10 files changed, 191 insertions, 29 deletions

diff --git a/ChangeLog b/ChangeLog
index bec42ac50..fb3fdaac5 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -43,6 +43,11 @@
    - djm@cvs.openbsd.org 2003/11/17 09:45:39
      [msg.c msg.h sshconnect2.c ssh-keysign.c]
      return error on msg send/receive failure (rather than fatal); ok markus@
+   - markus@cvs.openbsd.org 2003/11/17 11:06:07
+     [auth2-gss.c gss-genr.c gss-serv.c monitor.c monitor.h monitor_wrap.c]
+     [monitor_wrap.h sshconnect2.c ssh-gss.h]
+     replace "gssapi" with "gssapi-with-mic"; from Simon Wilkinson; 
+     test + ok jakob.
  - (djm) Bug #632: Don't call pam_end indirectly from within kbd-int
    conversation function
  - (djm) Export environment variables from authentication subprocess to 
@@ -1467,4 +1472,4 @@
  - Fix sshd BindAddress and -b options for systems using fake-getaddrinfo.
    Report from murple@murple.net, diagnosis from dtucker@zip.com.au
 
-$Id: ChangeLog,v 1.3111 2003/11/17 10:41:42 djm Exp $
+$Id: ChangeLog,v 1.3112 2003/11/17 11:18:21 djm Exp $
diff --git a/auth2-gss.c b/auth2-gss.c
index 84fb384f9..220862dc8 100644
--- a/auth2-gss.c
+++ b/auth2-gss.c
@@ -1,4 +1,4 @@
-/*      $OpenBSD: auth2-gss.c,v 1.5 2003/11/02 11:01:03 markus Exp $    */
+/*      $OpenBSD: auth2-gss.c,v 1.6 2003/11/17 11:06:07 markus Exp $    */
 
 /*
  * Copyright (c) 2001-2003 Simon Wilkinson. All rights reserved.
@@ -43,6 +43,7 @@
 extern ServerOptions options;
 
 static void input_gssapi_token(int type, u_int32_t plen, void *ctxt);
+static void input_gssapi_mic(int type, u_int32_t plen, void *ctxt);
 static void input_gssapi_exchange_complete(int type, u_int32_t plen, void *ctxt);
 static void input_gssapi_errtok(int, u_int32_t, void *);
 
@@ -129,7 +130,7 @@ input_gssapi_token(int type, u_int32_t plen, void *ctxt)
         Gssctxt *gssctxt;
         gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
         gss_buffer_desc recv_tok;
-        OM_uint32 maj_status, min_status;
+        OM_uint32 maj_status, min_status, flags;
         u_int len;
 
         if (authctxt == NULL || (authctxt->methoddata == NULL && !use_privsep))
@@ -142,7 +143,7 @@ input_gssapi_token(int type, u_int32_t plen, void *ctxt)
         packet_check_eom();
 
         maj_status = PRIVSEP(ssh_gssapi_accept_ctx(gssctxt, &recv_tok,
-            &send_tok, NULL));
+            &send_tok, &flags));
 
         xfree(recv_tok.value);
 
@@ -154,7 +155,7 @@ input_gssapi_token(int type, u_int32_t plen, void *ctxt)
                 }
                 authctxt->postponed = 0;
                 dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, NULL);
-                userauth_finish(authctxt, 0, "gssapi");
+                userauth_finish(authctxt, 0, "gssapi-with-mic");
         } else {
                 if (send_tok.length != 0) {
                         packet_start(SSH2_MSG_USERAUTH_GSSAPI_TOKEN);
@@ -163,8 +164,13 @@ input_gssapi_token(int type, u_int32_t plen, void *ctxt)
                 }
                 if (maj_status == GSS_S_COMPLETE) {
                         dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, NULL);
-                        dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE,
-                                     &input_gssapi_exchange_complete);
+                        if (flags & GSS_C_INTEG_FLAG)
+                                dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_MIC,
+                                    &input_gssapi_mic);
+                        else
+                                dispatch_set(
+                                    SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE,
+                                    &input_gssapi_exchange_complete);
                 }
         }
 
@@ -224,9 +230,8 @@ input_gssapi_exchange_complete(int type, u_int32_t plen, void *ctxt)
         gssctxt = authctxt->methoddata;
 
