[linux-block.git] / security / integrity / ima / ima_crypto.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) 2005,2006,2007,2008 IBM Corporation
 *
 * Authors:
 * Mimi Zohar <zohar@us.ibm.com>
 * Kylene Hall <kjhall@us.ibm.com>
 *
 * File: ima_crypto.c
 *	Calculates md5/sha1 file hash, template hash, boot-aggreate hash
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/kernel.h>
#include <linux/moduleparam.h>
#include <linux/ratelimit.h>
#include <linux/file.h>
#include <linux/crypto.h>
#include <linux/scatterlist.h>
#include <linux/err.h>
#include <linux/slab.h>
#include <crypto/hash.h>

#include "ima.h"

/* minimum file size for ahash use */
static unsigned long ima_ahash_minsize;
module_param_named(ahash_minsize, ima_ahash_minsize, ulong, 0644);
MODULE_PARM_DESC(ahash_minsize, "Minimum file size for ahash use");

/* default is 0 - 1 page. */
static int ima_maxorder;
static unsigned int ima_bufsize = PAGE_SIZE;

static int param_set_bufsize(const char *val, const struct kernel_param *kp)
{
	unsigned long long size;
	int order;

	size = memparse(val, NULL);
	order = get_order(size);
	if (order >= MAX_ORDER)
		return -EINVAL;
	ima_maxorder = order;
	ima_bufsize = PAGE_SIZE << order;
	return 0;
}

static const struct kernel_param_ops param_ops_bufsize = {
	.set = param_set_bufsize,
	.get = param_get_uint,
};
#define param_check_bufsize(name, p) __param_check(name, p, unsigned int)

module_param_named(ahash_bufsize, ima_bufsize, bufsize, 0644);
MODULE_PARM_DESC(ahash_bufsize, "Maximum ahash buffer size");

static struct crypto_shash *ima_shash_tfm;
static struct crypto_ahash *ima_ahash_tfm;

int __init ima_init_crypto(void)
{
	long rc;

	ima_shash_tfm = crypto_alloc_shash(hash_algo_name[ima_hash_algo], 0, 0);
	if (IS_ERR(ima_shash_tfm)) {
		rc = PTR_ERR(ima_shash_tfm);
		pr_err("Can not allocate %s (reason: %ld)\n",
		       hash_algo_name[ima_hash_algo], rc);
		return rc;
	}
	pr_info("Allocated hash algorithm: %s\n",
		hash_algo_name[ima_hash_algo]);
	return 0;
}

static struct crypto_shash *ima_alloc_tfm(enum hash_algo algo)
{
	struct crypto_shash *tfm = ima_shash_tfm;
	int rc;

	if (algo < 0 || algo >= HASH_ALGO__LAST)
		algo = ima_hash_algo;

	if (algo != ima_hash_algo) {
		tfm = crypto_alloc_shash(hash_algo_name[algo], 0, 0);
		if (IS_ERR(tfm)) {
			rc = PTR_ERR(tfm);
			pr_err("Can not allocate %s (reason: %d)\n",
			       hash_algo_name[algo], rc);
		}
	}
	return tfm;
}

static void ima_free_tfm(struct crypto_shash *tfm)
{
	if (tfm != ima_shash_tfm)
		crypto_free_shash(tfm);
}

/**
 * ima_alloc_pages() - Allocate contiguous pages.
 * @max_size:       Maximum amount of memory to allocate.
 * @allocated_size: Returned size of actual allocation.
 * @last_warn:      Should the min_size allocation warn or not.
 *
 * Tries to do opportunistic allocation for memory first trying to allocate
 * max_size amount of memory and then splitting that until zero order is
 * reached. Allocation is tried without generating allocation warnings unless
 * last_warn is set. Last_warn set affects only last allocation of zero order.
 *
 * By default, ima_maxorder is 0 and it is equivalent to kmalloc(GFP_KERNEL)
 *
 * Return pointer to allocated memory, or NULL on failure.
 */
static void *ima_alloc_pages(loff_t max_size, size_t *allocated_size,
			     int last_warn)
{
	void *ptr;
	int order = ima_maxorder;
	gfp_t gfp_mask = __GFP_RECLAIM | __GFP_NOWARN | __GFP_NORETRY;

	if (order)
		order = min(get_order(max_size), order);

	for (; order; order--) {
		ptr = (void *)__get_free_pages(gfp_mask, order);
		if (ptr) {
			*allocated_size = PAGE_SIZE << order;
			return ptr;
		}
	}

	/* order is zero - one page */

	gfp_mask = GFP_KERNEL;

	if (!last_warn)
		gfp_mask |= __GFP_NOWARN;

	ptr = (void *)__get_free_pages(gfp_mask, 0);
	if (ptr) {
		*allocated_size = PAGE_SIZE;
		return ptr;
	}

