python-tlsh 3.17.0

TLSH (C++ Python extension)

TLSH - C++ extension for Python

TLSH (Trend Micro Locality Sensitive Hash) is a fuzzy matching library. Given a byte stream with a minimum length of 50 bytes TLSH generates a hash value which can be used for similarity comparisons. Similar objects will have similar hash values which allows for the detection of similar objects by comparing their hash values. Note that the byte stream should have a sufficient amount of complexity. For example, a byte stream of identical bytes will not generate a hash value.

Usage

import tlsh

tlsh.hash(data)

Note that in default mode the data must contain at least 50 bytes to generate a hash value and that it must have a certain amount of randomness. If you use the "conservative" option, then the data must contain at least 256 characters. For example, tlsh.hash(str(os.urandom(256))), should always generate a hash.
To get the hash value of a file, try tlsh.hash(open(file, 'rb').read()).

tlsh.diff(h1, h2)
tlsh.diffxlen(h1, h2)

The diffxlen function removes the file length component of the tlsh header from the comparison. If a file with a repeating pattern is compared to a file with only a single instance of the pattern, then the difference will be increased if the file lenght is included. But by using the diffxlen function, the file length will be removed from consideration.

Example

import tlsh

h1 = tlsh.hash(data)
h2 = tlsh.hash(similar_data)
score = tlsh.diff(h1, h2)

h3 = tlsh.Tlsh()
with open('file', 'rb') as f:
    for buf in iter(lambda: f.read(512), b''):
        h3.update(buf)
    h3.final()
assert h3.diff(h) == 0
score = h3.diff(h1)