#!/usr/bin/env python
# KEY SOURCE KEY BACKUP
#
# Generate and export KEKEK:
# hal_rpc_pkey_generate_rsa()
# hal_rpc_pkey_get_public_key()
#
# Load KEKEK public <---------------- Export KEKEK public
#
# hal_rpc_pkey_load()
# hal_rpc_pkey_export()
#
# Export PKCS #8 and KEK ----------> Load PKCS #8 and KEK, import key
#
# hal_rpc_pkey_import()
import sys
import json
import uuid
import atexit
import getpass
import argparse
from cryptech.libhal import *
def main():
parser = argparse.ArgumentParser(
formatter_class = argparse.ArgumentDefaultsHelpFormatter,
description = __doc__)
subparsers = parser.add_subparsers(
title = "Commands (use \"--help\" after command name for help with individual commands)",
metavar = "")
parser.add_argument(
"-p", "--pin",
help = "wheel PIN")
subparser = defcmd(subparsers, cmd_setup)
group = subparser.add_mutually_exclusive_group()
group.add_argument(
"-n", "--new", action = "store_true",
help = "force creation of new KEKEK")
group.add_argument(
"-u", "--uuid",
help = "UUID of existing KEKEK to use")
subparser.add_argument(
"-k", "--keylen", type = int, default = 2048,
help = "length of new KEKEK if we need to create one")
subparser.add_argument(
"-o", "--output", type = argparse.FileType("w"), default = "-",
help = "output file")
subparser = defcmd(subparsers, cmd_export)
subparser.add_argument(
"-i", "--input", type = argparse.FileType("r"), default = "-",
help = "input file")
subparser.add_argument(
"-o", "--output", type = argparse.FileType("w"), default = "-",
help = "output file")
subparser = defcmd(subparsers, cmd_import)
subparser.add_argument(
"-i", "--input", type = argparse.FileType("r"), default = "-",
help = "input file")
args = parser.parse_args()
hsm = HSM()
try:
hsm.login(HAL_USER_WHEEL, args.pin or getpass.getpass("Wheel PIN: "))
except HALError as e:
sys.exit("Couldn't log into HSM: {}".format(e))
try:
sys.exit(args.func(args, hsm))
finally:
hsm.logout()
def defcmd(subparsers, func):
assert func.__name__.startswith("cmd_")
subparser = subparsers.add_parser(func.__name__[4:],
description = func.__doc__,
help = func.__doc__.strip().splitlines()[0])
subparser.set_defaults(func = func)
return subparser
def b64(bytes):
return bytes.encode("base64").splitlines()
def b64join(lines):
return "".join(lines).decode("base64")
def cmd_setup(args, hsm):
"""
Set up backup HSM for subsequent import.
Generates an RSA keypair with appropriate usage settings
to use as a key-encryption-key-encryption-key (KEKEK), and
writes the KEKEK to a JSON file for transfer to primary HSM.
