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digitalmars.D - std.md5 and my.md5

reply Regan Heath <regan netwin.co.nz> writes:
Hi,

After writing my own version of the md5 algo, then discovering the std.md5 
implementation, I thought I would ask peoples thoughts on which version 
they prefer and why. Mainly to discover what I have done right/wrong when 
I wrote it.

So if anyone is interested I am attaching my source.

Comments of all shapes and sizes are desired and most welcome, 
particularly...

- The fact that I have used a class and std.md5 uses a struct.
- The naming of the functions.

std.md5 does have a 'sum' function which I do not, one could be added 
trivially.


I think I made some mistakes, for example:

- My functions take char[] whereas std.md5 takes void[]
- my digest is a char[] std.md5 uses a ubyte[]

..etc..

Anything you say, can and will be used.. to enable me to write better D 
code!

Regan

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Jun 07 2004
parent reply Arcane Jill <Arcane_member pathlink.com> writes:
In article <opr872elh35a2sq9 digitalmars.com>, Regan Heath says...

- My functions take char[] whereas std.md5 takes void[]
- my digest is a char[] std.md5 uses a ubyte[]


char is most definitely the wrong type. A char stores a fragment of a UTF-8
encoded character stream. You need a ubyte.

But it's nice to find someone else interested in crypto things. If you craft any
other hash functions (the rest of the MD- family, the SHA- family, the new Tiger
algorithm, and so on) there will definitely be a place for them in the
forthcoming etc.crypto heirarchy. (We might have to haggle over the API a
little). :-)

Arcane Jill
Jun 07 2004
next sibling parent reply "Walter" <newshound digitalmars.com> writes:
"Arcane Jill" <Arcane_member pathlink.com> wrote in message
news:ca1mnp$2p58$1 digitaldaemon.com...

 But it's nice to find someone else interested in crypto things. If you


craft any

 other hash functions (the rest of the MD- family, the SHA- family, the new


Tiger

 algorithm, and so on) there will definitely be a place for them in the
 forthcoming etc.crypto heirarchy. (We might have to haggle over the API a
 little). :-)


I haven't added the SHA (Secure Hash Algorithm) because the description of
the algorithm says implementations need an export license. I don't know if
this is obsolete or not, as there are SHA implementations all over the web,
but I prefer that phobos not be encumbered with such problems.
Jun 07 2004
parent reply Arcane Jill <Arcane_member pathlink.com> writes:
In article <ca2brg$oaj$2 digitaldaemon.com>, Walter says...

I haven't added the SHA (Secure Hash Algorithm) because the description of
the algorithm says implementations need an export license.


Sensible, but as it happens your information is out of date. US export
restrictions on cryptography were relaxed in September 1998, and dropped
altogether in January 2000.

Put it like this. You know when you connect to an https:// web site, and you get
all that malarky with security certificates, and maybe a little padlock icon in
the corner of your browser if you're lucky? Well that's SSL, and the SSL
protocol includes an implementation of SHA-1. If SHA is illegal in your country,
then there must be an AWFUL lot of lawbreakers around, including Microsoft,
Netscape, ....

Anyway, I don't live in the US, so those dumb rules never did apply to me. It
always made me laugh that the US was not allowed to export to me that which I
already had. (I could export it to them!)



I don't know if
this is obsolete or not, as there are SHA implementations all over the web,
but I prefer that phobos not be encumbered with such problems.


Sounds like a job for Deimos then. The crypto community at large WANT
easy-to-use implementations of TLS (that's the successor to SSL) out there,
because apparently OpenSSL is just too damn hard to use. This is my goal, and I
shall achieve it in D, and I will have to write an AWFUL lot of stuff to get
there (big integers were just the start), but I will succeed.

Of more concern is the fact that Hans Dobbertin has demonstrated a weakness in
MD5 which now makes it unsuitable for serious crypto. There is every possibility
that it might be broken in the next few years. SHA-256 is the hashing algorithm
of choice these days.

To be honest, it hadn't occured to me that you might have put SHA in Phobos but
didn't. I largely figured I would be doing all the work myself anyway. But then,
I guess I'm still hoping that (the forthcoming) etc.crypto may eventually become
std.crypto...

:-)
Jill
Jun 07 2004
parent reply "Walter" <newshound digitalmars.com> writes:
"Arcane Jill" <Arcane_member pathlink.com> wrote in message
news:ca2e0r$rmg$1 digitaldaemon.com...

