Theodore Ts'po's random number gernerator for Linux, ported by me.

This code will only be included in your kernel if you have
'options DEVRANDOM', but that will fall away in a couple of days.
Obtained from: Theodore Ts'o, Linux

16 files changed, 866 insertions, 40 deletions

diff --git a/sys/amd64/amd64/machdep.c b/sys/amd64/amd64/machdep.c
index 2a21f8e66fab..a844229fc3c5 100644
--- a/sys/amd64/amd64/machdep.c
+++ b/sys/amd64/amd64/machdep.c
@@ -35,7 +35,7 @@
  * SUCH DAMAGE.
  *
  *	from: @(#)machdep.c	7.4 (Berkeley) 6/3/91
- *	$Id: machdep.c,v 1.143 1995/09/15 08:31:14 davidg Exp $
+ *	$Id: machdep.c,v 1.144 1995/10/10 05:05:28 bde Exp $
  */
 
 #include "npx.h"
@@ -126,6 +126,7 @@
 #include <i386/isa/isa.h>
 #include <i386/isa/isa_device.h>
 #include <i386/isa/rtc.h>
+#include <machine/random.h>
 
 extern void diediedie __P((void));
 extern void init386 __P((int first));
@@ -1351,6 +1352,9 @@ init386(first)
 #if	NISA >0
 	isa_defaultirq();
 #endif
+#ifdef DEVRANDOM
+	rand_initialize();
+#endif
 
 	r_gdt.rd_limit = sizeof(gdt) - 1;
 	r_gdt.rd_base =  (int) gdt;
diff --git a/sys/amd64/amd64/mem.c b/sys/amd64/amd64/mem.c
index 6abd68e36732..e2ddf1b3bea6 100644
--- a/sys/amd64/amd64/mem.c
+++ b/sys/amd64/amd64/mem.c
@@ -38,7 +38,7 @@
  *
  *	from: Utah $Hdr: mem.c 1.13 89/10/08$
  *	from: @(#)mem.c	7.2 (Berkeley) 5/9/91
- *	$Id: mem.c,v 1.13 1995/09/15 23:49:23 davidg Exp $
+ *	$Id: mem.c,v 1.14 1995/09/20 13:01:17 davidg Exp $
  */
 
 /*
@@ -62,6 +62,8 @@
 #include <vm/vm_prot.h>
 #include <vm/pmap.h>
 
+#include <machine/random.h>
+
 #ifdef	DEVFS
 #include <sys/devfsext.h>
 #include "sys/kernel.h"
@@ -70,12 +72,16 @@ int mmopen();
 void memdev_init(void *data) /* data not used */
 {
   void * x;
-/*            path	name	devsw   minor	type   uid gid perm*/
-   x=dev_add("/misc",	"mem",	mmopen, 0,	DV_CHR, 0,  2, 0640);
-   x=dev_add("/misc",	"kmem",	mmopen, 1,	DV_CHR, 0,  2, 0640);
-   x=dev_add("/misc",	"null",	mmopen, 2,	DV_CHR, 0,  0, 0666);
-   x=dev_add("/misc",	"zero",	mmopen, 12,	DV_CHR, 0,  0, 0666);
-   x=dev_add("/misc",	"io",	mmopen, 14,	DV_CHR, 0,  2, 0640);
+/*            path	name		devsw   minor	type   uid gid perm*/
+   x=dev_add("/misc",	"mem",		mmopen, 0,	DV_CHR, 0,  2, 0640);
+   x=dev_add("/misc",	"kmem",		mmopen, 1,	DV_CHR, 0,  2, 0640);
+   x=dev_add("/misc",	"null",		mmopen, 2,	DV_CHR, 0,  0, 0666);
+#ifdef DEVRANDOM
+   x=dev_add("/misc",	"random",	mmopen, 3,	DV_CHR, 0,  0, 0666);
+   x=dev_add("/misc",	"urandom",	mmopen, 4,	DV_CHR, 0,  0, 0666);
+#endif
+   x=dev_add("/misc",	"zero",		mmopen, 12,	DV_CHR, 0,  0, 0666);
+   x=dev_add("/misc",	"io",		mmopen, 14,	DV_CHR, 0,  2, 0640);
 }
 SYSINIT(memdev,SI_SUB_DEVFS, SI_ORDER_ANY, memdev_init, NULL)
 #endif /*DEVFS*/
@@ -132,9 +138,12 @@ mmrw(dev, uio, flags)
 {
 	register int o;
 	register u_int c, v;
+#ifdef DEVRANDOM
+	u_int poolsize;
+#endif
 	register struct iovec *iov;
 	int error = 0;
-	caddr_t zbuf = NULL;
+	caddr_t buf = NULL;
 
 	while (uio->uio_resid > 0 && error == 0) {
 		iov = uio->uio_iov;
@@ -191,19 +200,56 @@ mmrw(dev, uio, flags)
 			c = iov->iov_len;
 			break;
 
+#ifdef DEVRANDOM
+/* minor device 3 (/dev/random) is source of filth on read, rathole on write */
+		case 3:
+			if (uio->uio_rw == UIO_WRITE) {
+				c = iov->iov_len;
+				break;
+			}
+			if (buf == NULL)
+				buf = (caddr_t)
+				    malloc(CLBYTES, M_TEMP, M_WAITOK);
+			c = min(iov->iov_len, CLBYTES);
+			poolsize = read_random(buf, c);
+			if (poolsize == 0) {
+				if (buf)
+					free(buf, M_TEMP);
+				return (0);
+			}
+			c = min(c, poolsize);
+			error = uiomove(buf, (int)c, uio);
+			continue;
+
+/* minor device 4 (/dev/urandom) is source of muck on read, rathole on write */
+		case 4:
+			if (uio->uio_rw == UIO_WRITE) {
+				c = iov->iov_len;
+				break;
+			}
+			if (buf == NULL)
+				buf = (caddr_t)
+				    malloc(CLBYTES, M_TEMP, M_WAITOK);
+			c = min(iov->iov_len, CLBYTES);
+			poolsize = read_random_unlimited(buf, c);
+			c = min(c, poolsize);
+			error = uiomove(buf, (int)c, uio);
+			continue;
+#endif
+
 /* minor device 12 (/dev/zero) is source of nulls on read, rathole on write */
 		case 12:
 			if (uio->uio_rw == UIO_WRITE) {
 				c = iov->iov_len;
 				break;
 			}
-			if (zbuf == NULL) {
-				zbuf = (caddr_t)
+			if (buf == NULL) {
+				buf = (caddr_t)
 				    malloc(CLBYTES, M_TEMP, M_WAITOK);
-				bzero(zbuf, CLBYTES);
+				bzero(buf, CLBYTES);
 			}
 			c = min(iov->iov_len, CLBYTES);
-			error = uiomove(zbuf, (int)c, uio);
+			error = uiomove(buf, (int)c, uio);
 			continue;
 
