From: rasky <rasky@38d2e660-2303-0410-9eaa-f027e97ec537>
Date: Wed, 29 Sep 2010 16:51:03 +0000 (+0000)
Subject: SEC: fix first seeding of x917 to be fully deterministic.
X-Git-Tag: 2.6.0~37
X-Git-Url: https://codewiz.org/gitweb?a=commitdiff_plain;h=1bb0ad8f023538906d593d44a872cf4c091499c9;p=bertos.git

SEC: fix first seeding of x917 to be fully deterministic.


git-svn-id: https://src.develer.com/svnoss/bertos/trunk@4364 38d2e660-2303-0410-9eaa-f027e97ec537
---

diff --git a/bertos/sec/prng/x917.c b/bertos/sec/prng/x917.c
index 63888c8f..d2c84f71 100644
--- a/bertos/sec/prng/x917.c
+++ b/bertos/sec/prng/x917.c
@@ -103,17 +103,24 @@ static void x917_reseed(PRNG *ctx_, const uint8_t *seed)
 	//     of the seed, and use the result as new seed.
 	//   * Generate and throw away a block to update the state.
 	X917Context *ctx = (X917Context *)ctx_;
+	const size_t klen = sizeof(ctx->key);
+	const size_t blen = sizeof(ctx->state);
 
-	size_t klen = sizeof(ctx->key);
-	size_t blen = sizeof(ctx->state);
-
-	uint8_t buf[klen];
-	x917_generate(ctx_, buf, klen);
+	if (!ctx->rng.seeded)
+	{
+		memcpy(ctx->key, seed, klen);
+		memcpy(ctx->state, seed+klen, blen);
+	}
+	else
+	{
+		uint8_t buf[klen];
+		x917_generate(ctx_, buf, klen);
 
-	xor_block(ctx->key, buf, seed, klen);
-	xor_block(ctx->state, ctx->state, seed+klen, blen);
+		xor_block(ctx->key, buf, seed, klen);
+		xor_block(ctx->state, ctx->state, seed+klen, blen);
 
-	PURGE(buf);
+		PURGE(buf);
+	}
 }
 
 /*********************************************************************/