diff options
Diffstat (limited to 'security/integrity/digsig.c')
| -rw-r--r-- | security/integrity/digsig.c | 110 |
1 files changed, 79 insertions, 31 deletions
diff --git a/security/integrity/digsig.c b/security/integrity/digsig.c index f45d6edecf99..45c3e5dda355 100644 --- a/security/integrity/digsig.c +++ b/security/integrity/digsig.c @@ -1,21 +1,16 @@ +// SPDX-License-Identifier: GPL-2.0-only /* * Copyright (C) 2011 Intel Corporation * * Author: * Dmitry Kasatkin <dmitry.kasatkin@intel.com> - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation, version 2 of the License. - * */ -#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt - #include <linux/err.h> #include <linux/sched.h> #include <linux/slab.h> #include <linux/cred.h> +#include <linux/kernel_read_file.h> #include <linux/key-type.h> #include <linux/digsig.h> #include <linux/vmalloc.h> @@ -35,19 +30,19 @@ static const char * const keyring_name[INTEGRITY_KEYRING_MAX] = { ".ima", #endif ".platform", + ".machine", }; #ifdef CONFIG_IMA_KEYRINGS_PERMIT_SIGNED_BY_BUILTIN_OR_SECONDARY -#define restrict_link_to_ima restrict_link_by_builtin_and_secondary_trusted +#define restrict_link_to_ima restrict_link_by_digsig_builtin_and_secondary #else -#define restrict_link_to_ima restrict_link_by_builtin_trusted +#define restrict_link_to_ima restrict_link_by_digsig_builtin #endif -int integrity_digsig_verify(const unsigned int id, const char *sig, int siglen, - const char *digest, int digestlen) +static struct key *integrity_keyring_from_id(const unsigned int id) { - if (id >= INTEGRITY_KEYRING_MAX || siglen < 2) - return -EINVAL; + if (id >= INTEGRITY_KEYRING_MAX) + return ERR_PTR(-EINVAL); if (!keyring[id]) { keyring[id] = @@ -56,25 +51,53 @@ int integrity_digsig_verify(const unsigned int id, const char *sig, int siglen, int err = PTR_ERR(keyring[id]); pr_err("no %s keyring: %d\n", keyring_name[id], err); keyring[id] = NULL; - return err; + return ERR_PTR(err); } } + return keyring[id]; +} + +int integrity_digsig_verify(const unsigned int id, const char *sig, int siglen, + const char *digest, int digestlen) +{ + struct key *keyring; + + if (siglen < 2) + return -EINVAL; + + keyring = integrity_keyring_from_id(id); + if (IS_ERR(keyring)) + return PTR_ERR(keyring); + switch (sig[1]) { case 1: /* v1 API expect signature without xattr type */ - return digsig_verify(keyring[id], sig + 1, siglen - 1, - digest, digestlen); - case 2: - return asymmetric_verify(keyring[id], sig, siglen, - digest, digestlen); + return digsig_verify(keyring, sig + 1, siglen - 1, digest, + digestlen); + case 2: /* regular file data hash based signature */ + case 3: /* struct ima_file_id data based signature */ + return asymmetric_verify(keyring, sig, siglen, digest, + digestlen); } return -EOPNOTSUPP; } -static int __integrity_init_keyring(const unsigned int id, key_perm_t perm, - struct key_restriction *restriction) +int integrity_modsig_verify(const unsigned int id, const struct modsig *modsig) +{ + struct key *keyring; + + keyring = integrity_keyring_from_id(id); + if (IS_ERR(keyring)) + return PTR_ERR(keyring); + + return ima_modsig_verify(keyring, modsig); +} + +static int __init __integrity_init_keyring(const unsigned int id, + key_perm_t perm, + struct key_restriction *restriction) { const struct cred *cred = current_cred(); int err = 0; @@ -87,6 +110,13 @@ static int __integrity_init_keyring(const unsigned int id, key_perm_t perm, pr_info("Can't allocate %s keyring (%d)\n", keyring_name[id], err); keyring[id] = NULL; + } else { + if (id == INTEGRITY_KEYRING_PLATFORM) + set_platform_trusted_keys(keyring[id]); + if (id == INTEGRITY_KEYRING_MACHINE && imputed_trust_enabled()) + set_machine_trusted_keys(keyring[id]); + if (id == INTEGRITY_KEYRING_IMA) + load_module_cert(keyring[id]); } return err; @@ -96,11 +126,14 @@ int __init integrity_init_keyring(const unsigned int id) { struct key_restriction *restriction; key_perm_t perm; + int ret; perm = (KEY_POS_ALL & ~KEY_POS_SETATTR) | KEY_USR_VIEW | KEY_USR_READ | KEY_USR_SEARCH; - if (id == INTEGRITY_KEYRING_PLATFORM) { + if (id == INTEGRITY_KEYRING_PLATFORM || + (id == INTEGRITY_KEYRING_MACHINE && + !IS_ENABLED(CONFIG_INTEGRITY_CA_MACHINE_KEYRING))) { restriction = NULL; goto out; } @@ -112,15 +145,28 @@ int __init integrity_init_keyring(const unsigned int id) if (!restriction) return -ENOMEM; - restriction->check = restrict_link_to_ima; - perm |= KEY_USR_WRITE; + if (id == INTEGRITY_KEYRING_MACHINE) + restriction->check = restrict_link_by_ca; + else + restriction->check = restrict_link_to_ima; + + /* + * MOK keys can only be added through a read-only runtime services + * UEFI variable during boot. No additional keys shall be allowed to + * load into the machine keyring following init from userspace. + */ + if (id != INTEGRITY_KEYRING_MACHINE) + perm |= KEY_USR_WRITE; out: - return __integrity_init_keyring(id, perm, restriction); + ret = __integrity_init_keyring(id, perm, restriction); + if (ret) + kfree(restriction); + return ret; } -int __init integrity_add_key(const unsigned int id, const void *data, - off_t size, key_perm_t perm) +static int __init integrity_add_key(const unsigned int id, const void *data, + off_t size, key_perm_t perm) { key_ref_t key; int rc = 0; @@ -133,7 +179,8 @@ int __init integrity_add_key(const unsigned int id, const void *data, KEY_ALLOC_NOT_IN_QUOTA); if (IS_ERR(key)) { rc = PTR_ERR(key); - pr_err("Problem loading X.509 certificate %d\n", rc); + if (id != INTEGRITY_KEYRING_MACHINE) + pr_err("Problem loading X.509 certificate %d\n", rc); } else { pr_notice("Loaded X.509 cert '%s'\n", key_ref_to_ptr(key)->description); @@ -146,17 +193,18 @@ int __init integrity_add_key(const unsigned int id, const void *data, int __init integrity_load_x509(const unsigned int id, const char *path) { - void *data; - loff_t size; + void *data = NULL; + size_t size; int rc; key_perm_t perm; - rc = kernel_read_file_from_path(path, &data, &size, 0, + rc = kernel_read_file_from_path(path, 0, &data, INT_MAX, NULL, READING_X509_CERTIFICATE); if (rc < 0) { pr_err("Unable to open file: %s (%d)", path, rc); return rc; } + size = rc; perm = (KEY_POS_ALL & ~KEY_POS_SETATTR) | KEY_USR_VIEW | KEY_USR_READ; |