 #ifdef notyet
@@ -263,8 +309,8 @@ mmrw(dev, uio, flags)
 		uio->uio_offset += c;
 		uio->uio_resid -= c;
 	}
-	if (zbuf)
-		free(zbuf, M_TEMP);
+	if (buf)
+		free(buf, M_TEMP);
 	return (error);
 }
 
@@ -293,3 +339,41 @@ int memmmap(dev_t dev, int offset, int nprot)
 	}
 }
 
+#ifdef DEVRANDOM
+
+/*
+ * Allow userland to select which interrupts will be used in the muck
+ * gathering business.
+ */
+
+int
+mmioctl(dev_t dev, int cmd, caddr_t cmdarg, int flags, struct proc *p)
+{
+	if (minor(dev) != 3 && minor(dev) != 4)
+		return (ENODEV);
+
+	if (*(u_int16_t *)cmdarg >= 16)
+		return (EINVAL);
+
+	switch (cmd){
+
+		case MEM_SETIRQ:
+			interrupt_allowed |= 1 << *(u_int16_t *)cmdarg;
+			break;
+
+		case MEM_CLEARIRQ:
+			interrupt_allowed &= ~(1 << *(u_int16_t *)cmdarg);
+			break;
+
+		case MEM_RETURNIRQ:
+			*(u_int16_t *)cmdarg = interrupt_allowed;
+			break;
+
+		default:
+			return (ENOTTY);
+	}
+	return (0);
+}
+#else
+d_ioctl_t *mmioctl = enodev;
+#endif
diff --git a/sys/amd64/isa/vector.S b/sys/amd64/isa/vector.S
index bbed601c550d..c630bee4cf3a 100644
--- a/sys/amd64/isa/vector.S
+++ b/sys/amd64/isa/vector.S
@@ -1,6 +1,6 @@
 /*
  *	from: vector.s, 386BSD 0.1 unknown origin
- *	$Id: vector.s,v 1.11 1994/12/03 10:03:19 bde Exp $
+ *	$Id: vector.s,v 1.12 1995/04/15 21:32:18 bde Exp $
  */
 
 #include <i386/isa/icu.h>
@@ -53,6 +53,16 @@
 #define	MAYBE_PUSHL_ES
 #endif
 
+#ifdef DEVRANDOM
+#define	ADDENTROPY(irq_num) \
+	/* Add this interrupt to the pool of entropy */ \
+	pushl	$irq_num ; \
+	call	_add_interrupt_randomness ; \
+	addl	$4,%esp
+#else
+#define	ADDENTROPY(irq_num)
+#endif
+
 /*
  * Macros for interrupt interrupt entry, call to handler, and exit.
  *
@@ -194,6 +204,8 @@ Xresume/**/irq_num: ; \
 	FASTER_NOP ; \
 	outb	%al,$icu+1 ; \
 	sti ;			/* XXX _doreti repeats the cli/sti */ \
+	/* Add this interrupt to the pool of entropy */ \
+	ADDENTROPY(irq_num) ; \
 	MEXITCOUNT ; \
 	/* We could usually avoid the following jmp by inlining some of */ \
 	/* _doreti, but it's probably better to use less cache. */ \
diff --git a/sys/amd64/isa/vector.s b/sys/amd64/isa/vector.s
index bbed601c550d..c630bee4cf3a 100644
--- a/sys/amd64/isa/vector.s
+++ b/sys/amd64/isa/vector.s
@@ -1,6 +1,6 @@
 /*
  *	from: vector.s, 386BSD 0.1 unknown origin
- *	$Id: vector.s,v 1.11 1994/12/03 10:03:19 bde Exp $
+ *	$Id: vector.s,v 1.12 1995/04/15 21:32:18 bde Exp $
  */
 
 #include <i386/isa/icu.h>
@@ -53,6 +53,16 @@
 #define	MAYBE_PUSHL_ES
 #endif
 
+#ifdef DEVRANDOM
+#define	ADDENTROPY(irq_num) \
+	/* Add this interrupt to the pool of entropy */ \
+	pushl	$irq_num ; \
+	call	_add_interrupt_randomness ; \
+	addl	$4,%esp
+#else
+#define	ADDENTROPY(irq_num)
+#endif
+
 /*
  * Macros for interrupt interrupt entry, call to handler, and exit.
  *
@@ -194,6 +204,8 @@ Xresume/**/irq_num: ; \
 	FASTER_NOP ; \
 	outb	%al,$icu+1 ; \
 	sti ;			/* XXX _doreti repeats the cli/sti */ \
+	/* Add this interrupt to the pool of entropy */ \
+	ADDENTROPY(irq_num) ; \
 	MEXITCOUNT ; \
 	/* We could usually avoid the following jmp by inlining some of */ \
 	/* _doreti, but it's probably better to use less cache. */ \
diff --git a/sys/conf/files.i386 b/sys/conf/files.i386
index 7379b708a720..8f50bc2bfb7d 100644
--- a/sys/conf/files.i386
+++ b/sys/conf/files.i386
@@ -1,7 +1,7 @@
 # This file tells config what files go into building a kernel,
 # files marked standard are always included.
 #
-#	$Id: files.i386,v 1.109 1995/09/16 17:03:23 bde Exp $
+#	$Id: files.i386,v 1.110 1995/10/10 08:04:10 swallace Exp $
 #
 aic7xxx_asm			optional	ahc	device-driver	   \
 	dependency 	"$S/dev/aic7xxx/aic7xxx_asm.c"			   \
@@ -107,6 +107,7 @@ i386/isa/matcd/matcd.c		optional	matcd	device-driver
 i386/isa/pcibus.c		optional	pci	device-driver
 i386/isa/pcic.c			optional	ze	device-driver
 i386/isa/pcic.c			optional	zp	device-driver
+i386/isa/random.c		standard
 i386/eisa/eisaconf.c		optional	eisa
 i386/eisa/eisadevs.c		optional	eisa
 i386/isa/pcvt/pcvt_drv.c	optional	vt	device-driver
diff --git a/sys/dev/syscons/syscons.c b/sys/dev/syscons/syscons.c
index 327e329763fe..6080597d5900 100644
--- a/sys/dev/syscons/syscons.c
+++ b/sys/dev/syscons/syscons.c
@@ -25,7 +25,7 @@
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *
- *  $Id: syscons.c,v 1.125 1995/09/10 21:35:12 bde Exp $
+ *  $Id: syscons.c,v 1.126 1995/10/14 07:08:09 bde Exp $
  */
 
