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some system-specific adjustments for RNG routines

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move some system-specific seed-related stuff from hacklib.c to
a system-specific source file and #define SYS_RANDOM_SEED to
utilize it during build.

Windows changes for random seed generation using
crypto next gen (CNG) api routines.

Corresponding vms changes due to disentangling of VMS and
unix when the unix seed bits got moved (untested).
This commit is contained in:
nhmall
2019-01-13 20:54:11 -05:00
committed by Patric Mueller
parent f9433b2a87
commit 6c114640f5
11 changed files with 161 additions and 58 deletions
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32
src/hacklib.c
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@@ -51,6 +51,8 @@
boolean fuzzymatch (const char *, const char *,
const char *, boolean)
void setrandom (void)
void init_random (void)
void reseed_random (void)
time_t getnow (void)
int getyear (void)
char * yymmdd (time_t)
@@ -848,34 +850,20 @@ extern struct tm *FDECL(localtime, (time_t *));
#endif
STATIC_DCL struct tm *NDECL(getlt);
#ifdef SYS_RANDOM_SEED
extern unsigned long NDECL(sys_random_seed);
#endif
/* Returns a number suitable as seed for the random number generator. */
static unsigned long
get_random_seed()
{
unsigned long seed = 0;
#ifdef DEV_RANDOM
FILE *fptr = NULL;
fptr = fopen(DEV_RANDOM, "r");
if (fptr) {
fread(&seed, sizeof(long), 1, fptr);
}
fclose(fptr);
#ifdef SYS_RANDOM_SEED
/* Platform-specific seed if one is provided */
seed = sys_random_seed();
#else
seed = (unsigned long) getnow(); /* time((TIME_type) 0) */
# if defined(UNIX) || defined(VMS)
{
unsigned long pid = (unsigned long) getpid();
/* Quick dirty band-aid to prevent PRNG prediction */
if (pid) {
if (!(pid & 3L))
pid -= 1L;
seed *= pid;
}
}
# endif
#endif
return seed;
}
@@ -927,7 +915,7 @@ reseed_random()
{
/* only reseed if we are certain that the seed generation is unguessable
* by the players. */
#ifdef DEV_RANDOM
#if defined(SYS_RANDOM_SEED)
init_random();
#endif
}