]> andersk Git - openssh.git/blobdiff - auth2-gss.c
- djm@cvs.openbsd.org 2010/01/30 02:54:53
[openssh.git] / auth2-gss.c
index c7651112d10a8820530decb9c2e0d7ecdf0ea6d5..0e08d889cd0988b58eaf4ec37f357766e8cc2038 100644 (file)
@@ -1,4 +1,4 @@
-/*     $OpenBSD: auth2-gss.c,v 1.1 2003/08/22 10:56:08 markus Exp $    */
+/* $OpenBSD: auth2-gss.c,v 1.16 2007/10/29 00:52:45 dtucker Exp $ */
 
 /*
  * Copyright (c) 2001-2003 Simon Wilkinson. All rights reserved.
 
 #ifdef GSSAPI
 
+#include <sys/types.h>
+
+#include <stdarg.h>
+
+#include "xmalloc.h"
+#include "key.h"
+#include "hostfile.h"
 #include "auth.h"
 #include "ssh2.h"
-#include "xmalloc.h"
 #include "log.h"
 #include "dispatch.h"
+#include "buffer.h"
 #include "servconf.h"
-#include "compat.h"
 #include "packet.h"
-#include "monitor_wrap.h"
-
 #include "ssh-gss.h"
+#include "monitor_wrap.h"
 
 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 *);
 
 /*
  * We only support those mechanisms that we know about (ie ones that we know
- * how to check local user kuserok and the like
+ * how to check local user kuserok and the like)
  */
 static int
 userauth_gssapi(Authctxt *authctxt)
 {
-       gss_OID_desc oid = {0, NULL};
+       gss_OID_desc goid = {0, NULL};
        Gssctxt *ctxt = NULL;
        int mechs;
        gss_OID_set supported;
        int present;
        OM_uint32 ms;
        u_int len;
-       char *doid = NULL;
+       u_char *doid = NULL;
 
        if (!authctxt->valid || authctxt->user == NULL)
                return (0);
@@ -78,17 +84,18 @@ userauth_gssapi(Authctxt *authctxt)
                if (doid)
                        xfree(doid);
 
+               present = 0;
                doid = packet_get_string(&len);
 
-               if (doid[0] != SSH_GSS_OIDTYPE || doid[1] != len-2) {
-                       logit("Mechanism OID received using the old encoding form");
-                       oid.elements = doid;
-                       oid.length = len;
+               if (len > 2 && doid[0] == SSH_GSS_OIDTYPE &&
+                   doid[1] == len - 2) {
+                       goid.elements = doid + 2;
+                       goid.length   = len - 2;
+                       gss_test_oid_set_member(&ms, &goid, supported,
+                           &present);
                } else {
-                       oid.elements = doid + 2;
-                       oid.length   = len - 2;
+                       logit("Badly formed OID received");
                }
-               gss_test_oid_set_member(&ms, &oid, supported, &present);
        } while (mechs > 0 && !present);
 
        gss_release_oid_set(&ms, &supported);
@@ -98,14 +105,18 @@ userauth_gssapi(Authctxt *authctxt)
                return (0);
        }
 
-       if (GSS_ERROR(PRIVSEP(ssh_gssapi_server_ctx(&ctxt, &oid))))
+       if (GSS_ERROR(PRIVSEP(ssh_gssapi_server_ctx(&ctxt, &goid)))) {
+               if (ctxt != NULL)
+                       ssh_gssapi_delete_ctx(&ctxt);
+               xfree(doid);
                return (0);
+       }
 
-       authctxt->methoddata=(void *)ctxt;
+       authctxt->methoddata = (void *)ctxt;
 
        packet_start(SSH2_MSG_USERAUTH_GSSAPI_RESPONSE);
 
-       /* Return OID in same format as we received it*/
+       /* Return the OID that we received */
        packet_put_string(doid, len);
 
        packet_send();
@@ -125,7 +136,7 @@ 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))
@@ -138,7 +149,7 @@ 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);
 
@@ -150,7 +161,7 @@ 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);
@@ -159,8 +170,13 @@ 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);
                }
        }
 
@@ -175,12 +191,14 @@ input_gssapi_errtok(int type, u_int32_t plen, void *ctxt)
        gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
        gss_buffer_desc recv_tok;
        OM_uint32 maj_status;
+       u_int len;
 
        if (authctxt == NULL || (authctxt->methoddata == NULL && !use_privsep))
                fatal("No authentication or GSSAPI context");
 
        gssctxt = authctxt->methoddata;
-       recv_tok.value = packet_get_string(&recv_tok.length);
+       recv_tok.value = packet_get_string(&len);
+       recv_tok.length = len;
 
        packet_check_eom();
 
@@ -218,9 +236,8 @@ 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();
@@ -230,12 +247,53 @@ 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
 };
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