 #include "sc.h"
@@ -53,6 +53,7 @@
 #include <machine/frame.h>
 #include <machine/pc/display.h>
 #include <machine/apm_bios.h>
+#include <machine/random.h>
 
 #include <i386/isa/isa.h>
 #include <i386/isa/isa_device.h>
@@ -2202,6 +2203,10 @@ next_code:
     else
 	goto next_code;
 
+#ifdef DEVRANDOM
+    add_keyboard_randomness(scancode);
+#endif
+
     if (cur_console->status & KBD_RAW_MODE)
 	return scancode;
 #if ASYNCH
diff --git a/sys/i386/conf/files.i386 b/sys/i386/conf/files.i386
index 7379b708a720..8f50bc2bfb7d 100644
--- a/sys/i386/conf/files.i386
+++ b/sys/i386/conf/files.i386
@@ -1,7 +1,7 @@
 # This file tells config what files go into building a kernel,
 # files marked standard are always included.
 #
-#	$Id: files.i386,v 1.109 1995/09/16 17:03:23 bde Exp $
+#	$Id: files.i386,v 1.110 1995/10/10 08:04:10 swallace Exp $
 #
 aic7xxx_asm			optional	ahc	device-driver	   \
 	dependency 	"$S/dev/aic7xxx/aic7xxx_asm.c"			   \
@@ -107,6 +107,7 @@ i386/isa/matcd/matcd.c		optional	matcd	device-driver
 i386/isa/pcibus.c		optional	pci	device-driver
 i386/isa/pcic.c			optional	ze	device-driver
 i386/isa/pcic.c			optional	zp	device-driver
+i386/isa/random.c		standard
 i386/eisa/eisaconf.c		optional	eisa
 i386/eisa/eisadevs.c		optional	eisa
 i386/isa/pcvt/pcvt_drv.c	optional	vt	device-driver
diff --git a/sys/i386/i386/conf.c b/sys/i386/i386/conf.c
index f2ca17f48874..f95ce6f5d062 100644
--- a/sys/i386/i386/conf.c
+++ b/sys/i386/i386/conf.c
@@ -42,7 +42,7 @@
  * SUCH DAMAGE.
  *
  *	from: @(#)conf.c	5.8 (Berkeley) 5/12/91
- *	$Id: conf.c,v 1.101 1995/10/14 05:25:45 bde Exp $
+ *	$Id: conf.c,v 1.102 1995/10/14 15:40:42 davidg Exp $
  */
 
 #include <sys/param.h>
@@ -472,6 +472,7 @@ d_open_t	mmopen;
 d_close_t	mmclose;
 d_rdwr_t	mmrw;
 d_mmap_t	memmmap;
+d_ioctl_t	mmioctl;
 #define	mmselect	seltrue
 
 #include "pty.h"
@@ -1087,7 +1088,7 @@ struct cdevsw	cdevsw[] =
 	  cttyioctl,	nullstop,	nullreset,	nodevtotty,/* tty */
 	  cttyselect,	nommap,		NULL },
 	{ mmopen,	mmclose,	mmrw,		mmrw,		/*2*/
-	  noioc,	nullstop,	nullreset,	nodevtotty,/* memory */
+	  mmioctl,	nullstop,	nullreset,	nodevtotty,/* memory */
 	  mmselect,	memmmap,	NULL },
 	{ wdopen,	wdclose,	rawread,	rawwrite,	/*3*/
 	  wdioctl,	nostop,		nullreset,	nodevtotty,/* wd */
diff --git a/sys/i386/i386/machdep.c b/sys/i386/i386/machdep.c
index 2a21f8e66fab..a844229fc3c5 100644
--- a/sys/i386/i386/machdep.c
+++ b/sys/i386/i386/machdep.c
@@ -35,7 +35,7 @@
  * SUCH DAMAGE.
  *
  *	from: @(#)machdep.c	7.4 (Berkeley) 6/3/91
- *	$Id: machdep.c,v 1.143 1995/09/15 08:31:14 davidg Exp $
+ *	$Id: machdep.c,v 1.144 1995/10/10 05:05:28 bde Exp $
  */
 
 #include "npx.h"
@@ -126,6 +126,7 @@
 #include <i386/isa/isa.h>
 #include <i386/isa/isa_device.h>
 #include <i386/isa/rtc.h>
+#include <machine/random.h>
 
 extern void diediedie __P((void));
 extern void init386 __P((int first));
@@ -1351,6 +1352,9 @@ init386(first)
 #if	NISA >0
 	isa_defaultirq();
 #endif
+#ifdef DEVRANDOM
+	rand_initialize();
+#endif
 
 	r_gdt.rd_limit = sizeof(gdt) - 1;
 	r_gdt.rd_base =  (int) gdt;
diff --git a/sys/i386/i386/mem.c b/sys/i386/i386/mem.c
index 6abd68e36732..e2ddf1b3bea6 100644
--- a/sys/i386/i386/mem.c
+++ b/sys/i386/i386/mem.c
@@ -38,7 +38,7 @@
  *
  *	from: Utah $Hdr: mem.c 1.13 89/10/08$
  *	from: @(#)mem.c	7.2 (Berkeley) 5/9/91
- *	$Id: mem.c,v 1.13 1995/09/15 23:49:23 davidg Exp $
+ *	$Id: mem.c,v 1.14 1995/09/20 13:01:17 davidg Exp $
  */
 
