Added and updated documentation

utils/helpers.py

@@ -4,6 +4,7 @@ from hashlib import sha1
 
 
 def generate_random_long(signed=True):
+    """Generates a random long integer (8 bytes), which is optionally signed"""
     result = random.getrandbits(64)
     if not signed:
         result &= 0xFFFFFFFFFFFFFFFF  # Ensure it's unsigned
@@ -12,6 +13,7 @@ def generate_random_long(signed=True):
 
 
 def generate_random_bytes(count):
+    """Generates a random bytes array"""
     with BinaryWriter() as writer:
         for _ in range(count):
             writer.write(random.getrandbits(8))
@@ -20,6 +22,7 @@ def generate_random_bytes(count):
 
 
 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
 
     buffer = [0] * 48
@@ -47,10 +50,12 @@ def calc_key(shared_key, msg_key, client):
 
 
 def calc_msg_key(data):
+    """Calculates the message key from the given data"""
     return sha1(data)[4:20]
 
 
 def calc_msg_key_offset(data, offset, limit):
+    """Calculates the message key from offset given data, with an optional offset and limit"""
     # TODO untested, may not be offset like this
     # In the original code it was as parameters for the sha function, not slicing the array
     return sha1(data[offset:offset + limit])[4:20]