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![Kirill A. Shutemov](/assets/img/avatar_default.png)
MAX_ORDER currently defined as number of orders page allocator supports: user can ask buddy allocator for page order between 0 and MAX_ORDER-1. This definition is counter-intuitive and lead to number of bugs all over the kernel. Change the definition of MAX_ORDER to be inclusive: the range of orders user can ask from buddy allocator is 0..MAX_ORDER now. [kirill@shutemov.name: fix min() warning] Link: https://lkml.kernel.org/r/20230315153800.32wib3n5rickolvh@box [akpm@linux-foundation.org: fix another min_t warning] [kirill@shutemov.name: fixups per Zi Yan] Link: https://lkml.kernel.org/r/20230316232144.b7ic4cif4kjiabws@box.shutemov.name [akpm@linux-foundation.org: fix underlining in docs] Link: https://lore.kernel.org/oe-kbuild-all/202303191025.VRCTk6mP-lkp@intel.com/ Link: https://lkml.kernel.org/r/20230315113133.11326-11-kirill.shutemov@linux.intel.com Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Reviewed-by: Michael Ellerman <mpe@ellerman.id.au> [powerpc] Cc: "Kirill A. Shutemov" <kirill@shutemov.name> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
882 lines
20 KiB
C
882 lines
20 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Copyright (C) 2005,2006,2007,2008 IBM Corporation
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*
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* Authors:
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* Mimi Zohar <zohar@us.ibm.com>
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* Kylene Hall <kjhall@us.ibm.com>
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*
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* File: ima_crypto.c
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* Calculates md5/sha1 file hash, template hash, boot-aggreate hash
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*/
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#include <linux/kernel.h>
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#include <linux/moduleparam.h>
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#include <linux/ratelimit.h>
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#include <linux/file.h>
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#include <linux/crypto.h>
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#include <linux/scatterlist.h>
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#include <linux/err.h>
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#include <linux/slab.h>
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#include <crypto/hash.h>
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#include "ima.h"
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/* minimum file size for ahash use */
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static unsigned long ima_ahash_minsize;
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module_param_named(ahash_minsize, ima_ahash_minsize, ulong, 0644);
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MODULE_PARM_DESC(ahash_minsize, "Minimum file size for ahash use");
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/* default is 0 - 1 page. */
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static int ima_maxorder;
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static unsigned int ima_bufsize = PAGE_SIZE;
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static int param_set_bufsize(const char *val, const struct kernel_param *kp)
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{
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unsigned long long size;
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int order;
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size = memparse(val, NULL);
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order = get_order(size);
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if (order > MAX_ORDER)
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return -EINVAL;
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ima_maxorder = order;
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ima_bufsize = PAGE_SIZE << order;
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return 0;
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}
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static const struct kernel_param_ops param_ops_bufsize = {
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.set = param_set_bufsize,
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.get = param_get_uint,
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};
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#define param_check_bufsize(name, p) __param_check(name, p, unsigned int)
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module_param_named(ahash_bufsize, ima_bufsize, bufsize, 0644);
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MODULE_PARM_DESC(ahash_bufsize, "Maximum ahash buffer size");
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static struct crypto_shash *ima_shash_tfm;
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static struct crypto_ahash *ima_ahash_tfm;
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struct ima_algo_desc {
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struct crypto_shash *tfm;
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enum hash_algo algo;
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};
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int ima_sha1_idx __ro_after_init;
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int ima_hash_algo_idx __ro_after_init;
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/*
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* Additional number of slots reserved, as needed, for SHA1
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* and IMA default algo.
