#!/usr/bin/env python
# Test of key backup code, will evolve into unit tests and a user
# backup script after initial debugging.
# 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
#
# {
# "kekek-uuid": "[UUID]",
# "kekek": "[Base64]"
# }
#
# hal_rpc_pkey_load()
# hal_rpc_pkey_export()
#
# Export PKCS #8 and KEK ----------> Load PKCS #8 and KEK, import key:
#
# {
# "kekek-uuid": "[UUID]",
# "pkey": "[Base64]",
# "kek": "[Base64]"
# }
#
#
# hal_rpc_pkey_import()
from libhal import *
from Crypto.PublicKey import RSA
from Crypto.Cipher import AES, PKCS1_v1_5
from Crypto.Util.asn1 import DerObject, DerSequence, DerNull, DerOctetString, DerObjectId
from Crypto.Random import new as csprng
from struct import pack, unpack
def dumpasn1(der):
from subprocess import call
from tempfile import NamedTemporaryFile
with NamedTemporaryFile() as f:
f.write(der)
f.flush()
call(("dumpasn1", "-aop", f.name))
def t(x):
return filter(x.isType, x.typeTags)[0]
hal_asn1_oid_rsaEncryption = "\x2A\x86\x48\x86\xF7\x0D\x01\x01\x01"
hal_asn1_oid_aesKeyWrap = "\x60\x86\x48\x01\x65\x03\x04\x01\x30"
kek_length = 256/8 # We can determine this from the keywrap OID, this is for AES-256
def main():
kekek = RSA.importKey(kekek_pem)
from atexit import register as atexit
hsm = HSM()
#hsm.debug_io = args.io_log
hsm.login(HAL_USER_WHEEL, "fnord")
atexit(hsm.logout)
kekek_handle = hsm.pkey_load(type = HAL_KEY_TYPE_RSA_PUBLIC,
curve = HAL_CURVE_NONE,
der = kekek.publickey().exportKey(format = "DER"))
atexit(kekek_handle.delete)
print "KEKEK:", kekek_handle.uuid
pkey_handle = hsm.pkey_generate_ec(HAL_CURVE_P256, HAL_KEY_FLAG_EXPORTABLE)
atexit(pkey_handle.delete)
print "PKey: ", pkey_handle.uuid
pkcs8_der, kek_der = kekek_handle.export_pkey(pkey_handle)
pkcs8_alg, pkcs8_data = show_encrypted_pkcs8("PKCS #8:", pkcs8_der, hal_asn1_oid_aesKeyWrap)
kek_alg, kek_data = show_encrypted_pkcs8("KEK: ", kek_der, hal_asn1_oid_rsaEncryption)
# Voodoo to defend against Bleichenbacher Attack per Crypto.Cipher.PKCS1_v1_5 API documentation
kek = PKCS1_v1_5.new(kekek).decrypt(kek_data, csprng().read(kek_length))
pkey = AESKeyWrapWithPadding(kek).unwrap(pkcs8_data)
dumpasn1(pkey)
def show_encrypted_pkcs8(label, der, oid):
print
print label
dumpasn1(der)
print
result = parse_encrypted_pkcs8(der)
for name, value in zip(("algorithm", "encryptedData"), result):
print "{:14s} {}".format(name, "-".join("{:02x}".format(ord(v)) for v in value))
print
print "OID {}".format("matches" if result[0] == oid else "doesn't match")
return result
def parse_encrypted_pkcs8(der):
encryptedPrivateKeyInfo = DerSequence()
encryptedPrivateKeyInfo.decode(der)
encryptionAlgorithm = DerSequence()
encryptionAlgorithm.decode(encryptedPrivateKeyInfo[0])
algorithm = DerObjectId()
algorithm.decode(encryptionAlgorithm[0])
encryptedData = DerObject()
encryptedData.decode(encryptedPrivateKeyInfo[1])
return algorithm.payload, encryptedData.payload
class AESKeyWrapWithPadding(object):
"""
Implementation of AES Key Wrap With Padding from RFC 5649.
"""
class UnwrapError(Exception):
"Something went wrong during unwrap."
def __init__(self, key):
self.ctx = AES.new(key, AES.MODE_ECB)
def _encrypt(self, b1, b2):
aes_block = self.ctx.encrypt(b1 + b2)
return aes_block[:8], aes_block[8:]
def _decrypt(self, b1, b2):
aes_block = self.ctx.decrypt(b1 + b2)
return aes_block[:8], aes_block[8:]
@staticmethod
def _start_stop(start, stop): # Syntactic sugar
step = -1 if start > stop else 1
return xrange(start, stop + step, step)
def wrap(self, Q):
"RFC 5649 section 4.1."
m = len(Q) # Plaintext length
if m % 8 != 0: # Pad Q if needed
Q += "\x00" * (8 - (m % 8))
R = [pack(">LL", 0xa65959a6, m)] # Magic MSB(32,A), build LSB(32,A)
R.extend(Q[i : i + 8] # Append Q
for i in xrange(0, len(Q), 8))
n = len(R) - 1
if n == 1:
R[0], R[1] = self._encrypt(R[0], R[1])
else:
# RFC 3394 section 2.2.1
for j in self._start_stop(0, 5):
for i in self._start_stop(1, n):
R[0], R[i] = self._encrypt(R[0], R[i])
W0, W1 = unpack(">LL", R[0])
W1 ^= n * j + i
R[0] = pack(">LL", W0, W1)
assert len(R) == (n + 1) and all(len(r) == 8 for r in R)
return "".join(R)
def unwrap(self, C):
"RFC 5649 section 4.2."
if len(C) % 8 != 0:
raise self.UnwrapError("Ciphertext length {} is not an integral number of blocks"
.format(len(C)))
n = (len(C) / 8) - 1
R = [C[i : i + 8] for i in xrange(0, len(C), 8)]
if n == 1:
R[0], R[1] = self._decrypt(R[0], R[1])
else:
# RFC 3394 section 2.2.2 steps (1), (2), and part of (3)
for j in self._start_stop(5, 0):
for i in self._start_stop(n, 1):
W0, W1 = unpack(">LL", R[0])
W1 ^= n * j + i
R[0] = pack(">LL", W0, W1)
R[0], R[i] = self._decrypt(R[0], R[i])
magic, m = unpack(">LL", R[0])
if magic != 0xa65959a6:
raise self.UnwrapError("Magic value in AIV should have been 0xa65959a6, was 0x{:02x}"
.format(magic))
if m <= 8 * (n - 1) or m > 8 * n:
raise self.UnwrapError("Length encoded in AIV out of range: m {}, n {}".format(m, n))
R = "".join(R[1:])
assert len(R) == 8 * n
if any(r != "\x00" for r in R[m:]):
raise self.UnwrapError("Nonzero trailing bytes {}".format(R[m:].encode("hex")))
return R[:m]
# Static KEKEK for testing, this should come from the backup HSM.
kekek_pem = '''\
-----BEGIN PRIVATE KEY-----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-----END PRIVATE KEY-----
'''
if __name__ == "__main__":
main()
