Release 4.10 fs/ecryptfs/crypto.c

/**
 * eCryptfs: Linux filesystem encryption layer
 *
 * Copyright (C) 1997-2004 Erez Zadok
 * Copyright (C) 2001-2004 Stony Brook University
 * Copyright (C) 2004-2007 International Business Machines Corp.
 *   Author(s): Michael A. Halcrow <mahalcro@us.ibm.com>
 *              Michael C. Thompson <mcthomps@us.ibm.com>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation; either version 2 of the
 * License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
 * 02111-1307, USA.
 */

#include <crypto/hash.h>
#include <crypto/skcipher.h>
#include <linux/fs.h>
#include <linux/mount.h>
#include <linux/pagemap.h>
#include <linux/random.h>
#include <linux/compiler.h>
#include <linux/key.h>
#include <linux/namei.h>
#include <linux/file.h>
#include <linux/scatterlist.h>
#include <linux/slab.h>
#include <asm/unaligned.h>
#include "ecryptfs_kernel.h"


#define DECRYPT		0

#define ENCRYPT		1

/**
 * ecryptfs_to_hex
 * @dst: Buffer to take hex character representation of contents of
 *       src; must be at least of size (src_size * 2)
 * @src: Buffer to be converted to a hex string representation
 * @src_size: number of bytes to convert
 */


void ecryptfs_to_hex(char *dst, char *src, size_t src_size)
{
	int x;

	for (x = 0; x < src_size; x++)
		sprintf(&dst[x * 2], "%.2x", (unsigned char)src[x]);
}

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/**
 * ecryptfs_from_hex
 * @dst: Buffer to take the bytes from src hex; must be at least of
 *       size (src_size / 2)
 * @src: Buffer to be converted from a hex string representation to raw value
 * @dst_size: size of dst buffer, or number of hex characters pairs to convert
 */


void ecryptfs_from_hex(char *dst, char *src, int dst_size)
{
	int x;
	char tmp[3] = { 0, };

	for (x = 0; x < dst_size; x++) {
		tmp[0] = src[x * 2];
		tmp[1] = src[x * 2 + 1];
		dst[x] = (unsigned char)simple_strtol(tmp, NULL, 16);
	}
}

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static int ecryptfs_hash_digest(struct crypto_shash *tfm,
				char *src, int len, char *dst)
{
	SHASH_DESC_ON_STACK(desc, tfm);
	int err;

	desc->tfm = tfm;
	desc->flags = CRYPTO_TFM_REQ_MAY_SLEEP;
	err = crypto_shash_digest(desc, src, len, dst);
	shash_desc_zero(desc);
	return err;
}

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/**
 * ecryptfs_calculate_md5 - calculates the md5 of @src
 * @dst: Pointer to 16 bytes of allocated memory
 * @crypt_stat: Pointer to crypt_stat struct for the current inode
 * @src: Data to be md5'd
 * @len: Length of @src
 *
 * Uses the allocated crypto context that crypt_stat references to
 * generate the MD5 sum of the contents of src.
 */


static int ecryptfs_calculate_md5(char *dst,
				  struct ecryptfs_crypt_stat *crypt_stat,
				  char *src, int len)
{
	struct crypto_shash *tfm;
	int rc = 0;

	tfm = crypt_stat->hash_tfm;
	rc = ecryptfs_hash_digest(tfm, src, len, dst);
	if (rc) {
		printk(KERN_ERR
		       "%s: Error computing crypto hash; rc = [%d]\n",
		       __func__, rc);
		goto out;
	}
out:
	return rc;
}

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harvey harrison
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static int ecryptfs_crypto_api_algify_cipher_name(char **algified_name,
						  char *cipher_name,
						  char *chaining_modifier)
{
	int cipher_name_len = strlen(cipher_name);
	int chaining_modifier_len = strlen(chaining_modifier);
	int algified_name_len;
	int rc;

	algified_name_len = (chaining_modifier_len + cipher_name_len + 3);
	(*algified_name) = kmalloc(algified_name_len, GFP_KERNEL);
	if (!(*algified_name)) {
		rc = -ENOMEM;
		goto out;
	}
	snprintf((*algified_name), algified_name_len, "%s(%s)",
		 chaining_modifier, cipher_name);
	rc = 0;
out:
	return rc;
}

