Re: Can RSA PSS-R be done simply with OpenSSL?

[Andrew Tucker via openssl-users]

There is example code for doing RSA PSS with OpenSSL at
https://www.idrix.fr/Root/Samples/openssl_pss_signature.c



On Tue, May 12, 2020 at 11:59 AM John McCabe  wrote:

> Hi,
> I've searched around, but found nothing that appears to help.
>
> I'm developing some software where I may be given a file that's been
> created (signed) by using the Crypto++ library's implementation of RSA
> PSS-R, with a SHA1 hash. As I understand it, the complete file contents
> then effectively becomes the signature, and the receiving end needs to
> recover the original file contents and verify its signature.
>
> Is the receiving end something I can do with OpenSSL? I have a need to use
> OpenSSL features in the software I'm developing so, if possible, I'd rather
> avoid having to include Crypto++ in it!
>
> Any pointers would be gratefully appreciated. For what it's worth, this is
> something I'm fairly new to so, if what I'm asking isn't clear, or if it
> sounds like I have some concepts wrong, please let me know gently ;-)
>
> Many thanks
> John
>

Can RSA PSS-R be done simply with OpenSSL?

[John McCabe]

Hi,
I've searched around, but found nothing that appears to help.

I'm developing some software where I may be given a file that's been created 
(signed) by using the Crypto++ library's implementation of RSA PSS-R, with a 
SHA1 hash. As I understand it, the complete file contents then effectively 
becomes the signature, and the receiving end needs to recover the original file 
contents and verify its signature.

Is the receiving end something I can do with OpenSSL? I have a need to use 
OpenSSL features in the software I'm developing so, if possible, I'd rather 
avoid having to include Crypto++ in it!

Any pointers would be gratefully appreciated. For what it's worth, this is 
something I'm fairly new to so, if what I'm asking isn't clear, or if it sounds 
like I have some concepts wrong, please let me know gently ;-)

Many thanks
John