yubikey, only hash of the salt (as it was in the original implementation).
* Derive $k_luks with PBKDF2 from the yubikey $response (as the PBKDF2 salt) and the passphrase $k_user
(as the PBKDF2 password), so that if two-factor authentication is enabled
(a) a USB-MITM attack on the yubikey itself is not enough to break the system
(b) the potentially low-entropy $k_user is better protected against brute-force attacks
* Instead of using uuidgen, gather the salt (previously random uuid / uuid_r) directly from /dev/random.
* Length of the new salt in byte added as the parameter "saltLength", defaults to 16 byte.
Note: Length of the challenge is 64 byte, so saltLength > 64 may have no benefit over saltLengh = 64.
* Length of $k_luks derived with PBKDF2 in byte added as the parameter "keyLength", defaults to 64 byte.
Example: For a luks device with a 512-bit key, keyLength should be 64.
* Increase of the PBKDF2 iteration count per successful authentication added as the
parameter "iterationStep", defaults to 0.
Other changes:
* Add optional grace period before trying to find the yubikey, defaults to 2 seconds.
Full overview of the yubikey authentication process:
(1) Read $salt and $iterations from unencrypted device (UD).
(2) Calculate the $challenge from the $salt with a hash function.
Chosen instantiation: SHA-512($salt).
(3) Challenge the yubikey with the $challenge and receive the $response.
(4) Repeat three times:
(a) Prompt for the passphrase $k_user.
(b) Derive the key $k_luks for the luks device with a key derivation function from $k_user and $response.
Chosen instantiation: PBKDF2(HMAC-SHA-512, $k_user, $response, $iterations, keyLength).
(c) Try to open the luks device with $k_luks and escape loop (4) only on success.
(5) Proceed only if luks device was opened successfully, fail otherwise.
(6) Gather $new_salt from a cryptographically secure pseudorandom number generator
Chosen instantiation: /dev/random
(7) Calculate the $new_challenge from the $new_salt with the same hash function as (2).
(8) Challenge the yubikey with the $new_challenge and receive the $new_response.
(9) Derive the new key $new_k_luks for the luks device in the same manner as in (4) (b),
but with more iterations as given by iterationStep.
(10) Try to change the luks device's key $k_luks to $new_k_luks.
(11) If (10) was successful, write the $new_salt and the $new_iterations to the UD.
Note: $new_iterations = $iterations + iterationStep
Known (software) attack vectors:
* A MITM attack on the keyboard can recover $k_user. This, combined with a USB-MITM
attack on the yubikey for the $response (1) or the $new_response (2) will result in
(1) $k_luks being recovered,
(2) $new_k_luks being recovered.
* Any attacker with access to the RAM state of stage-1 at mid- or post-authentication
can recover $k_user, $k_luks, and $new_k_luks
* If an attacker has recovered $response or $new_response, he can perform a brute-force
attack on $k_user with it without the Yubikey needing to be present (using cryptsetup's
"luksOpen --verify-passphrase" oracle. He could even make a copy of the luks device's
luks header and run the brute-force attack without further access to the system.
* A USB-MITM attack on the yubikey will allow an attacker to attempt to brute-force
the yubikey's internal key ("shared secret") without it needing to be present anymore.
Credits:
* Florian Klien,
for the original concept and the reference implementation over at
https://github.com/flowolf/initramfs_ykfde
* Anthony Thysse,
for the reference implementation of accessing OpenSSL's PBKDF2 over at
http://www.ict.griffith.edu.au/anthony/software/pbkdf2.c
2014-02-05 16:10:59 +00:00
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|
|
( tr '[:lower:]' '[:upper:]' | sed -e 's/\([0-9A-F]\{2\}\)/\\\\\\x\1/gI' | xargs printf )
|
2014-01-28 03:02:51 +00:00
|
|
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}
|
2014-01-25 02:27:12 +00:00
|
|
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|
2017-09-15 21:48:51 +00:00
|
|
|
do_open_yubikey() {
|
Update to the Yubikey PBA
Security-relevant changes:
* No (salted) passphrase hash send to the yubikey, only hash of the salt (as it was in the original implementation).
* Derive $k_luks with PBKDF2 from the yubikey $response (as the PBKDF2 salt) and the passphrase $k_user
(as the PBKDF2 password), so that if two-factor authentication is enabled
(a) a USB-MITM attack on the yubikey itself is not enough to break the system
(b) the potentially low-entropy $k_user is better protected against brute-force attacks
* Instead of using uuidgen, gather the salt (previously random uuid / uuid_r) directly from /dev/random.
* Length of the new salt in byte added as the parameter "saltLength", defaults to 16 byte.
Note: Length of the challenge is 64 byte, so saltLength > 64 may have no benefit over saltLengh = 64.
* Length of $k_luks derived with PBKDF2 in byte added as the parameter "keyLength", defaults to 64 byte.
Example: For a luks device with a 512-bit key, keyLength should be 64.
* Increase of the PBKDF2 iteration count per successful authentication added as the
parameter "iterationStep", defaults to 0.
Other changes:
* Add optional grace period before trying to find the yubikey, defaults to 2 seconds.
Full overview of the yubikey authentication process:
(1) Read $salt and $iterations from unencrypted device (UD).
(2) Calculate the $challenge from the $salt with a hash function.
Chosen instantiation: SHA-512($salt).
(3) Challenge the yubikey with the $challenge and receive the $response.
(4) Repeat three times:
(a) Prompt for the passphrase $k_user.
(b) Derive the key $k_luks for the luks device with a key derivation function from $k_user and $response.
Chosen instantiation: PBKDF2(HMAC-SHA-512, $k_user, $response, $iterations, keyLength).
(c) Try to open the luks device with $k_luks and escape loop (4) only on success.
(5) Proceed only if luks device was opened successfully, fail otherwise.
(6) Gather $new_salt from a cryptographically secure pseudorandom number generator
Chosen instantiation: /dev/random
(7) Calculate the $new_challenge from the $new_salt with the same hash function as (2).
(8) Challenge the yubikey with the $new_challenge and receive the $new_response.
(9) Derive the new key $new_k_luks for the luks device in the same manner as in (4) (b),
but with more iterations as given by iterationStep.
(10) Try to change the luks device's key $k_luks to $new_k_luks.
(11) If (10) was successful, write the $new_salt and the $new_iterations to the UD.
Note: $new_iterations = $iterations + iterationStep
Known (software) attack vectors:
* A MITM attack on the keyboard can recover $k_user. This, combined with a USB-MITM
attack on the yubikey for the $response (1) or the $new_response (2) will result in
(1) $k_luks being recovered,
(2) $new_k_luks being recovered.
* Any attacker with access to the RAM state of stage-1 at mid- or post-authentication
can recover $k_user, $k_luks, and $new_k_luks
* If an attacker has recovered $response or $new_response, he can perform a brute-force
attack on $k_user with it without the Yubikey needing to be present (using cryptsetup's
"luksOpen --verify-passphrase" oracle. He could even make a copy of the luks device's
luks header and run the brute-force attack without further access to the system.
* A USB-MITM attack on the yubikey will allow an attacker to attempt to brute-force
the yubikey's internal key ("shared secret") without it needing to be present anymore.
Credits:
* Florian Klien,
for the original concept and the reference implementation over at
https://github.com/flowolf/initramfs_ykfde
* Anthony Thysse,
for the reference implementation of accessing OpenSSL's PBKDF2 over at
http://www.ict.griffith.edu.au/anthony/software/pbkdf2.c
2014-02-05 16:10:59 +00:00
|
|
|
# Make all of these local to this function
|
|
|
|
# to prevent their values being leaked
|
|
|
|
local salt
|
|
|
|
local iterations
|
2014-01-28 03:02:51 +00:00
|
|
|
local k_user
|
|
|
|
local challenge
|
Update to the Yubikey PBA
Security-relevant changes:
* No (salted) passphrase hash send to the yubikey, only hash of the salt (as it was in the original implementation).
* Derive $k_luks with PBKDF2 from the yubikey $response (as the PBKDF2 salt) and the passphrase $k_user
(as the PBKDF2 password), so that if two-factor authentication is enabled
(a) a USB-MITM attack on the yubikey itself is not enough to break the system
(b) the potentially low-entropy $k_user is better protected against brute-force attacks
* Instead of using uuidgen, gather the salt (previously random uuid / uuid_r) directly from /dev/random.
* Length of the new salt in byte added as the parameter "saltLength", defaults to 16 byte.
Note: Length of the challenge is 64 byte, so saltLength > 64 may have no benefit over saltLengh = 64.
* Length of $k_luks derived with PBKDF2 in byte added as the parameter "keyLength", defaults to 64 byte.
Example: For a luks device with a 512-bit key, keyLength should be 64.
* Increase of the PBKDF2 iteration count per successful authentication added as the
parameter "iterationStep", defaults to 0.
Other changes:
* Add optional grace period before trying to find the yubikey, defaults to 2 seconds.
Full overview of the yubikey authentication process:
(1) Read $salt and $iterations from unencrypted device (UD).
(2) Calculate the $challenge from the $salt with a hash function.
Chosen instantiation: SHA-512($salt).
(3) Challenge the yubikey with the $challenge and receive the $response.
(4) Repeat three times:
(a) Prompt for the passphrase $k_user.
(b) Derive the key $k_luks for the luks device with a key derivation function from $k_user and $response.
Chosen instantiation: PBKDF2(HMAC-SHA-512, $k_user, $response, $iterations, keyLength).
(c) Try to open the luks device with $k_luks and escape loop (4) only on success.
(5) Proceed only if luks device was opened successfully, fail otherwise.
(6) Gather $new_salt from a cryptographically secure pseudorandom number generator
Chosen instantiation: /dev/random
(7) Calculate the $new_challenge from the $new_salt with the same hash function as (2).
(8) Challenge the yubikey with the $new_challenge and receive the $new_response.
(9) Derive the new key $new_k_luks for the luks device in the same manner as in (4) (b),
but with more iterations as given by iterationStep.
(10) Try to change the luks device's key $k_luks to $new_k_luks.
(11) If (10) was successful, write the $new_salt and the $new_iterations to the UD.
Note: $new_iterations = $iterations + iterationStep
Known (software) attack vectors:
* A MITM attack on the keyboard can recover $k_user. This, combined with a USB-MITM
attack on the yubikey for the $response (1) or the $new_response (2) will result in
(1) $k_luks being recovered,
(2) $new_k_luks being recovered.
* Any attacker with access to the RAM state of stage-1 at mid- or post-authentication
can recover $k_user, $k_luks, and $new_k_luks
* If an attacker has recovered $response or $new_response, he can perform a brute-force
attack on $k_user with it without the Yubikey needing to be present (using cryptsetup's
"luksOpen --verify-passphrase" oracle. He could even make a copy of the luks device's
luks header and run the brute-force attack without further access to the system.
* A USB-MITM attack on the yubikey will allow an attacker to attempt to brute-force
the yubikey's internal key ("shared secret") without it needing to be present anymore.
Credits:
* Florian Klien,
for the original concept and the reference implementation over at
https://github.com/flowolf/initramfs_ykfde
* Anthony Thysse,
for the reference implementation of accessing OpenSSL's PBKDF2 over at
http://www.ict.griffith.edu.au/anthony/software/pbkdf2.c
2014-02-05 16:10:59 +00:00
|
|
|
local response
|
|
|
|
local k_luks
|
Replace the current Yubikey PBA implementation with the previous one.
Rationale:
* The main reason for choosing to implement the PBA in accordance
with the Yubico documentation was to prevent a MITM-USB-attack
successfully recovering the new LUKS key.
* However, a MITM-USB-attacker can read user id and password when
they were entered for PBA, which allows him to recover the new
challenge after the PBA is complete, with which he can challenge
the Yubikey, decrypt the new AES blob and recover the LUKS key.
* Additionally, since the Yubikey shared secret is stored in the
same AES blob, after such an attack not only is the LUKS device
compromised, the Yubikey is as well, since the shared secret
has also been recovered by the attacker.
