r13481: As far as I can tell, my changes in -r 12863 were dangerously untested.

We do need the gsskrb5_get_initiator_subkey() routine.  But we should
ensure that we do always get a valid key, to prevent any segfaults.

Without this code, we get a different session key compared with
Win2k3, and so kerberised smb signing fails.

Andrew Bartlett
(This used to be commit cfd0df16b74b0432670b33c7bf26316b741b1bde)

3 files changed, 62 insertions, 2 deletions

diff --git a/source4/heimdal/lib/gssapi/gssapi.h b/source4/heimdal/lib/gssapi/gssapi.h
index 6d48359b32..b93ad4e481 100644
--- a/source4/heimdal/lib/gssapi/gssapi.h
+++ b/source4/heimdal/lib/gssapi/gssapi.h
@@ -815,8 +815,10 @@ gsskrb5_extract_authtime_from_sec_context(OM_uint32 *minor_status,
 					  gss_ctx_id_t context_handle,
 					  time_t *authtime);
 OM_uint32
-gss_krb5_get_subkey(const gss_ctx_id_t context_handle,
-		    struct EncryptionKey **key);
+gsskrb5_get_initiator_subkey
+        (OM_uint32 * /*minor_status*/,
+	 const gss_ctx_id_t context_handle,
+	 gss_buffer_t /* subkey */);
 
 #define GSS_C_KRB5_COMPAT_DES3_MIC 1
 
diff --git a/source4/heimdal/lib/gssapi/gssapi_locl.h b/source4/heimdal/lib/gssapi/gssapi_locl.h
index 6fd8b0a4ac..bd5d0db2b5 100644
--- a/source4/heimdal/lib/gssapi/gssapi_locl.h
+++ b/source4/heimdal/lib/gssapi/gssapi_locl.h
@@ -226,6 +226,9 @@ gss_verify_mic_internal(OM_uint32 * minor_status,
 			gss_qop_t * qop_state,
 			char * type);
 
+OM_uint32
+gss_krb5_get_subkey(const gss_ctx_id_t context_handle,
+		    krb5_keyblock **key);
 
 krb5_error_code
 gss_address_to_krb5addr(OM_uint32 gss_addr_type,
diff --git a/source4/heimdal/lib/gssapi/wrap.c b/source4/heimdal/lib/gssapi/wrap.c
index 502137329c..d07a4d2599 100644
--- a/source4/heimdal/lib/gssapi/wrap.c
+++ b/source4/heimdal/lib/gssapi/wrap.c
@@ -36,6 +36,61 @@
 RCSID("$Id: wrap.c,v 1.31 2005/01/05 02:52:12 lukeh Exp $");
 
 OM_uint32
+gsskrb5_get_initiator_subkey(OM_uint32 *minor_status,
+			     gss_ctx_id_t context_handle,
+			     gss_buffer_t key)
+{
+    krb5_error_code ret;
+    krb5_keyblock *skey = NULL;
+
+    HEIMDAL_MUTEX_lock(&context_handle->ctx_id_mutex);
+    if (context_handle->more_flags & LOCAL) {
+	ret = krb5_auth_con_getlocalsubkey(gssapi_krb5_context,
+					   context_handle->auth_context, 
+					   &skey);
+	if (ret) {
+		*minor_status = ret;
+		return GSS_KRB5_S_KG_NO_SUBKEY; /* XXX */
+	}
+	
+    } else {
+	ret = krb5_auth_con_getremotesubkey(gssapi_krb5_context,
+					    context_handle->auth_context, 
+					    &skey);
+	if (ret) {
+		*minor_status = ret;
+		return GSS_KRB5_S_KG_NO_SUBKEY; /* XXX */
+	}
+    
+    }
+    
+    /* If there was no subkey, perhaps try this... */
+    if(skey == NULL) {
+	krb5_auth_con_getkey(gssapi_krb5_context,
+			     context_handle->auth_context, 
+			     &skey);
+    }
+
+    HEIMDAL_MUTEX_unlock(&context_handle->ctx_id_mutex);
+
+    /* ensure never to segfault */
+    if(skey == NULL) {
+	return GSS_KRB5_S_KG_NO_SUBKEY; /* XXX */
+    }
+
+    key->length = skey->keyvalue.length;
+    key->value  = malloc (key->length);
+    if (!key->value) {
+	    krb5_free_keyblock(gssapi_krb5_context, skey);
+	    *minor_status = ENOMEM;
+	    return GSS_S_FAILURE;
+    }
+    memcpy(key->value, skey->keyvalue.data, key->length);
+    krb5_free_keyblock(gssapi_krb5_context, skey);
+    return 0;
+}
+
+OM_uint32
 gss_krb5_get_subkey(const gss_ctx_id_t context_handle,
 		    krb5_keyblock **key)
 {