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/**
 * ecryptfs_derive_iv
 * @iv: destination for the derived iv vale
 * @crypt_stat: Pointer to crypt_stat struct for the current inode
 * @offset: Offset of the extent whose IV we are to derive
 *
 * Generate the initialization vector from the given root IV and page
 * offset.
 *
 * Returns zero on success; non-zero on error.
 */


int ecryptfs_derive_iv(char *iv, struct ecryptfs_crypt_stat *crypt_stat,
		       loff_t offset)
{
	int rc = 0;
	char dst[MD5_DIGEST_SIZE];
	char src[ECRYPTFS_MAX_IV_BYTES + 16];

	if (unlikely(ecryptfs_verbosity > 0)) {
		ecryptfs_printk(KERN_DEBUG, "root iv:\n");
		ecryptfs_dump_hex(crypt_stat->root_iv, crypt_stat->iv_bytes);
	}
	/* TODO: It is probably secure to just cast the least
         * significant bits of the root IV into an unsigned long and
         * add the offset to that rather than go through all this
         * hashing business. -Halcrow */
	memcpy(src, crypt_stat->root_iv, crypt_stat->iv_bytes);
	memset((src + crypt_stat->iv_bytes), 0, 16);
	snprintf((src + crypt_stat->iv_bytes), 16, "%lld", offset);
	if (unlikely(ecryptfs_verbosity > 0)) {
		ecryptfs_printk(KERN_DEBUG, "source:\n");
		ecryptfs_dump_hex(src, (crypt_stat->iv_bytes + 16));
	}
	rc = ecryptfs_calculate_md5(dst, crypt_stat, src,
				    (crypt_stat->iv_bytes + 16));
	if (rc) {
		ecryptfs_printk(KERN_WARNING, "Error attempting to compute "
				"MD5 while generating IV for a page\n");
		goto out;
	}
	memcpy(iv, dst, crypt_stat->iv_bytes);
	if (unlikely(ecryptfs_verbosity > 0)) {
		ecryptfs_printk(KERN_DEBUG, "derived iv:\n");
		ecryptfs_dump_hex(iv, crypt_stat->iv_bytes);
	}
out:
	return rc;
}

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/**
 * ecryptfs_init_crypt_stat
 * @crypt_stat: Pointer to the crypt_stat struct to initialize.
 *
 * Initialize the crypt_stat structure.
 */


int ecryptfs_init_crypt_stat(struct ecryptfs_crypt_stat *crypt_stat)
{
	struct crypto_shash *tfm;
	int rc;

	tfm = crypto_alloc_shash(ECRYPTFS_DEFAULT_HASH, 0, 0);
	if (IS_ERR(tfm)) {
		rc = PTR_ERR(tfm);
		ecryptfs_printk(KERN_ERR, "Error attempting to "
				"allocate crypto context; rc = [%d]\n",
				rc);
		return rc;
	}

	memset((void *)crypt_stat, 0, sizeof(struct ecryptfs_crypt_stat));
	INIT_LIST_HEAD(&crypt_stat->keysig_list);
	mutex_init(&crypt_stat->keysig_list_mutex);
	mutex_init(&crypt_stat->cs_mutex);
	mutex_init(&crypt_stat->cs_tfm_mutex);
	crypt_stat->hash_tfm = tfm;
	crypt_stat->flags |= ECRYPTFS_STRUCT_INITIALIZED;

	return 0;
}

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/**
 * ecryptfs_destroy_crypt_stat
 * @crypt_stat: Pointer to the crypt_stat struct to initialize.
 *
 * Releases all memory associated with a crypt_stat struct.
 */