 /*
@@ -62,6 +62,8 @@
 #include <vm/vm_prot.h>
 #include <vm/pmap.h>
 
+#include <machine/random.h>
+
 #ifdef	DEVFS
 #include <sys/devfsext.h>
 #include "sys/kernel.h"
@@ -70,12 +72,16 @@ int mmopen();
 void memdev_init(void *data) /* data not used */
 {
   void * x;
-/*            path	name	devsw   minor	type   uid gid perm*/
-   x=dev_add("/misc",	"mem",	mmopen, 0,	DV_CHR, 0,  2, 0640);
-   x=dev_add("/misc",	"kmem",	mmopen, 1,	DV_CHR, 0,  2, 0640);
-   x=dev_add("/misc",	"null",	mmopen, 2,	DV_CHR, 0,  0, 0666);
-   x=dev_add("/misc",	"zero",	mmopen, 12,	DV_CHR, 0,  0, 0666);
-   x=dev_add("/misc",	"io",	mmopen, 14,	DV_CHR, 0,  2, 0640);
+/*            path	name		devsw   minor	type   uid gid perm*/
+   x=dev_add("/misc",	"mem",		mmopen, 0,	DV_CHR, 0,  2, 0640);
+   x=dev_add("/misc",	"kmem",		mmopen, 1,	DV_CHR, 0,  2, 0640);
+   x=dev_add("/misc",	"null",		mmopen, 2,	DV_CHR, 0,  0, 0666);
+#ifdef DEVRANDOM
+   x=dev_add("/misc",	"random",	mmopen, 3,	DV_CHR, 0,  0, 0666);
+   x=dev_add("/misc",	"urandom",	mmopen, 4,	DV_CHR, 0,  0, 0666);
+#endif
+   x=dev_add("/misc",	"zero",		mmopen, 12,	DV_CHR, 0,  0, 0666);
+   x=dev_add("/misc",	"io",		mmopen, 14,	DV_CHR, 0,  2, 0640);
 }
 SYSINIT(memdev,SI_SUB_DEVFS, SI_ORDER_ANY, memdev_init, NULL)
 #endif /*DEVFS*/
@@ -132,9 +138,12 @@ mmrw(dev, uio, flags)
 {
 	register int o;
 	register u_int c, v;
+#ifdef DEVRANDOM
+	u_int poolsize;
+#endif
 	register struct iovec *iov;
 	int error = 0;
-	caddr_t zbuf = NULL;
+	caddr_t buf = NULL;
 
 	while (uio->uio_resid > 0 && error == 0) {
 		iov = uio->uio_iov;
@@ -191,19 +200,56 @@ mmrw(dev, uio, flags)
 			c = iov->iov_len;
 			break;
 
+#ifdef DEVRANDOM
+/* minor device 3 (/dev/random) is source of filth on read, rathole on write */
+		case 3:
+			if (uio->uio_rw == UIO_WRITE) {
+				c = iov->iov_len;
+				break;
+			}
+			if (buf == NULL)
+				buf = (caddr_t)
+				    malloc(CLBYTES, M_TEMP, M_WAITOK);
+			c = min(iov->iov_len, CLBYTES);
+			poolsize = read_random(buf, c);
+			if (poolsize == 0) {
+				if (buf)
+					free(buf, M_TEMP);
+				return (0);
+			}
+			c = min(c, poolsize);
+			error = uiomove(buf, (int)c, uio);
+			continue;
+
+/* minor device 4 (/dev/urandom) is source of muck on read, rathole on write */
+		case 4:
+			if (uio->uio_rw == UIO_WRITE) {
+				c = iov->iov_len;
+				break;
+			}
+			if (buf == NULL)
+				buf = (caddr_t)
+				    malloc(CLBYTES, M_TEMP, M_WAITOK);
+			c = min(iov->iov_len, CLBYTES);
+			poolsize = read_random_unlimited(buf, c);
+			c = min(c, poolsize);
+			error = uiomove(buf, (int)c, uio);
+			continue;
+#endif
+
 /* minor device 12 (/dev/zero) is source of nulls on read, rathole on write */
 		case 12:
 			if (uio->uio_rw == UIO_WRITE) {
 				c = iov->iov_len;
 				break;
 			}
-			if (zbuf == NULL) {
-				zbuf = (caddr_t)
+			if (buf == NULL) {
+				buf = (caddr_t)
 				    malloc(CLBYTES, M_TEMP, M_WAITOK);
-				bzero(zbuf, CLBYTES);
+				bzero(buf, CLBYTES);
 			}
 			c = min(iov->iov_len, CLBYTES);
-			error = uiomove(zbuf, (int)c, uio);
+			error = uiomove(buf, (int)c, uio);
 			continue;
 
 #ifdef notyet
@@ -263,8 +309,8 @@ mmrw(dev, uio, flags)
 		uio->uio_offset += c;
 		uio->uio_resid -= c;
 	}
-	if (zbuf)
-		free(zbuf, M_TEMP);
+	if (buf)
+		free(buf, M_TEMP);
 	return (error);
 }
 
