X-Git-Url: https://codewiz.org/gitweb?a=blobdiff_plain;f=bertos%2Fsec%2Fprng%2Fisaac.c;h=86c162700369b8f7b99366ccef5913c8c6601d45;hb=55574912ce4d7364597388a112805147a9618351;hp=d4246f718c5e9271cec834ebdd7a6f46ba786cd2;hpb=0483b8dfa8dc9dc01b6c2451bfd90867b1114f9f;p=bertos.git

diff --git a/bertos/sec/prng/isaac.c b/bertos/sec/prng/isaac.c
index d4246f71..86c16270 100644
--- a/bertos/sec/prng/isaac.c
+++ b/bertos/sec/prng/isaac.c
@@ -32,7 +32,7 @@
  *
  * \brief ISAAC implementation
  * \author Giovanni Bajo <rasky@develer.com>
- * 
+ *
  */
 
 /*
@@ -48,6 +48,7 @@ MODIFIED:
 
 #include "isaac.h"
 #include <sec/prng.h>
+#include <sec/util.h>
 #include <cfg/compiler.h>
 #include <cfg/macros.h>
 #include <string.h>
@@ -56,7 +57,7 @@ typedef uint32_t ub4;
 typedef uint16_t ub2;
 typedef uint8_t ub1;
 
-#define ind(mm,x)  (*(ub4 *)((ub1 *)(mm) + ((x) & ((CONFIG_ISAAC_RANDSIZ-1)<<2))))
+#define ind(mm,x)  (*(ub4 *)((size_t)(mm) + ((x) & ((CONFIG_ISAAC_RANDSIZ-1)<<2))))
 #define rngstep(mix,a,b,mm,m,m2,r,x) \
 { \
   x = *m;  \
@@ -65,7 +66,7 @@ typedef uint8_t ub1;
   *(r++) = b = ind(mm,y>>CONFIG_ISAAC_RANDSIZL) + x; \
 }
 
-static void isaac(ISAAC_Context *ctx)
+static void isaac(IsaacContext *ctx)
 {
 	register ub4 a,b,x,y,*m,*mm,*m2,*r,*mend;
 	mm=ctx->randmem; r=ctx->randrsl;
@@ -100,16 +101,16 @@ static void isaac(ISAAC_Context *ctx)
    h^=a>>9;  c+=h; a+=b; \
 }
 
-static void ISAAC_reseed(PRNG *ctx_, const uint8_t *seed)
+static void isaac_reseed(PRNG *ctx_, const uint8_t *seed)
 {
-	ISAAC_Context *ctx = (ISAAC_Context *)ctx_;
+	IsaacContext *ctx = (IsaacContext *)ctx_;
 	int i;
 	ub4 a,b,c,d,e,f,g,h;
 	ub4 *m,*r;
 
-	// Copy seed over half of randrsl, to reuse half of last-generated
-	// data as seed.
-	memcpy(ctx->randrsl, seed, sizeof(ctx->randrsl)/2);
+	// XOR the new seed over the current state, so to depend on
+	// the previously-generated output.
+	xor_block(ctx->randrsl, ctx->randrsl, seed, sizeof(ctx->randrsl));
 
 	ctx->randa = ctx->randb = ctx->randc = 0;
 	m=ctx->randmem;
@@ -141,23 +142,23 @@ static void ISAAC_reseed(PRNG *ctx_, const uint8_t *seed)
 	}
 }
 
-static void ISAAC_generate(PRNG *ctx_, uint8_t *data, size_t len)
+static void isaac_generate(PRNG *ctx_, uint8_t *data, size_t len)
 {
-	ISAAC_Context *ctx = (ISAAC_Context *)ctx_;
+	IsaacContext *ctx = (IsaacContext *)ctx_;
 
 	STATIC_ASSERT(sizeof(ctx->randrsl) == CONFIG_ISAAC_RANDSIZ*4);
 
 	while (len)
 	{
 		ASSERT(ctx->randcnt <= CONFIG_ISAAC_RANDSIZ*4);
-		
+
 		if (ctx->randcnt == CONFIG_ISAAC_RANDSIZ*4)
 		{
 			isaac(ctx);
-			ctx->randcnt = 0;			
+			ctx->randcnt = 0;
 		}
-		
-		size_t L = MIN(len, CONFIG_ISAAC_RANDSIZ*4 - (size_t)ctx->randcnt);	
+
+		size_t L = MIN(len, CONFIG_ISAAC_RANDSIZ*4 - (size_t)ctx->randcnt);
 		memcpy(data, (uint8_t*)ctx->randrsl + ctx->randcnt, L);
 		data += L;
 		ctx->randcnt += L;
@@ -168,11 +169,12 @@ static void ISAAC_generate(PRNG *ctx_, uint8_t *data, size_t len)
 
 /**********************************************************************/
 
-void ISAAC_init(ISAAC_Context *ctx)
+void isaac_init(IsaacContext *ctx)
 {
-	ctx->prng.reseed = ISAAC_reseed;
-	ctx->prng.generate = ISAAC_generate;
-	ctx->prng.seed_len = sizeof(ctx->randrsl) / 2;
+	ctx->prng.reseed = isaac_reseed;
+	ctx->prng.generate = isaac_generate;
+	ctx->prng.seed_len = sizeof(ctx->randrsl);
+	ctx->prng.seeded = 0;
 
 	ctx->randcnt = CONFIG_ISAAC_RANDSIZ*4;
 	memset(ctx->randrsl, 0, sizeof(ctx->randrsl));