[openssl-dev] global OpenSSL symbols in user apps

[Matt Caswell]

On 28/06/16 14:41, Richard Levitte wrote:
> In message <HE1PR04MB13062251B2EAC361D15CF999EE220 at HE1PR04MB1306.eurprd04.prod.outlook.com> on Tue, 28 Jun 2016 12:38:20 +0000, Catalin Vasile <cata.vasile at nxp.com> said:
> 
> cata.vasile> Hi,
> cata.vasile> 
> cata.vasile> Is there a way to use global non-API functions or variables in user apps?
> cata.vasile> For example: Is there a way to use OpenSSL_armcap_P in your user apps? I tried declaring it as "extern" variable, but at linking the linker says it cannot find the symbol.
> 
> Generally speaking: no.
> 
> Practically speaking, it depends.  Provided we're talking about shared
> libraries, it's a definite "no" on Windows, VMS, Linux and Solaris
> (the list of Unix platforms are likely to expand) because the
> non-public symbols aren't made available.

That's true in 1.1.0. I think they are available in 1.0.2/1.0.1 on Linux
and Solaris.

Matt

> 
> If we're talking about static libraries, no symbols are hidden.
> 
> I would *not* recommend fiddling with the non-public symbols.  You may
> be safe in one OpenSSL version, but you cannot know what's happening
> with them in the next.
> 
> Cheers,
> Richard
>