svn commit: r192544 - head/sys/kern
Ed Schouten
ed at FreeBSD.org
Thu May 21 16:19:55 UTC 2009
Author: ed
Date: Thu May 21 16:19:54 2009
New Revision: 192544
URL: http://svn.freebsd.org/changeset/base/192544
Log:
Add a new sysctl: kern.tty_inq_flush_secure.
When enabled all TTY input queue buffers are zeroed when flushing or
closing the TTY. Because TTY input queues are also used to store filled
in passwords, this may be an interesting switch to enable for security
minded people.
Modified:
head/sys/kern/tty_inq.c
Modified: head/sys/kern/tty_inq.c
==============================================================================
--- head/sys/kern/tty_inq.c Thu May 21 16:18:45 2009 (r192543)
+++ head/sys/kern/tty_inq.c Thu May 21 16:19:54 2009 (r192544)
@@ -68,6 +68,9 @@ SYSCTL_ULONG(_kern, OID_AUTO, tty_inq_nf
static unsigned long ttyinq_nslow = 0;
SYSCTL_ULONG(_kern, OID_AUTO, tty_inq_nslow, CTLFLAG_RD,
&ttyinq_nslow, 0, "Buffered reads to userspace on input");
+static int ttyinq_flush_secure = 0;
+SYSCTL_INT(_kern, OID_AUTO, tty_inq_flush_secure, CTLFLAG_RW,
+ &ttyinq_flush_secure, 0, "Zero buffers while flushing");
#define TTYINQ_QUOTESIZE (TTYINQ_DATASIZE / BMSIZE)
#define BMSIZE 32
@@ -376,28 +379,19 @@ ttyinq_findchar(struct ttyinq *ti, const
void
ttyinq_flush(struct ttyinq *ti)
{
+ struct ttyinq_block *tib = ti->ti_lastblock;
ti->ti_begin = 0;
ti->ti_linestart = 0;
ti->ti_reprint = 0;
ti->ti_end = 0;
-}
-
-#if 0
-void
-ttyinq_flush_safe(struct ttyinq *ti)
-{
- struct ttyinq_block *tib;
-
- ttyinq_flush(ti);
- /* Zero all data in the input queue to make it more safe */
- TAILQ_FOREACH(tib, &ti->ti_list, tib_list) {
- bzero(&tib->tib_quotes, sizeof tib->tib_quotes);
- bzero(&tib->tib_data, sizeof tib->tib_data);
+ /* Zero all data in the input queue to get rid of passwords. */
+ if (ttyinq_flush_secure) {
+ for (tib = ti->ti_firstblock; tib != NULL; tib = tib->tib_next)
+ bzero(&tib->tib_data, sizeof tib->tib_data);
}
}
-#endif
int
ttyinq_peekchar(struct ttyinq *ti, char *c, int *quote)
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