base/dispatch.c, rand/rand.c, and asm: Support `rdseed' for quick noise.

[catacomb] / rand / rand.c

diff --git a/rand/rand.c b/rand/rand.c
index f9f16d5..3b05633 100644 (file)
--- a/rand/rand.c
+++ b/rand/rand.c
@@ -161,24 +161,17 @@ CPU_DISPATCH(static, return, int, quick, (rand_pool *r), (r),
 
 static int trivial_quick(rand_pool *r) { return (-1); }
 
-#if __GNUC__ && (CPUFAM_X86 || CPUFAM_AMD64)
-static int rdrand_quick(rand_pool *r)
-{
-  unsigned long rr;
-  int i = 16;
-
-  __asm__ ("0: rdrand %0; jc 9f; dec %1; jnz 0b; 9:"
-          : "=r" (rr), "=r" (i) : "1" (i) : "cc");
-  if (!i) return (-1);
-  rand_add(r, &rr, sizeof(rr), 8*sizeof(rr));
-  return (0);
-}
+#if CPUFAM_X86 || CPUFAM_AMD64
+extern int rand_quick_x86ish_rdrand(rand_pool */*r*/);
+extern int rand_quick_x86ish_rdseed(rand_pool */*r*/);
 #endif
 
 static quick__functype *pick_quick(void)
 {
-#if __GNUC__ && (CPUFAM_X86 || CPUFAM_AMD64)
-  DISPATCH_PICK_COND(rand_quick, rdrand_quick,
+#if CPUFAM_X86 || CPUFAM_AMD64
+  DISPATCH_PICK_COND(rand_quick, rand_quick_x86ish_rdseed,
+                    cpu_feature_p(CPUFEAT_X86_RDSEED));
+  DISPATCH_PICK_COND(rand_quick, rand_quick_x86ish_rdrand,
                     cpu_feature_p(CPUFEAT_X86_RDRAND));
 #endif
   DISPATCH_PICK_FALLBACK(rand_quick, trivial_quick);
@@ -261,9 +254,7 @@ void rand_add(rand_pool *r, const void *p, size_t sz, unsigned goodbits)
   const octet *c = p;
   int i, rot;
 
-#if RAND_POOLSZ != 128
-#  error Polynomial in rand_add is out of date.  Fix it.
-#endif
+  STATIC_ASSERT(RAND_POOLSZ == 128, "Polynomial doesn't match pool size");
 
   RAND_RESOLVE(r);
 
@@ -316,6 +307,8 @@ void rand_gate(rand_pool *r)
   HASH_CTX hc;
   CIPHER_CTX cc;
 
+  STATIC_ASSERT(CIPHER_KEYSZ <= HASH_SZ, "rand cipher keysize too long");
+
   RAND_RESOLVE(r);
   QUICK(r);
 
@@ -323,6 +316,7 @@ void rand_gate(rand_pool *r)
 
   HASH_INIT(&hc);
   STORE32(g, r->gen); HASH(&hc, g, sizeof(g));
+  HASH(&hc, r->k.k, RAND_KEYSZ);
   HASH(&hc, r->pool, RAND_POOLSZ);
   HASH(&hc, r->buf, RAND_BUFSZ);
   HASH_DONE(&hc, h);
@@ -330,7 +324,6 @@ void rand_gate(rand_pool *r)
 
   /* --- Now mangle all of the data based on the hash --- */
 
-  assert(CIPHER_KEYSZ <= HASH_SZ);
   CIPHER_INIT(&cc, h, CIPHER_KEYSZ, 0);
   CIPHER_ENCRYPT(&cc, r->pool, r->pool, RAND_POOLSZ);
   CIPHER_ENCRYPT(&cc, r->buf, r->buf, RAND_BUFSZ);
@@ -366,6 +359,8 @@ void rand_stretch(rand_pool *r)
   HASH_CTX hc;
   CIPHER_CTX cc;
 
+  STATIC_ASSERT(CIPHER_KEYSZ <= HASH_SZ, "rand cipher keysize too long");
+
   RAND_RESOLVE(r);
   QUICK(r);
 
@@ -373,6 +368,7 @@ void rand_stretch(rand_pool *r)
 
   HASH_INIT(&hc);
   STORE32(g, r->gen); HASH(&hc, g, sizeof(g));
+  HASH(&hc, r->k.k, RAND_KEYSZ);
   HASH(&hc, r->pool, RAND_POOLSZ);
   HASH(&hc, r->buf, RAND_BUFSZ);
   HASH_DONE(&hc, h);
@@ -380,7 +376,6 @@ void rand_stretch(rand_pool *r)
 
   /* --- Now mangle the buffer based on the hash --- */
 
-  assert(CIPHER_KEYSZ <= HASH_SZ);
   CIPHER_INIT(&cc, h, CIPHER_KEYSZ, 0);
   CIPHER_ENCRYPT(&cc, r->buf, r->buf, RAND_BUFSZ);
   BURN(cc);