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*/
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int ima_extra_slots __ro_after_init;
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static struct ima_algo_desc *ima_algo_array;
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static int __init ima_init_ima_crypto(void)
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{
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long rc;
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ima_shash_tfm = crypto_alloc_shash(hash_algo_name[ima_hash_algo], 0, 0);
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if (IS_ERR(ima_shash_tfm)) {
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rc = PTR_ERR(ima_shash_tfm);
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pr_err("Can not allocate %s (reason: %ld)\n",
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hash_algo_name[ima_hash_algo], rc);
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return rc;
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}
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pr_info("Allocated hash algorithm: %s\n",
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hash_algo_name[ima_hash_algo]);
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return 0;
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}
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static struct crypto_shash *ima_alloc_tfm(enum hash_algo algo)
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{
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struct crypto_shash *tfm = ima_shash_tfm;
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int rc, i;
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if (algo < 0 || algo >= HASH_ALGO__LAST)
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algo = ima_hash_algo;
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if (algo == ima_hash_algo)
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return tfm;
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for (i = 0; i < NR_BANKS(ima_tpm_chip) + ima_extra_slots; i++)
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if (ima_algo_array[i].tfm && ima_algo_array[i].algo == algo)
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return ima_algo_array[i].tfm;
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tfm = crypto_alloc_shash(hash_algo_name[algo], 0, 0);
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if (IS_ERR(tfm)) {
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rc = PTR_ERR(tfm);
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pr_err("Can not allocate %s (reason: %d)\n",
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hash_algo_name[algo], rc);
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}
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return tfm;
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}
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int __init ima_init_crypto(void)
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{
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enum hash_algo algo;
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long rc;
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int i;
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rc = ima_init_ima_crypto();
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if (rc)
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return rc;
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ima_sha1_idx = -1;
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ima_hash_algo_idx = -1;
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for (i = 0; i < NR_BANKS(ima_tpm_chip); i++) {
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algo = ima_tpm_chip->allocated_banks[i].crypto_id;
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if (algo == HASH_ALGO_SHA1)
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ima_sha1_idx = i;
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if (algo == ima_hash_algo)
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ima_hash_algo_idx = i;
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}
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if (ima_sha1_idx < 0) {
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ima_sha1_idx = NR_BANKS(ima_tpm_chip) + ima_extra_slots++;
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if (ima_hash_algo == HASH_ALGO_SHA1)
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ima_hash_algo_idx = ima_sha1_idx;
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}
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if (ima_hash_algo_idx < 0)
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ima_hash_algo_idx = NR_BANKS(ima_tpm_chip) + ima_extra_slots++;
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ima_algo_array = kcalloc(NR_BANKS(ima_tpm_chip) + ima_extra_slots,
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sizeof(*ima_algo_array), GFP_KERNEL);
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if (!ima_algo_array) {
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rc = -ENOMEM;
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goto out;
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}
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for (i = 0; i < NR_BANKS(ima_tpm_chip); i++) {
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algo = ima_tpm_chip->allocated_banks[i].crypto_id;
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ima_algo_array[i].algo = algo;
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/* unknown TPM algorithm */
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if (algo == HASH_ALGO__LAST)
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continue;
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if (algo == ima_hash_algo) {
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ima_algo_array[i].tfm = ima_shash_tfm;
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continue;
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}
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ima_algo_array[i].tfm = ima_alloc_tfm(algo);
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if (IS_ERR(ima_algo_array[i].tfm)) {
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if (algo == HASH_ALGO_SHA1) {
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rc = PTR_ERR(ima_algo_array[i].tfm);
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ima_algo_array[i].tfm = NULL;
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goto out_array;
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}
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ima_algo_array[i].tfm = NULL;
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}
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}
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if (ima_sha1_idx >= NR_BANKS(ima_tpm_chip)) {
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if (ima_hash_algo == HASH_ALGO_SHA1) {
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ima_algo_array[ima_sha1_idx].tfm = ima_shash_tfm;
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} else {
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ima_algo_array[ima_sha1_idx].tfm =
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ima_alloc_tfm(HASH_ALGO_SHA1);
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if (IS_ERR(ima_algo_array[ima_sha1_idx].tfm)) {
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rc = PTR_ERR(ima_algo_array[ima_sha1_idx].tfm);
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goto out_array;
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}
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}
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ima_algo_array[ima_sha1_idx].algo = HASH_ALGO_SHA1;
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}
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if (ima_hash_algo_idx >= NR_BANKS(ima_tpm_chip) &&
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ima_hash_algo_idx != ima_sha1_idx) {
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ima_algo_array[ima_hash_algo_idx].tfm = ima_shash_tfm;
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ima_algo_array[ima_hash_algo_idx].algo = ima_hash_algo;
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}
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return 0;
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out_array:
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for (i = 0; i < NR_BANKS(ima_tpm_chip) + ima_extra_slots; i++) {
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if (!ima_algo_array[i].tfm ||
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ima_algo_array[i].tfm == ima_shash_tfm)
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continue;
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crypto_free_shash(ima_algo_array[i].tfm);
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}
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kfree(ima_algo_array);
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out:
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crypto_free_shash(ima_shash_tfm);
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return rc;
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}
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static void ima_free_tfm(struct crypto_shash *tfm)
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{
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int i;
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if (tfm == ima_shash_tfm)
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return;
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for (i = 0; i < NR_BANKS(ima_tpm_chip) + ima_extra_slots; i++)
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if (ima_algo_array[i].tfm == tfm)
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return;
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crypto_free_shash(tfm);
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}
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/**
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* ima_alloc_pages() - Allocate contiguous pages.
