Verify checksums about dpkt HOT 2 CLOSED

The following isn't pretty but seems to correctly verify both the IP and TCP objects' checksum. Though be aware that it assumes that the IP packet contains TCP or another object that has a sum member. In case you need to check for that, you'll find what you need in dpkt.ip.IP.__bytes__.

def verify_checksum(ip: dpkt.ip.IP):
    ip_sum = ip.sum
    tcp_sum = ip.data.sum
    ip.sum = 0
    ip.data.sum = 0
    ip.__bytes__()
    return ip_sum == ip.sum and tcp_sum == ip.data.sum

from dpkt.

This method works fine.
The function to calculate generic internet checksums in_cksum() is defined in dpkt.py. Clicking on "References" tab will show how it's used throughout the code in various protocol parsers.

from dpkt.