From: Alan T. DeKok <aland@freeradius.org>
Date: Thu, 28 Dec 2017 14:28:04 +0000 (-0500)
Subject: added fr_rand_buffer() to fill a buffer with random bytes
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=391af1f58013d62be1e041660fd744ba15365b64;p=thirdparty%2Ffreeradius-server.git

added fr_rand_buffer() to fill a buffer with random bytes
---

diff --git a/src/include/libradius.h b/src/include/libradius.h
index d5ec4ab825a..f86b885522f 100644
--- a/src/include/libradius.h
+++ b/src/include/libradius.h
@@ -223,6 +223,7 @@ typedef struct fr_randctx {
 void		fr_isaac(fr_randctx *ctx);
 void		fr_randinit(fr_randctx *ctx, int flag);
 uint32_t	fr_rand(void);	/* like rand(), but better. */
+void		fr_rand_buffer(void *start, size_t length) CC_HINT(nonnull);
 void		fr_rand_seed(void const *, size_t ); /* seed the random pool */
 
 
diff --git a/src/lib/util/mem.c b/src/lib/util/mem.c
index 975affaab1f..98076d4a06d 100644
--- a/src/lib/util/mem.c
+++ b/src/lib/util/mem.c
@@ -45,20 +45,8 @@ RADIUS_PACKET *fr_radius_alloc(TALLOC_CTX *ctx, bool new_vector)
 	rp->id = -1;
 
 	if (new_vector) {
-		int i;
-		uint32_t hash, base;
-
-		/*
-		 *	Don't expose the actual contents of the random
-		 *	pool.
-		 */
-		base = fr_rand();
-		for (i = 0; i < AUTH_VECTOR_LEN; i += sizeof(uint32_t)) {
-			hash = fr_rand() ^ base;
-			memcpy(rp->vector + i, &hash, sizeof(hash));
-		}
+		fr_rand_buffer(rp->vector, sizeof(rp->vector));
 	}
-	fr_rand();		/* stir the pool again */
 
 	return rp;
 }
diff --git a/src/lib/util/rand.c b/src/lib/util/rand.c
index 5ac904d1934..c719d007b0e 100644
--- a/src/lib/util/rand.c
+++ b/src/lib/util/rand.c
@@ -108,3 +108,32 @@ uint32_t fr_rand(void)
 
 	return num;
 }
+
+void fr_rand_buffer(void *start, size_t length)
+{
+	uint32_t x;
+	uint8_t *buffer = start;
+	size_t buflen = length;
+
+	if (buflen > 4) {
+		size_t i;
+
+		for (i = 0; i < buflen; i += 4) {
+			x = fr_rand();
+			memcpy(buffer + i, &x, sizeof(x));
+		}
+
+		/*
+		 *	Keep only the last bytes in the word.
+		 */
+		i = buflen & ~0x03;
+		buffer += i;
+		buflen &= 0x03;
+	}
+
+	if (!buflen) return;
+
+	x = fr_rand();
+
+	memcpy(buffer, &x, buflen);
+}