X-Git-Url: https://git.lizzy.rs/?a=blobdiff_plain;f=sys%2Fsrc%2F9%2Fport%2Frandom.c;h=b27e5720dbd9c427f17ec62075c9ad8e7e9f4416;hb=4f85115526a87063489dc7cf347343bd520159b1;hp=d401e7e0181eccbe1f7a58b099cdbb64402f2c7c;hpb=7713145638f45c07c47b9ef8c859d518d88f6127;p=plan9front.git

diff --git a/sys/src/9/port/random.c b/sys/src/9/port/random.c
index d401e7e01..b27e5720d 100644
--- a/sys/src/9/port/random.c
+++ b/sys/src/9/port/random.c
@@ -89,7 +89,6 @@ ulong
 randomread(void *p, ulong n)
 {
 	Chachastate c;
-	ulong b;
 
 	if(n == 0)
 		return 0;
@@ -97,12 +96,13 @@ randomread(void *p, ulong n)
 	if(hwrandbuf != nil)
 		(*hwrandbuf)(p, n);
 
-	/* copy chacha state and advance block counter */
+	/* copy chacha state, rekey and increment iv */
 	qlock(rs);
 	c = *rs;
-	b = rs->input[12];
-	rs->input[12] += (n + ChachaBsize-1)/ChachaBsize;
-	if(rs->input[12] < b) rs->input[13]++;
+	chacha_encrypt((uchar*)&rs->input[4], 32, &c);
+	if(++rs->input[13] == 0)
+		if(++rs->input[14] == 0)
+			++rs->input[15];
 	qunlock(rs);
 
 	/* encrypt the buffer, can fault */
@@ -120,3 +120,28 @@ genrandom(uchar *p, int n)
 {
 	randomread(p, n);
 }
+
+/* used by rand(),nrand() */
+long
+lrand(void)
+{
+	/* xoroshiro128+ algorithm */
+	static int seeded = 0;
+	static uvlong s[2];
+	static Lock lk;
+	ulong r;
+
+	if(seeded == 0){
+		randomread(s, sizeof(s));
+		seeded = (s[0] | s[1]) != 0;
+	}
+
+	lock(&lk);
+	r = (s[0] + s[1]) >> 33;
+	s[1] ^= s[0];
+ 	s[0] = (s[0] << 55 | s[0] >> 9) ^ s[1] ^ (s[1] << 14);
+ 	s[1] = (s[1] << 36 | s[1] >> 28);
+	unlock(&lk);
+
+ 	return r;
+}