	*allocated_size = 0;
	return NULL;
}

/**
 * ima_free_pages() - Free pages allocated by ima_alloc_pages().
 * @ptr:  Pointer to allocated pages.
 * @size: Size of allocated buffer.
 */
static void ima_free_pages(void *ptr, size_t size)
{
	if (!ptr)
		return;
	free_pages((unsigned long)ptr, get_order(size));
}

static struct crypto_ahash *ima_alloc_atfm(enum hash_algo algo)
{
	struct crypto_ahash *tfm = ima_ahash_tfm;
	int rc;

	if (algo < 0 || algo >= HASH_ALGO__LAST)
		algo = ima_hash_algo;

	if (algo != ima_hash_algo || !tfm) {
		tfm = crypto_alloc_ahash(hash_algo_name[algo], 0, 0);
		if (!IS_ERR(tfm)) {
			if (algo == ima_hash_algo)
				ima_ahash_tfm = tfm;
		} else {
			rc = PTR_ERR(tfm);
			pr_err("Can not allocate %s (reason: %d)\n",
			       hash_algo_name[algo], rc);
		}
	}
	return tfm;
}

static void ima_free_atfm(struct crypto_ahash *tfm)
{
	if (tfm != ima_ahash_tfm)
		crypto_free_ahash(tfm);
}

static inline int ahash_wait(int err, struct crypto_wait *wait)
{

	err = crypto_wait_req(err, wait);

	if (err)
		pr_crit_ratelimited("ahash calculation failed: err: %d\n", err);

	return err;
}

static int ima_calc_file_hash_atfm(struct file *file,
				   struct ima_digest_data *hash,
				   struct crypto_ahash *tfm)
{
	loff_t i_size, offset;
	char *rbuf[2] = { NULL, };
	int rc, rbuf_len, active = 0, ahash_rc = 0;
	struct ahash_request *req;
	struct scatterlist sg[1];
	struct crypto_wait wait;
	size_t rbuf_size[2];

	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 out1;

	i_size = i_size_read(file_inode(file));

	if (i_size == 0)
		goto out2;

	/*
	 * Try to allocate maximum size of memory.
	 * Fail if even a single page cannot be allocated.
	 */
	rbuf[0] = ima_alloc_pages(i_size, &rbuf_size[0], 1);
	if (!rbuf[0]) {
		rc = -ENOMEM;
		goto out1;
	}

	/* Only allocate one buffer if that is enough. */
	if (i_size > rbuf_size[0]) {
		/*
		 * Try to allocate secondary buffer. If that fails fallback to
		 * using single buffering. Use previous memory allocation size
		 * as baseline for possible allocation size.
		 */
		rbuf[1] = ima_alloc_pages(i_size - rbuf_size[0],
					  &rbuf_size[1], 0);
	}

	for (offset = 0; offset < i_size; offset += rbuf_len) {
		if (!rbuf[1] && offset) {
			/* Not using two buffers, and it is not the first
			 * read/request, wait for the completion of the
			 * previous ahash_update() request.
			 */
			rc = ahash_wait(ahash_rc, &wait);
			if (rc)
				goto out3;
		}
		/* read buffer */
		rbuf_len = min_t(loff_t, i_size - offset, rbuf_size[active]);
		rc = integrity_kernel_read(file, offset, rbuf[active],
					   rbuf_len);
		if (rc != rbuf_len)
			goto out3;

		if (rbuf[1] && offset) {
			/* Using two buffers, and it is not the first
			 * read/request, wait for the completion of the
			 * previous ahash_update() request.
			 */
			rc = ahash_wait(ahash_rc, &wait);
			if (rc)
				goto out3;
		}

		sg_init_one(&sg[0], rbuf[active], rbuf_len);
		ahash_request_set_crypt(req, sg, NULL, rbuf_len);

		ahash_rc = crypto_ahash_update(req);

		if (rbuf[1])
			active = !active; /* swap buffers, if we use two */
	}
	/* wait for the last update request to complete */
	rc = ahash_wait(ahash_rc, &wait);
out3:
	ima_free_pages(rbuf[0], rbuf_size[0]);
	ima_free_pages(rbuf[1], rbuf_size[1]);
out2:
	if (!rc) {
		ahash_request_set_crypt(req, NULL, hash->digest, 0);
		rc = ahash_wait(crypto_ahash_final(req), &wait);
	}
out1:
	ahash_request_free(req);
	return rc;
}

static int ima_calc_file_ahash(struct file *file, 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 = ima_calc_file_hash_atfm(file, hash, tfm);

	ima_free_atfm(tfm);

	return rc;
}

static int ima_calc_file_hash_tfm(struct file *file,
				  struct ima_digest_data *hash,
				  struct crypto_shash *tfm)
{
	loff_t i_size, offset = 0;
	char *rbuf;
	int rc;
	SHASH_DESC_ON_STACK(shash, tfm);

	shash->tfm = tfm;

	hash->length = crypto_shash_digestsize(tfm);

	rc = crypto_shash_init(shash);
	if (rc != 0)
		return rc;

	i_size = i_size_read(file_inode(file));

	if (i_size == 0)
		goto out;