void ecryptfs_destroy_crypt_stat(struct ecryptfs_crypt_stat *crypt_stat)
{
	struct ecryptfs_key_sig *key_sig, *key_sig_tmp;

	crypto_free_skcipher(crypt_stat->tfm);
	crypto_free_shash(crypt_stat->hash_tfm);
	list_for_each_entry_safe(key_sig, key_sig_tmp,
				 &crypt_stat->keysig_list, crypt_stat_list) {
		list_del(&key_sig->crypt_stat_list);
		kmem_cache_free(ecryptfs_key_sig_cache, key_sig);
	}
	memset(crypt_stat, 0, sizeof(struct ecryptfs_crypt_stat));
}

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void ecryptfs_destroy_mount_crypt_stat(
	struct ecryptfs_mount_crypt_stat *mount_crypt_stat)
{
	struct ecryptfs_global_auth_tok *auth_tok, *auth_tok_tmp;

	if (!(mount_crypt_stat->flags & ECRYPTFS_MOUNT_CRYPT_STAT_INITIALIZED))
		return;
	mutex_lock(&mount_crypt_stat->global_auth_tok_list_mutex);
	list_for_each_entry_safe(auth_tok, auth_tok_tmp,
				 &mount_crypt_stat->global_auth_tok_list,
				 mount_crypt_stat_list) {
		list_del(&auth_tok->mount_crypt_stat_list);
		if (!(auth_tok->flags & ECRYPTFS_AUTH_TOK_INVALID))
			key_put(auth_tok->global_auth_tok_key);
		kmem_cache_free(ecryptfs_global_auth_tok_cache, auth_tok);
	}
	mutex_unlock(&mount_crypt_stat->global_auth_tok_list_mutex);
	memset(mount_crypt_stat, 0, sizeof(struct ecryptfs_mount_crypt_stat));
}

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/**
 * virt_to_scatterlist
 * @addr: Virtual address
 * @size: Size of data; should be an even multiple of the block size
 * @sg: Pointer to scatterlist array; set to NULL to obtain only
 *      the number of scatterlist structs required in array
 * @sg_size: Max array size
 *
 * Fills in a scatterlist array with page references for a passed
 * virtual address.
 *
 * Returns the number of scatterlist structs in array used
 */


int virt_to_scatterlist(const void *addr, int size, struct scatterlist *sg,
			int sg_size)
{
	int i = 0;
	struct page *pg;
	int offset;
	int remainder_of_page;

	sg_init_table(sg, sg_size);

	while (size > 0 && i < sg_size) {
		pg = virt_to_page(addr);
		offset = offset_in_page(addr);
		sg_set_page(&sg[i], pg, 0, offset);
		remainder_of_page = PAGE_SIZE - offset;
		if (size >= remainder_of_page) {
			sg[i].length = remainder_of_page;
			addr += remainder_of_page;
			size -= remainder_of_page;
		} else {
			sg[i].length = size;
			addr += size;
			size = 0;
		}
		i++;
	}
	if (size > 0)
		return -ENOMEM;
	return i;
}

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jens axboe
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herbert xu
herbert xu
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kirill a. shutemov
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struct extent_crypt_result {
	
struct completion completion;
	
int rc;
};



static void extent_crypt_complete(struct crypto_async_request *req, int rc)
{
	struct extent_crypt_result *ecr = req->data;

	if (rc == -EINPROGRESS)
		return;

	ecr->rc = rc;
	complete(&ecr->completion);
}

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/**
 * crypt_scatterlist
 * @crypt_stat: Pointer to the crypt_stat struct to initialize.
 * @dst_sg: Destination of the data after performing the crypto operation
 * @src_sg: Data to be encrypted or decrypted
 * @size: Length of data
 * @iv: IV to use
 * @op: ENCRYPT or DECRYPT to indicate the desired operation
 *
 * Returns the number of bytes encrypted or decrypted; negative value on error
 */


static int crypt_scatterlist(struct ecryptfs_crypt_stat *crypt_stat,
			     struct scatterlist *dst_sg,
			     struct scatterlist *src_sg, int size,
			     unsigned char *iv, int op)
{
	struct skcipher_request *req = NULL;
	struct extent_crypt_result ecr;
	int rc = 0;

