Commit 2667162d authored by Andy Polyakov's avatar Andy Polyakov
Browse files

cryptlib.c: OPENSSL_ia32cap environment variable to interpret ~ as cpuid mask.

parent 66b86a4f

crypto/cryptlib.c

+6 −3
Original line number Diff line number Diff line
@@ -144,12 +144,15 @@ void OPENSSL_cpuid_setup(void) 
    if (trigger)	return;



    trigger=1;

    if ((env=getenv("OPENSSL_ia32cap")))

    if ((env=getenv("OPENSSL_ia32cap"))) {

	int off = (env[0]=='~')?1:0;

#if defined(_WIN32)

    {	if (!sscanf(env,"%I64i",&vec)) vec = strtoul(env,NULL,0);   }

    	if (!sscanf(env+off,"%I64i",&vec)) vec = strtoul(env+off,NULL,0);

#else

	vec = strtoull(env,NULL,0);

	vec = strtoull(env+off,NULL,0);

#endif

	if (off) vec = OPENSSL_ia32_cpuid()&~vec;

    }

    else

	vec = OPENSSL_ia32_cpuid();

doc/crypto/OPENSSL_ia32cap.pod

+4 −4
Original line number Diff line number Diff line
@@ -61,10 +61,10 @@ capable CPU, but under control of OS that does not enable XMM 
registers. Even though you can manipulate the value programmatically,

you most likely will find it more appropriate to set up an environment

variable with the same name prior starting target application, e.g. on

Intel P4 processor 'env OPENSSL_ia32cap=0x16980010 apps/openssl', to

achieve same effect without modifying the application source code.

Alternatively you can reconfigure the toolkit with no-sse2 option and

recompile.

Intel P4 processor 'env OPENSSL_ia32cap=0x16980010 apps/openssl', or

better yet 'env OPENSSL_ia32cap=~0x1000000 apps/openssl' to achieve same

effect without modifying the application source code. Alternatively you

can reconfigure the toolkit with no-sse2 option and recompile.



Less intuituve is clearing bit #28. The truth is that it's not copied

from CPUID output verbatim, but is adjusted to reflect whether or not