	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)
			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, modified_flags = 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)) {
			/*
			 * Cannot open the file again, lets modify f_flags
			 * of original and continue
			 */
			pr_info_ratelimited("Unable to reopen file for reading.\n");
			f = file;
			f->f_flags |= FMODE_READ;
			modified_flags = true;
		} else {
			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);
	else if (modified_flags)
		f->f_flags &= ~FMODE_READ;
	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_desc *td,
					 int num_fields,
					 struct ima_digest_data *hash,
					 struct crypto_shash *tfm)
{
	SHASH_DESC_ON_STACK(shash, tfm);
	int rc, i;

	shash->tfm = tfm;

	hash->length = crypto_shash_digestsize(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 : 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, hash->digest);

	return rc;
}

int ima_calc_field_array_hash(struct ima_field_data *field_data,
			      struct ima_template_desc *desc, int num_fields,
			      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_field_array_hash_tfm(field_data, desc, num_fields,
					   hash, tfm);

	ima_free_tfm(tfm);

	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 __init 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");
}

/*
 * Calculate the boot aggregate hash
 */
static int __init ima_calc_boot_aggregate_tfm(char *digest,
					      struct crypto_shash *tfm)
{
	struct tpm_digest d = { .alg_id = TPM_ALG_SHA1, .digest = {0} };
	int rc;
	u32 i;
	SHASH_DESC_ON_STACK(shash, tfm);

	shash->tfm = tfm;

	rc = crypto_shash_init(shash);
	if (rc != 0)
		return rc;

	/* cumulative sha1 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, TPM_DIGEST_SIZE);
	}
	if (!rc)
		crypto_shash_final(shash, digest);
	return rc;
}

int __init ima_calc_boot_aggregate(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);

	hash->length = crypto_shash_digestsize(tfm);
	rc = ima_calc_boot_aggregate_tfm(hash->digest, tfm);

	ima_free_tfm(tfm);

