From: Sahir Hidayatullah (sahirh@mielesecurity.com)
Date: Thu Sep 22 2005 - 05:44:50 EDT
> Why aren't alt characters feasible alt255 is an easy one for anyone to
> remember and if the policy for passwords dictates the requirement then
> most large firms would accept this especially if it made the password in
> the current view untouchable for the for seable future
>
Just as most password cracking tools don't support this range, you run a
real risk of breaking your applications that were not coded with this
consideration. Programatically, since everything after alt+127 is part of
the extended ASCII character set, many applications will have filters and
parsers that don't consider this range.
For example, imagine an application has a function that checks if the
input password is alphanumeric + special characters -- chances are strong
that the programmer will check if the characters are within the ascii
range from 48 - 126.
(reference this ascii table:
http://www.cdrummond.qc.ca/cegep/informat/Professeurs/Alain/files/ascii.htm)
If you have an alt + <something above 126> in your password, that function
will fail. You might have account lockout scenarios, where a user was
allowed to change the password with an extended character, but the
application login screen checks for alphanumeric+special chars (I have
seen this happen).
This is just a small example off the top of my head, there are many more
scenarios were you can run into trouble with extended characters.
Unfortunately security foresight is not usually something that goes hand
in hand with application development.
Of course, you could have all your apps recoded properly, but thats rather
like nuking your house to solve a roach problem ;)
Cheers,
Sahir Hidayatullah
Technical Consultant - Information Security.
>
> -----Original Message-----
> From: Craig Wright <cwright@bdosyd.com.au>
> To: Bryan McAninch <BMcAninch@PENSON.COM>; pen-test@securityfocus.com
> <pen-test@securityfocus.com>
> CC: pand0ra.usa@gmail.com <pand0ra.usa@gmail.com>
> Sent: Tue Sep 20 02:01:34 2005
> Subject: RE: Whitespace in passwords
>
> Precomputed tables - all lanman fits into 64Gb - time to post about a
> week
> Complete tables - all NTLM MD5 etc should fit to about 2.5 Gb - there are
> external usb drive packs larger than this
>
> Re the 1024-bit RSA keypair - there is some good work being done using
> quadratic methods
>
> The point is that anyone can download a "14 character all lowercase
> passphrase with numbers" precomputed database and crack all of these in
> milliseconds with an old P3
>
> The "14 character all lowercase passphrase with numbers" set is only 3gb
> and it took me a week to generate - without dedicating the hosts - see lm
> configuration #5 at http://www.antsight.com/zsl/rainbowcrack/
>
> Go further lm #6 and I quote from the page "This charset includes all
> possbile characters on a standard keyboard (not including those alt+xxx
> characters)"
>
> As previously stated - with standard users (ie any large firm) alt+xxx
> chars are NOT feasible
>
> Regards
> Craig
>
> PS
>
> Some reading for those (like me) that enjoy maths re the RSA keys
>
> Biehl and J. Buchmann, An analysis of the reduction algorithm for binary
> quadratic forms, <i>Voronoi's Impact on Modern Science</i> (Kyiv,
> Ukriaine) (P. Engel and H. Syta, eds.), Vol. 1, Institute of Mathematics
> of National Academy of Sciences (1999).
>
> Dan Boneh , Matthew K. Franklin, Identity-Based Encryption from the Weil
> Pairing, Proceedings of the 21st Annual International Cryptology
> Conference on Advances in Cryptology, p.213-229, August 19-23, 2001
>
> D.A. Cox, <i>Primes of the form x<sup>2</sup> + ny<sup>2</sup></i>, John
> Wiley & Sons, New York (1989).
>
> Damian Weber , Thomas F. Denny, The Solution of McCurley's Discrete Log
> Challenge, Proceedings of the 18th Annual International Cryptology
> Conference on Advances in Cryptology, p.458-471, August 23-27, 1998
>
> -----Original Message-----
> From: Bryan McAninch [mailto:BMcAninch@PENSON.COM]
> Sent: 20 September 2005 3:21
> To: pen-test@securityfocus.com
> Cc: pand0ra.usa@gmail.com
> Subject: RE: Whitespace in passwords
>
>
> As I understand it, the central limit theorem states that a randomized
> brute force attempt only takes x^y/x or x^(y-1) operations to crack a
> given keyspace, where x is the base (number of valid characters), y is the
> exponentiation variable (length) and x^y is the keyspace (total
> combinations).