* Furthermore, with this method an attacker could also bruteforce
the AES blob, if he has access to the unencrypted device, which
would again compromise the Yubikey, should he be successful.
* Finally, with this method, once the LUKS key has been recovered
once, the encryption is permanently broken, while with the previous
system, the LUKS key itself it changed at every successful boot,
so recovering it once will not necessarily result in a permanent
breakage and will also not compromise the Yubikey itself (since
its secret is never stored anywhere but on the Yubikey itself).
Summary:
The current implementation opens up up vulnerability to brute-forcing
the AES blob, while retaining the current MITM-USB attack, additionally
making the consequences of this attack permanent and extending it to
the Yubikey itself.
2014-02-03 21:50:17 +00:00
|
|
|
local opened
|
Update to the Yubikey PBA
Security-relevant changes:
* No (salted) passphrase hash send to the yubikey, only hash of the salt (as it was in the original implementation).
* Derive $k_luks with PBKDF2 from the yubikey $response (as the PBKDF2 salt) and the passphrase $k_user
(as the PBKDF2 password), so that if two-factor authentication is enabled
(a) a USB-MITM attack on the yubikey itself is not enough to break the system
(b) the potentially low-entropy $k_user is better protected against brute-force attacks
* Instead of using uuidgen, gather the salt (previously random uuid / uuid_r) directly from /dev/random.
* Length of the new salt in byte added as the parameter "saltLength", defaults to 16 byte.
Note: Length of the challenge is 64 byte, so saltLength > 64 may have no benefit over saltLengh = 64.
* Length of $k_luks derived with PBKDF2 in byte added as the parameter "keyLength", defaults to 64 byte.
Example: For a luks device with a 512-bit key, keyLength should be 64.
* Increase of the PBKDF2 iteration count per successful authentication added as the
parameter "iterationStep", defaults to 0.
Other changes:
* Add optional grace period before trying to find the yubikey, defaults to 2 seconds.
Full overview of the yubikey authentication process:
(1) Read $salt and $iterations from unencrypted device (UD).
(2) Calculate the $challenge from the $salt with a hash function.
Chosen instantiation: SHA-512($salt).
(3) Challenge the yubikey with the $challenge and receive the $response.
(4) Repeat three times:
(a) Prompt for the passphrase $k_user.
(b) Derive the key $k_luks for the luks device with a key derivation function from $k_user and $response.
Chosen instantiation: PBKDF2(HMAC-SHA-512, $k_user, $response, $iterations, keyLength).
(c) Try to open the luks device with $k_luks and escape loop (4) only on success.
(5) Proceed only if luks device was opened successfully, fail otherwise.
(6) Gather $new_salt from a cryptographically secure pseudorandom number generator
Chosen instantiation: /dev/random
(7) Calculate the $new_challenge from the $new_salt with the same hash function as (2).
(8) Challenge the yubikey with the $new_challenge and receive the $new_response.
(9) Derive the new key $new_k_luks for the luks device in the same manner as in (4) (b),
but with more iterations as given by iterationStep.
(10) Try to change the luks device's key $k_luks to $new_k_luks.
(11) If (10) was successful, write the $new_salt and the $new_iterations to the UD.
Note: $new_iterations = $iterations + iterationStep
Known (software) attack vectors:
* A MITM attack on the keyboard can recover $k_user. This, combined with a USB-MITM
attack on the yubikey for the $response (1) or the $new_response (2) will result in
(1) $k_luks being recovered,
(2) $new_k_luks being recovered.
* Any attacker with access to the RAM state of stage-1 at mid- or post-authentication
can recover $k_user, $k_luks, and $new_k_luks
* If an attacker has recovered $response or $new_response, he can perform a brute-force
attack on $k_user with it without the Yubikey needing to be present (using cryptsetup's
"luksOpen --verify-passphrase" oracle. He could even make a copy of the luks device's
luks header and run the brute-force attack without further access to the system.
* A USB-MITM attack on the yubikey will allow an attacker to attempt to brute-force
the yubikey's internal key ("shared secret") without it needing to be present anymore.
Credits:
* Florian Klien,
for the original concept and the reference implementation over at
https://github.com/flowolf/initramfs_ykfde
* Anthony Thysse,
for the reference implementation of accessing OpenSSL's PBKDF2 over at
http://www.ict.griffith.edu.au/anthony/software/pbkdf2.c
2014-02-05 16:10:59 +00:00
|
|
|
local new_salt
|
|
|
|
local new_iterations
|
|
|
|
local new_challenge
|
|
|
|
local new_response
|
|
|
|
local new_k_luks
|
2014-01-29 16:20:05 +00:00
|
|
|
|
2018-06-10 20:18:21 +00:00
|
|
|
mount -t ${yubikey.storage.fsType} ${yubikey.storage.device} /crypt-storage || \
|
2020-12-20 21:35:59 +00:00
|
|
|
die "Failed to mount YubiKey salt storage device"
|
2014-01-29 16:20:05 +00:00
|
|
|
|
2018-06-10 20:18:21 +00:00
|
|
|
salt="$(cat /crypt-storage${yubikey.storage.path} | sed -n 1p | tr -d '\n')"
|
|
|
|
iterations="$(cat /crypt-storage${yubikey.storage.path} | sed -n 2p | tr -d '\n')"
|
Update to the Yubikey PBA
Security-relevant changes:
* No (salted) passphrase hash send to the yubikey, only hash of the salt (as it was in the original implementation).
* Derive $k_luks with PBKDF2 from the yubikey $response (as the PBKDF2 salt) and the passphrase $k_user
(as the PBKDF2 password), so that if two-factor authentication is enabled
(a) a USB-MITM attack on the yubikey itself is not enough to break the system
(b) the potentially low-entropy $k_user is better protected against brute-force attacks
* Instead of using uuidgen, gather the salt (previously random uuid / uuid_r) directly from /dev/random.
* Length of the new salt in byte added as the parameter "saltLength", defaults to 16 byte.
Note: Length of the challenge is 64 byte, so saltLength > 64 may have no benefit over saltLengh = 64.
* Length of $k_luks derived with PBKDF2 in byte added as the parameter "keyLength", defaults to 64 byte.
Example: For a luks device with a 512-bit key, keyLength should be 64.
* Increase of the PBKDF2 iteration count per successful authentication added as the
parameter "iterationStep", defaults to 0.
Other changes:
* Add optional grace period before trying to find the yubikey, defaults to 2 seconds.
Full overview of the yubikey authentication process:
(1) Read $salt and $iterations from unencrypted device (UD).
(2) Calculate the $challenge from the $salt with a hash function.
Chosen instantiation: SHA-512($salt).
(3) Challenge the yubikey with the $challenge and receive the $response.
(4) Repeat three times:
(a) Prompt for the passphrase $k_user.
(b) Derive the key $k_luks for the luks device with a key derivation function from $k_user and $response.
Chosen instantiation: PBKDF2(HMAC-SHA-512, $k_user, $response, $iterations, keyLength).
(c) Try to open the luks device with $k_luks and escape loop (4) only on success.
(5) Proceed only if luks device was opened successfully, fail otherwise.
(6) Gather $new_salt from a cryptographically secure pseudorandom number generator
Chosen instantiation: /dev/random
(7) Calculate the $new_challenge from the $new_salt with the same hash function as (2).
(8) Challenge the yubikey with the $new_challenge and receive the $new_response.
(9) Derive the new key $new_k_luks for the luks device in the same manner as in (4) (b),
but with more iterations as given by iterationStep.
(10) Try to change the luks device's key $k_luks to $new_k_luks.
(11) If (10) was successful, write the $new_salt and the $new_iterations to the UD.
Note: $new_iterations = $iterations + iterationStep
Known (software) attack vectors:
* A MITM attack on the keyboard can recover $k_user. This, combined with a USB-MITM
attack on the yubikey for the $response (1) or the $new_response (2) will result in
(1) $k_luks being recovered,
(2) $new_k_luks being recovered.
* Any attacker with access to the RAM state of stage-1 at mid- or post-authentication
can recover $k_user, $k_luks, and $new_k_luks
* If an attacker has recovered $response or $new_response, he can perform a brute-force
attack on $k_user with it without the Yubikey needing to be present (using cryptsetup's
"luksOpen --verify-passphrase" oracle. He could even make a copy of the luks device's
luks header and run the brute-force attack without further access to the system.
* A USB-MITM attack on the yubikey will allow an attacker to attempt to brute-force
the yubikey's internal key ("shared secret") without it needing to be present anymore.
Credits:
* Florian Klien,
for the original concept and the reference implementation over at
https://github.com/flowolf/initramfs_ykfde
* Anthony Thysse,
for the reference implementation of accessing OpenSSL's PBKDF2 over at
http://www.ict.griffith.edu.au/anthony/software/pbkdf2.c
2014-02-05 16:10:59 +00:00
|
|
|
challenge="$(echo -n $salt | openssl-wrap dgst -binary -sha512 | rbtohex)"
|
|
|
|
response="$(ykchalresp -${toString yubikey.slot} -x $challenge 2>/dev/null)"
|
2014-01-25 02:27:12 +00:00
|
|
|
|
2014-01-28 03:02:51 +00:00
|
|
|
for try in $(seq 3); do
|
|
|
|
${optionalString yubikey.twoFactor ''
|
2016-07-17 10:25:34 +00:00
|
|
|
echo -n "Enter two-factor passphrase: "
|
2020-12-20 21:24:14 +00:00
|
|
|
k_user=
|
|
|
|
while true; do
|
|
|
|
if [ -e /crypt-ramfs/passphrase ]; then
|
|
|
|
echo "reused"
|
|
|
|
k_user=$(cat /crypt-ramfs/passphrase)
|
|
|
|
break
|
|
|
|
else
|
|
|
|
# Try reading it from /dev/console with a timeout
|
|
|
|
IFS= read -t 1 -r k_user
|
|
|
|
if [ -n "$k_user" ]; then
|
|
|
|
${if luks.reusePassphrases then ''
|
|
|
|
# Remember it for the next device
|
|
|
|
echo -n "$k_user" > /crypt-ramfs/passphrase
|
|
|
|
'' else ''
|
|
|
|
# Don't save it to ramfs. We are very paranoid
|
|
|
|
''}
|
|
|
|
echo
|
|
|
|
break
|
|
|
|
fi
|
|
|
|
fi
|
|
|
|
done
|
2014-01-28 03:02:51 +00:00
|
|
|
''}
|
|
|
|
|
Update to the Yubikey PBA
Security-relevant changes:
* No (salted) passphrase hash send to the yubikey, only hash of the salt (as it was in the original implementation).
* Derive $k_luks with PBKDF2 from the yubikey $response (as the PBKDF2 salt) and the passphrase $k_user
(as the PBKDF2 password), so that if two-factor authentication is enabled
(a) a USB-MITM attack on the yubikey itself is not enough to break the system
(b) the potentially low-entropy $k_user is better protected against brute-force attacks
* Instead of using uuidgen, gather the salt (previously random uuid / uuid_r) directly from /dev/random.
* Length of the new salt in byte added as the parameter "saltLength", defaults to 16 byte.
Note: Length of the challenge is 64 byte, so saltLength > 64 may have no benefit over saltLengh = 64.
* Length of $k_luks derived with PBKDF2 in byte added as the parameter "keyLength", defaults to 64 byte.
Example: For a luks device with a 512-bit key, keyLength should be 64.
* Increase of the PBKDF2 iteration count per successful authentication added as the
parameter "iterationStep", defaults to 0.
Other changes:
* Add optional grace period before trying to find the yubikey, defaults to 2 seconds.
Full overview of the yubikey authentication process:
(1) Read $salt and $iterations from unencrypted device (UD).
(2) Calculate the $challenge from the $salt with a hash function.
Chosen instantiation: SHA-512($salt).
(3) Challenge the yubikey with the $challenge and receive the $response.
