[gnutls-help] Details about the GNU TLS

[Daiki Ueno]

Hello Prasanna,

Thank you for reaching out to us.

POKA PRASANNA <poka.prasanna at gmail.com> writes:

> Hi,
>     I am Prasanna Poka pursuing my master's in Chemnitz University of Technology. As
> part of my Master Thesis, I am looking for a TLS library which is lightweight and supports
> my requirements. I have gone through the product flyer of the GNU TLS and it almost
> suits my requirements. Still I could not find some other details. I request you to please
> let me know about the following details.

Before answering to those questions, I would like to remind that:
- While the portability of GnuTLS is guaranteed by the Gnulib library[1],
  GnuTLS makes use of the system libraries (p11-kit, libtasn1, etc)
  which may not be portable enough for your use-case.
- The crypto algorithms are implemented in the Nettle library[2], unless
  they are overridden by the internal acceleration code
  (lib/accelerated).

> * What is the range of the memory footprint this library provides?

I think that depends on the configuration (both at the build time and
run time), as well as your use-case.  I would suggest running the
example tools (gnutls-cli, gnutls-serv) under the valgrind massif
tool[3] and exercise the desired scenario.

> * Can we use this library for ARM Cortex M33 and M4 microcontrollers?

That depends on what OS is used; Dmitry (Cc'ed) might have insight on
those controllers.

> * Is the Brain pool curve supported by GNU TLS?

No, Nettle currently doesn't support Brainpool curves.

> * Can this library be used on FreeRTOS, MbedOS?

I'm unfamiliar with those embedded operating systems, but I guess it's
unlikely unless they provide POSIX compatibility.

Footnotes:
[1]  https://www.gnu.org/software/gnulib/

[2]  https://www.lysator.liu.se/~nisse/nettle/

[3]  https://www.valgrind.org/docs/manual/ms-manual.html

Regards,
-- 
Daiki Ueno