>
> For example (pardon the formatting):
>
> 60^7/60 = 2799360000000/60 = 46656000000 -> 60^(7-1) =
> 60^6 = 46656000000 operations
> 86^7/86 = 34792782221696/86 = 404567235136 -> 86^(7-1) =
> 86^6 = 404567235136 operations
> 62^8/62 = 218340105584896/62 = 3521614606208 -> 62^(8-1) =
> 62^7 = 3521614606208 operations
> 86^8/86 = 2992179271065856/86 = 34792782221696 -> 86^(8-1) =
> 86^7 = 34792782221696 operations
> 36^14/36 = 6140942214464815497216/36 = 170581728179578208256 -> 36^(14-1)=
> 36^13 = 170581728179578208256 operations
>
> This is why public key authentication is recommended over passwords
> authentication. Given a mere 1024-bit key, it would theoretically take
> 2^1023 operations to crack the key:
>
> 2^1024 = (1.797693134862315907729305190789 * 10^308)/2 =
> 8.9884656743115795386465259539451 * 10^307 -> 10^1023 =
> 8.9884656743115795386465259539451 * 10^307
>
> Taking the 36^14 password above and comparing it to a 1024-bit RSA
> keypair, you have the follwing difference:
>
> (2^1023) - (36^13) = (8.9884656743115795386465259539451 * 10^307) -
> (170581728179578208256) = 8.9884656743115795386465259539451e * 10^307 more
> operations with a 1024-bit RSA keypair, quite a difference! :)
>
> Cheers,
> Bryan
>
> -----Original Message-----
> From: Tim [mailto:pand0ra.usa@gmail.com]
> Sent: Monday, September 12, 2005 01:01 PM
> To: pen-test@securityfocus.com
> Subject: Re: Whitespace in passwords
>
> It all about the math. Let's write it out, say you have a machine that
> runs 3,000,000 combinations per second (about a 1.6 GHz machine). In this
> example we will use the Windows LanMan Challange/Response (which is bad to
> begin with, but the main key in this is that it does not use a salt).
>
> 60 possible characters and the password is 7 characters long.(no spaces)
> 60^7 = 2,799,360,000,000 = 10.8 days (A-Z, 0-9, special)
>
> 86 possible characters and the password is 7 characters long.(no spaces)
> 86^7 = 34,792,782,221,696 = 134.23 days (A-Z, a-z, 0-9, special)
>
> 62 possible characters and the password is 8 characters long.(no spaces)
> 62^8 = 218,340,105,584,896 = 2.3 years (A-Z, 0-9, special)
>
> 86 possible characters and the password is 8 characters long.(no spaces)
> 86^8 = 2992179271065856 = 31.62 years (A-Z, a-z, 0-9, special)
>
> 36 possible characters and the password is 14 characters long. (no spaces)
> 36^14 = 6,140,942,214,464,815,497,216 combinations = 64,909,333 years
> (a-z, 0-9) 2bigbrown1dogs (throw some special characters in) We have 2 big
> brown dogs! (25 characters using numbers, upper and lower, and special
> cahracters, you do the math). Microsoft Windows supports up to ~250
> characters for the passwords/phrases.
>
> The point here is that a 14 character all lowercase passphrase with
> numbers is millions of time more difficult that a 'strong' 8 character
> password with all sorts of characters. A space is just another character
> and don't believe that it will protect you from getting your password
> cracked (security through obsecurity?). Also, keep in mind that if you use
> a algo that has a salt and supports many characters you will be much
> better off. Instead of making things more complex for your users (which
> also increses the risk of them posting their password on a stick-it note)
> make the passphrase easy for them to remember.
>
> Side note: Disable LanMan on all Windows machines if you are not running
> any Windows 95/98/ME machines. It is there for backward compatability and
> is still enabled by default on Windows 2003 Servers.
