Exploring GIT Commit Hashes & Generating Cryptographic Zeros

So I was trying to research what goes into generating a GIT commit hash and I thought I would try to personalize the cryptographic hash output a little bit. My computer isn’t that powerful but it may be possible to generate more zeros!

import time, hashlib, subprocess

head = subprocess.check_output("git cat-file commit HEAD | sed -e 's/> .*$/> %d %s/'", shell=True)
secs = int(time.time())
rnds = (secs - 99999999)
offs = "-0500"
begs = ("0" * 6)
ghsh = ""

while (not ghsh.startswith(begs)):
    rnds = (rnds + 1)
    comm = (head % (secs, offs, rnds, offs))
    data = ("commit %d\0%s" % (len(comm), comm))
    ghsh = hashlib.sha1(data).hexdigest()

chk = raw_input("Commit hash [%s]?: " % (ghsh)).strip()
if (chk.lower().startswith("y")):
    comd = ("GIT_COMMITTER_DATE='%d %s' git commit -a --amend --no-edit --date='%d %s'" % (rnds, offs, secs, offs))
    subprocess.call(comd, shell=True)

2 thoughts on “Exploring GIT Commit Hashes & Generating Cryptographic Zeros”

  1. I like that I’m not all the way there understanding it but I recognize things like hash and other features when dealing with crypto I know a bunch of legit sites that are free but maybe you can school meon the coding I’m learning but it’s tough

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  2. Cool toy, but why use python 2 exclusively? This makes it a lot less accessible to most Linux users these days (2022). Simply replace `raw_input` by `input`, decode head with `.decode()`, encode data with `data.encode()` and it will run with python 3. Might break python 2 compatibility, but who has that preinstalled these days anyways?

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