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* @max_size: Maximum amount of memory to allocate.
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* @allocated_size: Returned size of actual allocation.
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* @last_warn: Should the min_size allocation warn or not.
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*
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* Tries to do opportunistic allocation for memory first trying to allocate
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* max_size amount of memory and then splitting that until zero order is
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* reached. Allocation is tried without generating allocation warnings unless
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* last_warn is set. Last_warn set affects only last allocation of zero order.
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*
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* By default, ima_maxorder is 0 and it is equivalent to kmalloc(GFP_KERNEL)
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*
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* Return pointer to allocated memory, or NULL on failure.
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*/
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static void *ima_alloc_pages(loff_t max_size, size_t *allocated_size,
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int last_warn)
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{
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void *ptr;
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int order = ima_maxorder;
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gfp_t gfp_mask = __GFP_RECLAIM | __GFP_NOWARN | __GFP_NORETRY;
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if (order)
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order = min(get_order(max_size), order);
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for (; order; order--) {
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ptr = (void *)__get_free_pages(gfp_mask, order);
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if (ptr) {
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*allocated_size = PAGE_SIZE << order;
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return ptr;
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}
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}
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/* order is zero - one page */
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gfp_mask = GFP_KERNEL;
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if (!last_warn)
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gfp_mask |= __GFP_NOWARN;
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ptr = (void *)__get_free_pages(gfp_mask, 0);
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if (ptr) {
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*allocated_size = PAGE_SIZE;
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return ptr;
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}
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*allocated_size = 0;
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return NULL;
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}
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/**
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* ima_free_pages() - Free pages allocated by ima_alloc_pages().
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* @ptr: Pointer to allocated pages.
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* @size: Size of allocated buffer.
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*/
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static void ima_free_pages(void *ptr, size_t size)
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{
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if (!ptr)
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return;
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free_pages((unsigned long)ptr, get_order(size));
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}
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static struct crypto_ahash *ima_alloc_atfm(enum hash_algo algo)
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{
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struct crypto_ahash *tfm = ima_ahash_tfm;
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int rc;
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if (algo < 0 || algo >= HASH_ALGO__LAST)
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algo = ima_hash_algo;
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if (algo != ima_hash_algo || !tfm) {
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tfm = crypto_alloc_ahash(hash_algo_name[algo], 0, 0);
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if (!IS_ERR(tfm)) {
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if (algo == ima_hash_algo)
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ima_ahash_tfm = tfm;
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} else {
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rc = PTR_ERR(tfm);
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pr_err("Can not allocate %s (reason: %d)\n",
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hash_algo_name[algo], rc);
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}
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}
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return tfm;
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}
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static void ima_free_atfm(struct crypto_ahash *tfm)
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{
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if (tfm != ima_ahash_tfm)
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crypto_free_ahash(tfm);
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}
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static inline int ahash_wait(int err, struct crypto_wait *wait)
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{
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err = crypto_wait_req(err, wait);
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if (err)
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pr_crit_ratelimited("ahash calculation failed: err: %d\n", err);
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return err;
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}
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static int ima_calc_file_hash_atfm(struct file *file,
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struct ima_digest_data *hash,
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struct crypto_ahash *tfm)
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{
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loff_t i_size, offset;
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char *rbuf[2] = { NULL, };
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int rc, rbuf_len, active = 0, ahash_rc = 0;
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struct ahash_request *req;
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struct scatterlist sg[1];
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struct crypto_wait wait;
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size_t rbuf_size[2];
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hash->length = crypto_ahash_digestsize(tfm);
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req = ahash_request_alloc(tfm, GFP_KERNEL);
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if (!req)
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return -ENOMEM;
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crypto_init_wait(&wait);
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ahash_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG |
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CRYPTO_TFM_REQ_MAY_SLEEP,
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crypto_req_done, &wait);
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rc = ahash_wait(crypto_ahash_init(req), &wait);
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if (rc)
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goto out1;
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i_size = i_size_read(file_inode(file));
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if (i_size == 0)
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goto out2;
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/*
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* Try to allocate maximum size of memory.
