- djm@cvs.openbsd.org 2006/08/18 13:54:54
[gss-genr.c ssh-gss.h sshconnect2.c]
bz #1218 - disable SPNEGO as per RFC4462; diff from simon AT sxw.org.uk
ok markus@
diff --git a/ChangeLog b/ChangeLog
index 63b3da3..167c65d 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -34,6 +34,10 @@
[misc.h]
reorder so prototypes are sorted by the files they refer to; no
binary change
+ - djm@cvs.openbsd.org 2006/08/18 13:54:54
+ [gss-genr.c ssh-gss.h sshconnect2.c]
+ bz #1218 - disable SPNEGO as per RFC4462; diff from simon AT sxw.org.uk
+ ok markus@
20060817
- (dtucker) [openbsd-compat/fake-rfc2553.c openbsd-compat/setproctitle.c]
@@ -5255,4 +5259,4 @@
- (djm) Trim deprecated options from INSTALL. Mention UsePAM
- (djm) Fix quote handling in sftp; Patch from admorten AT umich.edu
-$Id: ChangeLog,v 1.4493 2006/08/18 14:33:05 djm Exp $
+$Id: ChangeLog,v 1.4494 2006/08/18 14:33:34 djm Exp $
diff --git a/gss-genr.c b/gss-genr.c
index da39479..1bb67e8 100644
--- a/gss-genr.c
+++ b/gss-genr.c
@@ -1,7 +1,7 @@
-/* $OpenBSD: gss-genr.c,v 1.13 2006/08/03 03:34:42 deraadt Exp $ */
+/* $OpenBSD: gss-genr.c,v 1.14 2006/08/18 13:54:54 djm Exp $ */
/*
- * Copyright (c) 2001-2003 Simon Wilkinson. All rights reserved.
+ * Copyright (c) 2001-2006 Simon Wilkinson. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
@@ -291,4 +291,33 @@
return (ssh_gssapi_acquire_cred(*ctx));
}
+int
+ssh_gssapi_check_mechanism(Gssctxt **ctx, gss_OID oid, char *host)
+{
+ gss_buffer_desc token = GSS_C_EMPTY_BUFFER;
+ OM_uint32 major, minor;
+ gss_OID_desc spnego_oid = {6, (void *)"\x2B\x06\x01\x05\x05\x02"};
+
+ /* RFC 4462 says we MUST NOT do SPNEGO */
+ if (oid->length == spnego_oid.length &&
+ (memcmp(oid->elements, spnego_oid.elements, oid->length) == 0))
+ return -1;
+
+ ssh_gssapi_build_ctx(ctx);
+ ssh_gssapi_set_oid(*ctx, oid);
+ major = ssh_gssapi_import_name(*ctx, host);
+ if (!GSS_ERROR(major)) {
+ major = ssh_gssapi_init_ctx(*ctx, 0, GSS_C_NO_BUFFER, &token,
+ NULL);
+ gss_release_buffer(&minor, &token);
+ gss_delete_sec_context(&minor, &(*ctx)->context,
+ GSS_C_NO_BUFFER);
+ }
+
+ if (GSS_ERROR(major))
+ ssh_gssapi_delete_ctx(ctx);
+
+ return (!GSS_ERROR(major));
+}
+
#endif /* GSSAPI */
diff --git a/ssh-gss.h b/ssh-gss.h
index 0837c9b..a188d61 100644
--- a/ssh-gss.h
+++ b/ssh-gss.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: ssh-gss.h,v 1.7 2006/08/03 03:34:42 deraadt Exp $ */
+/* $OpenBSD: ssh-gss.h,v 1.8 2006/08/18 13:54:54 djm Exp $ */
/*
* Copyright (c) 2001-2003 Simon Wilkinson. All rights reserved.
*
@@ -118,6 +118,7 @@
OM_uint32 ssh_gssapi_sign(Gssctxt *, gss_buffer_t, gss_buffer_t);
OM_uint32 ssh_gssapi_server_ctx(Gssctxt **, gss_OID);
void ssh_gssapi_buildmic(Buffer *, const char *, const char *, const char *);
+int ssh_gssapi_check_mechanism(Gssctxt **, gss_OID, char *);
/* In the server */
int ssh_gssapi_userok(char *name);
diff --git a/sshconnect2.c b/sshconnect2.c
index e58d078..8b2e633 100644
--- a/sshconnect2.c
+++ b/sshconnect2.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: sshconnect2.c,v 1.160 2006/08/03 03:34:42 deraadt Exp $ */
+/* $OpenBSD: sshconnect2.c,v 1.161 2006/08/18 13:54:54 djm Exp $ */
/*
* Copyright (c) 2000 Markus Friedl. All rights reserved.
*
@@ -508,25 +508,18 @@
/* Check to see if the mechanism is usable before we offer it */
while (mech < gss_supported->count && !ok) {
- if (gssctxt)
- ssh_gssapi_delete_ctx(&gssctxt);
- ssh_gssapi_build_ctx(&gssctxt);
- ssh_gssapi_set_oid(gssctxt, &gss_supported->elements[mech]);
-
/* My DER encoding requires length<128 */
if (gss_supported->elements[mech].length < 128 &&
- !GSS_ERROR(ssh_gssapi_import_name(gssctxt,
- authctxt->host))) {
+ ssh_gssapi_check_mechanism(&gssctxt,
+ &gss_supported->elements[mech], authctxt->host)) {
ok = 1; /* Mechanism works */
} else {
mech++;
}
}
- if (!ok) {
- ssh_gssapi_delete_ctx(&gssctxt);
+ if (!ok)
return 0;
- }
authctxt->methoddata=(void *)gssctxt;