Darren

From: CryptEncrypt Input block size (Darren_at_discussions.microsoft.com)
Date: 08/06/04


Date: Thu, 5 Aug 2004 23:09:09 -0700

Hi,

When using CryptEncrypt to encrypt data, it takes in a
BYTE* of plaintext to be encrypted. Looking at the sample
code in MSDN, the input block size is 1000 - 1000 %
ENCRYPTION_BLOCK_SIZE. As far as I understand, block
cipher algorithms typically have an input block size of
around 64-bit or 128-bit... definitely not as large as
1000-bytes (or so).

Does this mean that the input block size should only be 64-
bit or 128-bit (or whatever size the algorithm requires)?
Or is the CryptEncrypt function capable of accepting large
chunks of data as long as it is a multiple of the block
size (and it will break the data up into the proper block
sizes and run through the required number of passes in the
one function call)?

Thanks,
Darren.