From: Matthew Dillon <dillon@apollo.backplane.com>
Date: Tue, 25 Feb 2014 22:44:49 +0000 (-0800)
Subject: kernel - Change add_buffer_randomness() a little
X-Git-Tag: v3.9.0~465
X-Git-Url: https://gitweb.dragonflybsd.org/~tuxillo/dragonfly.git/commitdiff_plain/cf9961f7f4ec50a50716c84bb9b9a86cffe4caee

kernel - Change add_buffer_randomness() a little

* Move the securelevel and seedenable stuff to the /dev/random code,
  remove it from add_buffer_randomness().

* Adjust GENERIC and X86_64_GENERIC to include the chip RNGs by default.
---

diff --git a/sys/config/GENERIC b/sys/config/GENERIC
index 8f0d21e2e9..faaa51f200 100644
--- a/sys/config/GENERIC
+++ b/sys/config/GENERIC
@@ -375,3 +375,10 @@ device		fwe		# Ethernet over FireWire (non-standard!)
 device		mmc
 device		mmcsd
 device		sdhci
+
+# RNG
+#
+device          aesni           # hardware crypto/RNG for AES-NI
+#device          glxsb           # Geode LX Security Block
+device          padlock         # hardware crypto/RNG for VIA C3/C7/Eden
+device          rdrand          # hardware RNG for RdRand
diff --git a/sys/config/X86_64_GENERIC b/sys/config/X86_64_GENERIC
index 79a63a9f17..7066422dd2 100644
--- a/sys/config/X86_64_GENERIC
+++ b/sys/config/X86_64_GENERIC
@@ -351,3 +351,10 @@ device		fwe		# Ethernet over FireWire (non-standard!)
 device		mmc
 device		mmcsd
 device		sdhci
+
+# RNG
+#
+device          aesni           # hardware crypto/RNG for AES-NI
+#device          glxsb           # Geode LX Security Block
+device          padlock         # hardware crypto/RNG for VIA C3/C7/Eden
+device          rdrand          # hardware RNG for RdRand
diff --git a/sys/kern/kern_memio.c b/sys/kern/kern_memio.c
index bdf358fa2b..af98f0352e 100644
--- a/sys/kern/kern_memio.c
+++ b/sys/kern/kern_memio.c
@@ -56,6 +56,7 @@
 #include <sys/signalvar.h>
 #include <sys/uio.h>
 #include <sys/vnode.h>
+#include <sys/sysctl.h>
 
 #include <sys/signal2.h>
 #include <sys/mplock2.h>
@@ -95,6 +96,8 @@ static int random_ioctl (cdev_t, u_long, caddr_t, int, struct ucred *);
 
 struct mem_range_softc mem_range_softc;
 
+static int seedenable;
+SYSCTL_INT(_kern, OID_AUTO, seedenable, CTLFLAG_RW, &seedenable, 0, "");
 
 static int
 mmopen(struct dev_open_args *ap)
@@ -235,8 +238,13 @@ mmrw(cdev_t dev, struct uio *uio, int flags)
 			c = min(iov->iov_len, PAGE_SIZE);
 			if (uio->uio_rw == UIO_WRITE) {
 				error = uiomove(buf, (int)c, uio);
-				if (error == 0)
+				if (error == 0 &&
+				    seedenable &&
+				    securelevel <= 0) {
 					error = add_buffer_randomness(buf, c);
+				} else if (error == 0) {
+					error = EPERM;
+				}
 			} else {
 				poolsize = read_random(buf, c);
 				if (poolsize == 0) {
diff --git a/sys/kern/kern_nrandom.c b/sys/kern/kern_nrandom.c
index cc40e3c7ac..0eb9ef097e 100644
--- a/sys/kern/kern_nrandom.c
+++ b/sys/kern/kern_nrandom.c
@@ -407,8 +407,6 @@ static int sysctl_kern_random(SYSCTL_HANDLER_ARGS);
 
 static int nrandevents;
 SYSCTL_INT(_kern, OID_AUTO, nrandevents, CTLFLAG_RD, &nrandevents, 0, "");
-static int seedenable;
-SYSCTL_INT(_kern, OID_AUTO, seedenable, CTLFLAG_RW, &seedenable, 0, "");
 SYSCTL_PROC(_kern, OID_AUTO, random, CTLFLAG_RD | CTLFLAG_ANYBODY, 0, 0,
 		sysctl_kern_random, "I", "Acquire random data");
 
@@ -487,26 +485,21 @@ add_true_randomness(int val)
 int
 add_buffer_randomness(const char *buf, int bytes)
 {
-	int error;
 	int i;
 
-	if (seedenable && securelevel <= 0) {
-		while (bytes >= sizeof(int)) {
-			add_true_randomness(*(const int *)buf);
-			buf += sizeof(int);
-			bytes -= sizeof(int);
-		}
-		error = 0;
-
-		/*
-		 * Warm up the generator to get rid of weak initial states.
-		 */
-		for (i = 0; i < 10; ++i)
-			IBAA_Call();
-	} else {
-		error = EPERM;
+	while (bytes >= sizeof(int)) {
+		add_true_randomness(*(const int *)buf);
+		buf += sizeof(int);
+		bytes -= sizeof(int);
 	}
-	return (error);
+
+	/*
+	 * Warm up the generator to get rid of weak initial states.
+	 */
+	for (i = 0; i < 10; ++i)
+		IBAA_Call();
+
+	return 0;
 }
 
 /*