RSA sign/verify and hash generation functions

Nikos Mavrogiannopoulos nmav at gnutls.org
Wed Dec 8 23:22:55 CET 2010


On 12/08/2010 09:17 PM, Murray S. Kucherawy wrote:
> Here's something interesting I found while trying to figure this out.
> % openssl rsa -in key.pem -text
> Private-Key: (1024 bit)
> modulus:
>     00:b8:19:41:ab:f9:df:fa:48:53:73:54:b6:29:a6:
[...]
> ...and then dumping the modulus and private exponent through code that uses the same format as OpenSSL:> 
> modulus:
>     b8:19:41:ab:f9:df:fa:48:53:73:54:b6:29:a6:19:
> Note that when using GnuTLS, the leading "00" octet in the modulus is missing.
> Is this expected?  Could it explain the different signature I get from
GnuTLS 2.11.6?

The export_raw() functions do not add the leading zero. Adding them
would be better (and I'll modify them to do), but it doesn't explain the
different signature.

regards,
Nikos




More information about the Gnutls-help mailing list