When we miss one or more packets in stateful mode *and* need to

perform a key change, *and* our sequence numbers have wrapped,
ensure that the number of key changes is calculated correctly.

The previous code counted down from a negative number to zero,
re-encrypting the current key on each iteration - this took some
time and strangely enough got the answer wrong !!!

Spell stateful correctly while I'm here.

4 files changed, 21 insertions, 18 deletions

diff --git a/usr.sbin/ppp/ppp/ccp.c b/usr.sbin/ppp/ppp/ccp.c
index 08127c5a1d7..d8c8120ff9c 100644
--- a/usr.sbin/ppp/ppp/ccp.c
+++ b/usr.sbin/ppp/ppp/ccp.c
@@ -25,7 +25,7 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- * $OpenBSD: ccp.c,v 1.21 2001/07/03 22:23:56 brian Exp $
+ * $OpenBSD: ccp.c,v 1.22 2001/07/07 03:08:49 brian Exp $
  */
 
 #include <sys/param.h>
@@ -197,7 +197,7 @@ ccp_ReportStatus(struct cmdargs const *arg)
     prompt_Printf(arg->prompt, "any bits, ");
   switch (ccp->cfg.mppe.state) {
   case MPPE_STATEFUL:
-    prompt_Printf(arg->prompt, "statefull");
+    prompt_Printf(arg->prompt, "stateful");
     break;
   case MPPE_STATELESS:
     prompt_Printf(arg->prompt, "stateless");
diff --git a/usr.sbin/ppp/ppp/command.c b/usr.sbin/ppp/ppp/command.c
index a97e5ede111..49b2e64e854 100644
--- a/usr.sbin/ppp/ppp/command.c
+++ b/usr.sbin/ppp/ppp/command.c
@@ -25,7 +25,7 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- * $OpenBSD: command.c,v 1.61 2001/07/03 22:23:52 brian Exp $
+ * $OpenBSD: command.c,v 1.62 2001/07/07 03:08:49 brian Exp $
  */
 
 #include <sys/param.h>
@@ -1636,7 +1636,7 @@ SetVariable(struct cmdargs const *arg)
         l->ccp.cfg.mppe.state = MPPE_ANYSTATE;
       else if (!strcasecmp(arg->argv[arg->argn + 1], "stateless"))
         l->ccp.cfg.mppe.state = MPPE_STATELESS;
-      else if (!strcasecmp(arg->argv[arg->argn + 1], "statefull"))
+      else if (!strcasecmp(arg->argv[arg->argn + 1], "stateful"))
         l->ccp.cfg.mppe.state = MPPE_STATEFUL;
       else {
         log_Printf(LogWARN, "%s: Invalid state value\n",
@@ -2108,7 +2108,7 @@ static struct cmdtab const SetCommands[] = {
   (const void *) VAR_WINSIZE},
 #ifdef HAVE_DES
   {"mppe", NULL, SetVariable, LOCAL_AUTH | LOCAL_CX_OPT,
-  "MPPE key size and state", "set mppe [40|56|128|* [statefull|stateless|*]]", 
+  "MPPE key size and state", "set mppe [40|56|128|* [stateful|stateless|*]]", 
   (const void *) VAR_MPPE},
 #endif
   {"device", "line", SetVariable, LOCAL_AUTH | LOCAL_CX,
diff --git a/usr.sbin/ppp/ppp/mppe.c b/usr.sbin/ppp/ppp/mppe.c
index a1b0a246058..2f6cf6d3ad2 100644
--- a/usr.sbin/ppp/ppp/mppe.c
+++ b/usr.sbin/ppp/ppp/mppe.c
@@ -23,7 +23,7 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- * $OpenBSD: mppe.c,v 1.7 2001/07/03 22:23:56 brian Exp $
+ * $OpenBSD: mppe.c,v 1.8 2001/07/07 03:08:49 brian Exp $
  */
 
 #include <sys/types.h>
@@ -70,12 +70,13 @@
 #define	MPPE_OPT_BITMASK	0xe0
 #define	MPPE_OPT_MASK		(MPPE_OPT_STATELESS | MPPE_OPT_BITMASK)
 
