[openssl-dev] global OpenSSL symbols in user apps

[Richard Levitte]

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.

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

-- 
Richard Levitte         levitte at openssl.org
OpenSSL Project         http://www.openssl.org/~levitte/