Querying LDAP by date

Question

The Problem:

Certain LDAP date fields, like createTimestamp or pwdChangedTime, are kept in a "generalized datetime format":

{"createTimestamp": "20100226142156Z"}

Which contains both date and time components inside.

The Question:

What is the canonical way to query LDAP records by a specific date?

Example use case: get all users created yesterday.

Answer 1

First of all, we need a reusable function to convert from datetime to a generalized time format:

def convert_datetime_to_generalized_time(dt):
    """Convert datetime object to generalized time format."""
    dt = dt.timetuple()
    gtime = str(dt.tm_year) + ''.join('0' * (2 - len(str(item))) + str(item)
                                      for item in (dt.tm_mon, dt.tm_mday, dt.tm_hour, dt.tm_min, dt.tm_sec))
    return gtime + 'Z'

Now, there is no direct way to filter the date component of a generalized time stamp. The idea would be to ask the date to be:

• greater or equal to than date with a 00:00:00 time part
• less than or equal to date with a 23:59:59 time part

Implementation:

import datetime

def get_ldap_date_range_query(dt):
    start_date = dt.replace(hour=0, minute=0, second=0)
    end_date = dt.replace(hour=23, minute=59, second=59)

    return "(&(createTimestamp>=%s)(createTimestamp<=%s))" % (convert_datetime_to_generalized_time(start_date),
                                                              convert_datetime_to_generalized_time(end_date))

print(get_ldap_date_range_query(datetime.datetime.now() - datetime.timedelta(days=1)))

This would print an LDAP query which would match all users created yesterday:

(&(createTimestamp>=20160604000000Z)(createTimestamp<=20160604235959Z))

Hope that would help someone in the future.