gss: add gss_mg_name_to_oid internal API

Add a new function for future internal use, gss_mg_name_to_oid(), which takes
either a dot-separated OID or a "short" mechanism name (such as
"sanon-x25519"), and returns a mechanism OID.

lib/gssapi/gssapi_mech.h

@@ -701,6 +701,9 @@ gss_cred_id_t
 _gss_mg_find_mech_cred(gss_const_cred_id_t cred_handle,
 		       gss_const_OID mech_type);
 
+GSSAPI_LIB_FUNCTION gss_const_OID
+GSSAPI_CALLCONV gss_mg_name_to_oid(const char *);
+
 #include <krb5.h>
 
 /*

lib/gssapi/libgssapi-exports.def

@@ -69,6 +69,7 @@ EXPORTS
 	gss_krb5_set_allowable_enctypes
 	gss_localname
 	gss_mg_collect_error
+	gss_mg_name_to_oid
         gss_mo_get
         gss_mo_set
         gss_mo_list

lib/gssapi/mech/gss_mech_switch.c

@@ -490,3 +490,21 @@ _gss_mg_support_mechanism(gss_const_OID mech)
 	}
 	return NULL;
 }
+
+GSSAPI_LIB_FUNCTION gss_const_OID GSSAPI_CALLCONV
+gss_mg_name_to_oid(const char *name)
+{
+	struct _gss_mech_switch *m;
+	gss_OID oid = GSS_C_NO_OID;
+
+	if (isdigit(name[0]) && _gss_string_to_oid(name, &oid) == 0)
+		return oid;
+
+	_gss_load_mech();
+	HEIM_TAILQ_FOREACH(m, &_gss_mechs, gm_link) {
+		if (m->gm_mech.gm_name &&
+		    strcmp(m->gm_mech.gm_name, name) == 0)
+			return m->gm_mech_oid;
+	}
+	return NULL;
+}

lib/gssapi/version-script.map

@@ -69,6 +69,7 @@ HEIMDAL_GSS_2.0 {
 		gss_krb5_set_allowable_enctypes;
 		gss_localname;
 		gss_mg_collect_error;
+		gss_mg_name_to_oid;
 		gss_oid_equal;
 		gss_oid_to_str;
 		gss_pname_to_uid;