(4) Repeat three times:
(a) Prompt for the passphrase $k_user.
(b) Derive the key $k_luks for the luks device with a key derivation function from $k_user and $response.
Chosen instantiation: PBKDF2(HMAC-SHA-512, $k_user, $response, $iterations, keyLength).
(c) Try to open the luks device with $k_luks and escape loop (4) only on success.
(5) Proceed only if luks device was opened successfully, fail otherwise.
(6) Gather $new_salt from a cryptographically secure pseudorandom number generator
Chosen instantiation: /dev/random
(7) Calculate the $new_challenge from the $new_salt with the same hash function as (2).
(8) Challenge the yubikey with the $new_challenge and receive the $new_response.
(9) Derive the new key $new_k_luks for the luks device in the same manner as in (4) (b),
but with more iterations as given by iterationStep.
(10) Try to change the luks device's key $k_luks to $new_k_luks.
(11) If (10) was successful, write the $new_salt and the $new_iterations to the UD.
Note: $new_iterations = $iterations + iterationStep
Known (software) attack vectors:
* A MITM attack on the keyboard can recover $k_user. This, combined with a USB-MITM
attack on the yubikey for the $response (1) or the $new_response (2) will result in
(1) $k_luks being recovered,
(2) $new_k_luks being recovered.
* Any attacker with access to the RAM state of stage-1 at mid- or post-authentication
can recover $k_user, $k_luks, and $new_k_luks
* If an attacker has recovered $response or $new_response, he can perform a brute-force
attack on $k_user with it without the Yubikey needing to be present (using cryptsetup's
"luksOpen --verify-passphrase" oracle. He could even make a copy of the luks device's
luks header and run the brute-force attack without further access to the system.
* A USB-MITM attack on the yubikey will allow an attacker to attempt to brute-force
the yubikey's internal key ("shared secret") without it needing to be present anymore.
Credits:
* Florian Klien,
for the original concept and the reference implementation over at
https://github.com/flowolf/initramfs_ykfde
* Anthony Thysse,
for the reference implementation of accessing OpenSSL's PBKDF2 over at
http://www.ict.griffith.edu.au/anthony/software/pbkdf2.c
2014-02-05 16:10:59 +00:00
|
|
|
if [ ! -z "$k_user" ]; then
|
|
|
|
k_luks="$(echo -n $k_user | pbkdf2-sha512 ${toString yubikey.keyLength} $iterations $response | rbtohex)"
|
|
|
|
else
|
|
|
|
k_luks="$(echo | pbkdf2-sha512 ${toString yubikey.keyLength} $iterations $response | rbtohex)"
|
|
|
|
fi
|
2014-01-29 16:20:05 +00:00
|
|
|
|
2017-09-15 21:48:51 +00:00
|
|
|
echo -n "$k_luks" | hextorb | ${csopen} --key-file=-
|
2014-01-29 16:20:05 +00:00
|
|
|
|
2017-09-15 21:47:36 +00:00
|
|
|
if [ $? == 0 ]; then
|
Replace the current Yubikey PBA implementation with the previous one.
Rationale:
* The main reason for choosing to implement the PBA in accordance
with the Yubico documentation was to prevent a MITM-USB-attack
successfully recovering the new LUKS key.
* However, a MITM-USB-attacker can read user id and password when
they were entered for PBA, which allows him to recover the new
challenge after the PBA is complete, with which he can challenge
the Yubikey, decrypt the new AES blob and recover the LUKS key.
* Additionally, since the Yubikey shared secret is stored in the
same AES blob, after such an attack not only is the LUKS device
compromised, the Yubikey is as well, since the shared secret
has also been recovered by the attacker.
* Furthermore, with this method an attacker could also bruteforce
the AES blob, if he has access to the unencrypted device, which
would again compromise the Yubikey, should he be successful.
* Finally, with this method, once the LUKS key has been recovered
once, the encryption is permanently broken, while with the previous
system, the LUKS key itself it changed at every successful boot,
so recovering it once will not necessarily result in a permanent
breakage and will also not compromise the Yubikey itself (since
its secret is never stored anywhere but on the Yubikey itself).
Summary:
The current implementation opens up up vulnerability to brute-forcing
the AES blob, while retaining the current MITM-USB attack, additionally
making the consequences of this attack permanent and extending it to
the Yubikey itself.
2014-02-03 21:50:17 +00:00
|
|
|
opened=true
|
2020-12-20 21:24:14 +00:00
|
|
|
${if luks.reusePassphrases then ''
|
|
|
|
# We don't rm here because we might reuse it for the next device
|
|
|
|
'' else ''
|
|
|
|
rm -f /crypt-ramfs/passphrase
|
|
|
|
''}
|
Replace the current Yubikey PBA implementation with the previous one.
Rationale:
* The main reason for choosing to implement the PBA in accordance
with the Yubico documentation was to prevent a MITM-USB-attack
successfully recovering the new LUKS key.
* However, a MITM-USB-attacker can read user id and password when
they were entered for PBA, which allows him to recover the new
challenge after the PBA is complete, with which he can challenge
the Yubikey, decrypt the new AES blob and recover the LUKS key.
* Additionally, since the Yubikey shared secret is stored in the
same AES blob, after such an attack not only is the LUKS device
compromised, the Yubikey is as well, since the shared secret
has also been recovered by the attacker.
* Furthermore, with this method an attacker could also bruteforce
the AES blob, if he has access to the unencrypted device, which
would again compromise the Yubikey, should he be successful.
* Finally, with this method, once the LUKS key has been recovered
once, the encryption is permanently broken, while with the previous
system, the LUKS key itself it changed at every successful boot,
so recovering it once will not necessarily result in a permanent
breakage and will also not compromise the Yubikey itself (since
its secret is never stored anywhere but on the Yubikey itself).
Summary:
The current implementation opens up up vulnerability to brute-forcing
the AES blob, while retaining the current MITM-USB attack, additionally
making the consequences of this attack permanent and extending it to
the Yubikey itself.
2014-02-03 21:50:17 +00:00
|
|
|
break
|
2014-01-28 03:02:51 +00:00
|
|
|
else
|
Replace the current Yubikey PBA implementation with the previous one.
Rationale:
* The main reason for choosing to implement the PBA in accordance
with the Yubico documentation was to prevent a MITM-USB-attack
successfully recovering the new LUKS key.
* However, a MITM-USB-attacker can read user id and password when
they were entered for PBA, which allows him to recover the new
challenge after the PBA is complete, with which he can challenge
the Yubikey, decrypt the new AES blob and recover the LUKS key.
* Additionally, since the Yubikey shared secret is stored in the
same AES blob, after such an attack not only is the LUKS device
compromised, the Yubikey is as well, since the shared secret
has also been recovered by the attacker.
* Furthermore, with this method an attacker could also bruteforce
the AES blob, if he has access to the unencrypted device, which
would again compromise the Yubikey, should he be successful.
* Finally, with this method, once the LUKS key has been recovered
once, the encryption is permanently broken, while with the previous
system, the LUKS key itself it changed at every successful boot,
so recovering it once will not necessarily result in a permanent
breakage and will also not compromise the Yubikey itself (since
its secret is never stored anywhere but on the Yubikey itself).
Summary:
The current implementation opens up up vulnerability to brute-forcing
the AES blob, while retaining the current MITM-USB attack, additionally
making the consequences of this attack permanent and extending it to
the Yubikey itself.
2014-02-03 21:50:17 +00:00
|
|
|
opened=false
|
2014-01-29 16:20:05 +00:00
|
|
|
echo "Authentication failed!"
|
2014-01-28 03:02:51 +00:00
|
|
|
fi
|
|
|
|
done
|
|
|
|
|
2018-06-10 20:18:21 +00:00
|
|
|
[ "$opened" == false ] && die "Maximum authentication errors reached"
|
2014-01-25 02:27:12 +00:00
|
|
|
|
Update to the Yubikey PBA
Security-relevant changes:
* No (salted) passphrase hash send to the yubikey, only hash of the salt (as it was in the original implementation).
* Derive $k_luks with PBKDF2 from the yubikey $response (as the PBKDF2 salt) and the passphrase $k_user
(as the PBKDF2 password), so that if two-factor authentication is enabled
(a) a USB-MITM attack on the yubikey itself is not enough to break the system
(b) the potentially low-entropy $k_user is better protected against brute-force attacks
* Instead of using uuidgen, gather the salt (previously random uuid / uuid_r) directly from /dev/random.
* Length of the new salt in byte added as the parameter "saltLength", defaults to 16 byte.
Note: Length of the challenge is 64 byte, so saltLength > 64 may have no benefit over saltLengh = 64.
* Length of $k_luks derived with PBKDF2 in byte added as the parameter "keyLength", defaults to 64 byte.
Example: For a luks device with a 512-bit key, keyLength should be 64.
* Increase of the PBKDF2 iteration count per successful authentication added as the
parameter "iterationStep", defaults to 0.
Other changes:
* Add optional grace period before trying to find the yubikey, defaults to 2 seconds.
Full overview of the yubikey authentication process:
(1) Read $salt and $iterations from unencrypted device (UD).
(2) Calculate the $challenge from the $salt with a hash function.
Chosen instantiation: SHA-512($salt).
(3) Challenge the yubikey with the $challenge and receive the $response.
(4) Repeat three times:
(a) Prompt for the passphrase $k_user.
(b) Derive the key $k_luks for the luks device with a key derivation function from $k_user and $response.
Chosen instantiation: PBKDF2(HMAC-SHA-512, $k_user, $response, $iterations, keyLength).
(c) Try to open the luks device with $k_luks and escape loop (4) only on success.
(5) Proceed only if luks device was opened successfully, fail otherwise.
(6) Gather $new_salt from a cryptographically secure pseudorandom number generator
Chosen instantiation: /dev/random
(7) Calculate the $new_challenge from the $new_salt with the same hash function as (2).
(8) Challenge the yubikey with the $new_challenge and receive the $new_response.
(9) Derive the new key $new_k_luks for the luks device in the same manner as in (4) (b),
but with more iterations as given by iterationStep.
(10) Try to change the luks device's key $k_luks to $new_k_luks.
(11) If (10) was successful, write the $new_salt and the $new_iterations to the UD.
Note: $new_iterations = $iterations + iterationStep
Known (software) attack vectors:
* A MITM attack on the keyboard can recover $k_user. This, combined with a USB-MITM
attack on the yubikey for the $response (1) or the $new_response (2) will result in
(1) $k_luks being recovered,
(2) $new_k_luks being recovered.
* Any attacker with access to the RAM state of stage-1 at mid- or post-authentication
can recover $k_user, $k_luks, and $new_k_luks
* If an attacker has recovered $response or $new_response, he can perform a brute-force
attack on $k_user with it without the Yubikey needing to be present (using cryptsetup's
"luksOpen --verify-passphrase" oracle. He could even make a copy of the luks device's
luks header and run the brute-force attack without further access to the system.
* A USB-MITM attack on the yubikey will allow an attacker to attempt to brute-force
the yubikey's internal key ("shared secret") without it needing to be present anymore.
Credits:
* Florian Klien,
for the original concept and the reference implementation over at
https://github.com/flowolf/initramfs_ykfde
* Anthony Thysse,
for the reference implementation of accessing OpenSSL's PBKDF2 over at
http://www.ict.griffith.edu.au/anthony/software/pbkdf2.c
2014-02-05 16:10:59 +00:00
|
|
|
echo -n "Gathering entropy for new salt (please enter random keys to generate entropy if this blocks for long)..."
|
|
|
|
for i in $(seq ${toString yubikey.saltLength}); do
|
|
|
|
byte="$(dd if=/dev/random bs=1 count=1 2>/dev/null | rbtohex)";
|
|
|
|
new_salt="$new_salt$byte";
|
|
|
|
echo -n .
|
|
|
|
done;
|
|
|
|
echo "ok"
|
2014-01-25 02:27:12 +00:00
|
|
|
|
Update to the Yubikey PBA
Security-relevant changes:
* No (salted) passphrase hash send to the yubikey, only hash of the salt (as it was in the original implementation).