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* Fail if even a single page cannot be allocated.
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*/
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rbuf[0] = ima_alloc_pages(i_size, &rbuf_size[0], 1);
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if (!rbuf[0]) {
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rc = -ENOMEM;
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goto out1;
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}
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/* Only allocate one buffer if that is enough. */
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if (i_size > rbuf_size[0]) {
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/*
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* Try to allocate secondary buffer. If that fails fallback to
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* using single buffering. Use previous memory allocation size
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* as baseline for possible allocation size.
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*/
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rbuf[1] = ima_alloc_pages(i_size - rbuf_size[0],
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&rbuf_size[1], 0);
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}
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for (offset = 0; offset < i_size; offset += rbuf_len) {
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if (!rbuf[1] && offset) {
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/* Not using two buffers, and it is not the first
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* read/request, wait for the completion of the
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* previous ahash_update() request.
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*/
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rc = ahash_wait(ahash_rc, &wait);
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if (rc)
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goto out3;
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}
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/* read buffer */
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rbuf_len = min_t(loff_t, i_size - offset, rbuf_size[active]);
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rc = integrity_kernel_read(file, offset, rbuf[active],
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rbuf_len);
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if (rc != rbuf_len) {
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if (rc >= 0)
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rc = -EINVAL;
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/*
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* Forward current rc, do not overwrite with return value
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* from ahash_wait()
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*/
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ahash_wait(ahash_rc, &wait);
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goto out3;
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}
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if (rbuf[1] && offset) {
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/* Using two buffers, and it is not the first
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* read/request, wait for the completion of the
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* previous ahash_update() request.
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*/
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rc = ahash_wait(ahash_rc, &wait);
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if (rc)
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goto out3;
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}
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sg_init_one(&sg[0], rbuf[active], rbuf_len);
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ahash_request_set_crypt(req, sg, NULL, rbuf_len);
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ahash_rc = crypto_ahash_update(req);
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if (rbuf[1])
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active = !active; /* swap buffers, if we use two */
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}
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/* wait for the last update request to complete */
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rc = ahash_wait(ahash_rc, &wait);
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out3:
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ima_free_pages(rbuf[0], rbuf_size[0]);
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ima_free_pages(rbuf[1], rbuf_size[1]);
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out2:
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if (!rc) {
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ahash_request_set_crypt(req, NULL, hash->digest, 0);
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rc = ahash_wait(crypto_ahash_final(req), &wait);
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}
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out1:
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ahash_request_free(req);
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return rc;
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}
