add bin/bitbot-log to read/decrypt channel_log files

bin/bitbot-log

@@ -0,0 +1,38 @@
+#!/usr/bin/env python3
+
+import argparse
+
+arg_parser = argparse.ArgumentParser(
+    description="BitBot log decrypting utility")
+
+arg_parser.add_argument("key",
+    help="Location of private key for decrypting given log file")
+arg_parser.add_argument("log", help="Location of the log file to decrypt")
+
+args = arg_parser.parse_args()
+
+import base64
+from cryptography.hazmat.backends import default_backend
+from cryptography.hazmat.primitives import serialization
+from cryptography.hazmat.primitives import hashes
+from cryptography.hazmat.primitives.asymmetric import padding
+
+def a_decrypt(key, data):
+    out = key.decrypt(base64.b64decode(data), padding.OAEP(
+        mgf=padding.MGF1(algorithm=hashes.SHA256()),
+        algorithm=hashes.SHA256(), label=None))
+    return out.decode("utf8")
+
+with open(args.key, "rb") as key_file:
+    key_content = key_file.read()
+key = serialization.load_pem_private_key(
+    key_content, password=None, backend=default_backend())
+
+with open(args.log) as log_file:
+    lines = log_file.read().split("\n")
+lines = filter(None, lines)
+
+for line in lines:
+    if line[0] == "\x02":
+        line = a_decrypt(key, line[1:])
+    print(line)