	return rc;
}
Commit	Line	Data
b886d83c	1	// SPDX-License-Identifier: GPL-2.0-only
3323eec9 MZ	2	/*
	3	* Copyright (C) 2005,2006,2007,2008 IBM Corporation
	4	*
	5	* Authors:
	6	* Mimi Zohar <zohar@us.ibm.com>
	7	* Kylene Hall <kjhall@us.ibm.com>
	8	*
3323eec9	9	* File: ima_crypto.c
2bb930ab	10	* Calculates md5/sha1 file hash, template hash, boot-aggreate hash
3323eec9 MZ	11	*/
3323eec9 MZ	12
20ee451f JP	13	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
20ee451f JP	14
3323eec9	15	#include <linux/kernel.h>
3bcced39 DK	16	#include <linux/moduleparam.h>
3bcced39 DK	17	#include <linux/ratelimit.h>
3323eec9 MZ	18	#include <linux/file.h>
	19	#include <linux/crypto.h>
	20	#include <linux/scatterlist.h>
	21	#include <linux/err.h>
5a0e3ad6	22	#include <linux/slab.h>
76bb28f6	23	#include <crypto/hash.h>
1525b06d	24
3323eec9 MZ	25	#include "ima.h"
3323eec9 MZ	26
3bcced39 DK	27	/* minimum file size for ahash use */
	28	static unsigned long ima_ahash_minsize;
	29	module_param_named(ahash_minsize, ima_ahash_minsize, ulong, 0644);
	30	MODULE_PARM_DESC(ahash_minsize, "Minimum file size for ahash use");
	31
6edf7a89 DK	32	/* default is 0 - 1 page. */
	33	static int ima_maxorder;
	34	static unsigned int ima_bufsize = PAGE_SIZE;
	35
	36	static int param_set_bufsize(const char val, const struct kernel_param kp)
	37	{
	38	unsigned long long size;
	39	int order;
	40
	41	size = memparse(val, NULL);
	42	order = get_order(size);
	43	if (order >= MAX_ORDER)
	44	return -EINVAL;
	45	ima_maxorder = order;
	46	ima_bufsize = PAGE_SIZE << order;
	47	return 0;
	48	}
	49
9c27847d	50	static const struct kernel_param_ops param_ops_bufsize = {
6edf7a89 DK	51	.set = param_set_bufsize,
	52	.get = param_get_uint,
	53	};
	54	#define param_check_bufsize(name, p) __param_check(name, p, unsigned int)
	55
	56	module_param_named(ahash_bufsize, ima_bufsize, bufsize, 0644);
	57	MODULE_PARM_DESC(ahash_bufsize, "Maximum ahash buffer size");
	58
76bb28f6	59	static struct crypto_shash *ima_shash_tfm;
3bcced39	60	static struct crypto_ahash *ima_ahash_tfm;
76bb28f6	61
e4a9c519	62	int __init ima_init_crypto(void)
3323eec9	63	{
76bb28f6	64	long rc;
3323eec9	65
c7c8bb23	66	ima_shash_tfm = crypto_alloc_shash(hash_algo_name[ima_hash_algo], 0, 0);
76bb28f6 DK	67	if (IS_ERR(ima_shash_tfm)) {
76bb28f6 DK	68	rc = PTR_ERR(ima_shash_tfm);
c7c8bb23 DK	69	pr_err("Can not allocate %s (reason: %ld)\n",
c7c8bb23 DK	70	hash_algo_name[ima_hash_algo], rc);
3323eec9 MZ	71	return rc;
3323eec9 MZ	72	}
ab60368a PV	73	pr_info("Allocated hash algorithm: %s\n",
ab60368a PV	74	hash_algo_name[ima_hash_algo]);
76bb28f6	75	return 0;
3323eec9 MZ	76	}
3323eec9 MZ	77
723326b9 DK	78	static struct crypto_shash *ima_alloc_tfm(enum hash_algo algo)
	79	{
	80	struct crypto_shash *tfm = ima_shash_tfm;
	81	int rc;
	82
23c19e2c DK	83	if (algo < 0 \|\| algo >= HASH_ALGO__LAST)
	84	algo = ima_hash_algo;
	85
	86	if (algo != ima_hash_algo) {
723326b9 DK	87	tfm = crypto_alloc_shash(hash_algo_name[algo], 0, 0);
	88	if (IS_ERR(tfm)) {
	89	rc = PTR_ERR(tfm);
	90	pr_err("Can not allocate %s (reason: %d)\n",
	91	hash_algo_name[algo], rc);
	92	}
	93	}
	94	return tfm;
	95	}
	96
	97	static void ima_free_tfm(struct crypto_shash *tfm)
	98	{
	99	if (tfm != ima_shash_tfm)
	100	crypto_free_shash(tfm);
	101	}
	102
6edf7a89 DK	103	/**
	104	* ima_alloc_pages() - Allocate contiguous pages.
	105	* @max_size: Maximum amount of memory to allocate.
	106	* @allocated_size: Returned size of actual allocation.
	107	* @last_warn: Should the min_size allocation warn or not.
	108	*
	109	* Tries to do opportunistic allocation for memory first trying to allocate
	110	* max_size amount of memory and then splitting that until zero order is
	111	* reached. Allocation is tried without generating allocation warnings unless
	112	* last_warn is set. Last_warn set affects only last allocation of zero order.
	113	*
	114	* By default, ima_maxorder is 0 and it is equivalent to kmalloc(GFP_KERNEL)
	115	*
	116	* Return pointer to allocated memory, or NULL on failure.
	117	*/
	118	static void ima_alloc_pages(loff_t max_size, size_t allocated_size,
	119	int last_warn)
	120	{
	121	void *ptr;
