| David Howells | 631cc66 | 2012-09-26 10:09:51 +0100 | [diff] [blame] | 1 | /* Public keys for module signature verification |
| 2 | * |
| 3 | * Copyright (C) 2012 Red Hat, Inc. All Rights Reserved. |
| 4 | * Written by David Howells (dhowells@redhat.com) |
| 5 | * |
| 6 | * This program is free software; you can redistribute it and/or |
| 7 | * modify it under the terms of the GNU General Public Licence |
| 8 | * as published by the Free Software Foundation; either version |
| 9 | * 2 of the Licence, or (at your option) any later version. |
| 10 | */ |
| 11 | |
| 12 | #include <linux/kernel.h> |
| 13 | #include <linux/sched.h> |
| 14 | #include <linux/cred.h> |
| 15 | #include <linux/err.h> |
| 16 | #include <keys/asymmetric-type.h> |
| 17 | #include "module-internal.h" |
| 18 | |
| 19 | struct key *modsign_keyring; |
| 20 | |
| 21 | extern __initdata const u8 modsign_certificate_list[]; |
| 22 | extern __initdata const u8 modsign_certificate_list_end[]; |
| 23 | asm(".section .init.data,\"aw\"\n" |
| 24 | "modsign_certificate_list:\n" |
| 25 | ".incbin \"signing_key.x509\"\n" |
| 26 | ".incbin \"extra_certificates\"\n" |
| 27 | "modsign_certificate_list_end:" |
| 28 | ); |
| 29 | |
| 30 | /* |
| 31 | * We need to make sure ccache doesn't cache the .o file as it doesn't notice |
| 32 | * if modsign.pub changes. |
| 33 | */ |
| 34 | static __initdata const char annoy_ccache[] = __TIME__ "foo"; |
| 35 | |
| 36 | /* |
| 37 | * Load the compiled-in keys |
| 38 | */ |
| 39 | static __init int module_verify_init(void) |
| 40 | { |
| 41 | pr_notice("Initialise module verification\n"); |
| 42 | |
| 43 | modsign_keyring = key_alloc(&key_type_keyring, ".module_sign", |
| 44 | KUIDT_INIT(0), KGIDT_INIT(0), |
| 45 | current_cred(), |
| 46 | (KEY_POS_ALL & ~KEY_POS_SETATTR) | |
| 47 | KEY_USR_VIEW | KEY_USR_READ, |
| 48 | KEY_ALLOC_NOT_IN_QUOTA); |
| 49 | if (IS_ERR(modsign_keyring)) |
| 50 | panic("Can't allocate module signing keyring\n"); |
| 51 | |
| 52 | if (key_instantiate_and_link(modsign_keyring, NULL, 0, NULL, NULL) < 0) |
| 53 | panic("Can't instantiate module signing keyring\n"); |
| 54 | |
| 55 | return 0; |
| 56 | } |
| 57 | |
| 58 | /* |
| 59 | * Must be initialised before we try and load the keys into the keyring. |
| 60 | */ |
| 61 | device_initcall(module_verify_init); |
| 62 | |
| 63 | /* |
| 64 | * Load the compiled-in keys |
| 65 | */ |
| 66 | static __init int load_module_signing_keys(void) |
| 67 | { |
| 68 | key_ref_t key; |
| 69 | const u8 *p, *end; |
| 70 | size_t plen; |
| 71 | |
| 72 | pr_notice("Loading module verification certificates\n"); |
| 73 | |
| 74 | end = modsign_certificate_list_end; |
| 75 | p = modsign_certificate_list; |
| 76 | while (p < end) { |
| 77 | /* Each cert begins with an ASN.1 SEQUENCE tag and must be more |
| 78 | * than 256 bytes in size. |
| 79 | */ |
| 80 | if (end - p < 4) |
| 81 | goto dodgy_cert; |
| 82 | if (p[0] != 0x30 && |
| 83 | p[1] != 0x82) |
| 84 | goto dodgy_cert; |
| 85 | plen = (p[2] << 8) | p[3]; |
| 86 | plen += 4; |
| 87 | if (plen > end - p) |
| 88 | goto dodgy_cert; |
| 89 | |
| 90 | key = key_create_or_update(make_key_ref(modsign_keyring, 1), |
| 91 | "asymmetric", |
| 92 | NULL, |
| 93 | p, |
| 94 | plen, |
| 95 | (KEY_POS_ALL & ~KEY_POS_SETATTR) | |
| 96 | KEY_USR_VIEW, |
| 97 | KEY_ALLOC_NOT_IN_QUOTA); |
| 98 | if (IS_ERR(key)) |
| 99 | pr_err("MODSIGN: Problem loading in-kernel X.509 certificate (%ld)\n", |
| 100 | PTR_ERR(key)); |
| 101 | else |
| 102 | pr_notice("MODSIGN: Loaded cert '%s'\n", |
| 103 | key_ref_to_ptr(key)->description); |
| 104 | p += plen; |
| 105 | } |
| 106 | |
| 107 | return 0; |
| 108 | |
| 109 | dodgy_cert: |
| 110 | pr_err("MODSIGN: Problem parsing in-kernel X.509 certificate list\n"); |
| 111 | return 0; |
| 112 | } |
| 113 | late_initcall(load_module_signing_keys); |