def _create_private_key(self, pubkey, subkey=True):
""" Create a private (sub)key from public key and firmware key material """
fp = bytes(pubkey.fingerprint)
if fp not in self._keys:
return None
key = self._keys[fp]
pubkm = pubkey._key.keymaterial
if key.algo == KeyAlgo.RSA2048 or key.algo == KeyAlgo.RSA4096:
assert pubkey._key.pkalg in [PubKeyAlgorithm.RSAEncryptOrSign,
PubKeyAlgorithm.RSAEncrypt, PubKeyAlgorithm.RSASign]
plen = len(key.priv) // 2
km = RSAPriv()
km.n = pubkm.n
km.e = pubkm.e
km.p = MPI(MPIs.bytes_to_int(key.priv[:plen]))
km.q = MPI(MPIs.bytes_to_int(key.priv[plen:]))
km.d = MPI(rsa.rsa_crt_iqmp((km.p-1) * (km.q-1), km.e))
km.u = MPI(rsa.rsa_crt_iqmp(km.q, km.p))
elif key.algo == KeyAlgo.CURVE25519:
km = ECDHPriv()
km.oid = EllipticCurveOID.Curve25519
km.p = pubkm.p
km.kdf = pubkm.kdf
# GnuPG stores the secret value in the wrong order
# https://lists.gnupg.org/pipermail/gnupg-devel/2018-February/033437.html
km.s = MPI(MPIs.bytes_to_int(key.priv, 'little'))
elif key.algo == KeyAlgo.ED25519:
# GNUK stores "SHA-512(secret)"
# PGP private key stores "secret"
logging.warning("Cannot extract Ed25519 key: GNUK format incompatible with PGP format\n"
" sha512(secret) = {}".format(hexlify(key.priv).decode('utf-8')))
return None
elif key.algo in [KeyAlgo.SECP256K1, KeyAlgo.NISTP256R1]:
# Secp256k1 can be used with both ECDH and ECDSA
if isinstance(pubkm, ECDSAPub):
km = ECDSAPriv()
elif isinstance(pubkm, ECDHPub):
km = ECDHPriv()
km.kdf = pubkm.kdf
else:
raise Exception("Curve {} cannot be used with algorithm {}".format(
str(key.algo), pubkm.__class__.__name__))
if key.algo == KeyAlgo.SECP256K1:
km.oid = EllipticCurveOID.SECP256K1
elif key.algo == KeyAlgo.NISTP256R1:
km.oid = EllipticCurveOID.NIST_P256
else:
raise Exception("Should not happen")
km.p = pubkm.p
km.s = MPI(MPIs.bytes_to_int(key.priv))
else:
# https://tools.ietf.org/html/draft-ietf-openpgp-rfc4880bis-06
raise Exception("Key algo {} not implemented yet".format(str(key.algo)))
km._compute_chksum()
privkey = PrivSubKeyV4() if subkey else PrivKeyV4()
privkey.pkalg = pubkey._key.pkalg
privkey.keymaterial = km
privkey.created = pubkey._key.created
privkey.update_hlen()
key = PGPKey()
key._key = privkey
key._signatures = pubkey._signatures
return key
def strip_signatures(key: PGPKey) -> None:
# pylint: disable=protected-access
key._signatures = SorteDeque()
