Compensate for dodgy Win98/WinME MSCHAPv2 responses later in the code

path... after we've talked to any RADIUS servers involved, so that we
haven't touched the data before it gets to the server.

5 files changed, 39 insertions, 34 deletions

diff --git a/usr.sbin/ppp/ppp/chap.c b/usr.sbin/ppp/ppp/chap.c
index 5701a431aa2..7558cdf2440 100644
--- a/usr.sbin/ppp/ppp/chap.c
+++ b/usr.sbin/ppp/ppp/chap.c
@@ -25,7 +25,7 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- * $OpenBSD: chap.c,v 1.35 2002/06/15 08:02:00 brian Exp $
+ * $OpenBSD: chap.c,v 1.36 2002/06/17 01:14:08 brian Exp $
  */
 
 #include <sys/param.h>
@@ -761,19 +761,13 @@ chap_Input(struct bundle *bundle, struct link *l, struct mbuf *bp)
           m_freem(bp);
           return NULL;
         }
-        if ((ans = malloc(alen + 2)) == NULL) {
+        if ((ans = malloc(alen + 1)) == NULL) {
           log_Printf(LogERROR, "Chap Input: Out of memory !\n");
           m_freem(bp);
           return NULL;
         }
         *ans = chap->auth.id;
         bp = mbuf_Read(bp, ans + 1, alen);
-        if (p->link.lcp.want_authtype == 0x81 && ans[alen] != '\0') {
-          log_Printf(LogWARN, "%s: Compensating for corrupt (Win98/WinME?) "
-                     "CHAP81 RESPONSE\n", l->name);
-          ans[alen] = '\0';
-        }
-        ans[alen+1] = '\0';
         bp = auth_ReadName(&chap->auth, bp, len);
 #ifndef NODES
         lanman = p->link.lcp.want_authtype == 0x80 &&
@@ -847,8 +841,11 @@ chap_Input(struct bundle *bundle, struct link *l, struct mbuf *bp)
         nlen = strlen(name);
 #ifndef NODES
         if (p->link.lcp.want_authtype == 0x81) {
-          chap->challenge.peer[0] = CHAP81_CHALLENGE_LEN;
-          memcpy(chap->challenge.peer + 1, ans + 1, CHAP81_CHALLENGE_LEN);
+          struct MSCHAPv2_resp *resp = (struct MSCHAPv2_resp *)(ans + 1);
+
+          chap->challenge.peer[0] = sizeof resp->PeerChallenge;
+          memcpy(chap->challenge.peer + 1, resp->PeerChallenge,
+                 sizeof resp->PeerChallenge);
         }
 #endif
 
@@ -857,16 +854,21 @@ chap_Input(struct bundle *bundle, struct link *l, struct mbuf *bp)
           if (!radius_Authenticate(&bundle->radius, &chap->auth,
                                    chap->auth.in.name, ans, alen + 1,
                                    chap->challenge.local + 1,
-                                   *chap->challenge.local,
-                                   chap->challenge.peer + 1,
-                                   *chap->challenge.peer))
+                                   *chap->challenge.local))
             chap_Failure(&chap->auth);
         } else
 #endif
         {
+          if (p->link.lcp.want_authtype == 0x81 && ans[alen] != '\0' &&
+              alen == sizeof(struct MSCHAPv2_resp)) {
+            struct MSCHAPv2_resp *resp = (struct MSCHAPv2_resp *)(ans + 1);
+
+            log_Printf(LogWARN, "%s: Compensating for corrupt (Win98/WinME?) "
+                       "CHAP81 RESPONSE\n", l->name);
+            resp->Flags = '\0';	/* rfc2759 says it *MUST* be zero */
+          }
           key = auth_GetSecret(bundle, name, nlen, p);
           if (key) {
-            char *myans;
 #ifndef NODES
             if (p->link.lcp.want_authtype == 0x80 &&
                 lanman && !IsEnabled(p->link.lcp.cfg.chap80lm)) {
@@ -887,8 +889,8 @@ chap_Input(struct bundle *bundle, struct link *l, struct mbuf *bp)
             } else
 #endif
             {
-              myans = chap_BuildAnswer(name, key, chap->auth.id,
-                                       chap->challenge.local,
+              char *myans = chap_BuildAnswer(name, key, chap->auth.id,
+                                             chap->challenge.local,
                                        p->link.lcp.want_authtype
 #ifndef NODES
                                        , chap->challenge.peer,
diff --git a/usr.sbin/ppp/ppp/chap.h b/usr.sbin/ppp/ppp/chap.h
index 35abb29b81b..2288210700b 100644
--- a/usr.sbin/ppp/ppp/chap.h
+++ b/usr.sbin/ppp/ppp/chap.h
@@ -25,7 +25,7 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- * $OpenBSD: chap.h,v 1.12 2002/03/31 02:38:49 brian Exp $
+ * $OpenBSD: chap.h,v 1.13 2002/06/17 01:14:08 brian Exp $
  */
 
 struct mbuf;
@@ -63,6 +63,13 @@ struct chap {
 #define auth2chap(a) \
   ((struct chap *)((char *)a - (int)&((struct chap *)0)->auth))
 
