[Cryptography Team] package structure

[Chris Muller]

I know we've talked about our package structure before
but..

As I work through this book, I have some fixes and
additions to our Crytography packages.  Here is a list
of things I plan to post in the coming days:

  - addition of entropic sources for seed material
  - addition of the CTR (counter) cipher mode
  - addition of the "Fortuna" random generator
  - fix for seriously broken MillerRabin algorithm
preventing generation of proper-sized asymmetric keys
(i.e., for Diffie-Hellman / ElGamal and maybe RSA
too). 

For the first one "entropic sources for seed
material".  It individually hashes unpredictable
strings from the users environment such as:

  - current directory
  - Time millisecondClockValue
  - World imageForm bits compressToByteArray
  - SmalltalkImage current vmStatisticsReportString
  - Sensor mousePoint
  - etc., etc.

and then finally SHA256 hashes the concatentation of
all of those hashes.  Slow, but totally unpredictable.

I've started by implementing SecureRandom
class>>#entropicSourcesDo: which is used by
SecureRandom class>>#randomSeed.  But SecureRandom is
in the "CryptographyBase" package, so I can't use SHA1
and SHA256.

It seems to me that many crypto primitives are built
from other ones.  Wouldn't it be easier to have
everything back in one package?  What are we trying to
accomplish here by having them all in separate
packages?

How should I proceed?

Thanks,
  Chris