Topic: Minimal memory footprint


I know this topic has been up before, and I can find information about it in the forum.

At least I can find info about minimum flash size of around 21kB using LeanPSK build switch.

- What is the minimum RAM (heap/stack) usage?
- Is it possible to allocate a single block of memory instead of using dynamic memory allocation?
   - My uTasker OS doesn't support free. It only supports malloc...

I need to use RSA, SHA256 and TLS v1.2.


Best regards


Re: Minimal memory footprint

[This was also answered through the wolfSSL support channel, but copying info here for user reference.]

wolfSSL's stack and heap usage will vary between 1-36kB depending on public key algorithm, key size, and math library being used.  wolfSSL has a Resource Use document available that details stack and heap usage, which can be obtained by emailing

As mentioned in this related post [1], wolfSSL contains a memory abstraction layer that allows applications to write and register their own memory handling functions (ie: malloc, realloc, free) with wolfSSL.  These are mapped by defining XMALLOC, XREALLOC, and XFREE at compile time.

[1] … xfree.html