Revert r288682

I meant to do this on ^/user/ngie/more-tests

Pointyhat to: ngie (use svn info next time...)

1 files changed, 277 insertions, 0 deletions

diff --git a/contrib/ipfilter/arc4random.c b/contrib/ipfilter/arc4random.c
new file mode 100644
index 0000000..04b0797
--- /dev/null
+++ b/contrib/ipfilter/arc4random.c
@@ -0,0 +1,277 @@
+/*-
+ * THE BEER-WARE LICENSE
+ *
+ * <dan@FreeBSD.ORG> wrote this file.  As long as you retain this notice you
+ * can do whatever you want with this stuff.  If we meet some day, and you
+ * think this stuff is worth it, you can buy me a beer in return.
+ *
+ * Dan Moschuk
+ */
+#if !defined(SOLARIS2) && !defined(__osf__)
+# include <sys/cdefs.h>
+#endif
+
+#include <sys/types.h>
+#include <sys/param.h>
+#ifdef __FreeBSD__
+# include <sys/kernel.h>
+#endif
+#if !defined(__osf__)
+# include <sys/random.h>
+#endif
+#ifdef __FreeBSD__
+# include <sys/libkern.h>
+#endif
+#include <sys/lock.h>
+#ifndef __osf__
+# include <sys/mutex.h>
+#endif
+#include <sys/time.h>
+
+#if defined(SOLARIS2) && (SOLARIS2 < 9)
+# include <netinet/in_systm.h>
+#endif
+#include <sys/socket.h>
+#include <net/if.h>
+#ifdef __osf__
+# include <net/route.h>
+#endif
+#include <netinet/in.h>
+#include <netinet/ip.h>
+#include "netinet/ip_compat.h"
+#ifdef HAS_SYS_MD5_H
+# include <sys/md5.h>
+#else
+# include "md5.h"
+#endif
+
+#ifdef NEED_LOCAL_RAND
+#if !defined(__GNUC__)
+# define __inline
+#endif
+
+#define	ARC4_RESEED_BYTES 65536
+#define	ARC4_RESEED_SECONDS 300
+#define	ARC4_KEYBYTES (256 / 8)
+
+static u_int8_t arc4_i, arc4_j;
+static int arc4_numruns = 0;
+static u_int8_t arc4_sbox[256];
+static time_t arc4_t_reseed;
+static ipfmutex_t arc4_mtx;
+static MD5_CTX md5ctx;
+
+static u_int8_t arc4_randbyte(void);
+static int ipf_read_random(void *dest, int length);
+
+static __inline void
+arc4_swap(u_int8_t *a, u_int8_t *b)
+{
+	u_int8_t c;
+
+	c = *a;
+	*a = *b;
+	*b = c;
+}
+
+/*
+ * Stir our S-box.
+ */
+static void
+arc4_randomstir (void)
+{
+	u_int8_t key[256];
+	int r, n;
+	struct timeval tv_now;
+
+	/*
+	 * XXX read_random() returns unsafe numbers if the entropy
+	 * device is not loaded -- MarkM.
+	 */
+	r = ipf_read_random(key, ARC4_KEYBYTES);
+	GETKTIME(&tv_now);
+	MUTEX_ENTER(&arc4_mtx);
+	/* If r == 0 || -1, just use what was on the stack. */
+	if (r > 0) {
+		for (n = r; n < sizeof(key); n++)
+			key[n] = key[n % r];
+	}
+
+	for (n = 0; n < 256; n++) {
+		arc4_j = (arc4_j + arc4_sbox[n] + key[n]) % 256;
+		arc4_swap(&arc4_sbox[n], &arc4_sbox[arc4_j]);
+	}
+
+	/* Reset for next reseed cycle. */
+	arc4_t_reseed = tv_now.tv_sec + ARC4_RESEED_SECONDS;
+	arc4_numruns = 0;
+
+	/*
+	 * Throw away the first N words of output, as suggested in the
+	 * paper "Weaknesses in the Key Scheduling Algorithm of RC4"
+	 * by Fluher, Mantin, and Shamir.  (N = 256 in our case.)
+	 */
+	for (n = 0; n < 256*4; n++)
+		arc4_randbyte();
+	MUTEX_EXIT(&arc4_mtx);
+}
+
+/*
+ * Initialize our S-box to its beginning defaults.
+ */
