c8424e776b
IMA will use the module_signature format for append signatures, so export the relevant definitions and factor out the code which verifies that the appended signature trailer is valid. Also, create a CONFIG_MODULE_SIG_FORMAT option so that IMA can select it and be able to use mod_check_sig() without having to depend on either CONFIG_MODULE_SIG or CONFIG_MODULES. s390 duplicated the definition of struct module_signature so now they can use the new <linux/module_signature.h> header instead. Signed-off-by: Thiago Jung Bauermann <bauerman@linux.ibm.com> Acked-by: Jessica Yu <jeyu@kernel.org> Reviewed-by: Philipp Rudo <prudo@linux.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
47 lines
1.1 KiB
C
47 lines
1.1 KiB
C
// SPDX-License-Identifier: GPL-2.0+
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/*
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* Module signature checker
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*
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* Copyright (C) 2012 Red Hat, Inc. All Rights Reserved.
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* Written by David Howells (dhowells@redhat.com)
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*/
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#include <linux/errno.h>
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#include <linux/printk.h>
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#include <linux/module_signature.h>
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#include <asm/byteorder.h>
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/**
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* mod_check_sig - check that the given signature is sane
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*
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* @ms: Signature to check.
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* @file_len: Size of the file to which @ms is appended.
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* @name: What is being checked. Used for error messages.
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*/
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int mod_check_sig(const struct module_signature *ms, size_t file_len,
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const char *name)
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{
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if (be32_to_cpu(ms->sig_len) >= file_len - sizeof(*ms))
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return -EBADMSG;
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if (ms->id_type != PKEY_ID_PKCS7) {
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pr_err("%s: Module is not signed with expected PKCS#7 message\n",
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name);
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return -ENOPKG;
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}
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if (ms->algo != 0 ||
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ms->hash != 0 ||
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ms->signer_len != 0 ||
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ms->key_id_len != 0 ||
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ms->__pad[0] != 0 ||
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ms->__pad[1] != 0 ||
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ms->__pad[2] != 0) {
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pr_err("%s: PKCS#7 signature info has unexpected non-zero params\n",
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name);
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return -EBADMSG;
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}
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return 0;
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}
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