	BUG_ON(!crypt_stat || !crypt_stat->tfm
	       || !(crypt_stat->flags & ECRYPTFS_STRUCT_INITIALIZED));
	if (unlikely(ecryptfs_verbosity > 0)) {
		ecryptfs_printk(KERN_DEBUG, "Key size [%zd]; key:\n",
				crypt_stat->key_size);
		ecryptfs_dump_hex(crypt_stat->key,
				  crypt_stat->key_size);
	}

	init_completion(&ecr.completion);

	mutex_lock(&crypt_stat->cs_tfm_mutex);
	req = skcipher_request_alloc(crypt_stat->tfm, GFP_NOFS);
	if (!req) {
		mutex_unlock(&crypt_stat->cs_tfm_mutex);
		rc = -ENOMEM;
		goto out;
	}

	skcipher_request_set_callback(req,
			CRYPTO_TFM_REQ_MAY_BACKLOG | CRYPTO_TFM_REQ_MAY_SLEEP,
			extent_crypt_complete, &ecr);
	/* Consider doing this once, when the file is opened */
	if (!(crypt_stat->flags & ECRYPTFS_KEY_SET)) {
		rc = crypto_skcipher_setkey(crypt_stat->tfm, crypt_stat->key,
					    crypt_stat->key_size);
		if (rc) {
			ecryptfs_printk(KERN_ERR,
					"Error setting key; rc = [%d]\n",
					rc);
			mutex_unlock(&crypt_stat->cs_tfm_mutex);
			rc = -EINVAL;
			goto out;
		}
		crypt_stat->flags |= ECRYPTFS_KEY_SET;
	}
	mutex_unlock(&crypt_stat->cs_tfm_mutex);
	skcipher_request_set_crypt(req, src_sg, dst_sg, size, iv);
	rc = op == ENCRYPT ? crypto_skcipher_encrypt(req) :
			     crypto_skcipher_decrypt(req);
	if (rc == -EINPROGRESS || rc == -EBUSY) {
		struct extent_crypt_result *ecr = req->base.data;

		wait_for_completion(&ecr->completion);
		rc = ecr->rc;
		reinit_completion(&ecr->completion);
	}
out:
	skcipher_request_free(req);
	return rc;
}

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trevor highland
trevor highland
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herbert xu
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wolfram sang
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/**
 * lower_offset_for_page
 *
 * Convert an eCryptfs page index into a lower byte offset
 */


static loff_t lower_offset_for_page(struct ecryptfs_crypt_stat *crypt_stat,
				    struct page *page)
{
	return ecryptfs_lower_header_size(crypt_stat) +
	       ((loff_t)page->index << PAGE_SHIFT);
}

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tyler hicks
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2
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michael halcrow
13
39.39%
1
16.67%
colin king
colin king
3
9.09%
1
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adrian bunk
adrian bunk
1
3.03%
1
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kirill a. shutemov
kirill a. shutemov
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33
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/**
 * crypt_extent
 * @crypt_stat: crypt_stat containing cryptographic context for the
 *              encryption operation
 * @dst_page: The page to write the result into
 * @src_page: The page to read from
 * @extent_offset: Page extent offset for use in generating IV
 * @op: ENCRYPT or DECRYPT to indicate the desired operation
 *
 * Encrypts or decrypts one extent of data.
 *
 * Return zero on success; non-zero otherwise
 */


static int crypt_extent(struct ecryptfs_crypt_stat *crypt_stat,
			struct page *dst_page,
			struct page *src_page,
			unsigned long extent_offset, int op)
{
	pgoff_t page_index = op == ENCRYPT ? src_page->index : dst_page->index;
	loff_t extent_base;
	char extent_iv[ECRYPTFS_MAX_IV_BYTES];
	struct scatterlist src_sg, dst_sg;
	size_t extent_size = crypt_stat->extent_size;
	int rc;