         /*
-         * We don't need to check the status, because the stored credentials
-         * which userok uses are only populated once the context init step
-         * has returned complete.
+         * We don't need to check the status, because we're only enabled in
+         * the dispatcher once the exchange is complete
          */
 
         packet_check_eom();
@@ -236,12 +241,53 @@ input_gssapi_exchange_complete(int type, u_int32_t plen, void *ctxt)
         authctxt->postponed = 0;
         dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, NULL);
         dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK, NULL);
+        dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_MIC, NULL);
+        dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE, NULL);
+        userauth_finish(authctxt, authenticated, "gssapi-with-mic");
+}
+
+static void
+input_gssapi_mic(int type, u_int32_t plen, void *ctxt)
+{
+        Authctxt *authctxt = ctxt;
+        Gssctxt *gssctxt;
+        int authenticated = 0;
+        Buffer b;
+        gss_buffer_desc mic, gssbuf;
+        u_int len;
+        
+        if (authctxt == NULL || (authctxt->methoddata == NULL && !use_privsep))
+                fatal("No authentication or GSSAPI context");
+        
+        gssctxt = authctxt->methoddata;
+        
+        mic.value = packet_get_string(&len);
+        mic.length = len;
+        
+        ssh_gssapi_buildmic(&b, authctxt->user, authctxt->service,
+            "gssapi-with-mic");
+        
+        gssbuf.value = buffer_ptr(&b);
+        gssbuf.length = buffer_len(&b);
+        
+        if (!GSS_ERROR(PRIVSEP(ssh_gssapi_checkmic(gssctxt, &gssbuf, &mic))))
+                authenticated = PRIVSEP(ssh_gssapi_userok(authctxt->user));
+        else
+                logit("GSSAPI MIC check failed");
+
+        buffer_free(&b);
+        xfree(mic.value);
+        
+        authctxt->postponed = 0;
+        dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, NULL);
+        dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK, NULL);
+        dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_MIC, NULL);
         dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE, NULL);
-        userauth_finish(authctxt, authenticated, "gssapi");
+        userauth_finish(authctxt, authenticated, "gssapi-with-mic");
 }
 
 Authmethod method_gssapi = {
-        "gssapi",
+        "gssapi-with-mic",
         userauth_gssapi,
         &options.gss_authentication
 };
diff --git a/gss-genr.c b/gss-genr.c
index bda12d6f1..6b7caad0e 100644
--- a/gss-genr.c
+++ b/gss-genr.c
@@ -1,4 +1,4 @@
-/*      $OpenBSD: gss-genr.c,v 1.1 2003/08/22 10:56:09 markus Exp $     */
+/*      $OpenBSD: gss-genr.c,v 1.2 2003/11/17 11:06:07 markus Exp $     */
 
 /*
  * Copyright (c) 2001-2003 Simon Wilkinson. All rights reserved.
@@ -33,9 +33,12 @@
 #include "compat.h"
 #include "log.h"
 #include "monitor_wrap.h"
+#include "ssh2.h"
 
 #include "ssh-gss.h"
 
+extern u_char *session_id2;
+extern u_int session_id2_len;
 
 /* Check that the OID in a data stream matches that in the context */
 int
@@ -245,6 +248,28 @@ ssh_gssapi_acquire_cred(Gssctxt *ctx)
 }
 
 OM_uint32
+ssh_gssapi_sign(Gssctxt *ctx, gss_buffer_t buffer, gss_buffer_t hash)
+{
+        if ((ctx->major = gss_get_mic(&ctx->minor, ctx->context,
+            GSS_C_QOP_DEFAULT, buffer, hash)))
+                ssh_gssapi_error(ctx);
+        
+        return (ctx->major);
+}
+
+void
+ssh_gssapi_buildmic(Buffer *b, const char *user, const char *service, 
+    const char *context) 
+{       
+        buffer_init(b);
+        buffer_put_string(b, session_id2, session_id2_len);
+        buffer_put_char(b, SSH2_MSG_USERAUTH_REQUEST);
+        buffer_put_cstring(b, user);
+        buffer_put_cstring(b, service);
+        buffer_put_cstring(b, context);
+}
+
+OM_uint32
 ssh_gssapi_server_ctx(Gssctxt **ctx, gss_OID oid) {
         if (*ctx)
                 ssh_gssapi_delete_ctx(ctx);
diff --git a/gss-serv.c b/gss-serv.c
index 6574f9750..de32a3f2e 100644
--- a/gss-serv.c
+++ b/gss-serv.c
@@ -1,4 +1,4 @@
-/*      $OpenBSD: gss-serv.c,v 1.4 2003/09/23 20:17:11 markus Exp $     */
+/*      $OpenBSD: gss-serv.c,v 1.5 2003/11/17 11:06:07 markus Exp $     */
 
