// SPDX-License-Identifier: GPL-2.0+/* * Module signature checker * * Copyright (C) 2012 Red Hat, Inc. All Rights Reserved. * Written by David Howells (dhowells@redhat.com) */ #include <linux/errno.h>#include <linux/printk.h>#include <linux/module_signature.h>#include <asm/byteorder.h> /** * mod_check_sig - check that the given signature is sane * * @ms:		Signature to check. * @file_len:	Size of the file to which @ms is appended. * @name:	What is being checked. Used for error messages. */int mod_check_sig(const struct module_signature *ms, size_t file_len,		  const char *name){	if (be32_to_cpu(ms->sig_len) >= file_len - sizeof(*ms))		return -EBADMSG; 	if (ms->id_type != PKEY_ID_PKCS7) {		pr_err("%s: Module is not signed with expected PKCS#7 message\n",		       name);		return -ENOPKG;	} 	if (ms->algo != 0 ||	    ms->hash != 0 ||	    ms->signer_len != 0 ||	    ms->key_id_len != 0 ||	    ms->__pad[0] != 0 ||	    ms->__pad[1] != 0 ||	    ms->__pad[2] != 0) {		pr_err("%s: PKCS#7 signature info has unexpected non-zero params\n",		       name);		return -EBADMSG;	} 	return 0;}