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@joongh
Last active July 30, 2024 16:57
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Python implementation of Toeplitz-based hash function. It is implemented to understand how the Toeplitz-based hash function works.
#!/usr/bin/env python
#-*- coding: utf-8 -*-
# Test data including the secret key, ip, port numbers and the hash values
# as the result is from "Intel Ethernet Controller 710 Series Datasheet".
KEY=[]
def reset_key():
global KEY
KEY = [
0x6d, 0x5a, 0x56, 0xda, 0x25, 0x5b, 0x0e, 0xc2,
0x41, 0x67, 0x25, 0x3d, 0x43, 0xa3, 0x8f, 0xb0,
0xd0, 0xca, 0x2b, 0xcb, 0xae, 0x7b, 0x30, 0xb4,
0x77, 0xcb, 0x2d, 0xa3, 0x80, 0x30, 0xf2, 0x0c,
0x6a, 0x42, 0xb7, 0x3b, 0xbe, 0xac, 0x01, 0xfa,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00
]
def print_key():
for k in KEY:
print bin(k)[2:].zfill(8),
print '\n'
def left_most_32bits_of_key():
return (KEY[0] << 24) | (KEY[1] << 16) | (KEY[2] << 8) | KEY[3]
def shift_key():
bitstr = ''
for k in KEY:
bitstr += bin(k)[2:].zfill(8)
shifted = bitstr[1:]
shifted += bitstr[0]
for i, k in enumerate(KEY):
KEY[i] = int(shifted[:8], 2)
shifted = shifted[8:]
def compute_hash(input_bytes, N):
reset_key()
result = 0;
bitstr = ''
for b in input_bytes:
bitstr += bin(b)[2:].zfill(8) # eliminate prefix "0b" and fill zeros to fit into 8 bits
for b in bitstr:
if b == '1':
result ^= left_most_32bits_of_key()
shift_key()
return result
def get_ip_number(ip):
ipnum = ip.split('.')
return int(ipnum[0]) << 24 | int(ipnum[1]) << 16 | int(ipnum[2]) << 8 | int(ipnum[3])
def get_input(srcip, dstip, srcport, dstport):
srcip_num = get_ip_number(srcip)
dstip_num = get_ip_number(dstip)
input_bytes = []
input_bytes.append((srcip_num & 0xff000000) >> 24)
input_bytes.append((srcip_num & 0x00ff0000) >> 16)
input_bytes.append((srcip_num & 0x0000ff00) >> 8)
input_bytes.append(srcip_num & 0x000000ff)
input_bytes.append((dstip_num & 0xff000000) >> 24)
input_bytes.append((dstip_num & 0x00ff0000) >> 16)
input_bytes.append((dstip_num & 0x0000ff00) >> 8)
input_bytes.append(dstip_num & 0x000000ff)
input_bytes.append((srcport & 0xff00) >> 8)
input_bytes.append(srcport & 0x00ff)
input_bytes.append((dstport & 0xff00) >> 8)
input_bytes.append(dstport & 0x00ff)
return input_bytes
example1 = ('66.9.149.187', '161.142.100.80', 2794, 1766)
example2 = ('199.92.111.2', '65.69.140.83', 14230, 4739)
if compute_hash(get_input(*example1), 12) == 0x51ccc178:
print 'example1: Hash OK'
else:
print 'example1: Hash NOT OK'
if compute_hash(get_input(*example2), 12) == 0xc626b0ea:
print 'example2: Hash OK'
else:
print 'example2: Hash NOT OK'
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