Simple DES question

From: adam (no@email.com)
Date: 03/09/03 

From: "adam" <no@email.com>
Date: Sun, 9 Mar 2003 06:49:54 +0100

I've read about DES in both Applied Cryptography and Handbook of Applied
Cryptography, including the official DES specification, but neither of them
say if b1 is the MSB or LSB. Sometimes it feels like they mean b1 = bit 0,
other times it seems like they mean b1 = bit 63. Which is it?

Are the keys, plaintext blocks, ciphertext blocks and other stuff supposed
to be in big endian or little endian format?

This is what I assume in my DES code (which isn't working according to the
test cases I've tried):

A number: b1b2b3..b64 = 2^63*b64+...+4*b3+2*b2+b1
Little-endian format
L(i) = Low 32 bits (b1b2..b32)
R(i) = High 32 bits (b33b34..b64)

S-boxes: b1b2b3b4b5b6 = 32*b6+16*b5+8*b4+4*b3+2*b2+b1:
 2*b1+b6 = row
 8*b5+4*b4+2*b3+b2 = column

And do you know of any _unoptimized_ DES C/C++ or assembler source code?

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