* Derive $k_luks with PBKDF2 from the yubikey $response (as the PBKDF2 salt) and the passphrase $k_user
(as the PBKDF2 password), so that if two-factor authentication is enabled
(a) a USB-MITM attack on the yubikey itself is not enough to break the system
(b) the potentially low-entropy $k_user is better protected against brute-force attacks
* Instead of using uuidgen, gather the salt (previously random uuid / uuid_r) directly from /dev/random.
* Length of the new salt in byte added as the parameter "saltLength", defaults to 16 byte.
Note: Length of the challenge is 64 byte, so saltLength > 64 may have no benefit over saltLengh = 64.
* Length of $k_luks derived with PBKDF2 in byte added as the parameter "keyLength", defaults to 64 byte.
Example: For a luks device with a 512-bit key, keyLength should be 64.
* Increase of the PBKDF2 iteration count per successful authentication added as the
parameter "iterationStep", defaults to 0.
Other changes:
* Add optional grace period before trying to find the yubikey, defaults to 2 seconds.
Full overview of the yubikey authentication process:
(1) Read $salt and $iterations from unencrypted device (UD).
(2) Calculate the $challenge from the $salt with a hash function.
Chosen instantiation: SHA-512($salt).
(3) Challenge the yubikey with the $challenge and receive the $response.
(4) Repeat three times:
(a) Prompt for the passphrase $k_user.
(b) Derive the key $k_luks for the luks device with a key derivation function from $k_user and $response.
Chosen instantiation: PBKDF2(HMAC-SHA-512, $k_user, $response, $iterations, keyLength).
(c) Try to open the luks device with $k_luks and escape loop (4) only on success.
(5) Proceed only if luks device was opened successfully, fail otherwise.
(6) Gather $new_salt from a cryptographically secure pseudorandom number generator
Chosen instantiation: /dev/random
(7) Calculate the $new_challenge from the $new_salt with the same hash function as (2).
(8) Challenge the yubikey with the $new_challenge and receive the $new_response.
(9) Derive the new key $new_k_luks for the luks device in the same manner as in (4) (b),
but with more iterations as given by iterationStep.
(10) Try to change the luks device's key $k_luks to $new_k_luks.
(11) If (10) was successful, write the $new_salt and the $new_iterations to the UD.
Note: $new_iterations = $iterations + iterationStep
Known (software) attack vectors:
* A MITM attack on the keyboard can recover $k_user. This, combined with a USB-MITM
attack on the yubikey for the $response (1) or the $new_response (2) will result in
(1) $k_luks being recovered,
(2) $new_k_luks being recovered.
* Any attacker with access to the RAM state of stage-1 at mid- or post-authentication
can recover $k_user, $k_luks, and $new_k_luks
* If an attacker has recovered $response or $new_response, he can perform a brute-force
attack on $k_user with it without the Yubikey needing to be present (using cryptsetup's
"luksOpen --verify-passphrase" oracle. He could even make a copy of the luks device's
luks header and run the brute-force attack without further access to the system.
* A USB-MITM attack on the yubikey will allow an attacker to attempt to brute-force
the yubikey's internal key ("shared secret") without it needing to be present anymore.
Credits:
* Florian Klien,
for the original concept and the reference implementation over at
https://github.com/flowolf/initramfs_ykfde
* Anthony Thysse,
for the reference implementation of accessing OpenSSL's PBKDF2 over at
http://www.ict.griffith.edu.au/anthony/software/pbkdf2.c
2014-02-05 16:10:59 +00:00
|
|
|
new_iterations="$iterations"
|
|
|
|
${optionalString (yubikey.iterationStep > 0) ''
|
|
|
|
new_iterations="$(($new_iterations + ${toString yubikey.iterationStep}))"
|
|
|
|
''}
|
2014-01-25 02:27:12 +00:00
|
|
|
|
Update to the Yubikey PBA
Security-relevant changes:
* No (salted) passphrase hash send to the yubikey, only hash of the salt (as it was in the original implementation).
* Derive $k_luks with PBKDF2 from the yubikey $response (as the PBKDF2 salt) and the passphrase $k_user
(as the PBKDF2 password), so that if two-factor authentication is enabled
(a) a USB-MITM attack on the yubikey itself is not enough to break the system
(b) the potentially low-entropy $k_user is better protected against brute-force attacks
* Instead of using uuidgen, gather the salt (previously random uuid / uuid_r) directly from /dev/random.
* Length of the new salt in byte added as the parameter "saltLength", defaults to 16 byte.
Note: Length of the challenge is 64 byte, so saltLength > 64 may have no benefit over saltLengh = 64.
* Length of $k_luks derived with PBKDF2 in byte added as the parameter "keyLength", defaults to 64 byte.
Example: For a luks device with a 512-bit key, keyLength should be 64.
* Increase of the PBKDF2 iteration count per successful authentication added as the
parameter "iterationStep", defaults to 0.
Other changes:
* Add optional grace period before trying to find the yubikey, defaults to 2 seconds.
Full overview of the yubikey authentication process:
(1) Read $salt and $iterations from unencrypted device (UD).
(2) Calculate the $challenge from the $salt with a hash function.
Chosen instantiation: SHA-512($salt).
(3) Challenge the yubikey with the $challenge and receive the $response.
(4) Repeat three times:
(a) Prompt for the passphrase $k_user.
(b) Derive the key $k_luks for the luks device with a key derivation function from $k_user and $response.
Chosen instantiation: PBKDF2(HMAC-SHA-512, $k_user, $response, $iterations, keyLength).
(c) Try to open the luks device with $k_luks and escape loop (4) only on success.
(5) Proceed only if luks device was opened successfully, fail otherwise.
(6) Gather $new_salt from a cryptographically secure pseudorandom number generator
Chosen instantiation: /dev/random
(7) Calculate the $new_challenge from the $new_salt with the same hash function as (2).
(8) Challenge the yubikey with the $new_challenge and receive the $new_response.
(9) Derive the new key $new_k_luks for the luks device in the same manner as in (4) (b),
but with more iterations as given by iterationStep.
(10) Try to change the luks device's key $k_luks to $new_k_luks.
(11) If (10) was successful, write the $new_salt and the $new_iterations to the UD.
Note: $new_iterations = $iterations + iterationStep
Known (software) attack vectors:
* A MITM attack on the keyboard can recover $k_user. This, combined with a USB-MITM
attack on the yubikey for the $response (1) or the $new_response (2) will result in
(1) $k_luks being recovered,
(2) $new_k_luks being recovered.
* Any attacker with access to the RAM state of stage-1 at mid- or post-authentication
can recover $k_user, $k_luks, and $new_k_luks
* If an attacker has recovered $response or $new_response, he can perform a brute-force
attack on $k_user with it without the Yubikey needing to be present (using cryptsetup's
"luksOpen --verify-passphrase" oracle. He could even make a copy of the luks device's
luks header and run the brute-force attack without further access to the system.
* A USB-MITM attack on the yubikey will allow an attacker to attempt to brute-force
the yubikey's internal key ("shared secret") without it needing to be present anymore.
Credits:
* Florian Klien,
for the original concept and the reference implementation over at
https://github.com/flowolf/initramfs_ykfde
* Anthony Thysse,
for the reference implementation of accessing OpenSSL's PBKDF2 over at
http://www.ict.griffith.edu.au/anthony/software/pbkdf2.c
2014-02-05 16:10:59 +00:00
|
|
|
new_challenge="$(echo -n $new_salt | openssl-wrap dgst -binary -sha512 | rbtohex)"
|
2014-01-25 02:27:12 +00:00
|
|
|
|
Update to the Yubikey PBA
Security-relevant changes:
* No (salted) passphrase hash send to the yubikey, only hash of the salt (as it was in the original implementation).
* Derive $k_luks with PBKDF2 from the yubikey $response (as the PBKDF2 salt) and the passphrase $k_user
(as the PBKDF2 password), so that if two-factor authentication is enabled
(a) a USB-MITM attack on the yubikey itself is not enough to break the system
(b) the potentially low-entropy $k_user is better protected against brute-force attacks
* Instead of using uuidgen, gather the salt (previously random uuid / uuid_r) directly from /dev/random.
* Length of the new salt in byte added as the parameter "saltLength", defaults to 16 byte.
Note: Length of the challenge is 64 byte, so saltLength > 64 may have no benefit over saltLengh = 64.
* Length of $k_luks derived with PBKDF2 in byte added as the parameter "keyLength", defaults to 64 byte.
Example: For a luks device with a 512-bit key, keyLength should be 64.
* Increase of the PBKDF2 iteration count per successful authentication added as the
parameter "iterationStep", defaults to 0.
Other changes:
* Add optional grace period before trying to find the yubikey, defaults to 2 seconds.
Full overview of the yubikey authentication process:
(1) Read $salt and $iterations from unencrypted device (UD).
(2) Calculate the $challenge from the $salt with a hash function.
Chosen instantiation: SHA-512($salt).
(3) Challenge the yubikey with the $challenge and receive the $response.
(4) Repeat three times:
(a) Prompt for the passphrase $k_user.
(b) Derive the key $k_luks for the luks device with a key derivation function from $k_user and $response.
Chosen instantiation: PBKDF2(HMAC-SHA-512, $k_user, $response, $iterations, keyLength).
(c) Try to open the luks device with $k_luks and escape loop (4) only on success.
(5) Proceed only if luks device was opened successfully, fail otherwise.
(6) Gather $new_salt from a cryptographically secure pseudorandom number generator
Chosen instantiation: /dev/random
(7) Calculate the $new_challenge from the $new_salt with the same hash function as (2).
(8) Challenge the yubikey with the $new_challenge and receive the $new_response.
(9) Derive the new key $new_k_luks for the luks device in the same manner as in (4) (b),
but with more iterations as given by iterationStep.
(10) Try to change the luks device's key $k_luks to $new_k_luks.
(11) If (10) was successful, write the $new_salt and the $new_iterations to the UD.
Note: $new_iterations = $iterations + iterationStep
Known (software) attack vectors:
* A MITM attack on the keyboard can recover $k_user. This, combined with a USB-MITM
attack on the yubikey for the $response (1) or the $new_response (2) will result in
(1) $k_luks being recovered,
(2) $new_k_luks being recovered.
* Any attacker with access to the RAM state of stage-1 at mid- or post-authentication
can recover $k_user, $k_luks, and $new_k_luks
* If an attacker has recovered $response or $new_response, he can perform a brute-force
attack on $k_user with it without the Yubikey needing to be present (using cryptsetup's
"luksOpen --verify-passphrase" oracle. He could even make a copy of the luks device's
luks header and run the brute-force attack without further access to the system.
* A USB-MITM attack on the yubikey will allow an attacker to attempt to brute-force
the yubikey's internal key ("shared secret") without it needing to be present anymore.
Credits:
* Florian Klien,
for the original concept and the reference implementation over at
https://github.com/flowolf/initramfs_ykfde
* Anthony Thysse,
for the reference implementation of accessing OpenSSL's PBKDF2 over at
http://www.ict.griffith.edu.au/anthony/software/pbkdf2.c
2014-02-05 16:10:59 +00:00
|
|
|
new_response="$(ykchalresp -${toString yubikey.slot} -x $new_challenge 2>/dev/null)"
|
2014-01-25 02:27:12 +00:00
|
|
|
|
Update to the Yubikey PBA
Security-relevant changes:
* No (salted) passphrase hash send to the yubikey, only hash of the salt (as it was in the original implementation).
* Derive $k_luks with PBKDF2 from the yubikey $response (as the PBKDF2 salt) and the passphrase $k_user
(as the PBKDF2 password), so that if two-factor authentication is enabled
(a) a USB-MITM attack on the yubikey itself is not enough to break the system
(b) the potentially low-entropy $k_user is better protected against brute-force attacks
* Instead of using uuidgen, gather the salt (previously random uuid / uuid_r) directly from /dev/random.