@@ -293,3 +339,41 @@ int memmmap(dev_t dev, int offset, int nprot)
 	}
 }
 
+#ifdef DEVRANDOM
+
+/*
+ * Allow userland to select which interrupts will be used in the muck
+ * gathering business.
+ */
+
+int
+mmioctl(dev_t dev, int cmd, caddr_t cmdarg, int flags, struct proc *p)
+{
+	if (minor(dev) != 3 && minor(dev) != 4)
+		return (ENODEV);
+
+	if (*(u_int16_t *)cmdarg >= 16)
+		return (EINVAL);
+
+	switch (cmd){
+
+		case MEM_SETIRQ:
+			interrupt_allowed |= 1 << *(u_int16_t *)cmdarg;
+			break;
+
+		case MEM_CLEARIRQ:
+			interrupt_allowed &= ~(1 << *(u_int16_t *)cmdarg);
+			break;
+
+		case MEM_RETURNIRQ:
+			*(u_int16_t *)cmdarg = interrupt_allowed;
+			break;
+
+		default:
+			return (ENOTTY);
+	}
+	return (0);
+}
+#else
+d_ioctl_t *mmioctl = enodev;
+#endif
diff --git a/sys/i386/include/random.h b/sys/i386/include/random.h
new file mode 100644
index 000000000000..78a6b06a894c
--- /dev/null
+++ b/sys/i386/include/random.h
@@ -0,0 +1,72 @@
+/*
+ * random.h -- A strong random number generator
+ *
+ * $Id$
+ *
+ * Version 0.92, last modified 21-Sep-95
+ * 
+ * Copyright Theodore Ts'o, 1994, 1995.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, and the entire permission notice in its entirety,
+ *    including the disclaimer of warranties.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote
+ *    products derived from this software without specific prior
+ *    written permission.
+ * 
+ * ALTERNATIVELY, this product may be distributed under the terms of
+ * the GNU Public License, in which case the provisions of the GPL are
+ * required INSTEAD OF the above restrictions.  (This clause is
+ * necessary due to a potential bad interaction between the GPL and
+ * the restrictions contained in a BSD-style copyright.)
+ * 
+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
+ * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
+ * OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+/*
+ * Many kernel routines will have a use for good random numbers,
+ * for example, for truely random TCP sequence numbers, which prevent
+ * certain forms of TCP spoofing attacks.
+ * 
+ */
+
+#ifndef _MACHINE_RANDOM_H_
+#define _MACHINE_RANDOM_H_ 1
+
+#include <sys/ioctl.h>
+
+#define	MEM_SETIRQ	_IOW('r', 1, int)	/* set interrupt */
+#define	MEM_CLEARIRQ	_IOW('r', 2, int)	/* clear interrupt */
+#define	MEM_RETURNIRQ	_IOR('r', 3, int)	/* return interrupt */
+
+/* Interrupts to be used in the randomising process */
+
+extern u_int16_t interrupt_allowed;
+
+/* Exported functions */
+
+void rand_initialize(void);
+void add_keyboard_randomness(u_char scancode);
+
+void get_random_bytes(void *buf, u_int nbytes);
+u_int read_random(char *buf, u_int size);
+u_int read_random_unlimited(char *buf, u_int size);
+
+#endif
diff --git a/sys/i386/isa/random.c b/sys/i386/isa/random.c
new file mode 100644
index 000000000000..af67c56bc803
--- /dev/null
+++ b/sys/i386/isa/random.c
@@ -0,0 +1,452 @@
+/*
+ * random.c -- A strong random number generator
+ *
+ * $Id$
+ *
+ * Version 0.92, last modified 21-Sep-95
+ * 
+ * Copyright Theodore Ts'o, 1994, 1995.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, and the entire permission notice in its entirety,
+ *    including the disclaimer of warranties.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote
+ *    products derived from this software without specific prior
+ *    written permission.
+ * 
+ * ALTERNATIVELY, this product may be distributed under the terms of
+ * the GNU Public License, in which case the provisions of the GPL are
+ * required INSTEAD OF the above restrictions.  (This clause is
+ * necessary due to a potential bad interaction between the GPL and
+ * the restrictions contained in a BSD-style copyright.)
+ * 
+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
+ * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
+ * OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#ifdef DEVRANDOM
+
+#include <sys/param.h>
+#include <sys/cdefs.h>
+#include <sys/kernel.h>
+#include <sys/uio.h>
+#include <sys/systm.h>
+#include <i386/isa/isa.h>
+#include <i386/isa/icu.h>
+#include <i386/isa/timerreg.h>
+#include <i386/isa/isa_device.h>
+#include <machine/random.h>
+
+#define RANDPOOL 512
+
+struct random_bucket {
+	int add_ptr;
+	int entropy_count;
+	int length;
+	int bit_length;
+	int delay_mix:1;
+	u_int8_t *pool;
+};
+
+struct timer_rand_state {
+	u_int32_t	last_time;
+	int 		last_delta;
+	int 		nbits;
+};
+
+static struct random_bucket random_state;
+static u_int32_t rand_pool_key[16];
+static u_int8_t random_pool[RANDPOOL];
+static u_int32_t random_counter[16];
+static struct timer_rand_state keyboard_timer_state;
+static struct timer_rand_state irq_timer_state[ICU_LEN];
+
+inthand2_t add_interrupt_randomness;
+u_int16_t interrupt_allowed = 0;
+	
+#ifndef MIN
+#define MIN(a,b) (((a) < (b)) ? (a) : (b))
+#endif
+	
+static void
+flush_random(struct random_bucket *random_state)
+{
+	random_state->add_ptr = 0;
+	random_state->bit_length = random_state->length * 8;
+	random_state->entropy_count = 0;
+	random_state->delay_mix = 0;
+}
+
+void
+rand_initialize(void)
+{
+	int irq;
+	long interrupts;
+
+	random_state.length = RANDPOOL;
+	random_state.pool = random_pool;
+	flush_random(&random_state);
+
+#if 0