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static int ima_calc_file_ahash(struct file *file, struct ima_digest_data *hash)
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{
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struct crypto_ahash *tfm;
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int rc;
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tfm = ima_alloc_atfm(hash->algo);
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if (IS_ERR(tfm))
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return PTR_ERR(tfm);
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rc = ima_calc_file_hash_atfm(file, hash, tfm);
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ima_free_atfm(tfm);
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return rc;
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}
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static int ima_calc_file_hash_tfm(struct file *file,
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struct ima_digest_data *hash,
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struct crypto_shash *tfm)
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{
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loff_t i_size, offset = 0;
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char *rbuf;
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int rc;
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SHASH_DESC_ON_STACK(shash, tfm);
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shash->tfm = tfm;
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hash->length = crypto_shash_digestsize(tfm);
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rc = crypto_shash_init(shash);
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if (rc != 0)
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return rc;
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i_size = i_size_read(file_inode(file));
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if (i_size == 0)
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goto out;
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|
|
rbuf = kzalloc(PAGE_SIZE, GFP_KERNEL);
|
|
if (!rbuf)
|
|
return -ENOMEM;
|
|
|
|
while (offset < i_size) {
|
|
int rbuf_len;
|
|
|
|
rbuf_len = integrity_kernel_read(file, offset, rbuf, PAGE_SIZE);
|
|
if (rbuf_len < 0) {
|
|
rc = rbuf_len;
|
|
break;
|
|
}
|
|
if (rbuf_len == 0) { /* unexpected EOF */
|
|
rc = -EINVAL;
|
|
break;
|
|
}
|
|
offset += rbuf_len;
|
|
|
|
rc = crypto_shash_update(shash, rbuf, rbuf_len);
|
|
if (rc)
|
|
break;
|
|
}
|
|
kfree(rbuf);
|
|
out:
|
|
if (!rc)
|
|
rc = crypto_shash_final(shash, hash->digest);
|
|
return rc;
|
|
}
|
|
|
|
static int ima_calc_file_shash(struct file *file, struct ima_digest_data *hash)
|
|
{
|
|
struct crypto_shash *tfm;
|
|
int rc;
|
|
|
|
tfm = ima_alloc_tfm(hash->algo);
|
|
if (IS_ERR(tfm))
|
|
return PTR_ERR(tfm);
|
|
|
|
rc = ima_calc_file_hash_tfm(file, hash, tfm);
|
|
|
|
ima_free_tfm(tfm);
|
|
|
|
return rc;
|
|
}
|
|
|
|
/*
|
|
* ima_calc_file_hash - calculate file hash
|
|
*
|
|
* Asynchronous hash (ahash) allows using HW acceleration for calculating
|
|
* a hash. ahash performance varies for different data sizes on different
|
|
* crypto accelerators. shash performance might be better for smaller files.
|
|
* The 'ima.ahash_minsize' module parameter allows specifying the best
|
|
* minimum file size for using ahash on the system.
|
|
*
|
|
* If the ima.ahash_minsize parameter is not specified, this function uses
|
|
* shash for the hash calculation. If ahash fails, it falls back to using
|
|
* shash.
|
|
*/
|
|
int ima_calc_file_hash(struct file *file, struct ima_digest_data *hash)
|
|
{
|
|
loff_t i_size;
|
|
int rc;
|
|
struct file *f = file;
|
|
bool new_file_instance = false;
|
|
|
|
/*
|
|
* For consistency, fail file's opened with the O_DIRECT flag on
|
|
* filesystems mounted with/without DAX option.
|
|
*/
|
|
if (file->f_flags & O_DIRECT) {
|
|
hash->length = hash_digest_size[ima_hash_algo];
|
|
hash->algo = ima_hash_algo;
|
|
return -EINVAL;
|
|
}
|
|
|
|
/* Open a new file instance in O_RDONLY if we cannot read */
|
|
if (!(file->f_mode & FMODE_READ)) {
|
|
int flags = file->f_flags & ~(O_WRONLY | O_APPEND |
|
|
O_TRUNC | O_CREAT | O_NOCTTY | O_EXCL);
|
|
flags |= O_RDONLY;
|
|
f = dentry_open(&file->f_path, flags, file->f_cred);
|
|
if (IS_ERR(f))
|
|
return PTR_ERR(f);
|
|
|
|
new_file_instance = true;
|
|
}
|
|
|
|
i_size = i_size_read(file_inode(f));
|
|
|
|
if (ima_ahash_minsize && i_size >= ima_ahash_minsize) {
|
|
rc = ima_calc_file_ahash(f, hash);
|
|
if (!rc)
|
|
goto out;
|
|
}
|
|
|
|
rc = ima_calc_file_shash(f, hash);
|
|
out:
|
|
if (new_file_instance)
|
|
fput(f);
|
|
return rc;
|
|
}
|
|
|
|
/*
|
|
* Calculate the hash of template data
|
|
*/
|
|
static int ima_calc_field_array_hash_tfm(struct ima_field_data *field_data,
|
|
struct ima_template_entry *entry,
|
|
int tfm_idx)
|
|
{
|
|
SHASH_DESC_ON_STACK(shash, ima_algo_array[tfm_idx].tfm);
|
|
struct ima_template_desc *td = entry->template_desc;
|
|
int num_fields = entry->template_desc->num_fields;
|
|
int rc, i;
|
|
|
|
shash->tfm = ima_algo_array[tfm_idx].tfm;
|
|
|
|
rc = crypto_shash_init(shash);
|
|
if (rc != 0)
|
|
return rc;
|
|
|
|
for (i = 0; i < num_fields; i++) {
|
|
u8 buffer[IMA_EVENT_NAME_LEN_MAX + 1] = { 0 };
|
|
u8 *data_to_hash = field_data[i].data;
|
|
u32 datalen = field_data[i].len;
|
|
u32 datalen_to_hash = !ima_canonical_fmt ?
