Re: CPSetKeyParam question

Hi Tom,

In CryptoAPI, when a CSP receive a call to CPSetKeyParam with KP_IV param,
the only parameter used to set the initialization vector of the key is
BYTE
*pbData. How the CSP know pbData's lentgh ? Because when an application
calls
CPGetKeyParam wtih pbData=NULL, the CSP retrieve the length of the key
IV...

Initialization vectors are used in block cyphers and are always the size of
one block. Since CPGetKeyParam works on a key, a particular encryption
algorithm and key size is associated with the key, and therefore also a well
defined block size.

This is analogous to the CPSetHashParam function with the HP_HASHVAL
parameter: The size of the hash is determined by the type of the hash and
isn't passed with the function.

Best regards,
Jan.


.

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