>
>
> On 9/11/05, dave kleiman <dave@isecureu.com> wrote:
>> They also do not have a lot of the Extended ASCII characters:
>>
>> http://www.securityfocus.com/archive/88/312263
>>
>>
>> Dave
>>
>> > -----Original Message-----
>> > From: Steve.Cummings@barclayscapital.com
>> > [mailto:Steve.Cummings@barclayscapital.com]
>> > Sent: Thursday, September 08, 2005 12:54
>> > To: AMeyers@msolgroup.com; Anders.Thulin@tietoenator.com;
>> > homegrown@bryanallott.net; pen-test@securityfocus.com
>> > Subject: Re: Whitespace in passwords
>> >
>> > Alt characters are also pretty cool
>> >
>> > Try alt 255 this is blank space
>> >
>> >
>> > -----Original Message-----
>> > From: Andrew Meyers <AMeyers@msolgroup.com>
>> > To: Anders Thulin <Anders.Thulin@tietoenator.com>; bryan allott
>> > <homegrown@bryanallott.net>; pen-test@securityfocus.com
>> > <pen-test@securityfocus.com>
>> > Sent: Thu Sep 08 01:40:34 2005
>> > Subject: RE: Whitespace in passwords
>> >
>> > I like pass phrases better because crackers like john and l0pht, by
>> > default, don't have white spaces in their list of characters.
>> >
>> >
>> > -------------------
>> > Andrew Meyers
>> > Systems Engineer
>> > Managed Solution
>> > Email: ameyers@mssandiego.com
>> > Phone: 619-220-0544 x115
>> > Fax: 619-220-0599
>> > http://www.mssandiego.com
>> >
>> > -----Original Message-----
>> > From: Anders Thulin [mailto:Anders.Thulin@tietoenator.com]
>> > Sent: Wednesday, September 07, 2005 3:17 AM
>> > To: bryan allott; pen-test@securityfocus.com
>> > Subject: RE: Whitespace in passwords
>> >
>> > > From: bryan allott [mailto:homegrown@bryanallott.net]
>> >
>> > > to the misnomer "passWORD" rather than passPHRASE but it seems
>> > > that [most?] people choose passes that dont contain whitespaces,
>> >
>> > Most people still stick to alphanumeric passwords, and most of
>> > those are passwords where the digits are placed at the end.
>> > Whitespace is probably not more special than any of the other
>> > 'specials' that appear on a standard keyboard. A problem is to know
>> > just what those are -- a look at a keyboard may lead a user to think
>> > the 'x' on the keypad is a different special character than the '*'.
>> >
>> > > my main question, re security, is wether the whitespace made the
>> > > password too vulnerable? [historically] and why this constraint is
>> > > introduced in many systems..
>> >
>> > Tradition, probably. In environments where users are given fixed
>> > passwords that they can't change themselves, space belongs together
>> > with S58, O0, and Il1 to the characters that probably will be
>> > misunderstood, and so cause calls to helpdesk.
>> > Anything that is likely to cause a help-desk call is a no-no in
>> > large environments.
>> >
>> > Another aspect is regularity of user interface design:
>> > should space be treated as significant when it appears first and
>> > last in a string in general, say a Search field in a text editor or
>> > a From- field in an e-mail program? If not, spaces first and last in
>> > passwords will be assumed to be insignificant as well -- and so
>> > become another source for helpdesk complaints.
>> > Regularity pays off.
>> >
>> > [but then, if
>> > > myth- why propogate it?]
>> >
>> > Probably also a case that password are seldom documented in
>> > detail, and few people are willing to sit down to find out details
>> > by experiment.
>> > (Windows NT hashes use the OEM character set ... which is another
>> > source of documentation problems.) So instructions for password
>> > construction tend to avoid mentioning characters that might be
>> > troublesome, even though there are some important things to know.
>> >
>> > For instance, dead accent keys (on my kbd ^ is one) usually don't
>> > change the base character in a password, so 'pass' and 'pāss' may
>> > produce the same password hash.
>> >
>> > The most useful character to have in a reasonably modern Windows
>> > password is EUR (Alt-Gr E on my kbd.) I suspect the reason why is
>> > well known -- if not, I'll leave it as an exercize. I'm sure there
>> > are similar 'oddities' on other password situations.
>> >
>> > > i'm thinking that whitespaces [if yr system can handle them, and
>> > > why not?] would add another measure of complexity in cracking
>> > > pwds?
>> >
>> > Of course they do. But ... if you alredy have an adequate
>> > password protection -- say, accounts are locked out after 25 failed
>> > attempts per day regardless of source -- the extra complexity
>> > doesn't add much protection. (If you have the password hashes,
>> > security has already failed, and any attempt to add a last line of
>> > defense in the form of password complexity is misguided: it's only a
>> > question of time before the passwords are discovered, and that time
>> > should not be left to users to ensure.)