+static void
+arc4_init(void)
+{
+	int n;
+
+	MD5Init(&md5ctx);
+
+	MUTEX_INIT(&arc4_mtx, "arc4_mtx");
+	arc4_i = arc4_j = 0;
+	for (n = 0; n < 256; n++)
+		arc4_sbox[n] = (u_int8_t) n;
+
+	arc4_t_reseed = 0;
+}
+
+
+/*
+ * Generate a random byte.
+ */
+static u_int8_t
+arc4_randbyte(void)
+{
+	u_int8_t arc4_t;
+
+	arc4_i = (arc4_i + 1) % 256;
+	arc4_j = (arc4_j + arc4_sbox[arc4_i]) % 256;
+
+	arc4_swap(&arc4_sbox[arc4_i], &arc4_sbox[arc4_j]);
+
+	arc4_t = (arc4_sbox[arc4_i] + arc4_sbox[arc4_j]) % 256;
+	return arc4_sbox[arc4_t];
+}
+
+/*
+ * MPSAFE
+ */
+void
+arc4rand(void *ptr, u_int len, int reseed)
+{
+	u_int8_t *p;
+	struct timeval tv;
+
+	GETKTIME(&tv);
+	if (reseed ||
+	   (arc4_numruns > ARC4_RESEED_BYTES) ||
+	   (tv.tv_sec > arc4_t_reseed))
+		arc4_randomstir();
+
+	MUTEX_ENTER(&arc4_mtx);
+	arc4_numruns += len;
+	p = ptr;
+	while (len--)
+		*p++ = arc4_randbyte();
+	MUTEX_EXIT(&arc4_mtx);
+}
+
+uint32_t
+ipf_random(void)
+{
+	uint32_t ret;
+
+	arc4rand(&ret, sizeof ret, 0);
+	return ret;
+}
+
+
+static u_char pot[ARC4_RESEED_BYTES];
+static u_char *pothead = pot, *pottail = pot;
+static int inpot = 0;
+
+/*
+ * This is not very strong, and this is understood, but the aim isn't to
+ * be cryptographically strong - it is just to make up something that is
+ * pseudo random.
+ */
+void
+ipf_rand_push(void *src, int length)
+{
+	static int arc4_inited = 0;
+	u_char *nsrc;
+	int mylen;
+
+	if (arc4_inited == 0) {
+		arc4_init();
+		arc4_inited = 1;
+	}
+
+	if (length < 64) {
+		MD5Update(&md5ctx, src, length);
+		return;
+	}
+
+	nsrc = src;
+	mylen = length;
+
+#if defined(_SYS_MD5_H) && defined(SOLARIS2)
+# define	buf	buf_un.buf8
+#endif
+	MUTEX_ENTER(&arc4_mtx);
+	while ((mylen > 64)  && (sizeof(pot) - inpot > sizeof(md5ctx.buf))) {
+		MD5Update(&md5ctx, nsrc, 64);
+		mylen -= 64;
+		nsrc += 64;
+		if (pottail + sizeof(md5ctx.buf) > pot + sizeof(pot)) {
+			int left, numbytes;
+
+			numbytes = pot + sizeof(pot) - pottail;
+			bcopy(md5ctx.buf, pottail, numbytes);
+			left = sizeof(md5ctx.buf) - numbytes;
+			pottail = pot;
+			bcopy(md5ctx.buf + sizeof(md5ctx.buf) - left,
+			      pottail, left);
+			pottail += left;
+		} else {
+			bcopy(md5ctx.buf, pottail, sizeof(md5ctx.buf));
+			pottail += sizeof(md5ctx.buf);
+		}
+		inpot += 64;
+	}
+	MUTEX_EXIT(&arc4_mtx);
+#if defined(_SYS_MD5_H) && defined(SOLARIS2)
+# undef buf
+#endif
+}
+
+
+static int
+ipf_read_random(void *dest, int length)
+{
+	if (length > inpot)
+		return 0;
+
+	MUTEX_ENTER(&arc4_mtx);
+	if (pothead + length > pot + sizeof(pot)) {
+		int left, numbytes;
+
+		left = length;
+		numbytes = pot + sizeof(pot) - pothead;
+		bcopy(pothead, dest, numbytes);
+		left -= numbytes;
+		pothead = pot;
+		bcopy(pothead, dest + length - left, left);
+		pothead += left;
+	} else {
+		bcopy(pothead, dest, length);
+		pothead += length;
+	}
+	inpot -= length;
+	if (inpot == 0)
+		pothead = pottail = pot;
+	MUTEX_EXIT(&arc4_mtx);
+
+	return length;
+}
+
+#endif /* NEED_LOCAL_RAND */