* Length of the new salt in byte added as the parameter "saltLength", defaults to 16 byte.
Note: Length of the challenge is 64 byte, so saltLength > 64 may have no benefit over saltLengh = 64.
* Length of $k_luks derived with PBKDF2 in byte added as the parameter "keyLength", defaults to 64 byte.
Example: For a luks device with a 512-bit key, keyLength should be 64.
* Increase of the PBKDF2 iteration count per successful authentication added as the
parameter "iterationStep", defaults to 0.
Other changes:
* Add optional grace period before trying to find the yubikey, defaults to 2 seconds.
Full overview of the yubikey authentication process:
(1) Read $salt and $iterations from unencrypted device (UD).
(2) Calculate the $challenge from the $salt with a hash function.
Chosen instantiation: SHA-512($salt).
(3) Challenge the yubikey with the $challenge and receive the $response.
(4) Repeat three times:
(a) Prompt for the passphrase $k_user.
(b) Derive the key $k_luks for the luks device with a key derivation function from $k_user and $response.
Chosen instantiation: PBKDF2(HMAC-SHA-512, $k_user, $response, $iterations, keyLength).
(c) Try to open the luks device with $k_luks and escape loop (4) only on success.
(5) Proceed only if luks device was opened successfully, fail otherwise.
(6) Gather $new_salt from a cryptographically secure pseudorandom number generator
Chosen instantiation: /dev/random
(7) Calculate the $new_challenge from the $new_salt with the same hash function as (2).
(8) Challenge the yubikey with the $new_challenge and receive the $new_response.
(9) Derive the new key $new_k_luks for the luks device in the same manner as in (4) (b),
but with more iterations as given by iterationStep.
(10) Try to change the luks device's key $k_luks to $new_k_luks.
(11) If (10) was successful, write the $new_salt and the $new_iterations to the UD.
Note: $new_iterations = $iterations + iterationStep
Known (software) attack vectors:
* A MITM attack on the keyboard can recover $k_user. This, combined with a USB-MITM
attack on the yubikey for the $response (1) or the $new_response (2) will result in
(1) $k_luks being recovered,
(2) $new_k_luks being recovered.
* Any attacker with access to the RAM state of stage-1 at mid- or post-authentication
can recover $k_user, $k_luks, and $new_k_luks
* If an attacker has recovered $response or $new_response, he can perform a brute-force
attack on $k_user with it without the Yubikey needing to be present (using cryptsetup's
"luksOpen --verify-passphrase" oracle. He could even make a copy of the luks device's
luks header and run the brute-force attack without further access to the system.
* A USB-MITM attack on the yubikey will allow an attacker to attempt to brute-force
the yubikey's internal key ("shared secret") without it needing to be present anymore.
Credits:
* Florian Klien,
for the original concept and the reference implementation over at
https://github.com/flowolf/initramfs_ykfde
* Anthony Thysse,
for the reference implementation of accessing OpenSSL's PBKDF2 over at
http://www.ict.griffith.edu.au/anthony/software/pbkdf2.c
2014-02-05 16:10:59 +00:00
|
|
|
if [ ! -z "$k_user" ]; then
|
|
|
|
new_k_luks="$(echo -n $k_user | pbkdf2-sha512 ${toString yubikey.keyLength} $new_iterations $new_response | rbtohex)"
|
|
|
|
else
|
|
|
|
new_k_luks="$(echo | pbkdf2-sha512 ${toString yubikey.keyLength} $new_iterations $new_response | rbtohex)"
|
|
|
|
fi
|
2014-01-29 16:20:05 +00:00
|
|
|
|
2018-06-10 20:18:21 +00:00
|
|
|
echo -n "$new_k_luks" | hextorb > /crypt-ramfs/new_key
|
|
|
|
echo -n "$k_luks" | hextorb | ${cschange} --key-file=- /crypt-ramfs/new_key
|
Replace the current Yubikey PBA implementation with the previous one.
Rationale:
* The main reason for choosing to implement the PBA in accordance
with the Yubico documentation was to prevent a MITM-USB-attack
successfully recovering the new LUKS key.
* However, a MITM-USB-attacker can read user id and password when
they were entered for PBA, which allows him to recover the new
challenge after the PBA is complete, with which he can challenge
the Yubikey, decrypt the new AES blob and recover the LUKS key.
* Additionally, since the Yubikey shared secret is stored in the
same AES blob, after such an attack not only is the LUKS device
compromised, the Yubikey is as well, since the shared secret
has also been recovered by the attacker.
* Furthermore, with this method an attacker could also bruteforce
the AES blob, if he has access to the unencrypted device, which
would again compromise the Yubikey, should he be successful.
* Finally, with this method, once the LUKS key has been recovered
once, the encryption is permanently broken, while with the previous
system, the LUKS key itself it changed at every successful boot,
so recovering it once will not necessarily result in a permanent
breakage and will also not compromise the Yubikey itself (since
its secret is never stored anywhere but on the Yubikey itself).
Summary:
The current implementation opens up up vulnerability to brute-forcing
the AES blob, while retaining the current MITM-USB attack, additionally
making the consequences of this attack permanent and extending it to
the Yubikey itself.
2014-02-03 21:50:17 +00:00
|
|
|
|
2017-09-15 21:47:36 +00:00
|
|
|
if [ $? == 0 ]; then
|
2018-06-10 20:18:21 +00:00
|
|
|
echo -ne "$new_salt\n$new_iterations" > /crypt-storage${yubikey.storage.path}
|
2014-01-25 02:27:12 +00:00
|
|
|
else
|
Update to the Yubikey PBA
Security-relevant changes:
* No (salted) passphrase hash send to the yubikey, only hash of the salt (as it was in the original implementation).
* Derive $k_luks with PBKDF2 from the yubikey $response (as the PBKDF2 salt) and the passphrase $k_user
(as the PBKDF2 password), so that if two-factor authentication is enabled
(a) a USB-MITM attack on the yubikey itself is not enough to break the system
(b) the potentially low-entropy $k_user is better protected against brute-force attacks
* Instead of using uuidgen, gather the salt (previously random uuid / uuid_r) directly from /dev/random.
* Length of the new salt in byte added as the parameter "saltLength", defaults to 16 byte.
Note: Length of the challenge is 64 byte, so saltLength > 64 may have no benefit over saltLengh = 64.
* Length of $k_luks derived with PBKDF2 in byte added as the parameter "keyLength", defaults to 64 byte.
Example: For a luks device with a 512-bit key, keyLength should be 64.
* Increase of the PBKDF2 iteration count per successful authentication added as the
parameter "iterationStep", defaults to 0.
Other changes:
* Add optional grace period before trying to find the yubikey, defaults to 2 seconds.
Full overview of the yubikey authentication process:
(1) Read $salt and $iterations from unencrypted device (UD).
(2) Calculate the $challenge from the $salt with a hash function.
Chosen instantiation: SHA-512($salt).
(3) Challenge the yubikey with the $challenge and receive the $response.
(4) Repeat three times:
(a) Prompt for the passphrase $k_user.
(b) Derive the key $k_luks for the luks device with a key derivation function from $k_user and $response.
Chosen instantiation: PBKDF2(HMAC-SHA-512, $k_user, $response, $iterations, keyLength).
(c) Try to open the luks device with $k_luks and escape loop (4) only on success.
(5) Proceed only if luks device was opened successfully, fail otherwise.
(6) Gather $new_salt from a cryptographically secure pseudorandom number generator
Chosen instantiation: /dev/random
(7) Calculate the $new_challenge from the $new_salt with the same hash function as (2).
(8) Challenge the yubikey with the $new_challenge and receive the $new_response.
(9) Derive the new key $new_k_luks for the luks device in the same manner as in (4) (b),
but with more iterations as given by iterationStep.
(10) Try to change the luks device's key $k_luks to $new_k_luks.
(11) If (10) was successful, write the $new_salt and the $new_iterations to the UD.
Note: $new_iterations = $iterations + iterationStep
Known (software) attack vectors:
* A MITM attack on the keyboard can recover $k_user. This, combined with a USB-MITM
attack on the yubikey for the $response (1) or the $new_response (2) will result in
(1) $k_luks being recovered,
(2) $new_k_luks being recovered.
* Any attacker with access to the RAM state of stage-1 at mid- or post-authentication
can recover $k_user, $k_luks, and $new_k_luks
* If an attacker has recovered $response or $new_response, he can perform a brute-force
attack on $k_user with it without the Yubikey needing to be present (using cryptsetup's
"luksOpen --verify-passphrase" oracle. He could even make a copy of the luks device's
luks header and run the brute-force attack without further access to the system.
* A USB-MITM attack on the yubikey will allow an attacker to attempt to brute-force
the yubikey's internal key ("shared secret") without it needing to be present anymore.
Credits:
* Florian Klien,
for the original concept and the reference implementation over at
https://github.com/flowolf/initramfs_ykfde
* Anthony Thysse,
for the reference implementation of accessing OpenSSL's PBKDF2 over at
http://www.ict.griffith.edu.au/anthony/software/pbkdf2.c
2014-02-05 16:10:59 +00:00
|
|
|
echo "Warning: Could not update LUKS key, current challenge persists!"
|
2014-01-25 02:27:12 +00:00
|
|
|
fi
|
|
|
|
|
2018-06-10 20:18:21 +00:00
|
|
|
rm -f /crypt-ramfs/new_key
|
|
|
|
umount /crypt-storage
|
2014-01-28 03:02:51 +00:00
|
|
|
}
|
|
|
|
|
2019-05-09 18:15:35 +00:00
|
|
|
open_with_hardware() {
|
2017-09-15 21:48:51 +00:00
|
|
|
if wait_yubikey ${toString yubikey.gracePeriod}; then
|
|
|
|
do_open_yubikey
|
|
|
|
else
|
2020-12-20 21:35:59 +00:00
|
|
|
echo "No YubiKey found, falling back to non-YubiKey open procedure"
|
2017-09-15 21:48:51 +00:00
|
|
|
open_normally
|
|
|
|
fi
|
|
|
|
}
|
2019-05-09 18:15:35 +00:00
|
|
|
''}
|
2014-01-28 03:02:51 +00:00
|
|
|
|
2019-05-09 18:15:35 +00:00
|
|
|
${optionalString (luks.gpgSupport && (gpgCard != null)) ''
|
|
|
|
|
|
|
|
do_open_gpg_card() {
|
|
|
|
# Make all of these local to this function
|
|
|
|
# to prevent their values being leaked
|
|
|
|
local pin
|
|
|
|
local opened
|
|
|
|
|
|
|
|
gpg --import /gpg-keys/${device}/pubkey.asc > /dev/null 2> /dev/null
|
|
|
|
|
|
|
|
gpg --card-status > /dev/null 2> /dev/null
|
|
|
|
|
|
|
|
for try in $(seq 3); do
|
|
|
|
echo -n "PIN for GPG Card associated with device ${device}: "
|
|
|
|
pin=
|
|
|
|
while true; do
|
|
|
|
if [ -e /crypt-ramfs/passphrase ]; then
|
|
|
|
echo "reused"
|
|
|
|
pin=$(cat /crypt-ramfs/passphrase)
|
|
|
|
break
|
|
|
|
else
|
|
|
|
# and try reading it from /dev/console with a timeout
|
|
|
|
IFS= read -t 1 -r pin
|
|
|
|
if [ -n "$pin" ]; then
|
|
|
|
${if luks.reusePassphrases then ''
|
|
|
|
# remember it for the next device
|
|
|
|
echo -n "$pin" > /crypt-ramfs/passphrase
|
|
|
|
'' else ''
|
|
|
|
# Don't save it to ramfs. We are very paranoid
|
|
|
|
''}
|
|
|
|
echo
|
|
|
|
break
|
|
|
|
fi
|
|
|
|
fi
|
|
|
|
done
|
|
|
|
echo -n "Verifying passphrase for ${device}..."