	122	int order = ima_maxorder;
71baba4b	123	gfp_t gfp_mask = __GFP_RECLAIM \| __GFP_NOWARN \| __GFP_NORETRY;
6edf7a89 DK	124
	125	if (order)
	126	order = min(get_order(max_size), order);
	127
	128	for (; order; order--) {
	129	ptr = (void *)__get_free_pages(gfp_mask, order);
	130	if (ptr) {
	131	*allocated_size = PAGE_SIZE << order;
	132	return ptr;
	133	}
	134	}
	135
	136	/* order is zero - one page */
	137
	138	gfp_mask = GFP_KERNEL;
	139
	140	if (!last_warn)
	141	gfp_mask \|= __GFP_NOWARN;
	142
	143	ptr = (void *)__get_free_pages(gfp_mask, 0);
	144	if (ptr) {
	145	*allocated_size = PAGE_SIZE;
	146	return ptr;
	147	}
	148
	149	*allocated_size = 0;
	150	return NULL;
	151	}
	152
	153	/**
	154	* ima_free_pages() - Free pages allocated by ima_alloc_pages().
	155	* @ptr: Pointer to allocated pages.
	156	* @size: Size of allocated buffer.
	157	*/
	158	static void ima_free_pages(void *ptr, size_t size)
	159	{
	160	if (!ptr)
	161	return;
	162	free_pages((unsigned long)ptr, get_order(size));
	163	}
	164
3bcced39 DK	165	static struct crypto_ahash *ima_alloc_atfm(enum hash_algo algo)
	166	{
	167	struct crypto_ahash *tfm = ima_ahash_tfm;
	168	int rc;
	169
9a8d289f MZ	170	if (algo < 0 \|\| algo >= HASH_ALGO__LAST)
	171	algo = ima_hash_algo;
	172
	173	if (algo != ima_hash_algo \|\| !tfm) {
3bcced39 DK	174	tfm = crypto_alloc_ahash(hash_algo_name[algo], 0, 0);
	175	if (!IS_ERR(tfm)) {
	176	if (algo == ima_hash_algo)
	177	ima_ahash_tfm = tfm;
	178	} else {
	179	rc = PTR_ERR(tfm);
	180	pr_err("Can not allocate %s (reason: %d)\n",
	181	hash_algo_name[algo], rc);
	182	}
	183	}
	184	return tfm;
	185	}
	186
	187	static void ima_free_atfm(struct crypto_ahash *tfm)
	188	{
	189	if (tfm != ima_ahash_tfm)
	190	crypto_free_ahash(tfm);
	191	}
	192
46f1414c	193	static inline int ahash_wait(int err, struct crypto_wait *wait)
3bcced39	194	{
3bcced39	195
46f1414c	196	err = crypto_wait_req(err, wait);
3bcced39	197
46f1414c	198	if (err)
3bcced39	199	pr_crit_ratelimited("ahash calculation failed: err: %d\n", err);
3bcced39 DK	200
	201	return err;
	202	}
	203
	204	static int ima_calc_file_hash_atfm(struct file *file,
	205	struct ima_digest_data *hash,
	206	struct crypto_ahash *tfm)
	207	{
	208	loff_t i_size, offset;
32c2e675	209	char *rbuf[2] = { NULL, };
a408e4a8	210	int rc, rbuf_len, active = 0, ahash_rc = 0;
3bcced39 DK	211	struct ahash_request *req;
3bcced39 DK	212	struct scatterlist sg[1];
46f1414c	213	struct crypto_wait wait;
32c2e675	214	size_t rbuf_size[2];
3bcced39 DK	215
	216	hash->length = crypto_ahash_digestsize(tfm);
	217
	218	req = ahash_request_alloc(tfm, GFP_KERNEL);
	219	if (!req)
	220	return -ENOMEM;
	221
46f1414c	222	crypto_init_wait(&wait);
3bcced39 DK	223	ahash_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG \|
3bcced39 DK	224	CRYPTO_TFM_REQ_MAY_SLEEP,
46f1414c	225	crypto_req_done, &wait);
3bcced39	226
46f1414c	227	rc = ahash_wait(crypto_ahash_init(req), &wait);
3bcced39 DK	228	if (rc)
	229	goto out1;
	230
	231	i_size = i_size_read(file_inode(file));
	232
	233	if (i_size == 0)
	234	goto out2;
	235
6edf7a89 DK	236	/*
	237	* Try to allocate maximum size of memory.
	238	* Fail if even a single page cannot be allocated.
	239	*/
32c2e675 DK	240	rbuf[0] = ima_alloc_pages(i_size, &rbuf_size[0], 1);
32c2e675 DK	241	if (!rbuf[0]) {
3bcced39 DK	242	rc = -ENOMEM;
	243	goto out1;
	244	}
	245
32c2e675 DK	246	/* Only allocate one buffer if that is enough. */
	247	if (i_size > rbuf_size[0]) {
	248	/*
	249	* Try to allocate secondary buffer. If that fails fallback to
	250	* using single buffering. Use previous memory allocation size
	251	* as baseline for possible allocation size.
	252	*/
	253	rbuf[1] = ima_alloc_pages(i_size - rbuf_size[0],
	254	&rbuf_size[1], 0);
	255	}
	256
3bcced39	257	for (offset = 0; offset < i_size; offset += rbuf_len) {
32c2e675 DK	258	if (!rbuf[1] && offset) {
	259	/* Not using two buffers, and it is not the first
	260	* read/request, wait for the completion of the
	261	* previous ahash_update() request.
	262	*/
46f1414c	263	rc = ahash_wait(ahash_rc, &wait);
32c2e675 DK	264	if (rc)
	265	goto out3;
	266	}
	267	/* read buffer */
	268	rbuf_len = min_t(loff_t, i_size - offset, rbuf_size[active]);