	extent_base = (((loff_t)page_index) * (PAGE_SIZE / extent_size));
	rc = ecryptfs_derive_iv(extent_iv, crypt_stat,
				(extent_base + extent_offset));
	if (rc) {
		ecryptfs_printk(KERN_ERR, "Error attempting to derive IV for "
			"extent [0x%.16llx]; rc = [%d]\n",
			(unsigned long long)(extent_base + extent_offset), rc);
		goto out;
	}

	sg_init_table(&src_sg, 1);
	sg_init_table(&dst_sg, 1);

	sg_set_page(&src_sg, src_page, extent_size,
		    extent_offset * extent_size);
	sg_set_page(&dst_sg, dst_page, extent_size,
		    extent_offset * extent_size);

	rc = crypt_scatterlist(crypt_stat, &dst_sg, &src_sg, extent_size,
			       extent_iv, op);
	if (rc < 0) {
		printk(KERN_ERR "%s: Error attempting to crypt page with "
		       "page_index = [%ld], extent_offset = [%ld]; "
		       "rc = [%d]\n", __func__, page_index, extent_offset, rc);
		goto out;
	}
	rc = 0;
out:
	return rc;
}

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tyler hicks
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36.68%
4
40.00%
joe perches
joe perches
9
3.93%
1
10.00%
kirill a. shutemov
kirill a. shutemov
1
0.44%
1
10.00%
harvey harrison
harvey harrison
1
0.44%
1
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/**
 * ecryptfs_encrypt_page
 * @page: Page mapped from the eCryptfs inode for the file; contains
 *        decrypted content that needs to be encrypted (to a temporary
 *        page; not in place) and written out to the lower file
 *
 * Encrypt an eCryptfs page. This is done on a per-extent basis. Note
 * that eCryptfs pages may straddle the lower pages -- for instance,
 * if the file was created on a machine with an 8K page size
 * (resulting in an 8K header), and then the file is copied onto a
 * host with a 32K page size, then when reading page 0 of the eCryptfs
 * file, 24K of page 0 of the lower file will be read and decrypted,
 * and then 8K of page 1 of the lower file will be read and decrypted.
 *
 * Returns zero on success; negative on error
 */


int ecryptfs_encrypt_page(struct page *page)
{
	struct inode *ecryptfs_inode;
	struct ecryptfs_crypt_stat *crypt_stat;
	char *enc_extent_virt;
	struct page *enc_extent_page = NULL;
	loff_t extent_offset;
	loff_t lower_offset;
	int rc = 0;

	ecryptfs_inode = page->mapping->host;
	crypt_stat =
		&(ecryptfs_inode_to_private(ecryptfs_inode)->crypt_stat);
	BUG_ON(!(crypt_stat->flags & ECRYPTFS_ENCRYPTED));
	enc_extent_page = alloc_page(GFP_USER);
	if (!enc_extent_page) {
		rc = -ENOMEM;
		ecryptfs_printk(KERN_ERR, "Error allocating memory for "
				"encrypted extent\n");
		goto out;
	}

	for (extent_offset = 0;
	     extent_offset < (PAGE_SIZE / crypt_stat->extent_size);
	     extent_offset++) {
		rc = crypt_extent(crypt_stat, enc_extent_page, page,
				  extent_offset, ENCRYPT);
		if (rc) {
			printk(KERN_ERR "%s: Error encrypting extent; "
			       "rc = [%d]\n", __func__, rc);
			goto out;
		}
	}

	lower_offset = lower_offset_for_page(crypt_stat, page);
	enc_extent_virt = kmap(enc_extent_page);
	rc = ecryptfs_write_lower(ecryptfs_inode, enc_extent_virt, lower_offset,
				  PAGE_SIZE);
	kunmap(enc_extent_page);
	if (rc < 0) {
		ecryptfs_printk(KERN_ERR,
			"Error attempting to write lower page; rc = [%d]\n",
			rc);
		goto out;
	}
	rc = 0;
out:
	if (enc_extent_page) {
		__free_page(enc_extent_page);
	}
	return rc;
}