+	/* XXX Dreadful hack - should be replaced by something more elegant */
+	interrupts = RANDOM_INTERRUPTS;
+
+	for (irq = 0; irq < ICU_LEN; irq++) {
+		interrupt_allowed[irq] = interrupts & 0x0001;
+		interrupts >>= 1;
+		printf("Randomising irq %d %s\n", irq, interrupt_allowed[irq] ?
+			"on" : "off");
+	}
+#endif
+}
+
+/*
+ * MD5 transform algorithm, taken from code written by Colin Plumb,
+ * and put into the public domain
+ */
+
+/* The four core functions - F1 is optimized somewhat */
+
+/* #define F1(x, y, z) (x & y | ~x & z) */
+#define F1(x, y, z) (z ^ (x & (y ^ z)))
+#define F2(x, y, z) F1(z, x, y)
+#define F3(x, y, z) (x ^ y ^ z)
+#define F4(x, y, z) (y ^ (x | ~z))
+
+/* This is the central step in the MD5 algorithm. */
+#define MD5STEP(f, w, x, y, z, data, s) \
+	( w += f(x, y, z) + data,  w = w<<s | w>>(32-s),  w += x )
+
+/*
+ * The core of the MD5 algorithm, this alters an existing MD5 hash to
+ * reflect the addition of 16 longwords of new data.  MD5Update blocks
+ * the data and converts bytes into longwords for this routine.
+ */
+static void
+MD5Transform(u_int32_t buf[4], u_int32_t const in[16])
+{
+	u_int32_t a, b, c, d;
+
+	a = buf[0];
+	b = buf[1];
+	c = buf[2];
+	d = buf[3];
+
+	MD5STEP(F1, a, b, c, d, in[ 0]+0xd76aa478,  7);
+	MD5STEP(F1, d, a, b, c, in[ 1]+0xe8c7b756, 12);
+	MD5STEP(F1, c, d, a, b, in[ 2]+0x242070db, 17);
+	MD5STEP(F1, b, c, d, a, in[ 3]+0xc1bdceee, 22);
+	MD5STEP(F1, a, b, c, d, in[ 4]+0xf57c0faf,  7);
+	MD5STEP(F1, d, a, b, c, in[ 5]+0x4787c62a, 12);
+	MD5STEP(F1, c, d, a, b, in[ 6]+0xa8304613, 17);
+	MD5STEP(F1, b, c, d, a, in[ 7]+0xfd469501, 22);
+	MD5STEP(F1, a, b, c, d, in[ 8]+0x698098d8,  7);
+	MD5STEP(F1, d, a, b, c, in[ 9]+0x8b44f7af, 12);
+	MD5STEP(F1, c, d, a, b, in[10]+0xffff5bb1, 17);
+	MD5STEP(F1, b, c, d, a, in[11]+0x895cd7be, 22);
+	MD5STEP(F1, a, b, c, d, in[12]+0x6b901122,  7);
+	MD5STEP(F1, d, a, b, c, in[13]+0xfd987193, 12);
+	MD5STEP(F1, c, d, a, b, in[14]+0xa679438e, 17);
+	MD5STEP(F1, b, c, d, a, in[15]+0x49b40821, 22);
+
+	MD5STEP(F2, a, b, c, d, in[ 1]+0xf61e2562,  5);
+	MD5STEP(F2, d, a, b, c, in[ 6]+0xc040b340,  9);
+	MD5STEP(F2, c, d, a, b, in[11]+0x265e5a51, 14);
+	MD5STEP(F2, b, c, d, a, in[ 0]+0xe9b6c7aa, 20);
+	MD5STEP(F2, a, b, c, d, in[ 5]+0xd62f105d,  5);
+	MD5STEP(F2, d, a, b, c, in[10]+0x02441453,  9);
+	MD5STEP(F2, c, d, a, b, in[15]+0xd8a1e681, 14);
+	MD5STEP(F2, b, c, d, a, in[ 4]+0xe7d3fbc8, 20);
+	MD5STEP(F2, a, b, c, d, in[ 9]+0x21e1cde6,  5);
+	MD5STEP(F2, d, a, b, c, in[14]+0xc33707d6,  9);
+	MD5STEP(F2, c, d, a, b, in[ 3]+0xf4d50d87, 14);
+	MD5STEP(F2, b, c, d, a, in[ 8]+0x455a14ed, 20);
+	MD5STEP(F2, a, b, c, d, in[13]+0xa9e3e905,  5);
+	MD5STEP(F2, d, a, b, c, in[ 2]+0xfcefa3f8,  9);
+	MD5STEP(F2, c, d, a, b, in[ 7]+0x676f02d9, 14);
+	MD5STEP(F2, b, c, d, a, in[12]+0x8d2a4c8a, 20);
+
+	MD5STEP(F3, a, b, c, d, in[ 5]+0xfffa3942,  4);
+	MD5STEP(F3, d, a, b, c, in[ 8]+0x8771f681, 11);
+	MD5STEP(F3, c, d, a, b, in[11]+0x6d9d6122, 16);
+	MD5STEP(F3, b, c, d, a, in[14]+0xfde5380c, 23);
+	MD5STEP(F3, a, b, c, d, in[ 1]+0xa4beea44,  4);
+	MD5STEP(F3, d, a, b, c, in[ 4]+0x4bdecfa9, 11);
+	MD5STEP(F3, c, d, a, b, in[ 7]+0xf6bb4b60, 16);
+	MD5STEP(F3, b, c, d, a, in[10]+0xbebfbc70, 23);
+	MD5STEP(F3, a, b, c, d, in[13]+0x289b7ec6,  4);
+	MD5STEP(F3, d, a, b, c, in[ 0]+0xeaa127fa, 11);
+	MD5STEP(F3, c, d, a, b, in[ 3]+0xd4ef3085, 16);
+	MD5STEP(F3, b, c, d, a, in[ 6]+0x04881d05, 23);
+	MD5STEP(F3, a, b, c, d, in[ 9]+0xd9d4d039,  4);
+	MD5STEP(F3, d, a, b, c, in[12]+0xe6db99e5, 11);
+	MD5STEP(F3, c, d, a, b, in[15]+0x1fa27cf8, 16);
+	MD5STEP(F3, b, c, d, a, in[ 2]+0xc4ac5665, 23);
+
+	MD5STEP(F4, a, b, c, d, in[ 0]+0xf4292244,  6);
+	MD5STEP(F4, d, a, b, c, in[ 7]+0x432aff97, 10);
+	MD5STEP(F4, c, d, a, b, in[14]+0xab9423a7, 15);
+	MD5STEP(F4, b, c, d, a, in[ 5]+0xfc93a039, 21);
+	MD5STEP(F4, a, b, c, d, in[12]+0x655b59c3,  6);
+	MD5STEP(F4, d, a, b, c, in[ 3]+0x8f0ccc92, 10);
+	MD5STEP(F4, c, d, a, b, in[10]+0xffeff47d, 15);
+	MD5STEP(F4, b, c, d, a, in[ 1]+0x85845dd1, 21);
+	MD5STEP(F4, a, b, c, d, in[ 8]+0x6fa87e4f,  6);
+	MD5STEP(F4, d, a, b, c, in[15]+0xfe2ce6e0, 10);
+	MD5STEP(F4, c, d, a, b, in[ 6]+0xa3014314, 15);
+	MD5STEP(F4, b, c, d, a, in[13]+0x4e0811a1, 21);
+	MD5STEP(F4, a, b, c, d, in[ 4]+0xf7537e82,  6);
+	MD5STEP(F4, d, a, b, c, in[11]+0xbd3af235, 10);
+	MD5STEP(F4, c, d, a, b, in[ 2]+0x2ad7d2bb, 15);
+	MD5STEP(F4, b, c, d, a, in[ 9]+0xeb86d391, 21);
+
+	buf[0] += a;
+	buf[1] += b;
+	buf[2] += c;
+	buf[3] += d;
+}
+
+#undef F1
+#undef F2
+#undef F3
+#undef F4
+#undef MD5STEP
+
+static void
+mix_bucket(struct random_bucket *v)
+{
+	struct random_bucket *r = v;
+	int	i, num_passes;
+	u_int32_t *p;
+	u_int32_t iv[4];
+
+	r->delay_mix = 0;
+	
+	/* Start IV from last block of the random pool */
+	memcpy(iv, r->pool + r->length - sizeof(iv), sizeof(iv));
+
+	num_passes = r->length / 16;
+	for (i = 0, p = (u_int32_t *) r->pool; i < num_passes; i++) {
+		MD5Transform(iv, rand_pool_key);
+		iv[0] = (*p++ ^= iv[0]);
+		iv[1] = (*p++ ^= iv[1]);
+		iv[2] = (*p++ ^= iv[2]);
+		iv[3] = (*p++ ^= iv[3]);
+	}
+	memcpy(rand_pool_key, r->pool, sizeof(rand_pool_key));
+	
+	/* Wipe iv from memory */
+	bzero(iv, sizeof(iv));
+
+	r->add_ptr = 0;
+}
+
+/*
+ * This function adds a byte into the entropy "pool".  It does not
