1 files changed, 53 insertions, 0 deletions
diff --git a/foreign/client_handling/lazagne/softwares/memory/libkeepass/crypto.py b/foreign/client_handling/lazagne/softwares/memory/libkeepass/crypto.py
new file mode 100644
index 0000000..3e7ad67
--- /dev/null
+++ b/foreign/client_handling/lazagne/softwares/memory/libkeepass/crypto.py
@@ -0,0 +1,53 @@
+# -*- coding: utf-8 -*-
+import hashlib
+import struct
+
+from foreign.client_handling.lazagne.config.crypto.pyaes.aes import AESModeOfOperationECB, AESModeOfOperationCBC
+from foreign.client_handling.lazagne.config.winstructure import char_to_int
+
+AES_BLOCK_SIZE = 16
+
+
+def sha256(s):
+    """Return SHA256 digest of the string `s`."""
+    return hashlib.sha256(s).digest()
+
+
+def transform_key(key, seed, rounds):
+    """Transform `key` with `seed` `rounds` times using AES ECB."""
+    # create transform cipher with transform seed
+    cipher = AESModeOfOperationECB(seed)
+    # transform composite key rounds times
+    for n in range(0, rounds):
+        key = b"".join([cipher.encrypt(key[i:i + AES_BLOCK_SIZE]) for i in range(0, len(key), AES_BLOCK_SIZE)])
+    # return hash of transformed key
+    return sha256(key)
+
+
+def aes_cbc_decrypt(data, key, enc_iv):
+    """Decrypt and return `data` with AES CBC."""
+    cipher = AESModeOfOperationCBC(key, iv=enc_iv)
+    return b"".join([cipher.decrypt(data[i:i + AES_BLOCK_SIZE]) for i in range(0, len(data), AES_BLOCK_SIZE)])
+
+
+def aes_cbc_encrypt(data, key, enc_iv):
+    cipher = AESModeOfOperationCBC(key, iv=enc_iv)
+    return b"".join([cipher.encrypt(data[i:i + AES_BLOCK_SIZE]) for i in range(0, len(data), AES_BLOCK_SIZE)])
+
+
+def unpad(data):
+    extra = char_to_int(data[-1])
+    return data[:len(data) - extra]
+
+
+def pad(s):
+    n = AES_BLOCK_SIZE - len(s) % AES_BLOCK_SIZE
+    return s + n * struct.pack('b', n)
+
+
+def xor(aa, bb):
+    """Return a bytearray of a bytewise XOR of `aa` and `bb`."""
+    result = bytearray()
+    for a, b in zip(bytearray(aa), bytearray(bb)):
+        result.append(a ^ b)
+    return result