ffprint, ffprint-ck - human-friendly, 128-bit secure, typo-detecting file fingerprints

ffprint

#!/usr/bin/env -S uv run --script
# /// script
# requires-python = ">=3.13"
# dependencies = [ "blake3"]
# ///
from sys import stdin
from blake3 import blake3
from itertools import batched, cycle

ALPHABET = '123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz'
COLORS = ['\033[1;36m', '\033[1;33m']  # bright cyan, bright yellow
RESET = '\033[0m'

def to_base58(b: bytes) -> str:
    n = int.from_bytes(b, 'big')
    chars = []
    while n:
        n, rem = divmod(n, 58)
        chars.append(ALPHABET[rem])
    return '1' * (len(b) - len(chars)) + ''.join(reversed(chars))

data   = stdin.buffer.read()
hashed = blake3(data).digest()[:16]
cksum  = blake3(hashed).digest()[:2]
fprint = to_base58(hashed + cksum)

chunks = map(''.join, batched(fprint, 5))
colored = ' '.join(f"{color}{chunk}{RESET}" for color, chunk in zip(cycle(COLORS), chunks))
print(colored)

ffprint-ck

#!/usr/bin/env -S uv run --script
# /// script
# requires-python = ">=3.13"
# dependencies = ["blake3"]
# ///
from sys import stdin, argv, exit, stderr
from blake3 import blake3

ALPHABET = '123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz'

def from_base58(s: str) -> bytes:
    n = 0
    for c in s: n = n*58 + ALPHABET.index(c)
    b = n.to_bytes((n.bit_length()+7)//8, 'big')
    pad = 0
    for c in s:
        if c=='1': pad+=1
        else: break
    return b'\0'*pad + b

if len(argv)<2:
    print("Usage: cat file | ffprint-ck <fingerprint>", file=stderr)
    exit(2)

fprint = argv[1].replace(' ','').strip()
try:  raw = from_base58(fprint)
except ValueError as e:
    print(f"Invalid Base58 fingerprint: {e}", file=stderr)
    exit(2)

if len(raw)<18:
    print("Fingerprint too short", file=stderr)
    exit(2)

hashed, cksum = raw[:-2], raw[-2:]
if blake3(hashed).digest()[:2] != cksum:
    print("Checksum invalid", file=stderr)
    exit(2)

data = stdin.buffer.read()
if blake3(data).digest()[:16] == hashed:
    print("Fingerprint match", file=stderr)
    exit(0)
else:
    print("Fingerprint mismatch", file=stderr)
    exit(1)