|
|
|
|
echo -n "$pin" | gpg -q --batch --passphrase-fd 0 --pinentry-mode loopback -d /gpg-keys/${device}/cryptkey.gpg 2> /dev/null | ${csopen} --key-file=- > /dev/null 2> /dev/null
|
|
|
|
if [ $? == 0 ]; then
|
|
|
|
echo " - success"
|
|
|
|
${if luks.reusePassphrases then ''
|
|
|
|
# we don't rm here because we might reuse it for the next device
|
|
|
|
'' else ''
|
|
|
|
rm -f /crypt-ramfs/passphrase
|
|
|
|
''}
|
|
|
|
break
|
|
|
|
else
|
|
|
|
echo " - failure"
|
|
|
|
# ask for a different one
|
|
|
|
rm -f /crypt-ramfs/passphrase
|
|
|
|
fi
|
|
|
|
done
|
|
|
|
|
|
|
|
[ "$opened" == false ] && die "Maximum authentication errors reached"
|
|
|
|
}
|
|
|
|
|
|
|
|
open_with_hardware() {
|
|
|
|
if wait_gpgcard ${toString gpgCard.gracePeriod}; then
|
|
|
|
do_open_gpg_card
|
|
|
|
else
|
|
|
|
echo "No GPG Card found, falling back to normal open procedure"
|
|
|
|
open_normally
|
|
|
|
fi
|
|
|
|
}
|
|
|
|
''}
|
|
|
|
|
2020-01-13 11:07:48 +00:00
|
|
|
${optionalString (luks.fido2Support && (fido2.credential != null)) ''
|
|
|
|
|
|
|
|
open_with_hardware() {
|
|
|
|
local passsphrase
|
|
|
|
|
2020-01-17 09:39:22 +00:00
|
|
|
${if fido2.passwordLess then ''
|
|
|
|
export passphrase=""
|
|
|
|
'' else ''
|
|
|
|
read -rsp "FIDO2 salt for ${device}: " passphrase
|
|
|
|
echo
|
|
|
|
''}
|
|
|
|
${optionalString (lib.versionOlder kernelPackages.kernel.version "5.4") ''
|
|
|
|
echo "On systems with Linux Kernel < 5.4, it might take a while to initialize the CRNG, you might want to use linuxPackages_latest."
|
|
|
|
echo "Please move your mouse to create needed randomness."
|
|
|
|
''}
|
|
|
|
echo "Waiting for your FIDO2 device..."
|
2020-10-13 09:01:23 +00:00
|
|
|
fido2luks open ${device} ${name} ${fido2.credential} --await-dev ${toString fido2.gracePeriod} --salt string:$passphrase
|
2020-01-17 09:39:22 +00:00
|
|
|
if [ $? -ne 0 ]; then
|
|
|
|
echo "No FIDO2 key found, falling back to normal open procedure"
|
|
|
|
open_normally
|
2020-01-13 11:07:48 +00:00
|
|
|
fi
|
|
|
|
}
|
|
|
|
''}
|
|
|
|
|
2020-06-14 10:03:00 +00:00
|
|
|
# commands to run right before we mount our device
|
|
|
|
${preOpenCommands}
|
|
|
|
|
2020-01-13 11:07:48 +00:00
|
|
|
${if (luks.yubikeySupport && (yubikey != null)) || (luks.gpgSupport && (gpgCard != null)) || (luks.fido2Support && (fido2.credential != null)) then ''
|
2019-05-09 18:15:35 +00:00
|
|
|
open_with_hardware
|
2017-09-15 21:48:51 +00:00
|
|
|
'' else ''
|
2014-01-28 03:02:51 +00:00
|
|
|
open_normally
|
2014-01-25 02:27:12 +00:00
|
|
|
''}
|
2020-06-14 10:03:00 +00:00
|
|
|
|
|
|
|
# commands to run right after we mounted our device
|
|
|
|
${postOpenCommands}
|
2012-03-03 16:07:18 +00:00
|
|
|
'';
|
|
|
|
|
2017-09-15 21:48:51 +00:00
|
|
|
askPass = pkgs.writeScriptBin "cryptsetup-askpass" ''
|
|
|
|
#!/bin/sh
|
|
|
|
|
|
|
|
${commonFunctions}
|
|
|
|
|
|
|
|
while true; do
|
|
|
|
wait_target "luks" /crypt-ramfs/device 10 "LUKS to request a passphrase" || die "Passphrase is not requested now"
|
|
|
|
device=$(cat /crypt-ramfs/device)
|
|
|
|
|
|
|
|
echo -n "Passphrase for $device: "
|
|
|
|
IFS= read -rs passphrase
|
|
|
|
echo
|
|
|
|
|
|
|
|
rm /crypt-ramfs/device
|
|
|
|
echo -n "$passphrase" > /crypt-ramfs/passphrase
|
|
|
|
done
|
|
|
|
'';
|
|
|
|
|
2016-05-25 11:23:32 +00:00
|
|
|
preLVM = filterAttrs (n: v: v.preLVM) luks.devices;
|
|
|
|
postLVM = filterAttrs (n: v: !v.preLVM) luks.devices;
|
2012-03-04 21:00:35 +00:00
|
|
|
|
2010-10-25 00:57:30 +00:00
|
|
|
in
|
|
|
|
{
|
2019-12-10 01:51:19 +00:00
|
|
|
imports = [
|
|
|
|
(mkRemovedOptionModule [ "boot" "initrd" "luks" "enable" ] "")
|
|
|
|
];
|
2010-10-25 00:57:30 +00:00
|
|
|
|
|
|
|
options = {
|
|
|
|
|
2013-01-13 09:04:26 +00:00
|
|
|
boot.initrd.luks.mitigateDMAAttacks = mkOption {
|
2013-10-23 16:22:26 +00:00
|
|
|
type = types.bool;
|
2013-01-13 09:04:26 +00:00
|
|
|
default = true;
|
|
|
|
description = ''
|
2013-07-23 16:56:12 +00:00
|
|
|
Unless enabled, encryption keys can be easily recovered by an attacker with physical
|
|
|
|
access to any machine with PCMCIA, ExpressCard, ThunderBolt or FireWire port.
|
2014-12-15 15:30:21 +00:00
|
|
|
More information is available at <link xlink:href="http://en.wikipedia.org/wiki/DMA_attack"/>.
|
2013-01-13 09:04:26 +00:00
|
|
|
|
2013-07-23 16:56:12 +00:00
|
|
|
This option blacklists FireWire drivers, but doesn't remove them. You can manually
|
|
|
|
load the drivers if you need to use a FireWire device, but don't forget to unload them!
|
2013-01-13 09:04:26 +00:00
|
|
|
'';
|
|
|
|
};
|
|
|
|
|
2013-01-13 10:44:16 +00:00
|
|
|
boot.initrd.luks.cryptoModules = mkOption {
|
2015-06-15 16:18:46 +00:00
|
|
|
type = types.listOf types.str;
|
2013-07-23 16:56:12 +00:00
|
|
|
default =
|
2013-10-09 17:11:47 +00:00
|
|
|
[ "aes" "aes_generic" "blowfish" "twofish"
|
|
|
|
"serpent" "cbc" "xts" "lrw" "sha1" "sha256" "sha512"
|
2019-06-07 20:15:35 +00:00
|
|
|
"af_alg" "algif_skcipher"
|
2013-07-23 16:56:12 +00:00
|
|
|
];
|
2013-01-13 10:44:16 +00:00
|
|
|
description = ''
|
2013-07-23 16:56:12 +00:00
|
|
|
A list of cryptographic kernel modules needed to decrypt the root device(s).
|
|
|
|
The default includes all common modules.
|
2013-01-13 10:44:16 +00:00
|
|
|
'';
|
|
|
|
};
|
|
|
|
|
2017-09-14 02:44:14 +00:00
|
|
|
boot.initrd.luks.forceLuksSupportInInitrd = mkOption {
|
|
|
|
type = types.bool;
|
|
|
|
default = false;
|
|
|
|
internal = true;
|
|
|
|
description = ''
|
|
|
|
Whether to configure luks support in the initrd, when no luks
|
|
|
|
devices are configured.
|
|
|
|
'';
|
|
|
|
};
|
|
|
|
|
2017-09-15 21:48:51 +00:00
|
|
|
boot.initrd.luks.reusePassphrases = mkOption {
|
|
|
|
type = types.bool;
|
|
|
|
default = true;
|
|
|
|
description = ''
|
|
|
|
When opening a new LUKS device try reusing last successful
|
|
|
|
passphrase.
|
|
|
|
|
|
|
|
Useful for mounting a number of devices that use the same
|
|
|
|
passphrase without retyping it several times.
|
|
|
|
|
|
|
|
Such setup can be useful if you use <command>cryptsetup
|
|
|
|
luksSuspend</command>. Different LUKS devices will still have
|
|
|
|
different master keys even when using the same passphrase.
|
|
|
|
'';
|
|
|
|
};
|
|
|
|
|
2012-03-03 16:07:18 +00:00
|
|
|
boot.initrd.luks.devices = mkOption {
|
2016-05-25 11:23:32 +00:00
|
|
|
default = { };
|
2019-08-13 21:52:01 +00:00
|
|
|
example = { luksroot.device = "/dev/disk/by-uuid/430e9eff-d852-4f68-aa3b-2fa3599ebe08"; };
|
2012-05-15 20:45:01 +00:00
|
|
|
description = ''
|
2016-05-25 11:23:32 +00:00
|
|
|
The encrypted disk that should be opened before the root
|
|
|
|
filesystem is mounted. Both LVM-over-LUKS and LUKS-over-LVM
|
2017-07-02 02:37:51 +00:00
|
|
|
setups are supported. The unencrypted devices can be accessed as
|
2016-05-25 11:23:32 +00:00
|
|
|
<filename>/dev/mapper/<replaceable>name</replaceable></filename>.
|
2010-10-25 00:57:30 +00:00
|
|
|
'';
|
2012-03-04 21:00:35 +00:00
|
|
|
|
2020-08-22 23:28:45 +00:00
|
|
|
type = with types; attrsOf (submodule (
|
2016-09-11 09:58:26 +00:00
|
|
|
{ name, ... }: { options = {
|
|
|
|
|
|
|
|
name = mkOption {
|
|
|
|
visible = false;
|
|
|
|
default = name;
|
|
|
|
example = "luksroot";
|
|
|
|
type = types.str;
|
|
|
|
description = "Name of the unencrypted device in <filename>/dev/mapper</filename>.";
|
|
|
|
};
|
2014-01-25 02:27:12 +00:00
|
|
|
|
2016-09-11 09:58:26 +00:00
|
|
|
device = mkOption {
|
|
|
|
example = "/dev/disk/by-uuid/430e9eff-d852-4f68-aa3b-2fa3599ebe08";
|
|
|
|
type = types.str;
|
|
|
|
description = "Path of the underlying encrypted block device.";
|
|
|
|
};
|
2014-08-29 16:43:03 +00:00
|
|
|
|
2016-09-11 09:58:26 +00:00
|
|
|
header = mkOption {
|
|
|
|
default = null;
|
|
|
|
example = "/root/header.img";
|
|
|
|
type = types.nullOr types.str;
|
|
|
|
description = ''
|
|
|
|
The name of the file or block device that
|
|
|
|
should be used as header for the encrypted device.
|
|
|
|
'';
|
|
|
|
};
|
2014-08-29 16:43:03 +00:00
|
|
|
|
2016-09-11 09:58:26 +00:00
|
|
|
keyFile = mkOption {
|
|
|
|
default = null;
|
|
|
|
example = "/dev/sdb1";
|
|
|
|
type = types.nullOr types.str;
|
|
|
|
description = ''
|
|
|
|
The name of the file (can be a raw device or a partition) that
|
|
|
|
should be used as the decryption key for the encrypted device. If
|
|
|
|
not specified, you will be prompted for a passphrase instead.
