X-Git-Url: https://codewiz.org/gitweb?a=blobdiff_plain;f=bertos%2Fsec%2Fprng%2Fisaac.c;h=f3320a5469fbe3ff426a2e566d1b7ab527bf34f0;hb=3d3ba83839f2a8faed6c373e5153d61672ce7fb6;hp=4e031c0be5d9a36d234088b8a39cd460a8a721d1;hpb=f2108fe515132a85c7e84e588789f482f8feb750;p=bertos.git

diff --git a/bertos/sec/prng/isaac.c b/bertos/sec/prng/isaac.c
index 4e031c0b..f3320a54 100644
--- a/bertos/sec/prng/isaac.c
+++ b/bertos/sec/prng/isaac.c
@@ -107,9 +107,9 @@ static void isaac_reseed(PRNG *ctx_, const uint8_t *seed)
 	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;
@@ -172,7 +172,7 @@ 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.seed_len = sizeof(ctx->randrsl);
 	ctx->prng.seeded = 0;
 
 	ctx->randcnt = CONFIG_ISAAC_RANDSIZ*4;