 /*
  * Copyright (c) 2001-2003 Simon Wilkinson. All rights reserved.
@@ -287,4 +287,14 @@ ssh_gssapi_userok(char *user)
         return (0);
 }
 
+/* Priviledged */
+OM_uint32
+ssh_gssapi_checkmic(Gssctxt *ctx, gss_buffer_t gssbuf, gss_buffer_t gssmic)
+{
+        ctx->major = gss_verify_mic(&ctx->minor, ctx->context,
+            gssbuf, gssmic, NULL);
+
+        return (ctx->major);
+}
+
 #endif
diff --git a/monitor.c b/monitor.c
index e83fb45a7..97f1ee9f4 100644
--- a/monitor.c
+++ b/monitor.c
@@ -25,7 +25,7 @@
  */
 
 #include "includes.h"
-RCSID("$OpenBSD: monitor.c,v 1.51 2003/11/04 08:54:09 djm Exp $");
+RCSID("$OpenBSD: monitor.c,v 1.52 2003/11/17 11:06:07 markus Exp $");
 
 #include <openssl/dh.h>
 
@@ -134,6 +134,7 @@ int mm_answer_pam_free_ctx(int, Buffer *);
 int mm_answer_gss_setup_ctx(int, Buffer *);
 int mm_answer_gss_accept_ctx(int, Buffer *);
 int mm_answer_gss_userok(int, Buffer *);
+int mm_answer_gss_checkmic(int, Buffer *);
 #endif
 
 static Authctxt *authctxt;
@@ -193,6 +194,7 @@ struct mon_table mon_dispatch_proto20[] = {
     {MONITOR_REQ_GSSSETUP, MON_ISAUTH, mm_answer_gss_setup_ctx},
     {MONITOR_REQ_GSSSTEP, MON_ISAUTH, mm_answer_gss_accept_ctx},
     {MONITOR_REQ_GSSUSEROK, MON_AUTH, mm_answer_gss_userok},
+    {MONITOR_REQ_GSSCHECKMIC, MON_ISAUTH, mm_answer_gss_checkmic},
 #endif
     {0, 0, NULL}
 };
@@ -1781,15 +1783,43 @@ mm_answer_gss_accept_ctx(int socket, Buffer *m)
 
         gss_release_buffer(&minor, &out);
 
-        /* Complete - now we can do signing */
         if (major==GSS_S_COMPLETE) {
                 monitor_permit(mon_dispatch, MONITOR_REQ_GSSSTEP, 0);
                 monitor_permit(mon_dispatch, MONITOR_REQ_GSSUSEROK, 1);
+                monitor_permit(mon_dispatch, MONITOR_REQ_GSSCHECKMIC, 1);
         }
         return (0);
 }
 
 int
+mm_answer_gss_checkmic(int socket, Buffer *m)
+{
+        gss_buffer_desc gssbuf, mic;
+        OM_uint32 ret;
+        u_int len;
+        
+        gssbuf.value = buffer_get_string(m, &len);
+        gssbuf.length = len;
+        mic.value = buffer_get_string(m, &len);
+        mic.length = len;
+        
+        ret = ssh_gssapi_checkmic(gsscontext, &gssbuf, &mic);
+        
+        xfree(gssbuf.value);
+        xfree(mic.value);
+        
+        buffer_clear(m);
+        buffer_put_int(m, ret);
+        
+        mm_request_send(socket, MONITOR_ANS_GSSCHECKMIC, m);
+        
+        if (!GSS_ERROR(ret))
+                monitor_permit(mon_dispatch, MONITOR_REQ_GSSUSEROK, 1);
+        
+        return (0);
+}
+
+int
 mm_answer_gss_userok(int socket, Buffer *m)
 {
         int authenticated;
@@ -1802,7 +1832,7 @@ mm_answer_gss_userok(int socket, Buffer *m)
         debug3("%s: sending result %d", __func__, authenticated);
         mm_request_send(socket, MONITOR_ANS_GSSUSEROK, m);
 