+ * update the entropy estimate.  The caller must do this if appropriate.
+ */
+static inline void
+add_entropy_byte(struct random_bucket *r, const u_int8_t ch, int delay)
+{
+	if (!delay && r->delay_mix)
+		mix_bucket(r);
+	r->pool[r->add_ptr++] ^= ch;
+	if (r->add_ptr >= r->length) {
+		if (delay) {
+			r->delay_mix = 1;
+			r->add_ptr = 0;
+		} else
+			mix_bucket(r);
+	}
+}
+
+/*
+ * This function adds some number of bytes into the entropy pool and
+ * updates the entropy count as appropriate.
+ */
+static void
+add_entropy(struct random_bucket *r, const u_int8_t *ptr, int length,
+	int entropy_level, int delay)
+{
+	while (length-- > 0)
+		add_entropy_byte(r, *ptr++, delay);
+		
+	r->entropy_count += entropy_level;
+	if (r->entropy_count > r->length*8)
+		r->entropy_count = r->length * 8;
+}
+
+/*
+ * This function adds entropy to the entropy "pool" by using timing
+ * delays.  It uses the timer_rand_state structure to make an estimate
+ * of how many bits of entropy this call has added to the pool.
+ */
+static void
+add_timer_randomness(struct random_bucket *r, struct timer_rand_state *state,
+	int delay)
+{
+	int	delta, delta2;
+	int	nbits;
+
+	/*
+	 * Calculate number of bits of randomness we probably
+	 * added.  We take into account the first and second order
+	 * delta's in order to make our estimate.
+	 */
+	delta = ticks - state->last_time;
+	delta2 = delta - state->last_delta;
+	state->last_time = ticks;
+	state->last_delta = delta;
+	if (delta < 0) delta = -delta;
+	if (delta2 < 0) delta2 = -delta2;
+	delta = MIN(delta, delta2) >> 1;
+	for (nbits = 0; delta; nbits++)
+		delta >>= 1;
+	
+	add_entropy(r, (u_int8_t *) &ticks, sizeof(ticks), nbits, delay);
+
+#if defined (__i386__)
+	/*
+	 * On a 386, read the high resolution timer.  We assume that
+	 * this gives us 2 bits of randomness.  XXX This needs
+	 * investigation.
+	 */ 
+	outb(TIMER_LATCH|TIMER_SEL0, TIMER_MODE); /* latch the count ASAP */
+	add_entropy_byte(r, inb(TIMER_CNTR0), 1);
+	add_entropy_byte(r, inb(TIMER_CNTR0), 1);
+	r->entropy_count += 2;
+	if (r->entropy_count > r->bit_length)
+		r->entropy_count = r->bit_length;
+#endif
+}
+
+void
+add_keyboard_randomness(u_char scancode)
+{
+	struct random_bucket *r = &random_state;
+
+	add_timer_randomness(r, &keyboard_timer_state, 0);
+	add_entropy_byte(r, scancode, 0);
+	r->entropy_count += 6;
+	if (r->entropy_count > r->bit_length)
+		r->entropy_count = r->bit_length;
+}
+
+void
+add_interrupt_randomness(int irq)
+{
+	static struct random_bucket *r = &random_state;
+	u_int16_t intbit = 1 << irq;
+
+/*	printf("Trapping interrupt %d\n", irq); */
+
+	if (interrupt_allowed & intbit) 
+		add_timer_randomness(r, &irq_timer_state[irq], 1);
+}
+
+/*
+ * This function extracts randomness from the "entropy pool", and
+ * returns it in a buffer.  This function computes how many remaining
+ * bits of entropy are left in the pool, but it does not restrict the
+ * number of bytes that are actually obtained.
+ */
+static inline u_int
+extract_entropy(struct random_bucket *r, char *buf, u_int nbytes)
+{
+	int passes, i;
+	u_int length, ret;
+	u_int32_t tmp[4];
+	u_int8_t *cp;
+	
+	add_entropy(r, (u_int8_t *) &ticks, sizeof(ticks), 0, 0);
+	
+	if (r->entropy_count > r->bit_length) 
+		r->entropy_count = r->bit_length;
+	if (nbytes > 32768)
+		nbytes = 32768;
+	ret = nbytes;
+	r->entropy_count -= ret * 8;
+	if (r->entropy_count < 0)
+		r->entropy_count = 0;
+	passes = r->length / 64;
+	while (nbytes) {
+		length = MIN(nbytes, 16);
+		for (i=0; i < 16; i++) {
+			if (++random_counter[i] != 0)
+				break;
+		}
+		tmp[0] = 0x67452301;
+		tmp[1] = 0xefcdab89;
+		tmp[2] = 0x98badcfe;
+		tmp[3] = 0x10325476;
+		MD5Transform(tmp, random_counter);
+		for (i = 0, cp = r->pool; i < passes; i++, cp+=64)
+			MD5Transform(tmp, (u_int32_t *) cp);
+		memcpy(buf, tmp, length);
+		nbytes -= length;
+		buf += length;
+	}
+	return ret;
+}
+
+/*
+ * This function is the exported kernel interface.  It returns some
+ * number of good random numbers, suitable for seeding TCP sequence
+ * numbers, etc.
+ */
+void
+get_random_bytes(void *buf, u_int nbytes)
+{
+	extract_entropy(&random_state, (char *) buf, nbytes);
+}
+
+u_int
+read_random(char * buf, u_int nbytes)
+{
+	if ((nbytes * 8) > random_state.entropy_count)
+		nbytes = random_state.entropy_count / 8;
+	
+	return extract_entropy(&random_state, buf, nbytes);
+}
+
+u_int
+read_random_unlimited(char * buf, u_int nbytes)
+{
+	return extract_entropy(&random_state, buf, nbytes);
+}
+
+#ifdef linux
+int
+read_random(struct inode * inode,struct file * file,char * buf,int nbytes)
+{
+	if ((nbytes * 8) > random_state.entropy_count)
+		nbytes = random_state.entropy_count / 8;
+	
+	return extract_entropy(&random_state, buf, nbytes, 1);
+}
+
+int
+read_random_unlimited(struct inode * inode,struct file * file,
+			  char * buf,int nbytes)
+{
+	return extract_entropy(&random_state, buf, nbytes, 1);
+}
+#endif
+
+#endif /* DEVRANDOM */
diff --git a/sys/i386/isa/syscons.c b/sys/i386/isa/syscons.c
index 327e329763fe..6080597d5900 100644
--- a/sys/i386/isa/syscons.c
+++ b/sys/i386/isa/syscons.c
@@ -25,7 +25,7 @@
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *
- *  $Id: syscons.c,v 1.125 1995/09/10 21:35:12 bde Exp $
+ *  $Id: syscons.c,v 1.126 1995/10/14 07:08:09 bde Exp $
  */
 
