The database field is 255 characters long, but the encryption adds quite a lot of fluff. From my testing, 69 characters is the longest password than can fit in.
Both FreeIPA and openldap cli tools seem to support passwords of up to 1000 characters. However, bypassing the database and using passwords longer than 69 characters lead to failures. Increasing the limit further would most likely require additional patches to net-ldap.
Added by Adam Ruzicka about 1 year ago
Fixes #36309 - Increase LDAP auth source password length limit
The database field is 255 characters long, but the encryption adds quite
a lot of fluff. From my testing, 69 characters is the longest password
than can fit in.
Both FreeIPA and openldap cli tools seem to support passwords
of up to 1000 characters. However, bypassing the database and using
passwords longer than 69 characters lead to failures. Increasing
the limit further would most likely require additional patches to
net-ldap.