-#define	MPPE_FLUSHED		0x8000
-#define	MPPE_ENCRYPTED		0x1000
-#define	MPPE_HEADER_BITMASK	0xf000
-#define	MPPE_HEADER_FLAG	0x00ff
-#define	MPPE_HEADER_FLAGMASK	0x00ff
-#define	MPPE_HEADER_FLAGSHIFT	8
+#define	MPPE_FLUSHED			0x8000
+#define	MPPE_ENCRYPTED			0x1000
+#define	MPPE_HEADER_BITMASK		0xf000
+#define	MPPE_HEADER_FLAG		0x00ff
+#define	MPPE_HEADER_FLAGMASK		0x00ff
+#define	MPPE_HEADER_FLAGSHIFT		8
+#define	MPPE_HEADER_STATEFUL_KEYCHANGES	16
 
 struct mppe_state {
   unsigned	stateless : 1;
@@ -276,6 +277,8 @@ MPPEInput(void *v, struct ccp *ccp, u_short *proto, struct mbuf *mp)
        */
       n = (prefix >> MPPE_HEADER_FLAGSHIFT) -
           (mip->cohnum >> MPPE_HEADER_FLAGSHIFT);
+      if (n < 0)
+        n += MPPE_HEADER_STATEFUL_KEYCHANGES;
       while (n--) {
         log_Printf(LogDEBUG, "MPPEInput: Key changed during catchup [%u]\n",
                    prefix);
@@ -388,7 +391,7 @@ MPPEDispOpts(struct lcp_opt *o)
   }
 
   snprintf(buf + len, sizeof buf - len, " bits, state%s",
-           (val & MPPE_OPT_STATELESS) ? "less" : "full");
+           (val & MPPE_OPT_STATELESS) ? "less" : "ful");
   len += strlen(buf + len);
 
   if (val & MPPE_OPT_COMPRESSED) {
diff --git a/usr.sbin/ppp/ppp/ppp.8 b/usr.sbin/ppp/ppp/ppp.8
index 289c82b3fe2..f1b048055c9 100644
--- a/usr.sbin/ppp/ppp/ppp.8
+++ b/usr.sbin/ppp/ppp/ppp.8
@@ -23,7 +23,7 @@
 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 .\" SUCH DAMAGE.
 .\"
-.\" $OpenBSD: ppp.8,v 1.113 2001/06/20 19:55:35 brian Exp $
+.\" $OpenBSD: ppp.8,v 1.114 2001/07/07 03:08:49 brian Exp $
 .\"
 .Dd September 20, 1995
 .Dt PPP 8
@@ -4910,14 +4910,14 @@ This will allow
 to do the necessary address translations to enable the process that
 triggers the connection to connect once the link is up despite the
 peer assigning us a new (dynamic) IP address.
-.It set mppe Op 40|56|128|* Op stateless|statefull|*
+.It set mppe Op 40|56|128|* Op stateless|stateful|*
 This option selects the encryption parameters used when negotiation
 MPPE.  MPPE can be disabled entirely with the
 .Dq disable mppe
 command.
 If no arguments are given,
 .Nm
-will attempt to negotiate a statefull link with a 128 bit key, but
+will attempt to negotiate a stateful link with a 128 bit key, but
 will agree to whatever the peer requests (including no encryption
 at all).
 .Pp
@@ -4931,9 +4931,9 @@ The first argument specifies the number of bits that
 .Nm
 should insist on during negotiations and the second specifies whether
 .Nm
-should insist on statefull or stateless mode.  In stateless mode, the
+should insist on stateful or stateless mode.  In stateless mode, the
 encryption dictionary is re-initialised with every packet according to
-an encryption key that is changed with every packet.  In statefull mode,
+an encryption key that is changed with every packet.  In stateful mode,
 the encryption dictionary is re-initialised every 256 packets or after
 the loss of any data and the key is changed every 256 packets.
 Stateless mode is less efficient but is better for unreliable transport