From 542962ddf96dd881e925f5f5cadf3ecaede6ef02 Mon Sep 17 00:00:00 2001
From: Brian Somers <brian@FreeBSD.org>
Date: Tue, 7 Nov 2000 23:19:11 +0000
Subject: [PATCH] Introduce another global (MPPE_IsServer) so that we initiate
 the MPPE session keys correctly.

I'm a bit dubious about this code.  It seems that the session keys
are initialised differently based on whether you're the client or
the server.  One side is the server if it issues the first challenge,
but of course you can issue a challenge from both sides.... at the
same time.  Sounds like another wonderful M$ assumption...

Ppp can now talk to itself correctly using encryption.

Problem solved by:	Ustimenko Semen <semen@iclub.nsu.ru>
Hair torn out by:	me
---
 usr.sbin/ppp/chap.c | 13 ++++++++-----
 usr.sbin/ppp/mppe.c |  7 +++++--
 usr.sbin/ppp/mppe.h |  1 +
 3 files changed, 14 insertions(+), 7 deletions(-)

diff --git a/usr.sbin/ppp/chap.c b/usr.sbin/ppp/chap.c
index be41362aa710..437fbc157418 100644
--- a/usr.sbin/ppp/chap.c
+++ b/usr.sbin/ppp/chap.c
@@ -203,7 +203,7 @@ chap_BuildAnswer(char *name, char *key, u_char id, char *challenge, u_char type
                        expkey, klen * 2, ntresponse);
 
     /* Generate MPPE MASTERKEY */
-    GetMasterKey(pwdhashhash, ntresponse, MPPE_MasterKey);
+    GetMasterKey(pwdhashhash, ntresponse, MPPE_MasterKey);    /* XXX Global ! */
 
     /* Generate AUTHRESPONSE to verify on auth success */
     GenerateAuthenticatorResponse(expkey, klen * 2, ntresponse, 
@@ -371,6 +371,7 @@ chap_Respond(struct chap *chap, char *name, char *key, u_char type
                ans, *ans + 1 + strlen(name), name);
 #ifdef HAVE_DES
     chap->NTRespSent = !lm;
+    MPPE_IsServer = 0;		/* XXX Global ! */
 #endif
     free(ans);
   } else
@@ -536,7 +537,7 @@ chap_Success(struct authinfo *authp)
 #ifdef HAVE_DES
   if (authp->physical->link.lcp.want_authtype == 0x81) {
     msg = auth2chap(authp)->authresponse;
-    MPPE_MasterKeyValid = 1;
+    MPPE_MasterKeyValid = 1;		/* XXX Global ! */
   } else
 #endif
     msg = "Welcome!!";
@@ -857,9 +858,11 @@ chap_Input(struct bundle *bundle, struct link *l, struct mbuf *bp)
                                        p->link.lcp.want_authtype
 #ifdef HAVE_DES
                                        , chap->challenge.peer,
-                                       chap->authresponse, lanman
-#endif
+                                       chap->authresponse, lanman);
+              MPPE_IsServer = 1;		/* XXX Global ! */
+#else
                                       );
+#endif
               if (myans == NULL)
                 key = NULL;
               else {
@@ -896,7 +899,7 @@ chap_Input(struct bundle *bundle, struct link *l, struct mbuf *bp)
                 
               } else {
                 /* Successful login */
-                MPPE_MasterKeyValid = 1;
+                MPPE_MasterKeyValid = 1;		/* XXX Global ! */
                 datalink_AuthOk(p->dl);
               }
             } else
diff --git a/usr.sbin/ppp/mppe.c b/usr.sbin/ppp/mppe.c
index 253bb5670412..d843ecbfd114 100644
--- a/usr.sbin/ppp/mppe.c
+++ b/usr.sbin/ppp/mppe.c
@@ -67,6 +67,7 @@ struct mppe_state {
 };
 
 int MPPE_MasterKeyValid = 0;
+int MPPE_IsServer = 0;
 char MPPE_MasterKey[MPPE_KEY_LEN];
 
 static void
@@ -340,7 +341,8 @@ MPPEInitInput(struct lcp_opt *o)
 
   log_Printf(LogDEBUG, "MPPE: InitInput: %d-bits\n", mip->keybits);
 
-  GetAsymetricStartKey(MPPE_MasterKey, mip->mastkey, mip->keylen, 0, 0);
+  GetAsymetricStartKey(MPPE_MasterKey, mip->mastkey, mip->keylen, 0,
+                       MPPE_IsServer);
   GetNewKeyFromSHA(mip->mastkey, mip->mastkey, mip->keylen, mip->sesskey);
 
   MPPEReduceSessionKey(mip);
@@ -381,7 +383,8 @@ MPPEInitOutput(struct lcp_opt *o)
 
   log_Printf(LogDEBUG, "MPPE: InitOutput: %d-bits\n", mop->keybits);
 
-  GetAsymetricStartKey(MPPE_MasterKey, mop->mastkey, mop->keylen, 1, 0);
+  GetAsymetricStartKey(MPPE_MasterKey, mop->mastkey, mop->keylen, 1,
+                       MPPE_IsServer);
   GetNewKeyFromSHA(mop->mastkey, mop->mastkey, mop->keylen, mop->sesskey);
 
   MPPEReduceSessionKey(mop);
diff --git a/usr.sbin/ppp/mppe.h b/usr.sbin/ppp/mppe.h
index ee54cdbd7523..c70a60906ba1 100644
--- a/usr.sbin/ppp/mppe.h
+++ b/usr.sbin/ppp/mppe.h
@@ -29,4 +29,5 @@
 #define MPPE_KEY_LEN	16
 extern const struct ccp_algorithm MPPEAlgorithm;
 extern int MPPE_MasterKeyValid;
+extern int MPPE_IsServer;
 extern char MPPE_MasterKey[];