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tyler hicks
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14.96%
6
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eric sandeen
eric sandeen
16
6.84%
1
8.33%
kirill a. shutemov
kirill a. shutemov
2
0.85%
1
8.33%
harvey harrison
harvey harrison
1
0.43%
1
8.33%
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100.00%

/**
 * ecryptfs_decrypt_page
 * @page: Page mapped from the eCryptfs inode for the file; data read
 *        and decrypted from the lower file will be written into this
 *        page
 *
 * Decrypt an eCryptfs page. This is done on a per-extent basis. Note
 * that eCryptfs pages may straddle the lower pages -- for instance,
 * if the file was created on a machine with an 8K page size
 * (resulting in an 8K header), and then the file is copied onto a
 * host with a 32K page size, then when reading page 0 of the eCryptfs
 * file, 24K of page 0 of the lower file will be read and decrypted,
 * and then 8K of page 1 of the lower file will be read and decrypted.
 *
 * Returns zero on success; negative on error
 */


int ecryptfs_decrypt_page(struct page *page)
{
	struct inode *ecryptfs_inode;
	struct ecryptfs_crypt_stat *crypt_stat;
	char *page_virt;
	unsigned long extent_offset;
	loff_t lower_offset;
	int rc = 0;

	ecryptfs_inode = page->mapping->host;
	crypt_stat =
		&(ecryptfs_inode_to_private(ecryptfs_inode)->crypt_stat);
	BUG_ON(!(crypt_stat->flags & ECRYPTFS_ENCRYPTED));

	lower_offset = lower_offset_for_page(crypt_stat, page);
	page_virt = kmap(page);
	rc = ecryptfs_read_lower(page_virt, lower_offset, PAGE_SIZE,
				 ecryptfs_inode);
	kunmap(page);
	if (rc < 0) {
		ecryptfs_printk(KERN_ERR,
			"Error attempting to read lower page; rc = [%d]\n",
			rc);
		goto out;
	}

	for (extent_offset = 0;
	     extent_offset < (PAGE_SIZE / crypt_stat->extent_size);
	     extent_offset++) {
		rc = crypt_extent(crypt_stat, page, page,
				  extent_offset, DECRYPT);
		if (rc) {
			printk(KERN_ERR "%s: Error encrypting extent; "
			       "rc = [%d]\n", __func__, rc);
			goto out;
		}
	}
out:
	return rc;
}

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michael halcrow
michael halcrow
152
83.06%
4
30.77%
tyler hicks
tyler hicks
28
15.30%
7
53.85%
kirill a. shutemov
kirill a. shutemov
2
1.09%
1
7.69%
harvey harrison
harvey harrison
1
0.55%
1
7.69%
Total
183
100.00%
13
100.00%


#define ECRYPTFS_MAX_SCATTERLIST_LEN 4

/**
 * ecryptfs_init_crypt_ctx
 * @crypt_stat: Uninitialized crypt stats structure
 *
 * Initialize the crypto context.
 *
 * TODO: Performance: Keep a cache of initialized cipher contexts;
 * only init if needed
 */


int ecryptfs_init_crypt_ctx(struct ecryptfs_crypt_stat *crypt_stat)
{
	char *full_alg_name;
	int rc = -EINVAL;

