[PATCH] MinGW, random_seed, CryptoAPI

[Bradley A. Town]

(I don't subscribe to the list -- I read it at lists.gnupg.org.  Please CC
me any replies.)

I have created patches to random.c, rndw32.c, util.h, and w32reg.c, but
together they are large (about 18k), so I'll send them to anyone that
wants/needs them.  Don't reply to the list for them, though -- just send
mail.  :)

These patches apply to MingW builds.  I'm compiling under Windows 2000
Professional using MinGW32 from Mumit Khan and configuration tools from
Cygwin.  Configure options:
configure --host=i386--mingw32 --disable-asm
(I couldn't get the assembly files to work, but I didn't try very hard.)

The following patches:
* Correct a bug with reading and writing random_seed (text vs. binary mode)
* Add the ability to use the icky Microsoft CryptoAPI *for random number
generation only* (Intel has a nice hardware RNG accessible through the
CryptoAPI) (Perhaps the CryptoAPI stuff should go into the entropy DLL?)
* Add a registry function for retrieving a number (which I then did not use,
but it's there)

GnuPG reads RNGToUse (REG_SZ) under HKCU/Software/GNU/GnuPG.  If it is not
present, or if it says "winseed", it uses the entropy DLL code.  If it says
"CryptoAPI", it uses the CryptoAPI.

Since several CSPs can be installed at one time, GnuPG reads ProvType
(REG_DWORD) under HKCU/Software/GNU/GnuPG/CryptoAPI.  If it is not present,
it fails.  Valid numbers are (as of the April 2000 Platform SDK) 1 through
22 (decimal).  A value of 1 might be sufficient for testing; 22 is the Intel
RNG.  (For info on the Intel RNG, check
http://developer.intel.com/design/security/rng/rng.htm .)  Values of
Container (REG_SZ) and Provider (REG_SZ) may also be provided.