|
|
|
|
'';
|
|
|
|
};
|
|
|
|
|
|
|
|
keyFileSize = mkOption {
|
|
|
|
default = null;
|
|
|
|
example = 4096;
|
|
|
|
type = types.nullOr types.int;
|
|
|
|
description = ''
|
|
|
|
The size of the key file. Use this if only the beginning of the
|
|
|
|
key file should be used as a key (often the case if a raw device
|
|
|
|
or partition is used as key file). If not specified, the whole
|
|
|
|
<literal>keyFile</literal> will be used decryption, instead of just
|
|
|
|
the first <literal>keyFileSize</literal> bytes.
|
|
|
|
'';
|
|
|
|
};
|
|
|
|
|
2018-06-03 19:25:06 +00:00
|
|
|
keyFileOffset = mkOption {
|
|
|
|
default = null;
|
|
|
|
example = 4096;
|
|
|
|
type = types.nullOr types.int;
|
|
|
|
description = ''
|
|
|
|
The offset of the key file. Use this in combination with
|
|
|
|
<literal>keyFileSize</literal> to use part of a file as key file
|
|
|
|
(often the case if a raw device or partition is used as a key file).
|
|
|
|
If not specified, the key begins at the first byte of
|
|
|
|
<literal>keyFile</literal>.
|
|
|
|
'';
|
|
|
|
};
|
|
|
|
|
2016-09-11 09:58:26 +00:00
|
|
|
# FIXME: get rid of this option.
|
|
|
|
preLVM = mkOption {
|
|
|
|
default = true;
|
|
|
|
type = types.bool;
|
|
|
|
description = "Whether the luksOpen will be attempted before LVM scan or after it.";
|
|
|
|
};
|
|
|
|
|
|
|
|
allowDiscards = mkOption {
|
|
|
|
default = false;
|
|
|
|
type = types.bool;
|
|
|
|
description = ''
|
|
|
|
Whether to allow TRIM requests to the underlying device. This option
|
|
|
|
has security implications; please read the LUKS documentation before
|
|
|
|
activating it.
|
|
|
|
'';
|
|
|
|
};
|
2014-08-29 16:43:03 +00:00
|
|
|
|
2017-12-14 12:43:14 +00:00
|
|
|
fallbackToPassword = mkOption {
|
2017-10-23 20:22:26 +00:00
|
|
|
default = false;
|
|
|
|
type = types.bool;
|
|
|
|
description = ''
|
|
|
|
Whether to fallback to interactive passphrase prompt if the keyfile
|
|
|
|
cannot be found. This will prevent unattended boot should the keyfile
|
|
|
|
go missing.
|
|
|
|
'';
|
|
|
|
};
|
|
|
|
|
2019-05-09 18:15:35 +00:00
|
|
|
gpgCard = mkOption {
|
|
|
|
default = null;
|
|
|
|
description = ''
|
|
|
|
The option to use this LUKS device with a GPG encrypted luks password by the GPG Smartcard.
|
|
|
|
If null (the default), GPG-Smartcard will be disabled for this device.
|
|
|
|
'';
|
|
|
|
|
|
|
|
type = with types; nullOr (submodule {
|
|
|
|
options = {
|
|
|
|
gracePeriod = mkOption {
|
|
|
|
default = 10;
|
|
|
|
type = types.int;
|
|
|
|
description = "Time in seconds to wait for the GPG Smartcard.";
|
|
|
|
};
|
|
|
|
|
|
|
|
encryptedPass = mkOption {
|
|
|
|
default = "";
|
|
|
|
type = types.path;
|
|
|
|
description = "Path to the GPG encrypted passphrase.";
|
|
|
|
};
|
|
|
|
|
|
|
|
publicKey = mkOption {
|
|
|
|
default = "";
|
|
|
|
type = types.path;
|
|
|
|
description = "Path to the Public Key.";
|
|
|
|
};
|
|
|
|
};
|
|
|
|
});
|
|
|
|
};
|
|
|
|
|
2020-01-13 11:07:48 +00:00
|
|
|
fido2 = {
|
|
|
|
credential = mkOption {
|
|
|
|
default = null;
|
|
|
|
example = "f1d00200d8dc783f7fb1e10ace8da27f8312d72692abfca2f7e4960a73f48e82e1f7571f6ebfcee9fb434f9886ccc8fcc52a6614d8d2";
|
2020-04-28 17:13:21 +00:00
|
|
|
type = types.nullOr types.str;
|
2020-01-13 11:07:48 +00:00
|
|
|
description = "The FIDO2 credential ID.";
|
|
|
|
};
|
|
|
|
|
|
|
|
gracePeriod = mkOption {
|
|
|
|
default = 10;
|
|
|
|
type = types.int;
|
|
|
|
description = "Time in seconds to wait for the FIDO2 key.";
|
|
|
|
};
|
|
|
|
|
|
|
|
passwordLess = mkOption {
|
|
|
|
default = false;
|
|
|
|
type = types.bool;
|
|
|
|
description = ''
|
|
|
|
Defines whatever to use an empty string as a default salt.
|
|
|
|
|
|
|
|
Enable only when your device is PIN protected, such as <link xlink:href="https://trezor.io/">Trezor</link>.
|
|
|
|
'';
|
|
|
|
};
|
|
|
|
};
|
|
|
|
|
2016-09-11 09:58:26 +00:00
|
|
|
yubikey = mkOption {
|
|
|
|
default = null;
|
|
|
|
description = ''
|
2020-12-20 21:35:59 +00:00
|
|
|
The options to use for this LUKS device in YubiKey-PBA.
|
|
|
|
If null (the default), YubiKey-PBA will be disabled for this device.
|
2016-09-11 09:58:26 +00:00
|
|
|
'';
|
|
|
|
|
|
|
|
type = with types; nullOr (submodule {
|
|
|
|
options = {
|
|
|
|
twoFactor = mkOption {
|
|
|
|
default = true;
|
|
|
|
type = types.bool;
|
2020-12-20 21:35:59 +00:00
|
|
|
description = "Whether to use a passphrase and a YubiKey (true), or only a YubiKey (false).";
|
2016-09-11 09:58:26 +00:00
|
|
|
};
|
|
|
|
|
|
|
|
slot = mkOption {
|
|
|
|
default = 2;
|
|
|
|
type = types.int;
|
2020-12-20 21:35:59 +00:00
|
|
|
description = "Which slot on the YubiKey to challenge.";
|
2016-09-11 09:58:26 +00:00
|
|
|
};
|
|
|
|
|
|
|
|
saltLength = mkOption {
|
|
|
|
default = 16;
|
|
|
|
type = types.int;
|
|
|
|
description = "Length of the new salt in byte (64 is the effective maximum).";
|
|
|
|
};
|
|
|
|
|
|
|
|
keyLength = mkOption {
|
|
|
|
default = 64;
|
|
|
|
type = types.int;
|
|
|
|
description = "Length of the LUKS slot key derived with PBKDF2 in byte.";
|
|
|
|
};
|
|
|
|
|
|
|
|
iterationStep = mkOption {
|
|
|
|
default = 0;
|
|
|
|
type = types.int;
|
|
|
|
description = "How much the iteration count for PBKDF2 is increased at each successful authentication.";
|
|
|
|
};
|
|
|
|
|
|
|
|
gracePeriod = mkOption {
|
2017-09-15 21:47:36 +00:00
|
|
|
default = 10;
|
2016-09-11 09:58:26 +00:00
|
|
|
type = types.int;
|
2020-12-20 21:35:59 +00:00
|
|
|
description = "Time in seconds to wait for the YubiKey.";
|
2016-09-11 09:58:26 +00:00
|
|
|
};
|
|
|
|
|
|
|
|
/* TODO: Add to the documentation of the current module:
|
|
|
|
|
|
|
|
Options related to the storing the salt.
|
|
|
|
*/
|
|
|
|
storage = {
|
|
|
|
device = mkOption {
|
|
|
|
default = "/dev/sda1";
|
|
|
|
type = types.path;
|
|
|
|
description = ''
|
|
|
|
An unencrypted device that will temporarily be mounted in stage-1.
|
|
|
|
Must contain the current salt to create the challenge for this LUKS device.
|
|
|
|
'';
|
|
|
|
};
|
|
|
|
|
|
|
|
fsType = mkOption {
|
|
|
|
default = "vfat";
|
|
|
|
type = types.str;
|
|
|
|
description = "The filesystem of the unencrypted device.";
|
|
|
|
};
|
|
|
|
|
|
|
|
path = mkOption {
|
|
|
|
default = "/crypt-storage/default";
|
|
|
|
type = types.str;
|
|
|
|
description = ''
|
|
|
|
Absolute path of the salt on the unencrypted device with
|
|
|
|
that device's root directory as "/".
|
|
|
|
'';
|
|
|
|
};
|
|
|
|
};
|
2014-01-25 02:27:12 +00:00
|
|
|
};
|
2016-09-11 09:58:26 +00:00
|
|
|
});
|
2014-01-25 02:27:12 +00:00
|
|
|
};
|
2020-06-14 10:03:00 +00:00
|
|
|
|
|
|
|
preOpenCommands = mkOption {
|
|
|
|
type = types.lines;
|
|
|
|
default = "";
|
|
|
|
example = ''
|
|
|
|
mkdir -p /tmp/persistent
|
|
|
|
mount -t zfs rpool/safe/persistent /tmp/persistent
|
|
|
|
'';
|
|
|
|
description = ''
|
|
|
|
Commands that should be run right before we try to mount our LUKS device.
|
|
|
|
This can be useful, if the keys needed to open the drive is on another partion.
|
|
|
|
'';
|
|
|
|
};
|
|
|
|
|
|
|
|
postOpenCommands = mkOption {
|
|
|
|
type = types.lines;
|
|
|
|
default = "";
|
|
|
|
example = ''
|
|
|
|
umount /tmp/persistent
|
|
|
|
'';
|
|
|
|
description = ''
|
|
|
|
Commands that should be run right after we have mounted our LUKS device.
|
|
|
|
'';
|
|
|
|
};
|
2018-06-10 20:18:21 +00:00
|
|
|
};
|
|
|
|
}));
|
2010-10-25 00:57:30 +00:00
|
|
|
};
|
2013-10-23 16:22:26 +00:00
|
|
|
|
2019-05-09 18:15:35 +00:00
|
|
|
boot.initrd.luks.gpgSupport = mkOption {
|
|
|
|
default = false;
|
|
|
|
type = types.bool;
|
|
|
|
description = ''
|
|
|
|
Enables support for authenticating with a GPG encrypted password.
|
|
|
|
'';
|
|
|
|
};
|
|
|
|
|
2014-01-25 02:27:12 +00:00
|
|
|
boot.initrd.luks.yubikeySupport = mkOption {
|
|
|
|
default = false;
|
|
|
|
type = types.bool;
|
2014-01-28 22:45:16 +00:00
|
|
|
description = ''
|
2020-12-20 21:35:59 +00:00
|
|
|
Enables support for authenticating with a YubiKey on LUKS devices.
|
2014-01-28 22:45:16 +00:00
|
|
|
See the NixOS wiki for information on how to properly setup a LUKS device
|
2020-12-20 21:35:59 +00:00
|
|
|
and a YubiKey to work with this feature.
|
2014-01-28 22:45:16 +00:00
|
|
|
'';
|
2014-01-25 02:27:12 +00:00
|
|
|
};
|
2020-01-13 11:07:48 +00:00
|
|
|
|
|
|
|
boot.initrd.luks.fido2Support = mkOption {
|
|
|
|
default = false;
|
|
|
|
type = types.bool;
|
|
|
|
description = ''
|
|
|
|
Enables support for authenticating with FIDO2 devices.