 In article <ca2brg$oaj$2 digitaldaemon.com>, Walter says...

I haven't added the SHA (Secure Hash Algorithm) because the description




of

the algorithm says implementations need an export license.


 Sensible, but as it happens your information is out of date. US export
 restrictions on cryptography were relaxed in September 1998, and dropped
 altogether in January 2000.


That's good news.


 Put it like this. You know when you connect to an https:// web site, and


you get

 all that malarky with security certificates, and maybe a little padlock


icon in

 the corner of your browser if you're lucky? Well that's SSL, and the SSL
 protocol includes an implementation of SHA-1. If SHA is illegal in your


country,

 then there must be an AWFUL lot of lawbreakers around, including


Microsoft,

 Netscape, ....


It was legal to use it, just not export it. That's why many software boxes
got marked 'not for export'. Of course, it was absurd to think that this
actually prevented anyone outside the country from getting it.


 Anyway, I don't live in the US, so those dumb rules never did apply to me.


It

 always made me laugh that the US was not allowed to export to me that


which I

 already had. (I could export it to them!)


It had the effect of forcing US software companies to have a separate export
product that was cryptographically crippled, putting them at a serious
disadvantage to foreign competitors who of course had strong encryption.


I don't know if
this is obsolete or not, as there are SHA implementations all over the




web,

but I prefer that phobos not be encumbered with such problems.


 Sounds like a job for Deimos then. The crypto community at large WANT
 easy-to-use implementations of TLS (that's the successor to SSL) out


there,

 because apparently OpenSSL is just too damn hard to use. This is my goal,


and I

 shall achieve it in D, and I will have to write an AWFUL lot of stuff to


get

 there (big integers were just the start), but I will succeed.

 Of more concern is the fact that Hans Dobbertin has demonstrated a


weakness in

 MD5 which now makes it unsuitable for serious crypto. There is every


possibility

 that it might be broken in the next few years. SHA-256 is the hashing


algorithm

 of choice these days.

 To be honest, it hadn't occured to me that you might have put SHA in


Phobos but

 didn't. I largely figured I would be doing all the work myself anyway. But


then,

 I guess I'm still hoping that (the forthcoming) etc.crypto may eventually


become

 std.crypto...


I hope so, too. Crypto is another of my interests, but generally not
explored because I spend all my time with compilers <g>.
Jun 07 2004
parent reply Stephan Wienczny <wienczny web.de> writes:
Maybe we will see a new break-through in cryptography if Walter has some 
  time for it ;-)
Something like the "Walter Hash"...

Walter wrote:

 
 
 I hope so, too. Crypto is another of my interests, but generally not
 explored because I spend all my time with compilers <g>.
Jun 07 2004
parent "Walter" <newshound digitalmars.com> writes:
Sadly, I don't have a good enough math background to pretend I can advance
that field.

"Stephan Wienczny" <wienczny web.de> wrote in message
news:ca2i7u$126p$1 digitaldaemon.com...

 Maybe we will see a new break-through in cryptography if Walter has some
   time for it ;-)
 Something like the "Walter Hash"...

 Walter wrote:

 I hope so, too. Crypto is another of my interests, but generally not
 explored because I spend all my time with compilers <g>.
Jun 07 2004
prev sibling parent Regan Heath <regan netwin.co.nz> writes:
On Mon, 7 Jun 2004 12:23:21 +0000 (UTC), Arcane Jill 
<Arcane_member pathlink.com> wrote:

 In article <opr872elh35a2sq9 digitalmars.com>, Regan Heath says...

 - My functions take char[] whereas std.md5 takes void[]
 - my digest is a char[] std.md5 uses a ubyte[]


 char is most definitely the wrong type. A char stores a fragment of a 
 UTF-8
 encoded character stream. You need a ubyte.


Yep... I realise that now :)


 But it's nice to find someone else interested in crypto things. If you 
 craft any
 other hash functions (the rest of the MD- family, the SHA- family, the 
 new Tiger
 algorithm, and so on) there will definitely be a place for them in the
 forthcoming etc.crypto heirarchy. (We might have to haggle over the API a
 little). :-)


I am such a newbie at crypto that I doubt I'll be much use, that won't 
stop me from having a go of course! (when I find the time)

I'll let you know what I'm gonna try next, when I decide what that is.

Regan.

-- 
Using M2, Opera's revolutionary e-mail client: http://www.opera.com/m2/
Jun 07 2004