>> >
>> > Anders Thulin anders.thulin@tietoenator.com 040-661 50 63
>> > TietoEnator Telecom & Media AB, Box 85, SE-201 20 Malmö
>> >
>> >
>> >
>> >
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>> > ----------
>> > For more information about Barclays Capital, please visit our web
>> > site at http://www.barcap.com.
>> >
>> >
>> > Internet communications are not secure and therefore the Barclays
>> > Group does not accept legal responsibility for the contents of this
>> > message. Although the Barclays Group operates anti-virus
>> > programmes, it does not accept responsibility for any damage
>> > whatsoever that is caused by viruses being passed. Any views or
>> > opinions presented are solely those of the author and do not
>> > necessarily represent those of the Barclays Group. Replies to this
>> > email may be monitored by the Barclays Group for operational or
>> > business reasons.
>> >
>> > --------------------------------------------------------------
>> > ----------
>> >
>> >
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>> > Check your website for vulnerabilities to SQL injection, Cross site
>> > scripting and other web attacks before hackers do!
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>>
>>
>>
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>
>
> --
> Tim Van Cleave
>
> ------------------------------------------------------------------------------
> Audit your website security with Acunetix Web Vulnerability Scanner:
>
> Hackers are concentrating their efforts on attacking applications on your
> website. Up to 75% of cyber attacks are launched on shopping carts, forms,
> login pages, dynamic content etc. Firewalls, SSL and locked-down servers
> are futile against web application hacking. Check your website for
> vulnerabilities to SQL injection, Cross site scripting and other web
> attacks before hackers do!
> Download Trial at:
>
> http://www.securityfocus.com/sponsor/pen-test_050831
> -------------------------------------------------------------------------------
>
>
> ------------------------------------------------------------------------------
> Audit your website security with Acunetix Web Vulnerability Scanner:
>
> Hackers are concentrating their efforts on attacking applications on your
> website. Up to 75% of cyber attacks are launched on shopping carts, forms,
> login pages, dynamic content etc. Firewalls, SSL and locked-down servers
> are futile against web application hacking. Check your website for
> vulnerabilities to SQL injection, Cross site scripting and other web
> attacks before hackers do!
> Download Trial at:
>
> http://www.securityfocus.com/sponsor/pen-test_050831
> -------------------------------------------------------------------------------
>
>
> ------------------------------------------------------------------------------
> Audit your website security with Acunetix Web Vulnerability Scanner:
>
> Hackers are concentrating their efforts on attacking applications on your
> website. Up to 75% of cyber attacks are launched on shopping carts, forms,
> login pages, dynamic content etc. Firewalls, SSL and locked-down servers
> are
> futile against web application hacking. Check your website for
> vulnerabilities
> to SQL injection, Cross site scripting and other web attacks before
> hackers do!
> Download Trial at:
>
> http://www.securityfocus.com/sponsor/pen-test_050831
> -------------------------------------------------------------------------------
>
>
>
> ------------------------------------------------------------------------------
> Audit your website security with Acunetix Web Vulnerability Scanner:
>
> Hackers are concentrating their efforts on attacking applications on your
> website. Up to 75% of cyber attacks are launched on shopping carts, forms,
> login pages, dynamic content etc. Firewalls, SSL and locked-down servers
> are
> futile against web application hacking. Check your website for
> vulnerabilities
> to SQL injection, Cross site scripting and other web attacks before
> hackers do!
> Download Trial at:
>
> http://www.securityfocus.com/sponsor/pen-test_050831
> -------------------------------------------------------------------------------
>
>
------------------------------------------------------------------------------
Audit your website security with Acunetix Web Vulnerability Scanner:
Hackers are concentrating their efforts on attacking applications on your
website. Up to 75% of cyber attacks are launched on shopping carts, forms,
login pages, dynamic content etc. Firewalls, SSL and locked-down servers are
futile against web application hacking. Check your website for vulnerabilities
to SQL injection, Cross site scripting and other web attacks before hackers do!
Download Trial at:
http://www.securityfocus.com/sponsor/pen-test_050831
-------------------------------------------------------------------------------
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