|
|
datalen : (__force u32)cpu_to_le32(datalen);
|
|
|
|
if (strcmp(td->name, IMA_TEMPLATE_IMA_NAME) != 0) {
|
|
rc = crypto_shash_update(shash,
|
|
(const u8 *) &datalen_to_hash,
|
|
sizeof(datalen_to_hash));
|
|
if (rc)
|
|
break;
|
|
} else if (strcmp(td->fields[i]->field_id, "n") == 0) {
|
|
memcpy(buffer, data_to_hash, datalen);
|
|
data_to_hash = buffer;
|
|
datalen = IMA_EVENT_NAME_LEN_MAX + 1;
|
|
}
|
|
rc = crypto_shash_update(shash, data_to_hash, datalen);
|
|
if (rc)
|
|
break;
|
|
}
|
|
|
|
if (!rc)
|
|
rc = crypto_shash_final(shash, entry->digests[tfm_idx].digest);
|
|
|
|
return rc;
|
|
}
|
|
|
|
int ima_calc_field_array_hash(struct ima_field_data *field_data,
|
|
struct ima_template_entry *entry)
|
|
{
|
|
u16 alg_id;
|
|
int rc, i;
|
|
|
|
rc = ima_calc_field_array_hash_tfm(field_data, entry, ima_sha1_idx);
|
|
if (rc)
|
|
return rc;
|
|
|
|
entry->digests[ima_sha1_idx].alg_id = TPM_ALG_SHA1;
|
|
|
|
for (i = 0; i < NR_BANKS(ima_tpm_chip) + ima_extra_slots; i++) {
|
|
if (i == ima_sha1_idx)
|
|
continue;
|
|
|
|
if (i < NR_BANKS(ima_tpm_chip)) {
|
|
alg_id = ima_tpm_chip->allocated_banks[i].alg_id;
|
|
entry->digests[i].alg_id = alg_id;
|
|
}
|
|
|
|
/* for unmapped TPM algorithms digest is still a padded SHA1 */
|
|
if (!ima_algo_array[i].tfm) {
|
|
memcpy(entry->digests[i].digest,
|
|
entry->digests[ima_sha1_idx].digest,
|
|
TPM_DIGEST_SIZE);
|
|
continue;
|
|
}
|
|
|
|
rc = ima_calc_field_array_hash_tfm(field_data, entry, i);
|
|
if (rc)
|
|
return rc;
|
|
}
|
|
return rc;
|
|
}
|
|
|
|
static int calc_buffer_ahash_atfm(const void *buf, loff_t len,
|
|
struct ima_digest_data *hash,
|
|
struct crypto_ahash *tfm)
|
|
{
|
|
struct ahash_request *req;
|
|
struct scatterlist sg;
|
|
struct crypto_wait wait;
|
|
int rc, ahash_rc = 0;
|
|
|
|
hash->length = crypto_ahash_digestsize(tfm);
|
|
|
|
req = ahash_request_alloc(tfm, GFP_KERNEL);
|
|
if (!req)
|
|
return -ENOMEM;
|
|
|
|
crypto_init_wait(&wait);
|
|
ahash_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG |
|
|
CRYPTO_TFM_REQ_MAY_SLEEP,
|
|
crypto_req_done, &wait);
|
|
|
|
rc = ahash_wait(crypto_ahash_init(req), &wait);
|
|
if (rc)
|
|
goto out;
|
|
|
|
sg_init_one(&sg, buf, len);
|
|
ahash_request_set_crypt(req, &sg, NULL, len);
|
|
|
|
ahash_rc = crypto_ahash_update(req);
|
|
|
|
/* wait for the update request to complete */
|
|