"""
result = {}
uuids = []
if args.uuid:
uuids.append(args.uuid)
elif not args.new:
uuids.extend(hsm.pkey_match(
type = HAL_KEY_TYPE_RSA_PRIVATE,
mask = HAL_KEY_FLAG_USAGE_KEYENCIPHERMENT | HAL_KEY_FLAG_TOKEN,
flags = HAL_KEY_FLAG_USAGE_KEYENCIPHERMENT | HAL_KEY_FLAG_TOKEN))
for uuid in uuids:
with hsm.pkey_open(uuid) as kekek:
if kekek.key_type != HAL_KEY_TYPE_RSA_PRIVATE:
sys.stderr.write("Key {} is not an RSA private key\n".format(uuid))
elif (kekek.key_flags & HAL_KEY_FLAG_USAGE_KEYENCIPHERMENT) == 0:
sys.stderr.write("Key {} does not allow key encipherment\n".format(uuid))
else:
result.update(kekek_uuid = str(kekek.uuid),
kekek_pubkey = b64(kekek.public_key))
break
if not result and not args.uuid:
with hsm.pkey_generate_rsa(
keylen = args.keylen,
flags = HAL_KEY_FLAG_USAGE_KEYENCIPHERMENT | HAL_KEY_FLAG_TOKEN) as kekek:
result.update(kekek_uuid = str(kekek.uuid),
kekek_pubkey = b64(kekek.public_key))
if not result:
sys.exit("Could not find suitable KEKEK")
result.update(comment = "KEKEK public key")
json.dump(result, args.output, indent = 4, sort_keys = True)
def key_flag_names(flags):
names = dict(digitalsignature = HAL_KEY_FLAG_USAGE_DIGITALSIGNATURE,
keyencipherment = HAL_KEY_FLAG_USAGE_KEYENCIPHERMENT,
dataencipherment = HAL_KEY_FLAG_USAGE_DATAENCIPHERMENT,
token = HAL_KEY_FLAG_TOKEN,
public = HAL_KEY_FLAG_PUBLIC,
exportable = HAL_KEY_FLAG_EXPORTABLE)
return ", ".join(sorted(k for k, v in names.iteritems() if (flags & v) != 0))
def cmd_export(args, hsm):
"""
Export encrypted keys from primary HSM.
Takes a JSON file containing KEKEK (generated by running this
script's "setup" command against the backup HSM), installs that
key on the primary HSM, and backs up keys encrypted to the KEKEK
by writing them to another JSON file for transfer to the backup HSM.
"""
db = json.load(args.input)
result = []
kekek = None
try:
kekek = hsm.pkey_load(der = b64join(db["kekek_pubkey"]),
flags = HAL_KEY_FLAG_USAGE_KEYENCIPHERMENT)
for uuid in hsm.pkey_match(mask = HAL_KEY_FLAG_EXPORTABLE,
flags = HAL_KEY_FLAG_EXPORTABLE):
with hsm.pkey_open(uuid) as pkey:
if pkey.key_type in (HAL_KEY_TYPE_RSA_PRIVATE, HAL_KEY_TYPE_EC_PRIVATE):
pkcs8, kek = kekek.export_pkey(pkey)
result.append(dict(
comment = "Encrypted private key",
pkcs8 = b64(pkcs8),
kek = b64(kek),
uuid = str(pkey.uuid),
flags = pkey.key_flags))
elif pkey.key_type in (HAL_KEY_TYPE_RSA_PUBLIC, HAL_KEY_TYPE_EC_PUBLIC):
result.append(dict(
comment = "Public key",
spki = b64(pkey.public_key),
uuid = str(pkey.uuid),
flags = pkey.key_flags))
finally:
if kekek is not None:
kekek.delete()
db.update(comment = "Cryptech Alpha encrypted key backup",
keys = result)
json.dump(db, args.output, indent = 4, sort_keys = True)
def cmd_import(args, hsm):
"""
Import encrypted keys into backup HSM.
Takes a JSON file containing a key backup (generated by running
this script's "export" command against the primary HSM) and imports
keys into the backup HSM.
"""
db = json.load(args.input)
with hsm.pkey_open(uuid.UUID(db["kekek_uuid"]).bytes) as kekek:
for k in db["keys"]:
pkcs8 = b64join(k.get("pkcs8", ""))
spki = b64join(k.get("spki", ""))
kek = b64join(k.get("kek", ""))
flags = k.get("flags", 0)
if pkcs8 and kek:
with kekek.import_pkey(pkcs8 = pkcs8, kek = kek, flags = flags) as pkey:
print "Imported {} as {}".format(k["uuid"], pkey.uuid)
elif spki:
with hsm.pkey_load(der = spki, flags = flags) as pkey:
print "Loaded {} as {}".format(k["uuid"], pkey.uuid)
if __name__ == "__main__":
main()
