diff options
| -rw-r--r-- | kernel/Makefile | 11 | ||||
| -rw-r--r-- | kernel/modsign_pubkey.c | 113 | ||||
| -rw-r--r-- | kernel/module-internal.h | 2 |
3 files changed, 124 insertions, 2 deletions
diff --git a/kernel/Makefile b/kernel/Makefile index 58c6f111267e..111a845460c9 100644 --- a/kernel/Makefile +++ b/kernel/Makefile @@ -55,7 +55,7 @@ obj-$(CONFIG_DEBUG_SPINLOCK) += spinlock.o obj-$(CONFIG_PROVE_LOCKING) += spinlock.o obj-$(CONFIG_UID16) += uid16.o obj-$(CONFIG_MODULES) += module.o -obj-$(CONFIG_MODULE_SIG) += module_signing.o +obj-$(CONFIG_MODULE_SIG) += module_signing.o modsign_pubkey.o obj-$(CONFIG_KALLSYMS) += kallsyms.o obj-$(CONFIG_BSD_PROCESS_ACCT) += acct.o obj-$(CONFIG_KEXEC) += kexec.o @@ -134,6 +134,13 @@ $(obj)/timeconst.h: $(src)/timeconst.pl FORCE $(call if_changed,timeconst) ifeq ($(CONFIG_MODULE_SIG),y) +# +# Pull the signing certificate and any extra certificates into the kernel +# +extra_certificates: + touch $@ + +kernel/modsign_pubkey.o: signing_key.x509 extra_certificates ############################################################################### # @@ -180,4 +187,4 @@ x509.genkey: @echo >>x509.genkey "subjectKeyIdentifier=hash" @echo >>x509.genkey "authorityKeyIdentifier=keyid" endif -CLEAN_FILES += signing_key.priv signing_key.x509 x509.genkey +CLEAN_FILES += signing_key.priv signing_key.x509 x509.genkey extra_certificates diff --git a/kernel/modsign_pubkey.c b/kernel/modsign_pubkey.c new file mode 100644 index 000000000000..4646eb2c3820 --- /dev/null +++ b/kernel/modsign_pubkey.c @@ -0,0 +1,113 @@ +/* Public keys for module signature verification + * + * Copyright (C) 2012 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public Licence + * as published by the Free Software Foundation; either version + * 2 of the Licence, or (at your option) any later version. + */ + +#include <linux/kernel.h> +#include <linux/sched.h> +#include <linux/cred.h> +#include <linux/err.h> +#include <keys/asymmetric-type.h> +#include "module-internal.h" + +struct key *modsign_keyring; + +extern __initdata const u8 modsign_certificate_list[]; +extern __initdata const u8 modsign_certificate_list_end[]; +asm(".section .init.data,\"aw\"\n" + "modsign_certificate_list:\n" + ".incbin \"signing_key.x509\"\n" + ".incbin \"extra_certificates\"\n" + "modsign_certificate_list_end:" + ); + +/* + * We need to make sure ccache doesn't cache the .o file as it doesn't notice + * if modsign.pub changes. + */ +static __initdata const char annoy_ccache[] = __TIME__ "foo"; + +/* + * Load the compiled-in keys + */ +static __init int module_verify_init(void) +{ + pr_notice("Initialise module verification\n"); + + modsign_keyring = key_alloc(&key_type_keyring, ".module_sign", + KUIDT_INIT(0), KGIDT_INIT(0), + current_cred(), + (KEY_POS_ALL & ~KEY_POS_SETATTR) | + KEY_USR_VIEW | KEY_USR_READ, + KEY_ALLOC_NOT_IN_QUOTA); + if (IS_ERR(modsign_keyring)) + panic("Can't allocate module signing keyring\n"); + + if (key_instantiate_and_link(modsign_keyring, NULL, 0, NULL, NULL) < 0) + panic("Can't instantiate module signing keyring\n"); + + return 0; +} + +/* + * Must be initialised before we try and load the keys into the keyring. + */ +device_initcall(module_verify_init); + +/* + * Load the compiled-in keys + */ +static __init int load_module_signing_keys(void) +{ + key_ref_t key; + const u8 *p, *end; + size_t plen; + + pr_notice("Loading module verification certificates\n"); + + end = modsign_certificate_list_end; + p = modsign_certificate_list; + while (p < end) { + /* Each cert begins with an ASN.1 SEQUENCE tag and must be more + * than 256 bytes in size. + */ + if (end - p < 4) + goto dodgy_cert; + if (p[0] != 0x30 && + p[1] != 0x82) + goto dodgy_cert; + plen = (p[2] << 8) | p[3]; + plen += 4; + if (plen > end - p) + goto dodgy_cert; + + key = key_create_or_update(make_key_ref(modsign_keyring, 1), + "asymmetric", + NULL, + p, + plen, + (KEY_POS_ALL & ~KEY_POS_SETATTR) | + KEY_USR_VIEW, + KEY_ALLOC_NOT_IN_QUOTA); + if (IS_ERR(key)) + pr_err("MODSIGN: Problem loading in-kernel X.509 certificate (%ld)\n", + PTR_ERR(key)); + else + pr_notice("MODSIGN: Loaded cert '%s'\n", + key_ref_to_ptr(key)->description); + p += plen; + } + + return 0; + +dodgy_cert: + pr_err("MODSIGN: Problem parsing in-kernel X.509 certificate list\n"); + return 0; +} +late_initcall(load_module_signing_keys); diff --git a/kernel/module-internal.h b/kernel/module-internal.h index 033c17fd70ef..6114a13419bd 100644 --- a/kernel/module-internal.h +++ b/kernel/module-internal.h @@ -9,5 +9,7 @@ * 2 of the Licence, or (at your option) any later version. */ +extern struct key *modsign_keyring; + extern int mod_verify_sig(const void *mod, unsigned long modlen, const void *sig, unsigned long siglen); |