1 /* 2 * Copyright (C) 2011 Intel Corporation 3 * 4 * Author: 5 * Dmitry Kasatkin <dmitry.kasatkin@intel.com> 6 * 7 * This program is free software; you can redistribute it and/or modify 8 * it under the terms of the GNU General Public License as published by 9 * the Free Software Foundation, version 2 of the License. 10 * 11 */ 12 13 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 14 15 #include <linux/err.h> 16 #include <linux/sched.h> 17 #include <linux/rbtree.h> 18 #include <linux/cred.h> 19 #include <linux/key-type.h> 20 #include <linux/digsig.h> 21 22 #include "integrity.h" 23 24 static struct key *keyring[INTEGRITY_KEYRING_MAX]; 25 26 #ifdef CONFIG_IMA_TRUSTED_KEYRING 27 static const char *keyring_name[INTEGRITY_KEYRING_MAX] = { 28 ".evm", 29 ".module", 30 ".ima", 31 }; 32 #else 33 static const char *keyring_name[INTEGRITY_KEYRING_MAX] = { 34 "_evm", 35 "_module", 36 "_ima", 37 }; 38 #endif 39 40 int integrity_digsig_verify(const unsigned int id, const char *sig, int siglen, 41 const char *digest, int digestlen) 42 { 43 if (id >= INTEGRITY_KEYRING_MAX) 44 return -EINVAL; 45 46 if (!keyring[id]) { 47 keyring[id] = 48 request_key(&key_type_keyring, keyring_name[id], NULL); 49 if (IS_ERR(keyring[id])) { 50 int err = PTR_ERR(keyring[id]); 51 pr_err("no %s keyring: %d\n", keyring_name[id], err); 52 keyring[id] = NULL; 53 return err; 54 } 55 } 56 57 switch (sig[1]) { 58 case 1: 59 /* v1 API expect signature without xattr type */ 60 return digsig_verify(keyring[id], sig + 1, siglen - 1, 61 digest, digestlen); 62 case 2: 63 return asymmetric_verify(keyring[id], sig, siglen, 64 digest, digestlen); 65 } 66 67 return -EOPNOTSUPP; 68 } 69 70 int integrity_init_keyring(const unsigned int id) 71 { 72 const struct cred *cred = current_cred(); 73 const struct user_struct *user = cred->user; 74 75 keyring[id] = keyring_alloc(keyring_name[id], KUIDT_INIT(0), 76 KGIDT_INIT(0), cred, 77 ((KEY_POS_ALL & ~KEY_POS_SETATTR) | 78 KEY_USR_VIEW | KEY_USR_READ), 79 KEY_ALLOC_NOT_IN_QUOTA, user->uid_keyring); 80 if (!IS_ERR(keyring[id])) 81 set_bit(KEY_FLAG_TRUSTED_ONLY, &keyring[id]->flags); 82 else 83 pr_info("Can't allocate %s keyring (%ld)\n", 84 keyring_name[id], PTR_ERR(keyring[id])); 85 return 0; 86 } 87