	ecryptfs_printk(KERN_DEBUG,
			"Initializing cipher [%s]; strlen = [%d]; "
			"key_size_bits = [%zd]\n",
			crypt_stat->cipher, (int)strlen(crypt_stat->cipher),
			crypt_stat->key_size << 3);
	mutex_lock(&crypt_stat->cs_tfm_mutex);
	if (crypt_stat->tfm) {
		rc = 0;
		goto out_unlock;
	}
	rc = ecryptfs_crypto_api_algify_cipher_name(&full_alg_name,
						    crypt_stat->cipher, "cbc");
	if (rc)
		goto out_unlock;
	crypt_stat->tfm = crypto_alloc_skcipher(full_alg_name, 0, 0);
	if (IS_ERR(crypt_stat->tfm)) {
		rc = PTR_ERR(crypt_stat->tfm);
		crypt_stat->tfm = NULL;
		ecryptfs_printk(KERN_ERR, "cryptfs: init_crypt_ctx(): "
				"Error initializing cipher [%s]\n",
				full_alg_name);
		goto out_free;
	}
	crypto_skcipher_set_flags(crypt_stat->tfm, CRYPTO_TFM_REQ_WEAK_KEY);
	rc = 0;
out_free:
	kfree(full_alg_name);
out_unlock:
	mutex_unlock(&crypt_stat->cs_tfm_mutex);
	return rc;
}

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michael halcrow
michael halcrow
130
73.45%
2
22.22%
kees cook
kees cook
18
10.17%
1
11.11%
akinobu mita
akinobu mita
12
6.78%
1
11.11%
tyler hicks
tyler hicks
8
4.52%
3
33.33%
eric sandeen
eric sandeen
7
3.95%
1
11.11%
herbert xu
herbert xu
2
1.13%
1
11.11%
Total
177
100.00%
9
100.00%



static void set_extent_mask_and_shift(struct ecryptfs_crypt_stat *crypt_stat)
{
	int extent_size_tmp;

	crypt_stat->extent_mask = 0xFFFFFFFF;
	crypt_stat->extent_shift = 0;
	if (crypt_stat->extent_size == 0)
		return;
	extent_size_tmp = crypt_stat->extent_size;
	while ((extent_size_tmp & 0x01) == 0) {
		extent_size_tmp >>= 1;
		crypt_stat->extent_mask <<= 1;
		crypt_stat->extent_shift++;
	}
}

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michael halcrow
68
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1
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68
100.00%
1
100.00%



void ecryptfs_set_default_sizes(struct ecryptfs_crypt_stat *crypt_stat)
{
	/* Default values; may be overwritten as we are parsing the
         * packets. */
	crypt_stat->extent_size = ECRYPTFS_DEFAULT_EXTENT_SIZE;
	set_extent_mask_and_shift(crypt_stat);
	crypt_stat->iv_bytes = ECRYPTFS_DEFAULT_IV_BYTES;
	if (crypt_stat->flags & ECRYPTFS_METADATA_IN_XATTR)
		crypt_stat->metadata_size = ECRYPTFS_MINIMUM_HEADER_EXTENT_SIZE;
	else {
		if (PAGE_SIZE <= ECRYPTFS_MINIMUM_HEADER_EXTENT_SIZE)
			crypt_stat->metadata_size =
				ECRYPTFS_MINIMUM_HEADER_EXTENT_SIZE;
		else
			crypt_stat->metadata_size = PAGE_SIZE;
	}
}

Contributors
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CommitProp
michael halcrow
michael halcrow
58
90.62%
3
50.00%
tyler hicks
tyler hicks
4
6.25%
2
33.33%
kirill a. shutemov
kirill a. shutemov
2
3.12%
1
16.67%
Total
64
100.00%
6
100.00%

/**
 * ecryptfs_compute_root_iv
 * @crypt_stats
 *
 * On error, sets the root IV to all 0's.
 */


int ecryptfs_compute_root_iv(struct ecryptfs_crypt_stat *crypt_stat)
{
	int rc = 0;
	char dst[MD5_DIGEST_SIZE];

