first add files

lib/Crypto/Cipher/_mode_ecb.pyi

@@ -0,0 +1,19 @@
+from typing import Union, overload
+
+from Crypto.Util._raw_api import SmartPointer
+
+Buffer = Union[bytes, bytearray, memoryview]
+
+__all__ = [ 'EcbMode' ]
+
+class EcbMode(object):
+    def __init__(self, block_cipher: SmartPointer) -> None: ...
+    @overload
+    def encrypt(self, plaintext: Buffer) -> bytes: ...
+    @overload
+    def encrypt(self, plaintext: Buffer, output: Union[bytearray, memoryview]) -> None: ...
+    @overload
+    def decrypt(self, plaintext: Buffer) -> bytes: ...
+    @overload
+    def decrypt(self, plaintext: Buffer, output: Union[bytearray, memoryview]) -> None: ...
+