def test_decryption_invalid_key(self) -> None:
"""
Tests that ONLY the owner of the receiver key can decrypt the ciphertext.
"""
sk_1 = encryption.decode_encryption_secret_key(_TEST_SECRET_KEY_1_BYTES)
sk = encryption.decode_encryption_secret_key(_TEST_SECRET_KEY_BYTES)
pk = encryption.get_encryption_public_key(sk)
ciphertext = encryption.encrypt(_TEST_PLAINTEXT, pk)
with self.assertRaises(encryption.InvalidSignature):
encryption.decrypt(ciphertext, sk_1)
def test_encrypt_decrypt(self) -> None:
"""
Tests the correct encrypt-decrypt flow: decrypt(encrypt(m)) == m
where m is encoded on NOTE_LENGTH/BYTE_LEN bytes.
"""
sk = encryption.decode_encryption_secret_key(_TEST_SECRET_KEY_BYTES)
pk = encryption.get_encryption_public_key(sk)
ciphertext = encryption.encrypt(_TEST_PLAINTEXT, pk)
plaintext = encryption.decrypt(ciphertext, sk)
self.assertEqual(_TEST_PLAINTEXT, plaintext)
def receive_note(
out_ev: MixOutputEvents, receiver_k_sk: EncryptionSecretKey
) -> Optional[Tuple[bytes, api.ZethNote]]:
"""
Given the receivers secret key, and the event data from a transaction
(encrypted notes), decrypt any that are intended for the receiver. Return
tuples `(<address-in-merkle-tree>, ZethNote)`. Callers should record the
address-in-merkle-tree along with ZethNote information, for convenience
when spending the notes.
"""
try:
plaintext = decrypt(out_ev.ciphertext, receiver_k_sk)
return (out_ev.commitment, proto_utils.zeth_note_from_bytes(plaintext))
except InvalidSignature:
return None
except ValueError:
return None