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-rw-r--r--encrypt_hook139
1 files changed, 139 insertions, 0 deletions
diff --git a/encrypt_hook b/encrypt_hook
new file mode 100644
index 000000000000..819c4cf60fe0
--- /dev/null
+++ b/encrypt_hook
@@ -0,0 +1,139 @@
+#!/usr/bin/ash
+
+run_hook() {
+ modprobe -a -q dm-crypt >/dev/null 2>&1
+ [ "${quiet}" = "y" ] && CSQUIET=">/dev/null"
+
+ # Get keyfile if specified
+ ckeyfile="/crypto_keyfile.bin"
+ if [ -n "$cryptkey" ]; then
+ IFS=: read ckdev ckarg1 ckarg2 <<EOF
+$cryptkey
+EOF
+
+ if [ "$ckdev" = "rootfs" ]; then
+ ckeyfile=$ckarg1
+ elif resolved=$(resolve_device "${ckdev}" ${rootdelay}); then
+ case ${ckarg1} in
+ *[!0-9]*)
+ # Use a file on the device
+ # ckarg1 is not numeric: ckarg1=filesystem, ckarg2=path
+ mkdir /ckey
+ mount -r -t "$ckarg1" "$resolved" /ckey
+ dd if="/ckey/$ckarg2" of="$ckeyfile" >/dev/null 2>&1
+ umount /ckey
+ ;;
+ *)
+ # Read raw data from the block device
+ # ckarg1 is numeric: ckarg1=offset, ckarg2=length
+ dd if="$resolved" of="$ckeyfile" bs=1 skip="$ckarg1" count="$ckarg2" >/dev/null 2>&1
+ ;;
+ esac
+ fi
+ [ ! -f ${ckeyfile} ] && echo "Keyfile could not be opened. Reverting to passphrase."
+ fi
+
+ if [ -n "${cryptdevice}" ]; then
+ DEPRECATED_CRYPT=0
+ IFS=: read cryptdev cryptname cryptoptions <<EOF
+$cryptdevice
+EOF
+ else
+ DEPRECATED_CRYPT=1
+ cryptdev="${root}"
+ cryptname="root"
+ fi
+
+ warn_deprecated() {
+ echo "The syntax 'root=${root}' where '${root}' is an encrypted volume is deprecated"
+ echo "Use 'cryptdevice=${root}:root root=/dev/mapper/root' instead."
+ }
+
+ for cryptopt in ${cryptoptions//,/ }; do
+ case ${cryptopt} in
+ allow-discards)
+ cryptargs="${cryptargs} --allow-discards"
+ ;;
+ *)
+ echo "Encryption option '${cryptopt}' not known, ignoring." >&2
+ ;;
+ esac
+ done
+
+ if resolved=$(resolve_device "${cryptdev}" ${rootdelay}); then
+ if cryptsetup isLuks ${resolved} >/dev/null 2>&1; then
+ [ ${DEPRECATED_CRYPT} -eq 1 ] && warn_deprecated
+ dopassphrase=1
+ # If keyfile exists, try to use that
+ if [ -f ${ckeyfile} ]; then
+ if eval cryptsetup --key-file ${ckeyfile} open --type luks ${resolved} ${cryptname} ${cryptargs} ${CSQUIET}; then
+ dopassphrase=0
+ else
+ echo "Invalid keyfile. Reverting to passphrase."
+ fi
+ fi
+ # Ask for a passphrase
+ if [ ${dopassphrase} -gt 0 ]; then
+ echo ""
+ echo "A password is required to access the ${cryptname} volume:"
+
+ #loop until we get a real password
+ while ! eval cryptsetup open --type luks ${resolved} ${cryptname} ${cryptargs} ${CSQUIET}; do
+ sleep 2;
+ done
+ fi
+ if [ -e "/dev/mapper/${cryptname}" ]; then
+ if [ ${DEPRECATED_CRYPT} -eq 1 ]; then
+ export root="/dev/mapper/root"
+ fi
+ else
+ err "Password succeeded, but ${cryptname} creation failed, aborting..."
+ exit 1
+ fi
+ elif [ -n "${crypto}" ]; then
+ [ ${DEPRECATED_CRYPT} -eq 1 ] && warn_deprecated
+ msg "Non-LUKS encrypted device found..."
+ if echo "$crypto" | awk -F: '{ exit(NF == 5) }'; then
+ err "Verify parameter format: crypto=hash:cipher:keysize:offset:skip"
+ err "Non-LUKS decryption not attempted..."
+ return 1
+ fi
+ exe="cryptsetup open --type plain $resolved $cryptname $cryptargs"
+ IFS=: read c_hash c_cipher c_keysize c_offset c_skip <<EOF
+$crypto
+EOF
+ [ -n "$c_hash" ] && exe="$exe --hash '$c_hash'"
+ [ -n "$c_cipher" ] && exe="$exe --cipher '$c_cipher'"
+ [ -n "$c_keysize" ] && exe="$exe --key-size '$c_keysize'"
+ [ -n "$c_offset" ] && exe="$exe --offset '$c_offset'"
+ [ -n "$c_skip" ] && exe="$exe --skip '$c_skip'"
+ if [ -f "$ckeyfile" ]; then
+ exe="$exe --key-file $ckeyfile"
+ else
+ exe="$exe --verify-passphrase"
+ echo ""
+ echo "A password is required to access the ${cryptname} volume:"
+ fi
+ eval "$exe $CSQUIET"
+
+ if [ $? -ne 0 ]; then
+ err "Non-LUKS device decryption failed. verify format: "
+ err " crypto=hash:cipher:keysize:offset:skip"
+ exit 1
+ fi
+ if [ -e "/dev/mapper/${cryptname}" ]; then
+ if [ ${DEPRECATED_CRYPT} -eq 1 ]; then
+ export root="/dev/mapper/root"
+ fi
+ else
+ err "Password succeeded, but ${cryptname} creation failed, aborting..."
+ exit 1
+ fi
+ else
+ err "Failed to open encryption mapping: The device ${cryptdev} is not a LUKS volume and the crypto= paramater was not specified."
+ fi
+ fi
+ rm -f ${ckeyfile}
+}
+
+# vim: set ft=sh ts=4 sw=4 et: