Totally refactored source files location

Now it *should* be easier to turn Telethon
into a pip package

telethon/helpers.py

@@ -0,0 +1,61 @@
+import os
+import hashlib
+
+# region Multiple utilities
+
+
+def generate_random_long(signed=True):
+    """Generates a random long integer (8 bytes), which is optionally signed"""
+    return int.from_bytes(os.urandom(8), signed=signed, byteorder='little')
+
+
+def ensure_parent_dir_exists(file_path):
+    """Ensures that the parent directory exists"""
+    parent = os.path.dirname(file_path)
+    if parent:
+        os.makedirs(parent, exist_ok=True)
+
+
+# endregion
+
+# region Cryptographic related utils
+
+
+def calc_key(shared_key, msg_key, client):
+    """Calculate the key based on Telegram guidelines, specifying whether it's the client or not"""
+    x = 0 if client else 8
+
+    sha1a = sha1(msg_key + shared_key[x:x + 32])
+    sha1b = sha1(shared_key[x + 32:x + 48] + msg_key + shared_key[x + 48:x + 64])
+    sha1c = sha1(shared_key[x + 64:x + 96] + msg_key)
+    sha1d = sha1(msg_key + shared_key[x + 96:x + 128])
+
+    key = sha1a[0:8] + sha1b[8:20] + sha1c[4:16]
+    iv = sha1a[8:20] + sha1b[0:8] + sha1c[16:20] + sha1d[0:8]
+
+    return key, iv
+
+
+def calc_msg_key(data):
+    """Calculates the message key from the given data"""
+    return sha1(data)[4:20]
+
+
+def generate_key_data_from_nonces(server_nonce, new_nonce):
+    """Generates the key data corresponding to the given nonces"""
+    hash1 = sha1(bytes(new_nonce + server_nonce))
+    hash2 = sha1(bytes(server_nonce + new_nonce))
+    hash3 = sha1(bytes(new_nonce + new_nonce))
+
+    key = hash1 + hash2[:12]
+    iv = hash2[12:20] + hash3 + new_nonce[:4]
+    return key, iv
+
+
+def sha1(data):
+    """Calculates the SHA1 digest for the given data"""
+    sha = hashlib.sha1()
+    sha.update(data)
+    return sha.digest()
+
+# endregion