+struct MSCHAPv2_resp {		/* rfc2759 */
+  char PeerChallenge[16];
+  char Reserved[8];
+  char NTResponse[24];
+  char Flags;
+};
+
 extern void chap_Init(struct chap *, struct physical *);
 extern void chap_ReInit(struct chap *);
 extern struct mbuf *chap_Input(struct bundle *, struct link *, struct mbuf *);
diff --git a/usr.sbin/ppp/ppp/pap.c b/usr.sbin/ppp/ppp/pap.c
index 145b5912dcc..aff29c34a73 100644
--- a/usr.sbin/ppp/ppp/pap.c
+++ b/usr.sbin/ppp/ppp/pap.c
@@ -25,7 +25,7 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- * $OpenBSD: pap.c,v 1.19 2002/05/16 14:27:21 brian Exp $
+ * $OpenBSD: pap.c,v 1.20 2002/06/17 01:14:08 brian Exp $
  */
 
 #include <sys/param.h>
@@ -266,7 +266,7 @@ pap_Input(struct bundle *bundle, struct link *l, struct mbuf *bp)
 #ifndef NORADIUS
       if (*bundle->radius.cfg.file) {
         if (!radius_Authenticate(&bundle->radius, authp, authp->in.name,
-                                 key, strlen(key), NULL, 0, NULL, 0))
+                                 key, strlen(key), NULL, 0))
           pap_Failure(authp);
       } else
 #endif
diff --git a/usr.sbin/ppp/ppp/radius.c b/usr.sbin/ppp/ppp/radius.c
index 29dab0c440b..bf27a3e0daa 100644
--- a/usr.sbin/ppp/ppp/radius.c
+++ b/usr.sbin/ppp/ppp/radius.c
@@ -23,7 +23,7 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- *	$OpenBSD: radius.c,v 1.19 2002/06/15 08:02:01 brian Exp $
+ *	$OpenBSD: radius.c,v 1.20 2002/06/17 01:14:08 brian Exp $
  *
  */
 
@@ -700,7 +700,7 @@ radius_put_physical_details(struct rad_handle *rad, struct physical *p)
 int
 radius_Authenticate(struct radius *r, struct authinfo *authp, const char *name,
                     const char *key, int klen, const char *nchallenge,
-                    int nclen, const char *pchallenge, int pclen)
+                    int nclen)
 {
   struct timeval tv;
   int got;
@@ -712,6 +712,7 @@ radius_Authenticate(struct radius *r, struct authinfo *authp, const char *name,
 #ifndef NODES
   struct mschap_response msresp;
   struct mschap2_response msresp2;
+  const struct MSCHAPv2_resp *keyv2;
 #endif
 
   if (!*r->cfg.file)
@@ -794,26 +795,21 @@ radius_Authenticate(struct radius *r, struct authinfo *authp, const char *name,
       break;
 
     case 0x81:
-      if (klen != 50) {
+      if (klen != sizeof(*keyv2) + 1) {
         log_Printf(LogERROR, "CHAP81: Unrecognised key length %d\n", klen);
         rad_close(r->cx.rad);
         return 0;
       }
 
-      if (pclen != sizeof msresp2.pchallenge) {
-        log_Printf(LogERROR, "CHAP81: Unrecognised peer challenge length %d\n",
-                   pclen);
-        rad_close(r->cx.rad);
-        return 0;
-      }
-
+      keyv2 = (const struct MSCHAPv2_resp *)(key + 1);
       rad_put_vendor_attr(r->cx.rad, RAD_VENDOR_MICROSOFT,
                           RAD_MICROSOFT_MS_CHAP_CHALLENGE, nchallenge, nclen);
       msresp2.ident = *key;
-      msresp2.flags = 0x00;
-      memcpy(msresp2.response, key + 25, 24);
+      msresp2.flags = keyv2->Flags;
+      memcpy(msresp2.response, keyv2->NTResponse, sizeof msresp2.response);
       memset(msresp2.reserved, '\0', sizeof msresp2.reserved);
-      memcpy(msresp2.pchallenge, pchallenge, pclen);
+      memcpy(msresp2.pchallenge, keyv2->PeerChallenge,
+             sizeof msresp2.pchallenge);
       rad_put_vendor_attr(r->cx.rad, RAD_VENDOR_MICROSOFT,
                           RAD_MICROSOFT_MS_CHAP2_RESPONSE, &msresp2,
                           sizeof msresp2);
diff --git a/usr.sbin/ppp/ppp/radius.h b/usr.sbin/ppp/ppp/radius.h
index 8fd1390694f..a59a8308d41 100644
--- a/usr.sbin/ppp/ppp/radius.h
+++ b/usr.sbin/ppp/ppp/radius.h
@@ -23,7 +23,7 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- *	$OpenBSD: radius.h,v 1.10 2002/06/15 08:02:01 brian Exp $
+ *	$OpenBSD: radius.h,v 1.11 2002/06/17 01:14:08 brian Exp $
  */
 
 #define	MPPE_POLICY_ALLOWED	1
@@ -85,7 +85,7 @@ extern void radius_Destroy(struct radius *);
 extern void radius_Show(struct radius *, struct prompt *);
 extern int radius_Authenticate(struct radius *, struct authinfo *,
                                const char *, const char *, int,
-                               const char *, int, const char *, int);
+                               const char *, int);
 extern void radius_Account(struct radius *, struct radacct *,
                            struct datalink *, int, struct in_addr *,
                            struct in_addr *, struct pppThroughput *);