-        auth_method="gssapi";
+        auth_method="gssapi-with-mic";
 
         /* Monitor loop will terminate if authenticated */
         return (authenticated);
diff --git a/monitor.h b/monitor.h
index a153f4168..621a4ad18 100644
--- a/monitor.h
+++ b/monitor.h
@@ -1,4 +1,4 @@
-/*      $OpenBSD: monitor.h,v 1.12 2003/09/23 20:17:11 markus Exp $     */
+/*      $OpenBSD: monitor.h,v 1.13 2003/11/17 11:06:07 markus Exp $     */
 
 /*
  * Copyright 2002 Niels Provos <provos@citi.umich.edu>
@@ -52,6 +52,7 @@ enum monitor_reqtype {
         MONITOR_REQ_GSSSETUP, MONITOR_ANS_GSSSETUP,
         MONITOR_REQ_GSSSTEP, MONITOR_ANS_GSSSTEP,
         MONITOR_REQ_GSSUSEROK, MONITOR_ANS_GSSUSEROK,
+        MONITOR_REQ_GSSCHECKMIC, MONITOR_ANS_GSSCHECKMIC,
         MONITOR_REQ_PAM_START,
         MONITOR_REQ_PAM_ACCOUNT, MONITOR_ANS_PAM_ACCOUNT,
         MONITOR_REQ_PAM_INIT_CTX, MONITOR_ANS_PAM_INIT_CTX,
diff --git a/monitor_wrap.c b/monitor_wrap.c
index fe1460422..c685535d3 100644
--- a/monitor_wrap.c
+++ b/monitor_wrap.c
@@ -25,7 +25,7 @@
  */
 
 #include "includes.h"
-RCSID("$OpenBSD: monitor_wrap.c,v 1.34 2003/10/15 09:48:45 markus Exp $");
+RCSID("$OpenBSD: monitor_wrap.c,v 1.35 2003/11/17 11:06:07 markus Exp $");
 
 #include <openssl/bn.h>
 #include <openssl/dh.h>
@@ -1134,6 +1134,25 @@ mm_ssh_gssapi_accept_ctx(Gssctxt *ctx, gss_buffer_desc *in,
         return (major);
 }
 
+OM_uint32
+mm_ssh_gssapi_checkmic(Gssctxt *ctx, gss_buffer_t gssbuf, gss_buffer_t gssmic)
+{
+        Buffer m;
+        OM_uint32 major;
+
+        buffer_init(&m);
+        buffer_put_string(&m, gssbuf->value, gssbuf->length);
+        buffer_put_string(&m, gssmic->value, gssmic->length);
+
+        mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSCHECKMIC, &m);
+        mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_GSSCHECKMIC,
+            &m);
+
+        major = buffer_get_int(&m);
+        buffer_free(&m);
+        return(major);
+}
+
 int
 mm_ssh_gssapi_userok(char *user)
 {
diff --git a/monitor_wrap.h b/monitor_wrap.h
index 76c02f13a..55be10b19 100644
--- a/monitor_wrap.h
+++ b/monitor_wrap.h
@@ -1,4 +1,4 @@
-/*      $OpenBSD: monitor_wrap.h,v 1.12 2003/09/23 20:17:11 markus Exp $        */
+/*      $OpenBSD: monitor_wrap.h,v 1.13 2003/11/17 11:06:07 markus Exp $        */
 
 /*
  * Copyright 2002 Niels Provos <provos@citi.umich.edu>
@@ -62,6 +62,7 @@ OM_uint32 mm_ssh_gssapi_server_ctx(Gssctxt **ctxt, gss_OID oid);
 OM_uint32 mm_ssh_gssapi_accept_ctx(Gssctxt *ctxt,
    gss_buffer_desc *recv, gss_buffer_desc *send, OM_uint32 *flags);
 int mm_ssh_gssapi_userok(char *user);
+OM_uint32 mm_ssh_gssapi_checkmic(Gssctxt *, gss_buffer_t, gss_buffer_t);
 #endif
 