rc = ahash_wait(ahash_rc, &wait);
|
|
if (!rc) {
|
|
ahash_request_set_crypt(req, NULL, hash->digest, 0);
|
|
rc = ahash_wait(crypto_ahash_final(req), &wait);
|
|
}
|
|
out:
|
|
ahash_request_free(req);
|
|
return rc;
|
|
}
|
|
|
|
static int calc_buffer_ahash(const void *buf, loff_t len,
|
|
struct ima_digest_data *hash)
|
|
{
|
|
struct crypto_ahash *tfm;
|
|
int rc;
|
|
|
|
tfm = ima_alloc_atfm(hash->algo);
|
|
if (IS_ERR(tfm))
|
|
return PTR_ERR(tfm);
|
|
|
|
rc = calc_buffer_ahash_atfm(buf, len, hash, tfm);
|
|
|
|
ima_free_atfm(tfm);
|
|
|
|
return rc;
|
|
}
|
|
|
|
static int calc_buffer_shash_tfm(const void *buf, loff_t size,
|
|
struct ima_digest_data *hash,
|
|
struct crypto_shash *tfm)
|
|
{
|
|
SHASH_DESC_ON_STACK(shash, tfm);
|
|
unsigned int len;
|
|
int rc;
|
|
|
|
shash->tfm = tfm;
|
|
|
|
hash->length = crypto_shash_digestsize(tfm);
|
|
|
|
rc = crypto_shash_init(shash);
|
|
if (rc != 0)
|
|
return rc;
|
|
|
|
while (size) {
|
|
len = size < PAGE_SIZE ? size : PAGE_SIZE;
|
|
rc = crypto_shash_update(shash, buf, len);
|
|
if (rc)
|
|
break;
|
|
buf += len;
|
|
size -= len;
|
|
}
|
|
|
|
if (!rc)
|
|
rc = crypto_shash_final(shash, hash->digest);
|
|
return rc;
|
|
}
|
|
|
|
static int calc_buffer_shash(const void *buf, loff_t len,
|
|
struct ima_digest_data *hash)
|
|
{
|
|
struct crypto_shash *tfm;
|
|
int rc;
|
|
|
|
tfm = ima_alloc_tfm(hash->algo);
|
|
if (IS_ERR(tfm))
|
|
return PTR_ERR(tfm);
|
|
|
|
rc = calc_buffer_shash_tfm(buf, len, hash, tfm);
|
|
|
|
ima_free_tfm(tfm);
|
|
return rc;
|
|
}
|
|
|
|
int ima_calc_buffer_hash(const void *buf, loff_t len,
|
|
struct ima_digest_data *hash)
|
|
{
|
|
int rc;
|
|
|
|
if (ima_ahash_minsize && len >= ima_ahash_minsize) {
|
|
rc = calc_buffer_ahash(buf, len, hash);
|
|
if (!rc)
|
|
return 0;
|
|
}
|
|
|
|
return calc_buffer_shash(buf, len, hash);
|
|
}
|
|
|
|
static void ima_pcrread(u32 idx, struct tpm_digest *d)
|
|
{
|
|
if (!ima_tpm_chip)
|
|
return;
|
|
|
|
if (tpm_pcr_read(ima_tpm_chip, idx, d) != 0)
|
|
pr_err("Error Communicating to TPM chip\n");
|
|
}
|
|
|
|
/*
|
|
* The boot_aggregate is a cumulative hash over TPM registers 0 - 7. With
|
|
* TPM 1.2 the boot_aggregate was based on reading the SHA1 PCRs, but with
|
|
* TPM 2.0 hash agility, TPM chips could support multiple TPM PCR banks,
|
|
* allowing firmware to configure and enable different banks.
