[openssl-users] RSA sign using SHA256 with mgf1 padding

[Mounir IDRASSI]

Hi,

I have written a sample few years ago that performs PSS signature using
SHA256 like what you need.
You can get it from
https://www.idrix.fr/Root/Samples/openssl_pss_signature.c
It uses the maximum salt length. You should check that the server
expects this as well.

Cheers,
--
Mounir IDRASSI

Le 29/08/2016 à 10:59, Moshe Wiener (mowiener) a écrit :
>
> Hello,
>
> I’m running an application which runs an authentication session with a
> server. The server provides some random data, and my application needs
> to sign it with its private key, and send back the signature. The
> server which knows the public key verifies the signature, and it good
> then the client which runs my application is authenticated.
>
> This session used to run OK, until the server was changed so instead
> of using PKCS#1_v1.5 now it uses PKCS#1_v2.1
>
> Now, the server uses signature algorithm of SHA256 WITH RSA AN DMGF1.
>
> In my application I use OpenSSL.
>
> I think that I need to use ‘RSA_padding_add_PKCS1_OAEP_mgf1’ but
> couldn’t figure out what to put in each of its arguments.
>
> Is there somewhere a sample code which implements RSA signature with
> mgf1 padding and a SHA256 hash?
>
> Many thanks,
>
> Moshe
>
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