 #ifdef USE_PAM
diff --git a/ssh-gss.h b/ssh-gss.h
index c76648ee0..2b6fe2130 100644
--- a/ssh-gss.h
+++ b/ssh-gss.h
@@ -1,4 +1,4 @@
-/*      $OpenBSD: ssh-gss.h,v 1.3 2003/10/02 08:26:53 markus Exp $      */
+/*      $OpenBSD: ssh-gss.h,v 1.4 2003/11/17 11:06:07 markus Exp $      */
 /*
  * Copyright (c) 2001-2003 Simon Wilkinson. All rights reserved.
  *
@@ -50,6 +50,7 @@
 #define SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE      63
 #define SSH2_MSG_USERAUTH_GSSAPI_ERROR                  64
 #define SSH2_MSG_USERAUTH_GSSAPI_ERRTOK                 65
+#define SSH2_MSG_USERAUTH_GSSAPI_MIC                    66
 
 #define SSH_GSS_OIDTYPE 0x06
 
@@ -108,11 +109,13 @@ void ssh_gssapi_error(Gssctxt *ctx);
 char *ssh_gssapi_last_error(Gssctxt *ctxt, OM_uint32 *maj, OM_uint32 *min);
 void ssh_gssapi_build_ctx(Gssctxt **ctx);
 void ssh_gssapi_delete_ctx(Gssctxt **ctx);
+OM_uint32 ssh_gssapi_sign(Gssctxt *, gss_buffer_t, gss_buffer_t);
 OM_uint32 ssh_gssapi_server_ctx(Gssctxt **ctx, gss_OID oid);
+void ssh_gssapi_buildmic(Buffer *, const char *, const char *, const char *);
 
 /* In the server */
 int ssh_gssapi_userok(char *name);
-
+OM_uint32 ssh_gssapi_checkmic(Gssctxt *, gss_buffer_t, gss_buffer_t);
 void ssh_gssapi_do_child(char ***envp, u_int *envsizep);
 void ssh_gssapi_cleanup_creds(void);
 void ssh_gssapi_storecreds(void);
diff --git a/sshconnect2.c b/sshconnect2.c
index 388a25741..f6368aadd 100644
--- a/sshconnect2.c
+++ b/sshconnect2.c
@@ -23,7 +23,7 @@
  */
 
 #include "includes.h"
-RCSID("$OpenBSD: sshconnect2.c,v 1.131 2003/11/17 09:45:39 djm Exp $");
+RCSID("$OpenBSD: sshconnect2.c,v 1.132 2003/11/17 11:06:07 markus Exp $");
 
 #include "openbsd-compat/sys-queue.h"
 
@@ -222,7 +222,7 @@ static char *authmethods_get(void);
 
 Authmethod authmethods[] = {
 #ifdef GSSAPI
-        {"gssapi",
+        {"gssapi-with-mic",
                 userauth_gssapi,
                 &options.gss_authentication,
                 NULL},
@@ -543,10 +543,12 @@ process_gssapi_token(void *ctxt, gss_buffer_t recv_tok)
         Authctxt *authctxt = ctxt;
         Gssctxt *gssctxt = authctxt->methoddata;
         gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
-        OM_uint32 status, ms;
+        gss_buffer_desc gssbuf, mic;
+        OM_uint32 status, ms, flags;
+        Buffer b;
         
         status = ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds,
-            recv_tok, &send_tok, NULL);
+            recv_tok, &send_tok, &flags);
 
         if (send_tok.length > 0) {
                 if (GSS_ERROR(status))
@@ -560,9 +562,29 @@ process_gssapi_token(void *ctxt, gss_buffer_t recv_tok)
         }
         
         if (status == GSS_S_COMPLETE) {
-                /* If that succeeded, send a exchange complete message */
-                packet_start(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE);
-                packet_send();
+                /* send either complete or MIC, depending on mechanism */
+                if (!(flags & GSS_C_INTEG_FLAG)) {
+                        packet_start(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE);
+                        packet_send();
+                } else {
+                        ssh_gssapi_buildmic(&b, authctxt->server_user,
+                            authctxt->service, "gssapi-with-mic");
+
+                        gssbuf.value = buffer_ptr(&b);
+                        gssbuf.length = buffer_len(&b);
+                        
+                        status = ssh_gssapi_sign(gssctxt, &gssbuf, &mic);
+                        
+                        if (!GSS_ERROR(status)) {
+                                packet_start(SSH2_MSG_USERAUTH_GSSAPI_MIC);
+                                packet_put_string(mic.value, mic.length);
+                                
+                                packet_send();
+                        }
+                                
+                        buffer_free(&b);
+                        gss_release_buffer(&ms, &mic);
+                }          
         }
         
         return status;