drop support for old external-keyx and gssapi methods

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

diff --git a/openssh/auth2-gss.c b/openssh/auth2-gss.c
index a192d282fdf80de169f1d0d6b4a05e83d97306c8..08fcf72cca7e95f4adee1b1d20048ff8928c41ec 100644 (file)
--- a/openssh/auth2-gss.c
+++ b/openssh/auth2-gss.c
@@ -47,6 +47,7 @@
 
 extern ServerOptions options;
 
+static void ssh_gssapi_userauth_error(Gssctxt *ctxt);
 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);
@@ -59,8 +60,8 @@ static int
 userauth_gsskeyex(Authctxt *authctxt)
 {
        int authenticated = 0;
-       Buffer b;
-       gss_buffer_desc mic, gssbuf;
+       Buffer b, b2;
+       gss_buffer_desc mic, gssbuf, gssbuf2;
        u_int len;
 
        mic.value = packet_get_string(&len);
@@ -74,13 +75,26 @@ userauth_gsskeyex(Authctxt *authctxt)
        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))))
-               authenticated = PRIVSEP(ssh_gssapi_userok(authctxt->user,
-                   authctxt->pw));
+                                                  &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,
+                                                      authctxt->pw));
+           }
+       }
        
        buffer_free(&b);
+       buffer_free(&b2);
        xfree(mic.value);
 
        return (authenticated);
@@ -102,7 +116,10 @@ userauth_gssapi(Authctxt *authctxt)
        u_int len;
        u_char *doid = NULL;
 
-       if (!authctxt->valid || authctxt->user == NULL)
+       /* authctxt->valid may be 0 if we haven't yet determined
+          username from gssapi context. */
+
+       if (authctxt->user == NULL)
                return (0);
 
        mechs = packet_get_int();
@@ -172,7 +189,7 @@ 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, flags;
+       OM_uint32 maj_status, min_status, flags=0;
        u_int len;
 
        if (authctxt == NULL || (authctxt->methoddata == NULL && !use_privsep))
@@ -190,6 +207,7 @@ input_gssapi_token(int type, u_int32_t plen, void *ctxt)
        xfree(recv_tok.value);
 
        if (GSS_ERROR(maj_status)) {
+               ssh_gssapi_userauth_error(gssctxt);
                if (send_tok.length != 0) {
                        packet_start(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK);
                        packet_put_string(send_tok.value, send_tok.length);
@@ -253,6 +271,32 @@ input_gssapi_errtok(int type, u_int32_t plen, void *ctxt)
        gss_release_buffer(&maj_status, &send_tok);
 }
 
+static void
+gssapi_set_username(Authctxt *authctxt)
+{
+    char *lname = NULL;
+
+    if ((authctxt->user == NULL) || (authctxt->user[0] == '\0')) {
+        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));
+#endif
+            }
+        } else {
+            debug("failed to set username from gssapi context");
+            packet_send_debug("failed to set username from gssapi context");
+        }
+    }
+}
+
 /*
  * This is called when the client thinks we've completed authentication.
  * It should only be enabled in the dispatch handler by the function above,
@@ -269,6 +313,8 @@ 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_username(authctxt);
+
        gssctxt = authctxt->methoddata;
 
        /*
@@ -278,8 +324,13 @@ input_gssapi_exchange_complete(int type, u_int32_t plen, void *ctxt)
 
        packet_check_eom();
 
-       authenticated = PRIVSEP(ssh_gssapi_userok(authctxt->user,
-           authctxt->pw));
+       /* user should be set if valid but we double-check here */
+       if (authctxt->valid && authctxt->user && authctxt->user[0]) {
+           authenticated = PRIVSEP(ssh_gssapi_userok(authctxt->user,
+                                                  authctxt->pw));
+       } else {
+           authenticated = 0;
+       }
 
        authctxt->postponed = 0;
        dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, NULL);
@@ -313,9 +364,15 @@ 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))))
-               authenticated = 
-                   PRIVSEP(ssh_gssapi_userok(authctxt->user, authctxt->pw));
+           if (authctxt->valid && authctxt->user && authctxt->user[0]) {
+            authenticated =
+                PRIVSEP(ssh_gssapi_userok(authctxt->user, authctxt->pw));
+           } else {
+            authenticated = 0;
+           }
        else
                logit("GSSAPI MIC check failed");
 
@@ -330,6 +387,23 @@ input_gssapi_mic(int type, u_int32_t plen, void *ctxt)
        userauth_finish(authctxt, authenticated, "gssapi-with-mic");
 }
 
+static void ssh_gssapi_userauth_error(Gssctxt *ctxt) {
+       char *errstr;
+       OM_uint32 maj,min;
+       
+       errstr=PRIVSEP(ssh_gssapi_last_error(ctxt,&maj,&min));
+       if (errstr) {
+               packet_start(SSH2_MSG_USERAUTH_GSSAPI_ERROR);
+               packet_put_int(maj);
+               packet_put_int(min);
+               packet_put_cstring(errstr);
+               packet_put_cstring("");
+               packet_send();
+               packet_write_wait();
+               xfree(errstr);
+       }
+}
+
 Authmethod method_gsskeyex = {
        "gssapi-keyex",
        userauth_gsskeyex,