e3c4abbf DK	269	rc = integrity_kernel_read(file, offset, rbuf[active],
e3c4abbf DK	270	rbuf_len);
32c2e675 DK	271	if (rc != rbuf_len)
	272	goto out3;
	273
	274	if (rbuf[1] && offset) {
	275	/* Using two buffers, and it is not the first
	276	* read/request, wait for the completion of the
	277	* previous ahash_update() request.
	278	*/
46f1414c	279	rc = ahash_wait(ahash_rc, &wait);
32c2e675 DK	280	if (rc)
32c2e675 DK	281	goto out3;
3bcced39	282	}
3bcced39	283
32c2e675	284	sg_init_one(&sg[0], rbuf[active], rbuf_len);
3bcced39 DK	285	ahash_request_set_crypt(req, sg, NULL, rbuf_len);
3bcced39 DK	286
32c2e675 DK	287	ahash_rc = crypto_ahash_update(req);
	288
	289	if (rbuf[1])
	290	active = !active; /* swap buffers, if we use two */
3bcced39	291	}
32c2e675	292	/* wait for the last update request to complete */
46f1414c	293	rc = ahash_wait(ahash_rc, &wait);
32c2e675	294	out3:
32c2e675 DK	295	ima_free_pages(rbuf[0], rbuf_size[0]);
32c2e675 DK	296	ima_free_pages(rbuf[1], rbuf_size[1]);
3bcced39 DK	297	out2:
	298	if (!rc) {
	299	ahash_request_set_crypt(req, NULL, hash->digest, 0);
46f1414c	300	rc = ahash_wait(crypto_ahash_final(req), &wait);
3bcced39 DK	301	}
	302	out1:
	303	ahash_request_free(req);
	304	return rc;
	305	}
	306
	307	static int ima_calc_file_ahash(struct file file, struct ima_digest_data hash)
	308	{
	309	struct crypto_ahash *tfm;
	310	int rc;
	311
	312	tfm = ima_alloc_atfm(hash->algo);
	313	if (IS_ERR(tfm))
	314	return PTR_ERR(tfm);
	315
	316	rc = ima_calc_file_hash_atfm(file, hash, tfm);
	317
	318	ima_free_atfm(tfm);
	319
	320	return rc;
	321	}
	322
c7c8bb23 DK	323	static int ima_calc_file_hash_tfm(struct file *file,
	324	struct ima_digest_data *hash,
	325	struct crypto_shash *tfm)
3323eec9	326	{
16bfa38b	327	loff_t i_size, offset = 0;
3323eec9	328	char *rbuf;
a408e4a8	329	int rc;
357aabed	330	SHASH_DESC_ON_STACK(shash, tfm);
3323eec9	331
357aabed	332	shash->tfm = tfm;
76bb28f6	333
723326b9 DK	334	hash->length = crypto_shash_digestsize(tfm);
723326b9 DK	335
357aabed	336	rc = crypto_shash_init(shash);
3323eec9 MZ	337	if (rc != 0)
	338	return rc;
	339
1d91ac62 DK	340	i_size = i_size_read(file_inode(file));
	341
	342	if (i_size == 0)
3323eec9	343	goto out;
1d91ac62 DK	344
	345	rbuf = kzalloc(PAGE_SIZE, GFP_KERNEL);
	346	if (!rbuf)
	347	return -ENOMEM;
	348
3323eec9 MZ	349	while (offset < i_size) {
	350	int rbuf_len;
	351
e3c4abbf	352	rbuf_len = integrity_kernel_read(file, offset, rbuf, PAGE_SIZE);
3323eec9 MZ	353	if (rbuf_len < 0) {
	354	rc = rbuf_len;
	355	break;
	356	}
16bfa38b MZ	357	if (rbuf_len == 0)
16bfa38b MZ	358	break;
3323eec9	359	offset += rbuf_len;
3323eec9	360
357aabed	361	rc = crypto_shash_update(shash, rbuf, rbuf_len);
3323eec9 MZ	362	if (rc)
	363	break;
	364	}
1d91ac62	365	kfree(rbuf);
3323eec9	366	out:
1d91ac62	367	if (!rc)
357aabed	368	rc = crypto_shash_final(shash, hash->digest);
3323eec9 MZ	369	return rc;
	370	}
	371
3bcced39	372	static int ima_calc_file_shash(struct file file, struct ima_digest_data hash)
c7c8bb23	373	{
723326b9	374	struct crypto_shash *tfm;
c7c8bb23 DK	375	int rc;
c7c8bb23 DK	376
723326b9 DK	377	tfm = ima_alloc_tfm(hash->algo);
	378	if (IS_ERR(tfm))
	379	return PTR_ERR(tfm);
c7c8bb23 DK	380
	381	rc = ima_calc_file_hash_tfm(file, hash, tfm);
	382
723326b9	383	ima_free_tfm(tfm);
c7c8bb23 DK	384
	385	return rc;
	386	}
	387
3bcced39 DK	388	/*
	389	* ima_calc_file_hash - calculate file hash
	390	*
	391	* Asynchronous hash (ahash) allows using HW acceleration for calculating
	392	* a hash. ahash performance varies for different data sizes on different
	393	* crypto accelerators. shash performance might be better for smaller files.
	394	* The 'ima.ahash_minsize' module parameter allows specifying the best
	395	* minimum file size for using ahash on the system.
	396	*
	397	* If the ima.ahash_minsize parameter is not specified, this function uses
	398	* shash for the hash calculation. If ahash fails, it falls back to using
	399	* shash.
	400	*/
	401	int ima_calc_file_hash(struct file file, struct ima_digest_data hash)
	402	{
	403	loff_t i_size;
	404	int rc;
a408e4a8 GR	405	struct file *f = file;