	BUG_ON(crypt_stat->iv_bytes > MD5_DIGEST_SIZE);
	BUG_ON(crypt_stat->iv_bytes <= 0);
	if (!(crypt_stat->flags & ECRYPTFS_KEY_VALID)) {
		rc = -EINVAL;
		ecryptfs_printk(KERN_WARNING, "Session key not valid; "
				"cannot generate root IV\n");
		goto out;
	}
	rc = ecryptfs_calculate_md5(dst, crypt_stat, crypt_stat->key,
				    crypt_stat->key_size);
	if (rc) {
		ecryptfs_printk(KERN_WARNING, "Error attempting to compute "
				"MD5 while generating root IV\n");
		goto out;
	}
	memcpy(crypt_stat->root_iv, dst, crypt_stat->iv_bytes);
out:
	if (rc) {
		memset(crypt_stat->root_iv, 0, crypt_stat->iv_bytes);
		crypt_stat->flags |= ECRYPTFS_SECURITY_WARNING;
	}
	return rc;
}

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michael halcrow
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145
100.00%
2
100.00%



static void ecryptfs_generate_new_key(struct ecryptfs_crypt_stat *crypt_stat)
{
	get_random_bytes(crypt_stat->key, crypt_stat->key_size);
	crypt_stat->flags |= ECRYPTFS_KEY_VALID;
	ecryptfs_compute_root_iv(crypt_stat);
	if (unlikely(ecryptfs_verbosity > 0)) {
		ecryptfs_printk(KERN_DEBUG, "Generated new session key:\n");
		ecryptfs_dump_hex(crypt_stat->key,
				  crypt_stat->key_size);
	}
}

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michael halcrow
michael halcrow
62
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2
100.00%
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62
100.00%
2
100.00%

/**
 * ecryptfs_copy_mount_wide_flags_to_inode_flags
 * @crypt_stat: The inode's cryptographic context
 * @mount_crypt_stat: The mount point's cryptographic context
 *
 * This function propagates the mount-wide flags to individual inode
 * flags.
 */


static void ecryptfs_copy_mount_wide_flags_to_inode_flags(
	struct ecryptfs_crypt_stat *crypt_stat,
	struct ecryptfs_mount_crypt_stat *mount_crypt_stat)
{
	if (mount_crypt_stat->flags & ECRYPTFS_XATTR_METADATA_ENABLED)
		crypt_stat->flags |= ECRYPTFS_METADATA_IN_XATTR;
	if (mount_crypt_stat->flags & ECRYPTFS_ENCRYPTED_VIEW_ENABLED)
		crypt_stat->flags |= ECRYPTFS_VIEW_AS_ENCRYPTED;
	if (mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES) {
		crypt_stat->flags |= ECRYPTFS_ENCRYPT_FILENAMES;
		if (mount_crypt_stat->flags
		    & ECRYPTFS_GLOBAL_ENCFN_USE_MOUNT_FNEK)
			crypt_stat->flags |= ECRYPTFS_ENCFN_USE_MOUNT_FNEK;
		else if (mount_crypt_stat->flags
			 & ECRYPTFS_GLOBAL_ENCFN_USE_FEK)
			crypt_stat->flags |= ECRYPTFS_ENCFN_USE_FEK;
	}
}

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89
100.00%
2
100.00%



static int ecryptfs_copy_mount_wide_sigs_to_inode_sigs(
	struct ecryptfs_crypt_stat *crypt_stat,
	struct ecryptfs_mount_crypt_stat *mount_crypt_stat)
{
	struct ecryptfs_global_auth_tok *global_auth_tok;
	int rc = 0;

	mutex_lock(&crypt_stat->keysig_list_mutex);
	mutex_lock(&mount_crypt_stat->global_auth_tok_list_mutex);

	list_for_each_entry(global_auth_tok,
			    &mount_crypt_stat->global_auth_tok_list,
			    mount_crypt_stat_list) {
		if (global_auth_tok->flags & ECRYPTFS_AUTH_TOK_FNEK)
			continue;
		rc = ecryptfs_add_keysig(crypt_stat, global_auth_tok->sig);
		if (rc) {
			printk(KERN_ERR "Error adding keysig; rc = [%d]\n", rc);
			goto out;
		}
	}

out