[prev in list] [next in list] [prev in thread] [next in thread] 

List:       ms-cryptoapi
Subject:    Re: Step hash output and signature production
From:       Rob Mig <rjmr () MAILCITY ! COM>
Date:       1998-09-18 16:30:37
[Download RAW message or body]


Dear Ilia:
Accordingly to the documentation applications using CryptoAPI need not add padding to \
their plaintext before it is encrypted, nor do they have to remove it after \
decrypting. This is all handled automatically by CryptoAPI. It is supposed that the \
default is PKCS Padding. When this method is used, a padding string is always added. \
The padding string consists of a sequence of bytes, each of which is equal to the \
total number of bytes in the padding string. If 24 bits of padding need to be added, \
then the padding string is “03 03 03.” If 64 bits of padding needs to be added, then \
the string is “08 08 08 08 08 08 08 08"

Regards and good luck!
Rob.

--

On Thu, 17 Sep 1998 22:33:14   Ilias Tranganidas wrote:
> Hello,
> I am using a smart card create a signature and I must use the Crypto
> API to verify it. The smart card has the following commands:
> 1. RSA key pair generation (512 bits the public module is readable)
> 2. SHA-1 hash function creation (20 bytes)
> 3. RSA signature creation (requires the hash output to be padded to 64
> bytes, accepts any pad characters)
> 
> The command to verify the signature in the Crypto API is
> CryptVerifySignature() that requires as a parameter a handle to a hash
> object.
> 
> So I presume that the padding is done internally. Can somebody point
> me to the way this padding is performed so that I can replicate it in
> the function that accesses the smart card?
> 
> Best Regards
> Ilias
> 
> 
> 
> 
> 
> _________________________________________________________
> DO YOU YAHOO!?
> Get your free @yahoo.com address at http://mail.yahoo.com
> 
> ----------------------------------------------------------------
> Users Guide http://www.microsoft.com/workshop/essentials/mail.asp
> contains important info including how to unsubscribe.  Save time, search
> the archives at http://discuss.microsoft.com/archives/index.html
> 


Get your FREE E-mail at http://mailcity.lycos.com
Get your PERSONALIZED START PAGE at http://personal.lycos.com

----------------------------------------------------------------
Users Guide http://www.microsoft.com/workshop/essentials/mail.asp
contains important info including how to unsubscribe.  Save time, search
the archives at http://discuss.microsoft.com/archives/index.html


[prev in list] [next in list] [prev in thread] [next in thread]