MAC: added util conversion functions

pcap_anonymize/layers/mac.py

@@ -21,6 +21,32 @@ special_macs = [
 ]
 
 
+def mac_str_to_bytes(mac: str) -> bytes:
+    """
+    Convert a MAC address string representation
+    to a bytes object.
+
+    Args:
+        mac (str): MAC address to convert
+    Returns:
+        bytes: MAC address as a bytes object
+    """
+    return bytes.fromhex(mac.replace(":", ""))
+
+
+def mac_bytes_to_str(mac: bytes) -> str:
+    """
+    Convert a MAC address bytes object
+    to its string representation.
+
+    Args:
+        mac (bytes): MAC address to convert
+    Returns:
+        str: MAC address as a string
+    """
+    return ":".join(f"{byte:02x}" for byte in mac)
+
+
 def get_ig_bit(mac: str) -> int:
     """
     Get the I/G bit of a given MAC address.
@@ -152,9 +178,8 @@ def anonymize_dhcp(dhcp: BOOTP) -> BOOTP:
         scapy.BOOTP: anonymized DHCP layer
     """
     # Anonymize client hardware address
-    chaddr = dhcp.getfieldval("chaddr")[0:6]
+    chaddr = mac_bytes_to_str(dhcp.getfieldval("chaddr")[0:6])
     dhcp.setfieldval("chaddr", anonymize_mac(chaddr))
-    dhcp.show()
 
     # Check if BOOTP layer contains DHCP options
     options = dhcp.getfieldval("options")

test/test_mac.py

 from scapy.layers.l2 import Ether, ARP
+from scapy.layers.dhcp import BOOTP, DHCP
 from pcap_anonymize.layers.mac import (
+    mac_str_to_bytes, mac_bytes_to_str,
     get_ig_bit, get_ul_bit,
     anonymize_mac,
     anonymize_ether,
@@ -11,12 +13,35 @@ from pcap_anonymize.layers.mac import (
 ### TEST CONSTANTS ###
 
 mac_multicast = "01:00:00:00:00:00"
+mac_multicast_bytes = b"\x01\x00\x00\x00\x00\x00"
 mac_laa = "02:00:00:00:00:00"
+mac_laa_bytes = b"\x02\x00\x00\x00\x00\x00"
 mac_uaa = "00:11:22:33:44:55"
+mac_uaa_bytes = b"\x00\x11\x22\x33\x44\x55"
 
 
 ### TEST FUNCTIONS ###
 
+def test_mac_str_to_bytes() -> None:
+    """
+    Test the function `mac_str_to_bytes`,
+    which converts a MAC address' string representation to bytes.
+    """
+    assert mac_str_to_bytes(mac_multicast) == mac_multicast_bytes
+    assert mac_str_to_bytes(mac_laa) == mac_laa_bytes
+    assert mac_str_to_bytes(mac_uaa) == mac_uaa_bytes
+
+
+def test_mac_bytes_to_str() -> None:
+    """
+    Test the function `mac_bytes_to_str`,
+    which converts a MAC address' bytes representation to a string.
+    """
+    assert mac_bytes_to_str(mac_multicast_bytes) == mac_multicast
+    assert mac_bytes_to_str(mac_laa_bytes) == mac_laa
+    assert mac_bytes_to_str(mac_uaa_bytes) == mac_uaa
+
+
 def test_get_ig_bit() -> None:
     """
     Test the function `get_ig_bit`.
@@ -145,3 +170,13 @@ def test_anonymize_arp_uaa() -> None:
     assert arp_uaa.hwsrc[10:] != mac_uaa[10:]
     assert arp_uaa.hwdst.startswith(mac_uaa[:8])
     assert arp_uaa.hwdst[10:] != mac_uaa[10:]
+
+
+# def test_anonymize_dhcp_multicast() -> None:
+#     """
+#     Test the function `anonymize_dhcp`,
+#     with multicast addresses.
+#     """
+#     dhcp = BOOTP(chaddr=mac_multicast)
+#     anonymize_dhcp(dhcp)
+#     assert dhcp.chaddr == mac_multicast