Namespaced, random token.

namespaced_token.py

from base64 import urlsafe_b64encode

from blake3 import blake3
import krock32
from time import time
import secrets
import math

def generate_token(namespace: str) -> str:
    """
    Generates a random, namespaced token with a time component.

    Example:

    |-A-|-|------------B--------------|
    NMSPC-9TWN1-HR7SV-MTX00-0H8VP-YCCJZ

    A = Namespace, padded to 5 chars. Max 5 chars. Uppercase.
    B = Blake3 hashed microtime.

    :param namespace: Namespace for the token.
    :return:
    """

    if not namespace.isalnum():
        raise ValueError("Namespace must be alphanumeric.")

    if not namespace.isupper():
        raise ValueError("Namespace must be entirely uppercase.")

    if len(namespace) > 5:
        raise ValueError("Namespace must not have more than 5 characters.")

    while len(namespace) < 5:
        namespace = f"{namespace}_"

    time_bytes = math.floor(time() * 100).to_bytes(6, "little")
    random_key = secrets.token_bytes(32)
    hashed_time_bytes = blake3(time_bytes, key=random_key).digest(length=16)

    encoder = krock32.Encoder()
    encoder.update(hashed_time_bytes)
    hashed_time_b32 = encoder.finalize()

    seg_token = "".join(
        [
            f"{char}-" if (idx + 1) % 5 == 0 else char
            for idx, char in enumerate(hashed_time_b32)
        ]
    )[:-1]

    ns_time_token = f"{namespace}-{seg_token}"[:-1]

    return ns_time_token