a408e4a8 GR	406	bool new_file_instance = false, modified_flags = false;
3bcced39	407
f3cc6b25 MZ	408	/*
	409	* For consistency, fail file's opened with the O_DIRECT flag on
	410	* filesystems mounted with/without DAX option.
	411	*/
	412	if (file->f_flags & O_DIRECT) {
	413	hash->length = hash_digest_size[ima_hash_algo];
	414	hash->algo = ima_hash_algo;
	415	return -EINVAL;
	416	}
	417
a408e4a8 GR	418	/* Open a new file instance in O_RDONLY if we cannot read */
	419	if (!(file->f_mode & FMODE_READ)) {
	420	int flags = file->f_flags & ~(O_WRONLY \| O_APPEND \|
	421	O_TRUNC \| O_CREAT \| O_NOCTTY \| O_EXCL);
	422	flags \|= O_RDONLY;
	423	f = dentry_open(&file->f_path, flags, file->f_cred);
	424	if (IS_ERR(f)) {
	425	/*
	426	* Cannot open the file again, lets modify f_flags
	427	* of original and continue
	428	*/
	429	pr_info_ratelimited("Unable to reopen file for reading.\n");
	430	f = file;
	431	f->f_flags \|= FMODE_READ;
	432	modified_flags = true;
	433	} else {
	434	new_file_instance = true;
	435	}
	436	}
	437
	438	i_size = i_size_read(file_inode(f));
3bcced39 DK	439
3bcced39 DK	440	if (ima_ahash_minsize && i_size >= ima_ahash_minsize) {
a408e4a8	441	rc = ima_calc_file_ahash(f, hash);
3bcced39	442	if (!rc)
a408e4a8	443	goto out;
3bcced39 DK	444	}
3bcced39 DK	445
a408e4a8 GR	446	rc = ima_calc_file_shash(f, hash);
	447	out:
	448	if (new_file_instance)
	449	fput(f);
	450	else if (modified_flags)
	451	f->f_flags &= ~FMODE_READ;
	452	return rc;
3bcced39 DK	453	}
3bcced39 DK	454
3323eec9	455	/*
a71dc65d	456	* Calculate the hash of template data
3323eec9	457	*/
a71dc65d	458	static int ima_calc_field_array_hash_tfm(struct ima_field_data *field_data,
b6f8f16f	459	struct ima_template_desc *td,
a71dc65d RS	460	int num_fields,
	461	struct ima_digest_data *hash,
	462	struct crypto_shash *tfm)
3323eec9	463	{
357aabed	464	SHASH_DESC_ON_STACK(shash, tfm);
a71dc65d	465	int rc, i;
3323eec9	466
357aabed	467	shash->tfm = tfm;
3323eec9	468
ea593993	469	hash->length = crypto_shash_digestsize(tfm);
c7c8bb23	470
357aabed	471	rc = crypto_shash_init(shash);
a71dc65d RS	472	if (rc != 0)
	473	return rc;
	474
	475	for (i = 0; i < num_fields; i++) {
e3b64c26 RS	476	u8 buffer[IMA_EVENT_NAME_LEN_MAX + 1] = { 0 };
	477	u8 *data_to_hash = field_data[i].data;
	478	u32 datalen = field_data[i].len;
98e1d55d AS	479	u32 datalen_to_hash =
98e1d55d AS	480	!ima_canonical_fmt ? datalen : cpu_to_le32(datalen);
e3b64c26	481
b6f8f16f	482	if (strcmp(td->name, IMA_TEMPLATE_IMA_NAME) != 0) {
357aabed	483	rc = crypto_shash_update(shash,
98e1d55d AS	484	(const u8 *) &datalen_to_hash,
98e1d55d AS	485	sizeof(datalen_to_hash));
b6f8f16f RS	486	if (rc)
b6f8f16f RS	487	break;
e3b64c26 RS	488	} else if (strcmp(td->fields[i]->field_id, "n") == 0) {
	489	memcpy(buffer, data_to_hash, datalen);
	490	data_to_hash = buffer;
	491	datalen = IMA_EVENT_NAME_LEN_MAX + 1;
b6f8f16f	492	}
357aabed	493	rc = crypto_shash_update(shash, data_to_hash, datalen);
a71dc65d RS	494	if (rc)
	495	break;
	496	}
	497
	498	if (!rc)
357aabed	499	rc = crypto_shash_final(shash, hash->digest);
a71dc65d RS	500
a71dc65d RS	501	return rc;
3323eec9 MZ	502	}
3323eec9 MZ	503
b6f8f16f RS	504	int ima_calc_field_array_hash(struct ima_field_data *field_data,
b6f8f16f RS	505	struct ima_template_desc *desc, int num_fields,
a71dc65d	506	struct ima_digest_data *hash)
ea593993 DK	507	{
	508	struct crypto_shash *tfm;
	509	int rc;
	510
	511	tfm = ima_alloc_tfm(hash->algo);
	512	if (IS_ERR(tfm))
	513	return PTR_ERR(tfm);
	514
b6f8f16f RS	515	rc = ima_calc_field_array_hash_tfm(field_data, desc, num_fields,
b6f8f16f RS	516	hash, tfm);
ea593993 DK	517
	518	ima_free_tfm(tfm);
	519
	520	return rc;
	521	}
	522
98304bcf MZ	523	static int calc_buffer_ahash_atfm(const void *buf, loff_t len,
	524	struct ima_digest_data *hash,
	525	struct crypto_ahash *tfm)
	526	{
	527	struct ahash_request *req;
	528	struct scatterlist sg;
46f1414c	529	struct crypto_wait wait;
98304bcf MZ	530	int rc, ahash_rc = 0;
	531
	532	hash->length = crypto_ahash_digestsize(tfm);
	533
	534	req = ahash_request_alloc(tfm, GFP_KERNEL);
	535	if (!req)
	536	return -ENOMEM;
	537
46f1414c	538	crypto_init_wait(&wait);
