IF U WANT TO DOWNLOAD THE PARTICULAR POST CLICK HERE
Accessing the bindery files directly
Alastair Grant, Cambridge University
1. Introduction
This document describes a command for accessing the NetWare 3.x bindery
files directly, bypassing the NetWare network API calls.
It can be used for fast bindery access, bulk user management, bypassing
security restrictions, investigating problems etc.
It is quite possible to destroy the bindery completely, or to reveal
information which could be used by hackers to obtain passwords. Users
are assumed to have a basic grasp of good procedures for security and
backup.
2. Command syntax
The basic format of the command is
bindery [options] bindery-spec action action ...
2.1 Specifying a bindery
A bindery specification takes the form
path/.extension
E.g. SYS:SYSTEM/.SYS. The path defaults to the current directory. The
extension defaults to .OLD.
Alternatively an 'active' bindery can be specified:
SERVER server
The bindery will be closed if necessary.
2.2 Actions on the bindery
INFO print info about the bindery
SCHEMA checks the bindery against the schema in BINDERY.SCH
DUMP obj dump all information for the specified object(s)
OBJ list all object records
PROP list all property records
VAL list all value records
VALDATA list all value records, with data
EXPORT export the bindery to a text file; see below
IMPORT import the bindery from a text file
ETC export user password information, suitable for input to the
password-cracking program described below
The following actions apply only if a bindery has been specified by the
SERVER parameter:
CLOSE close the bindery, i.e. make it available for direct access;
users attempting to access the bindery via NetWare API calls
will receive an error
OPEN open the bindery, which causes the server to reload it and
may take some time for large binderies
COPY directory
copy the bindery files into a directory elsewhere
3. Export/import
The bindery can be exported to and imported from a text file. This can
be used for various purposes:
- problem diagnosis and repair
- creation of large binderies given a set of user information
- compaction of binderies
- merging binderies or moving users between binderies while
preserving their passwords
To see the format of the export file, try exporting a small bindery.
4. Password cracking
Passwords are not stored in clear in the bindery. What is stored is a
16-byte value computed via a one-way function from the user's object id
and the password. Given the object id and password it is possible to
generate a candidate password which can be compared against that in the
bindery.
The ETC option of the BINDERY command produces a file containing the
required information, in a format superficially similar to /etc/passwd
on Unix:
userid:pw-hash:object-id:pw-len:name::
e.g.
ttidy:32d8998e098a05830f809b809ea02137:D0000001:8:Terry Tidy
This can then be input into bindery cracking programs. Separating the
functions in this way allows various forms of parallelism:
- the password file can be split into smaller chunks
- the same password file can be worked on by several cracking
programs each with different dictionaries or algorithms
- cracking programs can be run on faster machines
A cracking program BINCRACK is provided which takes such a file as
input. It has command syntax:
bincrack [/verify] [/numsub] pw-file dict-file
/verify lists the passwords that are being tried. /numsub tries
substituting numbers for letters, e.g. "1D10T". This takes a lot longer
as all possible combinations are tried. pw-file is an exported bindery
password file. dict-file is a simple word list.
Versions are available for MS-DOS and for Solaris 1 and Solaris 2 SPARC
systems.
Suitable wordlists can be found at
ftp://ftp.ox.ac.uk/pub/wordlists/
No comments:
Post a Comment