Re: Getting the SHA1 Hask of a certificate public key

On Fri, 16 Dec 2005 23:47:26 +0200, Mike B wrote:


> "lelteto" <lelteto@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote in message
>>
>> 1. WHY do you need the SHA-1 hash of the public key?
>>
>>2. If you plan to use the SHA-1 hash in YOUR (proprietary) .....
>>
> Don't make assumptions about MY proprietary software, my friend!
>
> Take a look at the PKWARE appnote and you will understand that MD5 is
> not the only hash used in everyday Crypto, and in particular, for
> supporting certificate based encryption in zip archives. (As
> implemented by RSA BSAFE cryptographic library).
>
> Your hashing recommendations will not work.
>
> In fact the SHA1 hash is quite straightforward to get (as I discovered
> eventually) by passing the CERT_KEY_IDENTIFIER_PROP_ID property constant
> to the CertGetCertificateContextProperty function.
>
> My concern is that this may not work for all certificates.
>
> regards
> Mike

As I recall, the form of the CERT_KEY_IDENTIFIER property will indeed
vary, depending on the certificate.

The hashing method described by Laszlo will work fine, though.

Regards,
John
.

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