1/* 2 * Copyright (C) 2005,2006,2007,2008 IBM Corporation 3 * 4 * Authors: 5 * Reiner Sailer <sailer@watson.ibm.com> 6 * Leendert van Doorn <leendert@watson.ibm.com> 7 * Mimi Zohar <zohar@us.ibm.com> 8 * 9 * This program is free software; you can redistribute it and/or 10 * modify it under the terms of the GNU General Public License as 11 * published by the Free Software Foundation, version 2 of the 12 * License. 13 * 14 * File: ima_init.c 15 * initialization and cleanup functions 16 */ 17#include <linux/module.h> 18#include <linux/scatterlist.h> 19#include <linux/slab.h> 20#include <linux/err.h> 21#include "ima.h" 22 23/* name for boot aggregate entry */ 24static const char *boot_aggregate_name = "boot_aggregate"; 25int ima_used_chip; 26 27/* Add the boot aggregate to the IMA measurement list and extend 28 * the PCR register. 29 * 30 * Calculate the boot aggregate, a SHA1 over tpm registers 0-7, 31 * assuming a TPM chip exists, and zeroes if the TPM chip does not 32 * exist. Add the boot aggregate measurement to the measurement 33 * list and extend the PCR register. 34 * 35 * If a tpm chip does not exist, indicate the core root of trust is 36 * not hardware based by invalidating the aggregate PCR value. 37 * (The aggregate PCR value is invalidated by adding one value to 38 * the measurement list and extending the aggregate PCR value with 39 * a different value.) Violations add a zero entry to the measurement 40 * list and extend the aggregate PCR value with ff...ff's. 41 */ 42static void __init ima_add_boot_aggregate(void) 43{ 44 struct ima_template_entry *entry; 45 const char *op = "add_boot_aggregate"; 46 const char *audit_cause = "ENOMEM"; 47 int result = -ENOMEM; 48 int violation = 1; 49 50 entry = kmalloc(sizeof(*entry), GFP_KERNEL); 51 if (!entry) 52 goto err_out; 53 54 memset(&entry->template, 0, sizeof(entry->template)); 55 strncpy(entry->template.file_name, boot_aggregate_name, 56 IMA_EVENT_NAME_LEN_MAX); 57 if (ima_used_chip) { 58 violation = 0; 59 result = ima_calc_boot_aggregate(entry->template.digest); 60 if (result < 0) { 61 audit_cause = "hashing_error"; 62 kfree(entry); 63 goto err_out; 64 } 65 } 66 result = ima_store_template(entry, violation, NULL); 67 if (result < 0) 68 kfree(entry); 69 return; 70err_out: 71 integrity_audit_msg(AUDIT_INTEGRITY_PCR, NULL, boot_aggregate_name, op, 72 audit_cause, result, 0); 73} 74 75int __init ima_init(void) 76{ 77 u8 pcr_i[IMA_DIGEST_SIZE]; 78 int rc; 79 80 ima_used_chip = 0; 81 rc = tpm_pcr_read(TPM_ANY_NUM, 0, pcr_i); 82 if (rc == 0) 83 ima_used_chip = 1; 84 85 if (!ima_used_chip) 86 pr_info("IMA: No TPM chip found, activating TPM-bypass!\n"); 87 88 ima_add_boot_aggregate(); /* boot aggregate must be first entry */ 89 ima_init_policy(); 90 91 return ima_fs_init(); 92} 93 94void __exit ima_cleanup(void) 95{ 96 ima_fs_cleanup(); 97} 98