How can I read Chrome Cache files?

Question

A forum I frequent was down today, and upon restoration, I discovered that the last two days of forum posting had been rolled back completely.

Needless to say, I\'d

Answer 1

Note: The below answer is out of date since the Chrome disk cache format has changed.

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Joachim Metz provides some documentation of the Chrome cache file format with references to further information.

For my use case, I only needed a list of cached URLs and their respective timestamps. I wrote a Python script to get these by parsing the data_* files under C:\Users\me\AppData\Local\Google\Chrome\User Data\Default\Cache\:

import datetime
with open('data_1', 'rb') as datafile:
    data = datafile.read()

for ptr in range(len(data)):
    fourBytes = data[ptr : ptr + 4]
    if fourBytes == b'http':

        # Found the string 'http'. Hopefully this is a Cache Entry
        endUrl = data.index(b'\x00', ptr)
        urlBytes = data[ptr : endUrl]
        try:
            url = urlBytes.decode('utf-8')
        except:
            continue

        # Extract the corresponding timestamp
        try:
            timeBytes = data[ptr - 72 : ptr - 64]
            timeInt = int.from_bytes(timeBytes, byteorder='little')
            secondsSince1601 = timeInt / 1000000
            jan1601 = datetime.datetime(1601, 1, 1, 0, 0, 0)
            timeStamp = jan1601 + datetime.timedelta(seconds=secondsSince1601)
        except:
            continue

        print('{} {}'.format(str(timeStamp)[:19], url))