Filter for files in MEGA cloud storage modified between a specific time range using Python

mega_cloud_files_modified_time_filter.py

import base64
import datetime

from mega import Mega

# Initiate MEGA client
mega = Mega()

# Login to MEGA. Make sure not to share your credentials, eg. in Github. For instance use env variables or a secrets manager.
EMAIL = ""
PASSWORD = ""
m = mega.login(EMAIL, PASSWORD)

# Get all files, may take a moment. Responds with a dictionary with MEGA node ID keys pointing to decrypted API response.
files = m.get_files()

def base64urldecode(data: str):
    """
    Base64 decode of MEGA node hash with specific character replacements

    functionality ported from https://github.com/meganz/webclient/blob/master/nodedec.js with help of ChatGPT
    """ 
    data += '=='.encode('utf-8')[(2 - len(data) * 3) & 3:].decode('utf-8')

    data = data.replace('-', '+').replace('_', '/').replace(',', '')

    try:
        return base64.urlsafe_b64decode(data.encode('utf-8'))
    except:
        return b''

def get_mtime_from_hash(hash: str):
    """
    Extract last modified time from MEGA node hash
    mtime is a unix style numerical timestamp

    functionality ported from https://github.com/meganz/webclient/blob/master/nodedec.js with help of ChatGPT
    """
    h = base64urldecode(hash)
    i = h[16]
    if i <= 4: # FIXME: change to 5 before the year 2106
        t = 0
        for j in range(i-1, -1, -1):
            t = t * 256 + h[17+j]
        return t
    else:
        return None


# Set filter range
to_ts = datetime.datetime(day=18, year=2020, month=7).timestamp()
from_ts = datetime.datetime(day=13, year=2020, month=7).timestamp()

# Get files with modified time between specified from and to timestamps
filtered_files = []
for file in files:
    try:
        c = files[file]["a"]["c"] #hash
        mtime = get_mtime_from_hash(c)
        if mtime < to_ts and mtime > from_ts:
            filtered_files.append(files[file])
    except:
        # We may fail to get hash if "a" field for file failed to decrypt
        pass

# Print names of listed files/folders
print([f["a"]["n"] for f in filtered_files])