|
|
|
|
'';
|
|
|
|
};
|
|
|
|
|
2010-10-25 00:57:30 +00:00
|
|
|
};
|
|
|
|
|
2017-09-14 02:44:14 +00:00
|
|
|
config = mkIf (luks.devices != {} || luks.forceLuksSupportInInitrd) {
|
2010-10-25 00:57:30 +00:00
|
|
|
|
2019-05-09 18:15:35 +00:00
|
|
|
assertions =
|
|
|
|
[ { assertion = !(luks.gpgSupport && luks.yubikeySupport);
|
2020-12-20 21:35:59 +00:00
|
|
|
message = "YubiKey and GPG Card may not be used at the same time.";
|
2019-05-09 18:15:35 +00:00
|
|
|
}
|
2020-01-13 11:07:48 +00:00
|
|
|
|
|
|
|
{ assertion = !(luks.gpgSupport && luks.fido2Support);
|
|
|
|
message = "FIDO2 and GPG Card may not be used at the same time.";
|
|
|
|
}
|
|
|
|
|
|
|
|
{ assertion = !(luks.fido2Support && luks.yubikeySupport);
|
2020-12-20 21:35:59 +00:00
|
|
|
message = "FIDO2 and YubiKey may not be used at the same time.";
|
2020-01-13 11:07:48 +00:00
|
|
|
}
|
2019-05-09 18:15:35 +00:00
|
|
|
];
|
|
|
|
|
2013-01-13 09:04:26 +00:00
|
|
|
# actually, sbp2 driver is the one enabling the DMA attack, but this needs to be tested
|
|
|
|
boot.blacklistedKernelModules = optionals luks.mitigateDMAAttacks
|
|
|
|
["firewire_ohci" "firewire_core" "firewire_sbp2"];
|
|
|
|
|
2012-03-03 16:07:18 +00:00
|
|
|
# Some modules that may be needed for mounting anything ciphered
|
2017-12-18 23:57:45 +00:00
|
|
|
boot.initrd.availableKernelModules = [ "dm_mod" "dm_crypt" "cryptd" "input_leds" ]
|
2018-02-25 20:36:19 +00:00
|
|
|
++ luks.cryptoModules
|
|
|
|
# workaround until https://marc.info/?l=linux-crypto-vger&m=148783562211457&w=4 is merged
|
|
|
|
# remove once 'modprobe --show-depends xts' shows ecb as a dependency
|
|
|
|
++ (if builtins.elem "xts" luks.cryptoModules then ["ecb"] else []);
|
2010-10-25 00:57:30 +00:00
|
|
|
|
2011-12-28 21:46:40 +00:00
|
|
|
# copy the cryptsetup binary and it's dependencies
|
2010-10-25 00:57:30 +00:00
|
|
|
boot.initrd.extraUtilsCommands = ''
|
2015-03-29 00:15:41 +00:00
|
|
|
copy_bin_and_libs ${pkgs.cryptsetup}/bin/cryptsetup
|
2017-09-15 21:48:51 +00:00
|
|
|
copy_bin_and_libs ${askPass}/bin/cryptsetup-askpass
|
|
|
|
sed -i s,/bin/sh,$out/bin/sh, $out/bin/cryptsetup-askpass
|
2015-10-18 10:50:36 +00:00
|
|
|
|
2014-01-25 02:27:12 +00:00
|
|
|
${optionalString luks.yubikeySupport ''
|
2017-03-11 21:23:00 +00:00
|
|
|
copy_bin_and_libs ${pkgs.yubikey-personalization}/bin/ykchalresp
|
|
|
|
copy_bin_and_libs ${pkgs.yubikey-personalization}/bin/ykinfo
|
2016-02-01 18:46:16 +00:00
|
|
|
copy_bin_and_libs ${pkgs.openssl.bin}/bin/openssl
|
Update to the Yubikey PBA
Security-relevant changes:
* No (salted) passphrase hash send to the yubikey, only hash of the salt (as it was in the original implementation).
* Derive $k_luks with PBKDF2 from the yubikey $response (as the PBKDF2 salt) and the passphrase $k_user
(as the PBKDF2 password), so that if two-factor authentication is enabled
(a) a USB-MITM attack on the yubikey itself is not enough to break the system
(b) the potentially low-entropy $k_user is better protected against brute-force attacks
* Instead of using uuidgen, gather the salt (previously random uuid / uuid_r) directly from /dev/random.
* Length of the new salt in byte added as the parameter "saltLength", defaults to 16 byte.
Note: Length of the challenge is 64 byte, so saltLength > 64 may have no benefit over saltLengh = 64.
* Length of $k_luks derived with PBKDF2 in byte added as the parameter "keyLength", defaults to 64 byte.
Example: For a luks device with a 512-bit key, keyLength should be 64.
* Increase of the PBKDF2 iteration count per successful authentication added as the
parameter "iterationStep", defaults to 0.
Other changes:
* Add optional grace period before trying to find the yubikey, defaults to 2 seconds.
Full overview of the yubikey authentication process:
(1) Read $salt and $iterations from unencrypted device (UD).
(2) Calculate the $challenge from the $salt with a hash function.
Chosen instantiation: SHA-512($salt).
(3) Challenge the yubikey with the $challenge and receive the $response.
(4) Repeat three times:
(a) Prompt for the passphrase $k_user.
(b) Derive the key $k_luks for the luks device with a key derivation function from $k_user and $response.
Chosen instantiation: PBKDF2(HMAC-SHA-512, $k_user, $response, $iterations, keyLength).
(c) Try to open the luks device with $k_luks and escape loop (4) only on success.
(5) Proceed only if luks device was opened successfully, fail otherwise.
(6) Gather $new_salt from a cryptographically secure pseudorandom number generator
Chosen instantiation: /dev/random
(7) Calculate the $new_challenge from the $new_salt with the same hash function as (2).
(8) Challenge the yubikey with the $new_challenge and receive the $new_response.
(9) Derive the new key $new_k_luks for the luks device in the same manner as in (4) (b),
but with more iterations as given by iterationStep.
(10) Try to change the luks device's key $k_luks to $new_k_luks.
(11) If (10) was successful, write the $new_salt and the $new_iterations to the UD.
Note: $new_iterations = $iterations + iterationStep
Known (software) attack vectors:
* A MITM attack on the keyboard can recover $k_user. This, combined with a USB-MITM
attack on the yubikey for the $response (1) or the $new_response (2) will result in
(1) $k_luks being recovered,
(2) $new_k_luks being recovered.
* Any attacker with access to the RAM state of stage-1 at mid- or post-authentication
can recover $k_user, $k_luks, and $new_k_luks
* If an attacker has recovered $response or $new_response, he can perform a brute-force
attack on $k_user with it without the Yubikey needing to be present (using cryptsetup's
"luksOpen --verify-passphrase" oracle. He could even make a copy of the luks device's
luks header and run the brute-force attack without further access to the system.
* A USB-MITM attack on the yubikey will allow an attacker to attempt to brute-force
the yubikey's internal key ("shared secret") without it needing to be present anymore.
Credits:
* Florian Klien,
for the original concept and the reference implementation over at
https://github.com/flowolf/initramfs_ykfde
* Anthony Thysse,
for the reference implementation of accessing OpenSSL's PBKDF2 over at
http://www.ict.griffith.edu.au/anthony/software/pbkdf2.c
2014-02-05 16:10:59 +00:00
|
|
|
|
2016-04-16 17:44:32 +00:00
|
|
|
cc -O3 -I${pkgs.openssl.dev}/include -L${pkgs.openssl.out}/lib ${./pbkdf2-sha512.c} -o pbkdf2-sha512 -lcrypto
|
2015-03-29 00:15:41 +00:00
|
|
|
strip -s pbkdf2-sha512
|
|
|
|
copy_bin_and_libs pbkdf2-sha512
|
2014-01-28 03:02:51 +00:00
|
|
|
|
2015-03-29 00:15:41 +00:00
|
|
|
mkdir -p $out/etc/ssl
|
2016-08-04 20:12:39 +00:00
|
|
|
cp -pdv ${pkgs.openssl.out}/etc/ssl/openssl.cnf $out/etc/ssl
|
2014-01-28 03:02:51 +00:00
|
|
|
|
2015-05-04 12:16:03 +00:00
|
|
|
cat > $out/bin/openssl-wrap <<EOF
|
|
|
|
#!$out/bin/sh
|
2015-10-18 14:55:28 +00:00
|
|
|
export OPENSSL_CONF=$out/etc/ssl/openssl.cnf
|
|
|
|
$out/bin/openssl "\$@"
|
2015-05-04 12:16:03 +00:00
|
|
|
EOF
|
|
|
|
chmod +x $out/bin/openssl-wrap
|
2014-01-25 02:27:12 +00:00
|
|
|
''}
|
2019-05-09 18:15:35 +00:00
|
|
|
|
2020-01-13 11:07:48 +00:00
|
|
|
${optionalString luks.fido2Support ''
|
|
|
|
copy_bin_and_libs ${pkgs.fido2luks}/bin/fido2luks
|
|
|
|
''}
|
|
|
|
|
|
|
|
|
2019-05-09 18:15:35 +00:00
|
|
|
${optionalString luks.gpgSupport ''
|
|
|
|
copy_bin_and_libs ${pkgs.gnupg}/bin/gpg
|
|
|
|
copy_bin_and_libs ${pkgs.gnupg}/bin/gpg-agent
|
|
|
|
copy_bin_and_libs ${pkgs.gnupg}/libexec/scdaemon
|
|
|
|
|
|
|
|
${concatMapStringsSep "\n" (x:
|
|
|
|
if x.gpgCard != null then
|
|
|
|
''
|
|
|
|
mkdir -p $out/secrets/gpg-keys/${x.device}
|
|
|
|
cp -a ${x.gpgCard.encryptedPass} $out/secrets/gpg-keys/${x.device}/cryptkey.gpg
|
|
|
|
cp -a ${x.gpgCard.publicKey} $out/secrets/gpg-keys/${x.device}/pubkey.asc
|
|
|
|
''
|
|
|
|
else ""
|
|
|
|
) (attrValues luks.devices)
|
|
|
|
}
|
|
|
|
''}
|
2011-12-28 21:46:40 +00:00
|
|
|
'';
|
|
|
|
|
|
|
|
boot.initrd.extraUtilsCommandsTest = ''
|
2011-12-28 22:37:38 +00:00
|
|
|
$out/bin/cryptsetup --version
|
2014-01-25 02:27:12 +00:00
|
|
|
${optionalString luks.yubikeySupport ''
|
|
|
|
$out/bin/ykchalresp -V
|
2014-01-28 03:02:51 +00:00
|
|
|
$out/bin/ykinfo -V
|
|
|
|
$out/bin/openssl-wrap version
|
2014-01-25 02:27:12 +00:00
|
|
|
''}
|
2019-05-09 18:15:35 +00:00
|
|
|
${optionalString luks.gpgSupport ''
|
|
|
|
$out/bin/gpg --version
|
|
|
|
$out/bin/gpg-agent --version
|
|
|
|
$out/bin/scdaemon --version
|
|
|
|
''}
|
2020-01-13 11:07:48 +00:00
|
|
|
${optionalString luks.fido2Support ''
|
|
|
|
$out/bin/fido2luks --version
|
|
|
|
''}
|
2010-10-25 00:57:30 +00:00
|
|
|
'';
|
|
|
|
|
2017-09-15 21:48:51 +00:00
|
|
|
boot.initrd.preFailCommands = postCommands;
|
|
|
|
boot.initrd.preLVMCommands = commonFunctions + preCommands + concatStrings (mapAttrsToList openCommand preLVM) + postCommands;
|
|
|
|
boot.initrd.postDeviceCommands = commonFunctions + preCommands + concatStrings (mapAttrsToList openCommand postLVM) + postCommands;
|
2012-03-08 20:49:26 +00:00
|
|
|
|
|
|
|
environment.systemPackages = [ pkgs.cryptsetup ];
|
2010-10-25 00:57:30 +00:00
|
|
|
};
|
2011-09-14 18:20:50 +00:00
|
|
|
}
|