X-Git-Url: http://andersk.mit.edu/gitweb/gssapi-openssh.git/blobdiff_plain/2ce0bfe419965b35c425fbf900bde08e27b8785a..d037a8b0691afd8685d1a1202b3bf88c9542a8a9:/openssh/auth2-gss.c

diff --git a/openssh/auth2-gss.c b/openssh/auth2-gss.c
index 1445e4f..2cf6929 100644
--- a/openssh/auth2-gss.c
+++ b/openssh/auth2-gss.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: auth2-gss.c,v 1.10 2005/07/17 07:17:54 djm 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.
@@ -28,17 +28,22 @@
 
 #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;
 
@@ -62,9 +67,55 @@ userauth_external(Authctxt *authctxt)
 	return 0;
 }
 
+/* 
+ * The 'gssapi_keyex' userauth mechanism.
+ */
+static int
+userauth_gsskeyex(Authctxt *authctxt)
+{
+	int authenticated = 0;
+	Buffer b, b2;
+	gss_buffer_desc mic, gssbuf, gssbuf2;
+	u_int len;
+
+	mic.value = packet_get_string(&len);
+	mic.length = len;
+
+	packet_check_eom();
+
+	ssh_gssapi_buildmic(&b, authctxt->user, authctxt->service,
+	    "gssapi-keyex");
+
+	gssbuf.value = buffer_ptr(&b);
+	gssbuf.length = buffer_len(&b);
+
+	/* client may have used empty username to determine target
+	   name from GSSAPI context */
+	ssh_gssapi_buildmic(&b2, "", authctxt->service, "gssapi-keyex");
+
+	gssbuf2.value = buffer_ptr(&b2);
+	gssbuf2.length = buffer_len(&b2);
+
+	/* gss_kex_context is NULL with privsep, so we can't check it here */
+	if (!GSS_ERROR(PRIVSEP(ssh_gssapi_checkmic(gss_kex_context, 
+						   &gssbuf, &mic))) ||
+	    !GSS_ERROR(PRIVSEP(ssh_gssapi_checkmic(gss_kex_context, 
+						   &gssbuf2, &mic)))) {
+	    if (authctxt->valid && authctxt->user && authctxt->user[0]) {
+		authenticated = PRIVSEP(ssh_gssapi_userok(authctxt->user));
+	    }
+	}
+	
+	buffer_free(&b);
+	buffer_free(&b2);
+	xfree(mic.value);
+
+	return (authenticated);
+}
+
 /*
  * 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)
@@ -115,15 +166,19 @@ userauth_gssapi(Authctxt *authctxt)
 
 	if (!present) {
 		xfree(doid);
+		authctxt->server_caused_failure = 1;
 		return (0);
 	}
 
 	if (GSS_ERROR(PRIVSEP(ssh_gssapi_server_ctx(&ctxt, &goid)))) {
+		if (ctxt != NULL)
+			ssh_gssapi_delete_ctx(&ctxt);
 		xfree(doid);
+		authctxt->server_caused_failure = 1;
 		return (0);
 	}
 
-	authctxt->methoddata=(void *)ctxt;
+	authctxt->methoddata = (void *)ctxt;
 
 	packet_start(SSH2_MSG_USERAUTH_GSSAPI_RESPONSE);
 
@@ -232,28 +287,28 @@ input_gssapi_errtok(int type, u_int32_t plen, void *ctxt)
 }
 
 static void
-gssapi_set_implicit_username(Authctxt *authctxt)
+gssapi_set_username(Authctxt *authctxt)
 {
+    char *lname = NULL;
+
     if ((authctxt->user == NULL) || (authctxt->user[0] == '\0')) {
-	char *lname = NULL;
-	PRIVSEP(ssh_gssapi_localname(&lname));
-	if (lname && lname[0] != '\0') {
-	    if (authctxt->user) xfree(authctxt->user);
-	    authctxt->user = lname;
-	    debug("set username to %s from gssapi context", lname);
-	    authctxt->pw = PRIVSEP(getpwnamallow(authctxt->user));
-	    if (authctxt->pw) {
-		authctxt->valid = 1;
-	    }
-	} else {
-	    debug("failed to set username from gssapi context");
-	}
-    }
-    if (authctxt->pw) {
+        PRIVSEP(ssh_gssapi_localname(&lname));
+        if (lname && lname[0] != '\0') {
+            if (authctxt->user) xfree(authctxt->user);
+            authctxt->user = lname;
+            debug("set username to %s from gssapi context", lname);
+            authctxt->pw = PRIVSEP(getpwnamallow(authctxt->user));
+            if (authctxt->pw) {
+                authctxt->valid = 1;
 #ifdef USE_PAM
-	if (options.use_pam)
-		PRIVSEP(start_pam(authctxt));
+                if (options.use_pam)
+                    PRIVSEP(start_pam(authctxt));
 #endif
+            }
+        } else {
+            debug("failed to set username from gssapi context");
+            packet_send_debug("failed to set username from gssapi context");
+        }
     }
 }
 
@@ -273,7 +328,7 @@ input_gssapi_exchange_complete(int type, u_int32_t plen, void *ctxt)
 	if (authctxt == NULL || (authctxt->methoddata == NULL && !use_privsep))
 		fatal("No authentication or GSSAPI context");
 
-	gssapi_set_implicit_username(authctxt);
+	gssapi_set_username(authctxt);
 
 	gssctxt = authctxt->methoddata;
 
@@ -327,8 +382,6 @@ input_gssapi_mic(int type, u_int32_t plen, void *ctxt)
 	if (authctxt == NULL || (authctxt->methoddata == NULL && !use_privsep))
 		fatal("No authentication or GSSAPI context");
 
-	gssapi_set_implicit_username(authctxt);
-
 	gssctxt = authctxt->methoddata;
 
 	mic.value = packet_get_string(&len);
@@ -340,6 +393,8 @@ input_gssapi_mic(int type, u_int32_t plen, void *ctxt)
 	gssbuf.value = buffer_ptr(&b);
 	gssbuf.length = buffer_len(&b);
 
+    gssapi_set_username(authctxt);
+
 	if (!GSS_ERROR(PRIVSEP(ssh_gssapi_checkmic(gssctxt, &gssbuf, &mic))))
 	    if (authctxt->valid && authctxt->user && authctxt->user[0]) {
 		authenticated = PRIVSEP(ssh_gssapi_userok(authctxt->user));
@@ -383,6 +438,12 @@ Authmethod method_external = {
 	&options.gss_authentication
 };
 	
+Authmethod method_gsskeyex = {
+	"gssapi-keyex",
+	userauth_gsskeyex,
+	&options.gss_authentication
+};
+
 Authmethod method_gssapi = {
 	"gssapi-with-mic",
 	userauth_gssapi_with_mic,