def deriveEncryptKey(keyBits):
"""
Derive a new encrypt key from the given decrypt key value.
:param Blob keyBits: The key value of the decrypt key.
:return: The new encrypt key.
:rtype: EncryptKey
"""
return EncryptKey(keyBits)
def deriveEncryptKey(keyBits):
"""
Derive a new encrypt key from the given decrypt key value.
:param Blob keyBits: The key value of the decrypt key (PKCS8-encoded
private key).
:return: The new encrypt key (DER-encoded public key).
:rtype: EncryptKey
"""
privateKey = TpmPrivateKey()
privateKey.loadPkcs8(keyBits.toBytes())
return EncryptKey(privateKey.derivePublicKey())
def deriveEncryptKey(keyBits):
"""
Derive a new encrypt key from the given decrypt key value.
:param Blob keyBits: The key value of the decrypt key (PKCS8-encoded
private key).
:return: The new encrypt key (DER-encoded public key).
:rtype: EncryptKey
"""
# Decode the PKCS #8 private key.
parsedNode = DerNode.parse(keyBits.buf(), 0)
pkcs8Children = parsedNode.getChildren()
algorithmIdChildren = DerNode.getSequence(pkcs8Children, 1).getChildren()
oidString = algorithmIdChildren[0].toVal()
if oidString != RsaAlgorithm.RSA_ENCRYPTION_OID:
raise RuntimeError("The PKCS #8 private key is not RSA_ENCRYPTION")
privateKey = serialization.load_der_private_key(
keyBits.toBytes(), password = None, backend = default_backend())
publicKeyDer = privateKey.public_key().public_bytes(
encoding = serialization.Encoding.DER,
format = serialization.PublicFormat.SubjectPublicKeyInfo)
return EncryptKey(Blob(publicKeyDer, False))