|
|
*
|
|
* Knowing which TPM bank is read to calculate the boot_aggregate digest
|
|
* needs to be conveyed to a verifier. For this reason, use the same
|
|
* hash algorithm for reading the TPM PCRs as for calculating the boot
|
|
* aggregate digest as stored in the measurement list.
|
|
*/
|
|
static int ima_calc_boot_aggregate_tfm(char *digest, u16 alg_id,
|
|
struct crypto_shash *tfm)
|
|
{
|
|
struct tpm_digest d = { .alg_id = alg_id, .digest = {0} };
|
|
int rc;
|
|
u32 i;
|
|
SHASH_DESC_ON_STACK(shash, tfm);
|
|
|
|
shash->tfm = tfm;
|
|
|
|
pr_devel("calculating the boot-aggregate based on TPM bank: %04x\n",
|
|
d.alg_id);
|
|
|
|
rc = crypto_shash_init(shash);
|
|
if (rc != 0)
|
|
return rc;
|
|
|
|
/* cumulative digest over TPM registers 0-7 */
|
|
for (i = TPM_PCR0; i < TPM_PCR8; i++) {
|
|
ima_pcrread(i, &d);
|
|
/* now accumulate with current aggregate */
|
|
rc = crypto_shash_update(shash, d.digest,
|
|
crypto_shash_digestsize(tfm));
|
|
if (rc != 0)
|
|
return rc;
|
|
}
|
|
/*
|
|
* Extend cumulative digest over TPM registers 8-9, which contain
|
|
* measurement for the kernel command line (reg. 8) and image (reg. 9)
|
|
* in a typical PCR allocation. Registers 8-9 are only included in
|
|
* non-SHA1 boot_aggregate digests to avoid ambiguity.
|
|
*/
|
|
if (alg_id != TPM_ALG_SHA1) {
|
|
for (i = TPM_PCR8; i < TPM_PCR10; i++) {
|
|
ima_pcrread(i, &d);
|
|
rc = crypto_shash_update(shash, d.digest,
|
|
crypto_shash_digestsize(tfm));
|
|
}
|
|
}
|
|
if (!rc)
|
|
crypto_shash_final(shash, digest);
|
|
return rc;
|
|
}
|
|
|
|
int ima_calc_boot_aggregate(struct ima_digest_data *hash)
|
|
{
|
|
struct crypto_shash *tfm;
|
|
u16 crypto_id, alg_id;
|
|
int rc, i, bank_idx = -1;
|
|
|
|
for (i = 0; i < ima_tpm_chip->nr_allocated_banks; i++) {
|
|
crypto_id = ima_tpm_chip->allocated_banks[i].crypto_id;
|
|
if (crypto_id == hash->algo) {
|
|
bank_idx = i;
|
|
break;
|
|
}
|
|
|
|
if (crypto_id == HASH_ALGO_SHA256)
|
|
bank_idx = i;
|
|
|
|
if (bank_idx == -1 && crypto_id == HASH_ALGO_SHA1)
|
|
bank_idx = i;
|
|
}
|
|
|
|
if (bank_idx == -1) {
|
|
pr_err("No suitable TPM algorithm for boot aggregate\n");
|
|
return 0;
|
|
}
|
|
|
|
hash->algo = ima_tpm_chip->allocated_banks[bank_idx].crypto_id;
|
|
|
|
tfm = ima_alloc_tfm(hash->algo);
|
|
if (IS_ERR(tfm))
|
|
return PTR_ERR(tfm);
|
|
|
|
hash->length = crypto_shash_digestsize(tfm);
|
|
alg_id = ima_tpm_chip->allocated_banks[bank_idx].alg_id;
|
|
rc = ima_calc_boot_aggregate_tfm(hash->digest, alg_id, tfm);
|
|
|
|
ima_free_tfm(tfm);
|
|
|
|
return rc;
|
|
}
|