// 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: 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; }