Re: CryptoAPI and private key /not public/ encryption with CryptEncrypt - can not use CryptHash* functions

From: Przemek Wasylko (wasylek_at_removeme.megapolis.pl)
Date: 12/27/04

  • Next message: Vishal Agarwal[MSFT]: "Re: CERT_E_WRONG_USAGE" 
    Date: Mon, 27 Dec 2004 13:28:48 +0100

    "Valery Pryamikov" <Valery@nospam.harper.no> wrote in message
    news:%23mZ5G636EHA.2700@TK2MSFTNGP14.phx.gbl...
    > Hi,
    > if you have hash value that fits some standard hash (ex. use MD5 if it is
    > 128 bits or SHA1 if hash is 160 bits or CALG_SSL3_SHAMD5 if it is 288
    > bits) then you can use CryptSetHashParam with HP_HASHVAL, and use
    > CryptSignHash to sign it.
    > Since cryptographic hash value is essentially a random number - no
    > restrictions could be added to CryptSetHashParam with HP_HASHVAL except
    > for bitlength. So, if you have value of RIPEMD-160 or HAVAL you can just
    > stick it's value into SHA1/MD5 hash and sign it.

    Hello,

    Thakn you for your answer. I have thought of solution of that kind (using
    CryptSetHashParam with HP_HASHVAL) but I was curious if it is possible to
    perfom such calculations normally, ie encrypting hash with private key and
    decrypting with public key. I guess by that it is not possible with
    cryptoapi ?

    Przemek Wasylko

  • Next message: Vishal Agarwal[MSFT]: "Re: CERT_E_WRONG_USAGE"

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