Date: Sat, 3 Mar 2001 15:00:49 -0800 From: Kris Kennaway <kris@obsecurity.org> To: audit@FreeBSD.org Subject: rand() patches Message-ID: <20010303150049.A33806@mollari.cthul.hu>
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[-- Attachment #1 --]
Please review the following patches which replace all uses of rand()
(and one of random() which I came across) with stronger variants.
Even the "fixed" version of rand() in -current is too weak (because of
interface constraints with rand_r()) to be used here.
Kris
Index: bin/ed/cbc.c
===================================================================
RCS file: /mnt/ncvs/src/bin/ed/cbc.c,v
retrieving revision 1.12
diff -u -r1.12 cbc.c
--- bin/ed/cbc.c 1999/08/27 23:14:12 1.12
+++ bin/ed/cbc.c 2001/02/27 18:38:17
@@ -57,12 +57,6 @@
/*
- * Define a divisor for rand() that yields a uniform distribution in the
- * range 0-255.
- */
-#define RAND_DIV (((unsigned) RAND_MAX + 1) >> 8)
-
-/*
* BSD and System V systems offer special library calls that do
* block move_liness and fills, so if possible we take advantage of them
*/
@@ -125,9 +119,8 @@
MEMZERO(ivec, 8);
/* initialize the padding vector */
- srand((unsigned) time((time_t *) 0));
for (i = 0; i < 8; i++)
- CHAR(pvec, i) = (char) (rand()/RAND_DIV);
+ CHAR(pvec, i) = (char) (arc4random() % 256);
#endif
}
Index: contrib/opie/libopie/newseed.c
===================================================================
RCS file: /mnt/ncvs/src/contrib/opie/libopie/newseed.c,v
retrieving revision 1.3
diff -u -r1.3 newseed.c
--- contrib/opie/libopie/newseed.c 2000/04/10 11:18:54 1.3
+++ contrib/opie/libopie/newseed.c 2001/02/27 18:15:19
@@ -16,6 +16,9 @@
*/
#include "opie_cfg.h"
+#if HAVE_STDLIB_H
+#include <stdlib.h>
+#endif /* HAVE_STDLIB_H */
#if HAVE_TIME_H
#include <time.h>
#endif /* HAVE_TIME_H */
@@ -84,12 +87,6 @@
{
{
- time_t now;
- time(&now);
- srand(now);
- }
-
- {
struct utsname utsname;
if (uname(&utsname) < 0) {
@@ -101,7 +98,7 @@
}
utsname.nodename[2] = 0;
- sprintf(seed, "%s%04d", utsname.nodename, (rand() % 9999) + 1);
+ sprintf(seed, "%s%04d", utsname.nodename, (arc4random() % 9999) + 1);
return 0;
}
}
Index: contrib/opie/libopie/randomchallenge.c
===================================================================
RCS file: /mnt/ncvs/src/contrib/opie/libopie/randomchallenge.c,v
retrieving revision 1.1.1.3
diff -u -r1.1.1.3 randomchallenge.c
--- contrib/opie/libopie/randomchallenge.c 2000/04/10 11:09:41 1.1.1.3
+++ contrib/opie/libopie/randomchallenge.c 2001/02/27 18:16:48
@@ -25,6 +25,9 @@
Created at NRL for OPIE 2.2 from opiesubr2.c
*/
+#if HAVE_STDLIB_H
+#include <stdlib.h>
+#endif /* HAVE_STDLIB_H */
#include "opie_cfg.h"
#include "opie.h"
@@ -41,5 +44,5 @@
if (opienewseed(buf))
strcpy(buf, "ke4452");
- sprintf(prompt, "otp-%s %d %s ext", algids[MDX], (rand() % 499) + 1, buf);
+ sprintf(prompt, "otp-%s %d %s ext", algids[MDX], (arc4random() % 499) + 1, buf);
}
Index: usr.bin/newkey/generic.c
===================================================================
RCS file: /mnt/ncvs/src/usr.bin/newkey/generic.c,v
retrieving revision 1.3
diff -u -r1.3 generic.c
--- usr.bin/newkey/generic.c 1999/08/28 01:04:33 1.3
+++ usr.bin/newkey/generic.c 2001/02/27 18:26:42
@@ -57,18 +57,9 @@
unsigned char *pass;
{
int i;
- int rseed;
- struct timeval tv;
- (void)gettimeofday(&tv, (struct timezone *)NULL);
- rseed = tv.tv_sec + tv.tv_usec;
- for (i = 0; i < 8; i++) {
- rseed ^= (rseed << 8) | pass[i];
- }
- srand(rseed);
-
for (i = 0; i < seedsize; i++) {
- seed[i] = (rand() & 0xff) ^ pass[i % 8];
+ seed[i] = (arc4random() & 0xff) ^ pass[i % 8];
}
}
Index: usr.sbin/pw/pw_user.c
===================================================================
RCS file: /mnt/ncvs/src/usr.sbin/pw/pw_user.c,v
retrieving revision 1.44
diff -u -r1.44 pw_user.c
--- usr.sbin/pw/pw_user.c 2000/12/29 18:04:49 1.44
+++ usr.sbin/pw/pw_user.c 2001/02/27 19:05:05
@@ -55,7 +55,6 @@
#define LOGNAMESIZE (MAXLOGNAME-1)
#endif
-static int randinit;
static char locked_str[] = "*LOCKED*";
static int print_user(struct passwd * pwd, int pretty, int v7);
@@ -1013,16 +1012,8 @@
/*
* Calculate a salt value
*/
- if (!randinit) {
- randinit = 1;
-#ifdef __FreeBSD__
- srandomdev();
-#else
- srandom((unsigned long) (time(NULL) ^ getpid()));
-#endif
- }
for (i = 0; i < 8; i++)
- salt[i] = chars[random() % 63];
+ salt[i] = chars[arc4random() % 63];
salt[i] = '\0';
return strcpy(buf, crypt(password, salt));
@@ -1086,15 +1077,7 @@
switch (cnf->default_password) {
case -1: /* Random password */
- if (!randinit) {
- randinit = 1;
-#ifdef __FreeBSD__
- srandomdev();
-#else
- srandom((unsigned long) (time(NULL) ^ getpid()));
-#endif
- }
- l = (random() % 8 + 8); /* 8 - 16 chars */
+ l = (arc4random() % 8 + 8); /* 8 - 16 chars */
pw_getrand(rndbuf, l);
for (i = 0; i < l; i++)
pwbuf[i] = chars[rndbuf[i] % (sizeof(chars)-1)];
[-- Attachment #2 --]
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