2 files changed, 51 insertions, 3 deletions

diff --git a/source4/auth/credentials/credentials_gensec.c b/source4/auth/credentials/credentials_gensec.c
index 077e4689ec..fcaa760ed4 100644
--- a/source4/auth/credentials/credentials_gensec.c
+++ b/source4/auth/credentials/credentials_gensec.c
@@ -24,8 +24,53 @@
 
 const struct gensec_security_ops **cli_credentials_gensec_list(struct cli_credentials *creds) 
 {
-	if (!creds->gensec_list) {
+	if (!creds || !creds->gensec_list) {
 		return gensec_security_all();
 	}
 	return creds->gensec_list;
 }
+
+static NTSTATUS cli_credentials_gensec_remove_mech(struct cli_credentials *creds,
+						   const struct gensec_security_ops *remove_mech) 
+{
+	const struct gensec_security_ops **gensec_list;
+	const struct gensec_security_ops **new_gensec_list;
+	int i, j;
+
+	gensec_list = cli_credentials_gensec_list(creds);
+
+	for (i=0; gensec_list && gensec_list[i]; i++) {
+		/* noop */
+	}
+
+	new_gensec_list = talloc_array(creds, const struct gensec_security_ops *, i + 1);
+	if (!new_gensec_list) {
+		return NT_STATUS_NO_MEMORY;
+	}
+
+	j = 0;
+	for (i=0; gensec_list && gensec_list[i]; i++) {
+		if (gensec_list[i] != remove_mech) {
+			new_gensec_list[j] = gensec_list[i];
+			j++;
+		}
+	}
+	new_gensec_list[j] = NULL; 
+	
+	creds->gensec_list = new_gensec_list;
+
+	return NT_STATUS_OK;
+}
+
+NTSTATUS cli_credentials_gensec_remove_oid(struct cli_credentials *creds,
+					   const char *oid) 
+{
+	const struct gensec_security_ops *gensec_by_oid;
+
+	gensec_by_oid = gensec_security_by_oid(NULL, oid);
+	if (!gensec_by_oid) {
+		return NT_STATUS_OK;
+	}
+
+	return cli_credentials_gensec_remove_mech(creds, gensec_by_oid);
+}
diff --git a/source4/auth/gensec/gensec.c b/source4/auth/gensec/gensec.c
index 0d79cb892c..26f245787b 100644
--- a/source4/auth/gensec/gensec.c
+++ b/source4/auth/gensec/gensec.c
@@ -53,8 +53,8 @@ static const struct gensec_security_ops *gensec_security_by_authtype(struct gens
 	return NULL;
 }
 
-static const struct gensec_security_ops *gensec_security_by_oid(struct gensec_security *gensec_security,
-								const char *oid_string)
+const struct gensec_security_ops *gensec_security_by_oid(struct gensec_security *gensec_security,
+							 const char *oid_string)
 {
 	int i, j;
 	const struct gensec_security_ops **backends;
@@ -805,6 +805,9 @@ NTSTATUS gensec_set_credentials(struct gensec_security *gensec_security, struct
 
 struct cli_credentials *gensec_get_credentials(struct gensec_security *gensec_security) 
 {
+	if (!gensec_security) {
+		return NULL;
+	}
 	return gensec_security->credentials;
 }