 #include "sc.h"
@@ -53,6 +53,7 @@
 #include <machine/frame.h>
 #include <machine/pc/display.h>
 #include <machine/apm_bios.h>
+#include <machine/random.h>
 
 #include <i386/isa/isa.h>
 #include <i386/isa/isa_device.h>
@@ -2202,6 +2203,10 @@ next_code:
     else
 	goto next_code;
 
+#ifdef DEVRANDOM
+    add_keyboard_randomness(scancode);
+#endif
+
     if (cur_console->status & KBD_RAW_MODE)
 	return scancode;
 #if ASYNCH
diff --git a/sys/i386/isa/vector.s b/sys/i386/isa/vector.s
index bbed601c550d..c630bee4cf3a 100644
--- a/sys/i386/isa/vector.s
+++ b/sys/i386/isa/vector.s
@@ -1,6 +1,6 @@
 /*
  *	from: vector.s, 386BSD 0.1 unknown origin
- *	$Id: vector.s,v 1.11 1994/12/03 10:03:19 bde Exp $
+ *	$Id: vector.s,v 1.12 1995/04/15 21:32:18 bde Exp $
  */
 
 #include <i386/isa/icu.h>
@@ -53,6 +53,16 @@
 #define	MAYBE_PUSHL_ES
 #endif
 
+#ifdef DEVRANDOM
+#define	ADDENTROPY(irq_num) \
+	/* Add this interrupt to the pool of entropy */ \
+	pushl	$irq_num ; \
+	call	_add_interrupt_randomness ; \
+	addl	$4,%esp
+#else
+#define	ADDENTROPY(irq_num)
+#endif
+
 /*
  * Macros for interrupt interrupt entry, call to handler, and exit.
  *
@@ -194,6 +204,8 @@ Xresume/**/irq_num: ; \
 	FASTER_NOP ; \
 	outb	%al,$icu+1 ; \
 	sti ;			/* XXX _doreti repeats the cli/sti */ \
+	/* Add this interrupt to the pool of entropy */ \
+	ADDENTROPY(irq_num) ; \
 	MEXITCOUNT ; \
 	/* We could usually avoid the following jmp by inlining some of */ \
 	/* _doreti, but it's probably better to use less cache. */ \
diff --git a/sys/isa/syscons.c b/sys/isa/syscons.c
index 327e329763fe..6080597d5900 100644
--- a/sys/isa/syscons.c
+++ b/sys/isa/syscons.c
@@ -25,7 +25,7 @@
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *
- *  $Id: syscons.c,v 1.125 1995/09/10 21:35:12 bde Exp $
+ *  $Id: syscons.c,v 1.126 1995/10/14 07:08:09 bde Exp $
  */
 
 #include "sc.h"
@@ -53,6 +53,7 @@
 #include <machine/frame.h>
 #include <machine/pc/display.h>
 #include <machine/apm_bios.h>
+#include <machine/random.h>
 
 #include <i386/isa/isa.h>
 #include <i386/isa/isa_device.h>
@@ -2202,6 +2203,10 @@ next_code:
     else
 	goto next_code;
 
+#ifdef DEVRANDOM
+    add_keyboard_randomness(scancode);
+#endif
+
     if (cur_console->status & KBD_RAW_MODE)
 	return scancode;
 #if ASYNCH
diff --git a/sys/sys/random.h b/sys/sys/random.h
new file mode 100644
index 000000000000..78a6b06a894c
--- /dev/null
+++ b/sys/sys/random.h
@@ -0,0 +1,72 @@
+/*
+ * random.h -- A strong random number generator
+ *
+ * $Id$
+ *
+ * Version 0.92, last modified 21-Sep-95
+ * 
+ * Copyright Theodore Ts'o, 1994, 1995.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, and the entire permission notice in its entirety,
+ *    including the disclaimer of warranties.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote
+ *    products derived from this software without specific prior
+ *    written permission.
+ * 
+ * ALTERNATIVELY, this product may be distributed under the terms of
+ * the GNU Public License, in which case the provisions of the GPL are
+ * required INSTEAD OF the above restrictions.  (This clause is
+ * necessary due to a potential bad interaction between the GPL and
+ * the restrictions contained in a BSD-style copyright.)
+ * 
+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
+ * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
+ * OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+/*
+ * Many kernel routines will have a use for good random numbers,
+ * for example, for truely random TCP sequence numbers, which prevent
+ * certain forms of TCP spoofing attacks.
+ * 
+ */
+
+#ifndef _MACHINE_RANDOM_H_
+#define _MACHINE_RANDOM_H_ 1
+
+#include <sys/ioctl.h>
+
+#define	MEM_SETIRQ	_IOW('r', 1, int)	/* set interrupt */
+#define	MEM_CLEARIRQ	_IOW('r', 2, int)	/* clear interrupt */
+#define	MEM_RETURNIRQ	_IOR('r', 3, int)	/* return interrupt */
+
+/* Interrupts to be used in the randomising process */
+
+extern u_int16_t interrupt_allowed;
+
+/* Exported functions */
+
+void rand_initialize(void);
+void add_keyboard_randomness(u_char scancode);
+
+void get_random_bytes(void *buf, u_int nbytes);
+u_int read_random(char *buf, u_int size);
+u_int read_random_unlimited(char *buf, u_int size);
+
+#endif