Commit b86d57bb authored by Andy Polyakov's avatar Andy Polyakov
Browse files

crypto/cryptlib.c: make OPENSS_cpuid_setup safe to use as constructor. 



Reviewed-by: default avatarKurt Roeckx <kurt@roeckx.be>
(Merged from https://github.com/openssl/openssl/pull/6752)
parent f529b5cf

crypto/cryptlib.c

+81 −18
Original line number Diff line number Diff line
@@ -19,29 +19,97 @@ 
extern unsigned int OPENSSL_ia32cap_P[4];



# if defined(OPENSSL_CPUID_OBJ) && !defined(OPENSSL_NO_ASM) && !defined(I386_ONLY)

#include <stdio.h>



/*

 * Purpose of these minimalistic and character-type-agnostic subroutines

 * is to break dependency on MSVCRT (on Windows) and locale. This makes

 * OPENSSL_cpuid_setup safe to use as "constructor". "Character-type-

 * agnostic" means that they work with either wide or 8-bit characters,

 * exploiting the fact that first 127 characters can be simply casted

 * between the sets, while the rest would be simply rejected by ossl_is*

 * subroutines.

 */

#  ifdef _WIN32

typedef WCHAR variant_char;



static variant_char *ossl_getenv(const char *name)

{

    /*

     * Since we pull only one environment variable, it's simpler to

     * to just ignore |name| and use equivalent wide-char L-literal.

     * As well as to ignore excessively long values...

     */

    static WCHAR value[48];

    DWORD len = GetEnvironmentVariableW(L"OPENSSL_ia32cap", value, 48);



    return (len > 0 && len < 48) ? value : NULL;

}

#  else

typedef char variant_char;

#   define ossl_getenv getenv

#  endif



#  include "internal/ctype.h"



static int todigit(variant_char c)

{

    if (ossl_isdigit(c))

        return c - '0';

    else if (ossl_isxdigit(c))

        return ossl_tolower(c) - 'a' + 10;



    /* return largest base value to make caller terminate the loop */

    return 16;

}



static uint64_t ossl_strtouint64(const variant_char *str)

{

    uint64_t ret = 0;

    unsigned int digit, base = 10;



    if (*str == '0') {

        base = 8, str++;

        if (ossl_tolower(*str) == 'x')

            base = 16, str++;

    }



    while((digit = todigit(*str++)) < base)

        ret = ret * base + digit;



    return ret;

}



static variant_char *ossl_strchr(const variant_char *str, char srch)

{   variant_char c;



    while((c = *str)) {

        if (c == srch)

	    return (variant_char *)str;

        str++;

    }



    return NULL;

}



#  define OPENSSL_CPUID_SETUP

typedef uint64_t IA32CAP;



void OPENSSL_cpuid_setup(void)

{

    static int trigger = 0;

    IA32CAP OPENSSL_ia32_cpuid(unsigned int *);

    IA32CAP vec;

    char *env;

    const variant_char *env;



    if (trigger)

        return;



    trigger = 1;

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

    if ((env = ossl_getenv("OPENSSL_ia32cap")) != NULL) {

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

#  if defined(_WIN32)

        if (!sscanf(env + off, "%I64i", &vec))

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

#  else

        if (!sscanf(env + off, "%lli", (long long *)&vec))

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

#  endif



        vec = ossl_strtouint64(env + off);



        if (off) {

            IA32CAP mask = vec;

            vec = OPENSSL_ia32_cpuid(OPENSSL_ia32cap_P) & ~mask;
@@ -60,17 +128,12 @@ void OPENSSL_cpuid_setup(void) 
            vec = OPENSSL_ia32_cpuid(OPENSSL_ia32cap_P);

        }



        if ((env = strchr(env, ':'))) {

        if ((env = ossl_strchr(env, ':')) != NULL) {

            IA32CAP vecx;



            env++;

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

#  if defined(_WIN32)

            if (!sscanf(env + off, "%I64i", &vecx))

                vecx = strtoul(env + off, NULL, 0);

#  else

            if (!sscanf(env + off, "%lli", (long long *)&vecx))

                vecx = strtoul(env + off, NULL, 0);

#  endif

            vecx = ossl_strtouint64(env + off);

            if (off) {

                OPENSSL_ia32cap_P[2] &= ~(unsigned int)vecx;

                OPENSSL_ia32cap_P[3] &= ~(unsigned int)(vecx >> 32);