SimpleSecureDelete.py

import threading
import time
import os
from random import SystemRandom
from argparse import ArgumentParser


class ProgressSpin(threading.Thread):
    def __init__(self, group=None, target=None, name=None, args=(), kwargs=None, *, daemon=False, sleep=0.5, maximum=100.0):
        super().__init__(group, target, name, args, kwargs, daemon=daemon)
        self.sleep = sleep
        self.value = 0
        self.maximum = maximum
        self.done = False

    @property
    def progress(self):
        return 100.0 * self.value / self.maximum

    @progress.setter
    def progress(self, percentage):
        if percentage > 100.0 or percentage < 0.0:
            raise ValueError("Progress percentage should be a value between 0.0 and 100.0")
        self.value = int(percentage * self.maximum)

    def run(self):
        print()
        i = 1
        while i:
            chars = {0: "/", 1: "-", 2: "\\", 3: "|"}
            print("\r{} {:03.02f}%".format(chars.get(i % 4), self.progress), end="")
            time.sleep(self.sleep)
            i += 1
            if i and (self.done or self.progress == 100.0):
                i = -1


class SecureDelete:
    def __init__(self, *, bs=1024):
        self.bs = bs
        self.rdev = SystemRandom()

    def erase(self, filename, count, callback=None):
        if not os.path.isfile(filename):
            raise IOError("The file '{}' does not exist.".format(filename))
        size = os.stat(filename).st_size
        if not size:
            return
        chunks, leftover = size // self.bs, size % self.bs
        cnt, total = 0, size * count
        with open(filename, "wb") as fout:
            for i in range(count):
                fout.seek(0)
                for n in range(chunks + 1):
                    tmp = leftover if n == chunks else self.bs
                    fout.write(os.urandom(tmp))
                    cnt += tmp
                    if callback:
                        callback(cnt, total)

p = ProgressSpin(sleep=0.25)
p.start()


def cb(count, total):
    if p.maximum != total:
        p.maximum = total
    p.value = count

if __name__ == "__main__":
    ap = ArgumentParser()
    ap.add_argument("-f", "--file", help="Location of the file to securely erase.", type=str, required=True)
    ap.add_argument("-c", "--count", help="", type=int, default=7)
    args = ap.parse_args()
    sd = SecureDelete()
    sd.erase(args.file, args.count, callback=cb)