98304bcf MZ	539	ahash_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG \|
98304bcf MZ	540	CRYPTO_TFM_REQ_MAY_SLEEP,
46f1414c	541	crypto_req_done, &wait);
98304bcf	542
46f1414c	543	rc = ahash_wait(crypto_ahash_init(req), &wait);
98304bcf MZ	544	if (rc)
	545	goto out;
	546
	547	sg_init_one(&sg, buf, len);
	548	ahash_request_set_crypt(req, &sg, NULL, len);
	549
	550	ahash_rc = crypto_ahash_update(req);
	551
	552	/* wait for the update request to complete */
46f1414c	553	rc = ahash_wait(ahash_rc, &wait);
98304bcf MZ	554	if (!rc) {
98304bcf MZ	555	ahash_request_set_crypt(req, NULL, hash->digest, 0);
46f1414c	556	rc = ahash_wait(crypto_ahash_final(req), &wait);
98304bcf MZ	557	}
	558	out:
	559	ahash_request_free(req);
	560	return rc;
	561	}
	562
	563	static int calc_buffer_ahash(const void *buf, loff_t len,
	564	struct ima_digest_data *hash)
	565	{
	566	struct crypto_ahash *tfm;
	567	int rc;
	568
	569	tfm = ima_alloc_atfm(hash->algo);
	570	if (IS_ERR(tfm))
	571	return PTR_ERR(tfm);
	572
	573	rc = calc_buffer_ahash_atfm(buf, len, hash, tfm);
	574
	575	ima_free_atfm(tfm);
	576
	577	return rc;
	578	}
	579
11d7646d DK	580	static int calc_buffer_shash_tfm(const void *buf, loff_t size,
	581	struct ima_digest_data *hash,
	582	struct crypto_shash *tfm)
	583	{
	584	SHASH_DESC_ON_STACK(shash, tfm);
	585	unsigned int len;
	586	int rc;
	587
	588	shash->tfm = tfm;
11d7646d DK	589
	590	hash->length = crypto_shash_digestsize(tfm);
	591
	592	rc = crypto_shash_init(shash);
	593	if (rc != 0)
	594	return rc;
	595
	596	while (size) {
	597	len = size < PAGE_SIZE ? size : PAGE_SIZE;
	598	rc = crypto_shash_update(shash, buf, len);
	599	if (rc)
	600	break;
	601	buf += len;
	602	size -= len;
	603	}
	604
	605	if (!rc)
	606	rc = crypto_shash_final(shash, hash->digest);
	607	return rc;
	608	}
	609
98304bcf MZ	610	static int calc_buffer_shash(const void *buf, loff_t len,
98304bcf MZ	611	struct ima_digest_data *hash)
11d7646d DK	612	{
	613	struct crypto_shash *tfm;
	614	int rc;
	615
	616	tfm = ima_alloc_tfm(hash->algo);
	617	if (IS_ERR(tfm))
	618	return PTR_ERR(tfm);
	619
	620	rc = calc_buffer_shash_tfm(buf, len, hash, tfm);
	621
	622	ima_free_tfm(tfm);
	623	return rc;
	624	}
	625
98304bcf MZ	626	int ima_calc_buffer_hash(const void *buf, loff_t len,
	627	struct ima_digest_data *hash)
	628	{
	629	int rc;
	630
	631	if (ima_ahash_minsize && len >= ima_ahash_minsize) {
	632	rc = calc_buffer_ahash(buf, len, hash);
	633	if (!rc)
	634	return 0;
	635	}
	636
	637	return calc_buffer_shash(buf, len, hash);
	638	}
	639
879b5892	640	static void __init ima_pcrread(u32 idx, struct tpm_digest *d)
3323eec9	641	{
ec403d8e	642	if (!ima_tpm_chip)
3323eec9 MZ	643	return;
3323eec9 MZ	644
879b5892	645	if (tpm_pcr_read(ima_tpm_chip, idx, d) != 0)
20ee451f	646	pr_err("Error Communicating to TPM chip\n");
3323eec9 MZ	647	}
	648
	649	/*
	650	* Calculate the boot aggregate hash
	651	*/
09ef5435 DK	652	static int __init ima_calc_boot_aggregate_tfm(char *digest,
09ef5435 DK	653	struct crypto_shash *tfm)
3323eec9	654	{
879b5892	655	struct tpm_digest d = { .alg_id = TPM_ALG_SHA1, .digest = {0} };
95adc6b4 TW	656	int rc;
95adc6b4 TW	657	u32 i;
357aabed	658	SHASH_DESC_ON_STACK(shash, tfm);
76bb28f6	659
357aabed	660	shash->tfm = tfm;
3323eec9	661
357aabed	662	rc = crypto_shash_init(shash);
3323eec9 MZ	663	if (rc != 0)
	664	return rc;
	665
	666	/* cumulative sha1 over tpm registers 0-7 */
	667	for (i = TPM_PCR0; i < TPM_PCR8; i++) {
879b5892	668	ima_pcrread(i, &d);
3323eec9	669	/* now accumulate with current aggregate */
879b5892	670	rc = crypto_shash_update(shash, d.digest, TPM_DIGEST_SIZE);
3323eec9 MZ	671	}
3323eec9 MZ	672	if (!rc)
357aabed	673	crypto_shash_final(shash, digest);
3323eec9 MZ	674	return rc;
3323eec9 MZ	675	}
09ef5435 DK	676
	677	int __init ima_calc_boot_aggregate(struct ima_digest_data *hash)
	678	{
	679	struct crypto_shash *tfm;
	680	int rc;
	681
	682	tfm = ima_alloc_tfm(hash->algo);
	683	if (IS_ERR(tfm))
	684	return PTR_ERR(tfm);
	685
	686	hash->length = crypto_shash_digestsize(tfm);
	687	rc = ima_calc_boot_aggregate_tfm(hash->digest, tfm);
	688
	689	ima_free_tfm(tfm);
	690
	691	return rc;
	692	}