Howto use libgrcypt for signature?

[Stef Bon]

2016-05-27 11:47 GMT+02:00 Justus Winter <justus at g10code.com>:
> Hi :)
>
> Quoting Stef Bon (2016-05-27 10:35:08)
>> I'm writing a fuse fs for sftp, and using libgcrypt for encryption,
>> hmac, digest and dh.
>
> Shouldn't you be rather using e.g. libssh then?  If using libgcrypt
> rather than openssl is important to you, libssh can be configured to
> use it at compile time.

No,

I've found it very complicated to use libssh with the fuse fs I want to write.
First the integration with my own eventloop is complicated to write.
I've asked the libssh devellist about this, no help there.
Second I want to extend the ssh/sftp protocol with handling extended
attributes (for use in the FUSE fs of course).
There is a request for the openssh developers, but they don't want to
do anything about it:

https://bugzilla.mindrot.org/show_bug.cgi?id=1953

Knowing this reaction I guess it's better to create my own ssh/sftp library.

>> Do I have to convert the strings to some s-expressions using a format first?

>Yes.

Just converting the string to an s-expression like:

gcry_sexp_build(&sig, NULL, "%b", sigH->len, sigH->ptr)

or do I have to use another hostkey algo specific format?

Stef