Datetime in bytes-CodePudding

I am trying to decode datetime from byte form. I tried various methods (seconds, minutes, hours form 1-1-1970, minutes form 1-1-1 etc). I also tried mysql encoding (https://dev.mysql.com/doc/internals/en/date-and-time-data-type-representation.html) with no effect either. Please help me find the datetime save key.

bf aa b8 c3 e5 2f
d7 be ba c3 e5 2f
80 a0 c0 c3 e5 2f
a7 fc bf c3 e5 2f
ae fd f2 c3 e5 2f
9e dd fa c3 e5 2f
c7 ce fa c3 e5 2f
b9 f5 82 c4 e5 2f
f8 95 f2 c3 e5 2f

Everything is around 01/14/2022 12:00

CodePudding user response：

Each value is a timestamp encoded into VARINT. Long time ago I've made next functions to decode/encode VARINT:

def to_varint(src):
    buf = b""
    while True:
        towrite = src & 0x7f
        src >>= 7
        if src:
            buf  = bytes((towrite | 0x80,))
        else:
            buf  = bytes((towrite,))
            break
    return buf

def from_varint(src):
    shift = 0
    result = 0
    for i in src:
        result |= (i & 0x7f) << shift
        shift  = 7
    return result

So using this function we can decode your values:

from datetime import datetime

...

values = """\
bf aa b8 c3 e5 2f
d7 be ba c3 e5 2f
80 a0 c0 c3 e5 2f
a7 fc bf c3 e5 2f
ae fd f2 c3 e5 2f
9e dd fa c3 e5 2f
c7 ce fa c3 e5 2f
b9 f5 82 c4 e5 2f
f8 95 f2 c3 e5 2f"""

for value in values.splitlines():
    timestamp = from_varint(bytes.fromhex(value))
    dt = datetime.fromtimestamp(timestamp / 1000)
    print(dt)

To get current timestamp in this encoding you can use next code:

current = to_varint(int(datetime.now().timestamp() * 1000)).hex(" ")