[GNU Crypto] AES (Rijndael) for J2ME

[Wes Biggs]

Hi all,

I converted a minimal version of the Rijndael cipher for use with J2ME 
MIDP, with an emphasis on reducing bytecode size (it assumes AES, i.e. 
128-bit key/blocksize, and uses none of the rest of the gnu.crypto 
framework).  It ends up at  about 4.5K when compiled without debug.  I 
can post or email it if it's useful to others.

I haven't put a lot of thought into how the general gnu.crypto 
architecture could best accommodate J2ME.  With minor compromises it 
might be feasible to have the existing Rijndael class wrap the minimal 
AES code, so they can both live in CVS and avoid code duplication -- 
J2ME users could just grab the one class.

Of course AES by itself is not too useful without PKI for key exchange, 
and it will be harder to convert an asymmetric algorithm that relies on 
BigInteger arithmetic (BouncyCastle has done this for the lightweight 
crypto package and the resulting classes are quite large).  But AES with 
key delivery via a push mechanism like SMS approximates the security 
environment of OMA DRM 1.0 separate delivery, which was my immediate goal.

I didn't see this discussed in the archives so I apologize if this is 
well-trodden ground.

Wes