Import of openssh-SNAP-20040105

[gssapi-openssh.git] / openssh / auth2-gss.c

diff --git a/openssh/auth2-gss.c b/openssh/auth2-gss.c
index 75b94b0097398f2d881e2aa0f50a923405644a24..9249988d394d5b5e5cb7c37386a652d59c6a2584 100644 (file)
--- a/openssh/auth2-gss.c
+++ b/openssh/auth2-gss.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: auth2-gss.c,v 1.3 2003/09/01 20:44:54 markus Exp $    */
+/*     $OpenBSD: auth2-gss.c,v 1.7 2003/11/21 11:57:03 djm 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 *);
 
@@ -78,17 +79,19 @@ 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;
-               } else {
+               if (len > 2 &&
+                  doid[0] == SSH_GSS_OIDTYPE &&
+                  doid[1] == len - 2) {
                        oid.elements = doid + 2;
                        oid.length   = len - 2;
+                       gss_test_oid_set_member(&ms, &oid, supported,
+                           &present);
+               } else {
+                       logit("Badly formed OID received");
                }
-               gss_test_oid_set_member(&ms, &oid, supported, &present);
        } while (mechs > 0 && !present);
 
        gss_release_oid_set(&ms, &supported);
@@ -107,7 +110,7 @@ userauth_gssapi(Authctxt *authctxt)
 
        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();
@@ -127,7 +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))
@@ -140,7 +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);
 
@@ -152,7 +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);
@@ -161,8 +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);
                }
        }
 
@@ -222,9 +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();
@@ -234,12 +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
 };