/*----- Header files ------------------------------------------------------*/
+#include "config.h"
+
#include <stdarg.h>
#include <stdio.h>
#include <string.h>
#include <mLib/sub.h>
#include "arena.h"
+#include "dispatch.h"
#include "paranoia.h"
#define RAND__HACKS
gctx rand_global = {
{ &gops },
- { { 0 }, 0, 0, 0,
+ { { 0 }, 0, 0, 0, 0,
{ 0 }, RAND_SECSZ, 0,
{ "Catacomb global random byte pool" },
&noise_source }
#define RAND_RESOLVE(r) \
do { if ((r) == RAND_GLOBAL) r = &rand_global.p; } while (0)
-#define TIMER(r) do { \
- if ((r)->s && (r)->s->timer) \
- (r)->s->timer(r); \
+#define GENCHECK(r) do { \
+ unsigned gen = rand_generation(); \
+ if (r->gen != gen) { r->gen = gen; rand_gate(r); } \
+} while (0)
+
+static int quick(rand_pool *);
+#define QUICK(r) do { \
+ quick(r); \
+ if ((r)->s && (r)->s->timer) (r)->s->timer(r); \
} while (0)
/*----- Main code ---------------------------------------------------------*/
RAND_RESOLVE(r);
memset(r->pool, 0, sizeof(r->pool));
memset(r->buf, 0, sizeof(r->buf));
+ r->gen = rand_generation();
r->i = 0;
r->irot = 0;
r->ibits = r->obits = 0;
r->s = s;
}
+/* --- @rand_quick@ --- *
+ *
+ * Arguments: @rand_pool *r@ = pointer to a randomness pool
+ *
+ * Returns: Zero on success; @-1@ on failure.
+ *
+ * Use Attempts to use some machine-specific `quick' source of
+ * entropy to top up @r@. This may not do anything at all on
+ * many systems.
+ */
+
+CPU_DISPATCH(static, return, int, quick, (rand_pool *r), (r),
+ pick_quick, trivial_quick);
+
+static int trivial_quick(rand_pool *r) { return (-1); }
+
+#if CPUFAM_X86 || CPUFAM_AMD64
+extern int rand_quick_x86ish_rdrand(rand_pool */*r*/);
+#endif
+
+static quick__functype *pick_quick(void)
+{
+#if CPUFAM_X86 || CPUFAM_AMD64
+ DISPATCH_PICK_COND(rand_quick, rand_quick_x86ish_rdrand,
+ cpu_feature_p(CPUFEAT_X86_RDRAND));
+#endif
+ DISPATCH_PICK_FALLBACK(rand_quick, trivial_quick);
+}
+
+int rand_quick(rand_pool *r) { RAND_RESOLVE(r); return (quick(r)); }
+
/* --- @rand_seed@ --- *
*
* Arguments: @rand_pool *r@ = pointer to a randomness pool
void rand_gate(rand_pool *r)
{
- octet h[HASH_SZ];
+ octet h[HASH_SZ], g[4];
HASH_CTX hc;
CIPHER_CTX cc;
RAND_RESOLVE(r);
- TIMER(r);
+ QUICK(r);
/* --- Hash up all the data in the pool --- */
HASH_INIT(&hc);
+ STORE32(g, r->gen); HASH(&hc, g, sizeof(g));
HASH(&hc, r->pool, RAND_POOLSZ);
HASH(&hc, r->buf, RAND_BUFSZ);
HASH_DONE(&hc, h);
r->obits = RAND_OBITS;
} else
r->ibits = 0;
- TIMER(r);
+ QUICK(r);
}
/* --- @rand_stretch@ --- *
void rand_stretch(rand_pool *r)
{
- octet h[HASH_SZ];
+ octet h[HASH_SZ], g[4];
HASH_CTX hc;
CIPHER_CTX cc;
RAND_RESOLVE(r);
- TIMER(r);
+ QUICK(r);
/* --- Hash up all the data in the buffer --- */
HASH_INIT(&hc);
+ STORE32(g, r->gen); HASH(&hc, g, sizeof(g));
HASH(&hc, r->pool, RAND_POOLSZ);
HASH(&hc, r->buf, RAND_BUFSZ);
HASH_DONE(&hc, h);
/* --- Now mangle the buffer based on the hash --- */
- assert(CIPHER_KEYSZ < HASH_SZ);
+ assert(CIPHER_KEYSZ <= HASH_SZ);
CIPHER_INIT(&cc, h, CIPHER_KEYSZ, 0);
CIPHER_ENCRYPT(&cc, r->buf, r->buf, RAND_BUFSZ);
BURN(cc);
/* --- Reset the various state variables --- */
r->o = RAND_SECSZ;
- TIMER(r);
+ QUICK(r);
}
/* --- @rand_get@ --- *
octet *o = p;
RAND_RESOLVE(r);
- TIMER(r);
+ GENCHECK(r);
+ QUICK(r);
if (!sz)
return;
rand_get(r, p, sz);
return;
}
- TIMER(r);
+ GENCHECK(r);
+ QUICK(r);
while (sz) {
size_t chunk = sz;
rand_seed(&g->p, va_arg(ap, unsigned));
break;
case RAND_TIMER:
- TIMER(&g->p);
+ QUICK(&g->p);
break;
case RAND_GOODBITS:
rc = rand_goodbits(&g->p);
"rand",
GRAND_CRYPTO, 0,
gmisc, gdestroy,
- gword, gbyte, gword, grand_range, gfill
+ gword, gbyte, gword, grand_defaultrange, gfill
};
/* --- @rand_create@ --- *