From c8424e776b093280d3fdd104d850706b3b229ac8 Mon Sep 17 00:00:00 2001 From: Thiago Jung Bauermann Date: Thu, 4 Jul 2019 15:57:34 -0300 Subject: MODSIGN: Export module signature definitions 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 header instead. Signed-off-by: Thiago Jung Bauermann Acked-by: Jessica Yu Reviewed-by: Philipp Rudo Cc: Heiko Carstens Signed-off-by: Mimi Zohar --- include/linux/module_signature.h | 44 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 44 insertions(+) create mode 100644 include/linux/module_signature.h (limited to 'include/linux/module_signature.h') diff --git a/include/linux/module_signature.h b/include/linux/module_signature.h new file mode 100644 index 000000000000..523617fc5b6a --- /dev/null +++ b/include/linux/module_signature.h @@ -0,0 +1,44 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ +/* + * Module signature handling. + * + * Copyright (C) 2012 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + */ + +#ifndef _LINUX_MODULE_SIGNATURE_H +#define _LINUX_MODULE_SIGNATURE_H + +/* In stripped ARM and x86-64 modules, ~ is surprisingly rare. */ +#define MODULE_SIG_STRING "~Module signature appended~\n" + +enum pkey_id_type { + PKEY_ID_PGP, /* OpenPGP generated key ID */ + PKEY_ID_X509, /* X.509 arbitrary subjectKeyIdentifier */ + PKEY_ID_PKCS7, /* Signature in PKCS#7 message */ +}; + +/* + * Module signature information block. + * + * The constituents of the signature section are, in order: + * + * - Signer's name + * - Key identifier + * - Signature data + * - Information block + */ +struct module_signature { + u8 algo; /* Public-key crypto algorithm [0] */ + u8 hash; /* Digest algorithm [0] */ + u8 id_type; /* Key identifier type [PKEY_ID_PKCS7] */ + u8 signer_len; /* Length of signer's name [0] */ + u8 key_id_len; /* Length of key identifier [0] */ + u8 __pad[3]; + __be32 sig_len; /* Length of signature data */ +}; + +int mod_check_sig(const struct module_signature *ms, size_t file_len, + const char *name); + +#endif /* _LINUX_MODULE_SIGNATURE_H */ -- cgit v1.2.3