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Commit a7550b30 authored by Jaegeuk Kim's avatar Jaegeuk Kim Committed by Theodore Ts'o
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ext4 crypto: migrate into vfs's crypto engine 

This patch removes the most parts of internal crypto codes.
And then, it modifies and adds some ext4-specific crypt codes to use the generic
facility.
Signed-off-by: default avatarJaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: default avatarTheodore Ts'o <tytso@mit.edu>
parent ff0031d8
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Showing with 297 additions and 1997 deletions
fs/ext4/Kconfig
View file @ a7550b30
......@@ -99,17 +99,9 @@ config EXT4_FS_SECURITY
extended attributes for file security labels, say N.
config EXT4_ENCRYPTION
tristate "Ext4 Encryption"
bool "Ext4 Encryption"
depends on EXT4_FS
select CRYPTO_AES
select CRYPTO_CBC
select CRYPTO_ECB
select CRYPTO_XTS
select CRYPTO_CTS
select CRYPTO_CTR
select CRYPTO_SHA256
select KEYS
select ENCRYPTED_KEYS
select FS_ENCRYPTION
help
Enable encryption of ext4 files and directories. This
feature is similar to ecryptfs, but it is more memory
......
fs/ext4/Makefile
View file @ a7550b30
......@@ -12,5 +12,3 @@ ext4-y := balloc.o bitmap.o dir.o file.o fsync.o ialloc.o inode.o page-io.o \
ext4-$(CONFIG_EXT4_FS_POSIX_ACL) += acl.o
ext4-$(CONFIG_EXT4_FS_SECURITY) += xattr_security.o
ext4-$(CONFIG_EXT4_FS_ENCRYPTION) += crypto_policy.o crypto.o \
crypto_key.o crypto_fname.o
fs/ext4/crypto.c deleted 100644 → 0
View file @ ff0031d8
This diff is collapsed.
fs/ext4/crypto_fname.c deleted 100644 → 0
View file @ ff0031d8
This diff is collapsed.
fs/ext4/crypto_key.c deleted 100644 → 0
View file @ ff0031d8
/*
* linux/fs/ext4/crypto_key.c
*
* Copyright (C) 2015, Google, Inc.
*
* This contains encryption key functions for ext4
*
* Written by Michael Halcrow, Ildar Muslukhov, and Uday Savagaonkar, 2015.
*/
#include <crypto/skcipher.h>
#include <keys/encrypted-type.h>
#include <keys/user-type.h>
#include <linux/random.h>
#include <linux/scatterlist.h>
#include <uapi/linux/keyctl.h>
#include "ext4.h"
#include "xattr.h"
static void derive_crypt_complete(struct crypto_async_request *req, int rc)
{
struct ext4_completion_result *ecr = req->data;
if (rc == -EINPROGRESS)
return;
ecr->res = rc;
complete(&ecr->completion);
}
/**
* ext4_derive_key_aes() - Derive a key using AES-128-ECB
* @deriving_key: Encryption key used for derivation.
* @source_key: Source key to which to apply derivation.
* @derived_key: Derived key.
*
* Return: Zero on success; non-zero otherwise.
*/
static int ext4_derive_key_aes(char deriving_key[EXT4_AES_128_ECB_KEY_SIZE],
char source_key[EXT4_AES_256_XTS_KEY_SIZE],
char derived_key[EXT4_AES_256_XTS_KEY_SIZE])
{
int res = 0;
struct skcipher_request *req = NULL;
DECLARE_EXT4_COMPLETION_RESULT(ecr);
struct scatterlist src_sg, dst_sg;
struct crypto_skcipher *tfm = crypto_alloc_skcipher("ecb(aes)", 0, 0);
if (IS_ERR(tfm)) {
res = PTR_ERR(tfm);
tfm = NULL;
goto out;
}
crypto_skcipher_set_flags(tfm, CRYPTO_TFM_REQ_WEAK_KEY);
req = skcipher_request_alloc(tfm, GFP_NOFS);
if (!req) {
res = -ENOMEM;
goto out;
}
skcipher_request_set_callback(req,
CRYPTO_TFM_REQ_MAY_BACKLOG | CRYPTO_TFM_REQ_MAY_SLEEP,
derive_crypt_complete, &ecr);
res = crypto_skcipher_setkey(tfm, deriving_key,
EXT4_AES_128_ECB_KEY_SIZE);
if (res < 0)
goto out;
sg_init_one(&src_sg, source_key, EXT4_AES_256_XTS_KEY_SIZE);
sg_init_one(&dst_sg, derived_key, EXT4_AES_256_XTS_KEY_SIZE);
skcipher_request_set_crypt(req, &src_sg, &dst_sg,
EXT4_AES_256_XTS_KEY_SIZE, NULL);
res = crypto_skcipher_encrypt(req);
if (res == -EINPROGRESS || res == -EBUSY) {
wait_for_completion(&ecr.completion);
res = ecr.res;
}
out:
skcipher_request_free(req);
crypto_free_skcipher(tfm);
return res;
}
void ext4_free_crypt_info(struct ext4_crypt_info *ci)
{
if (!ci)
return;
if (ci->ci_keyring_key)
key_put(ci->ci_keyring_key);
crypto_free_skcipher(ci->ci_ctfm);
kmem_cache_free(ext4_crypt_info_cachep, ci);
}
void ext4_free_encryption_info(struct inode *inode,
struct ext4_crypt_info *ci)
{
struct ext4_inode_info *ei = EXT4_I(inode);
struct ext4_crypt_info *prev;
if (ci == NULL)
ci = ACCESS_ONCE(ei->i_crypt_info);
if (ci == NULL)
return;
prev = cmpxchg(&ei->i_crypt_info, ci, NULL);
if (prev != ci)
return;
ext4_free_crypt_info(ci);
}
int _ext4_get_encryption_info(struct inode *inode)
{
struct ext4_inode_info *ei = EXT4_I(inode);
struct ext4_crypt_info *crypt_info;
char full_key_descriptor[EXT4_KEY_DESC_PREFIX_SIZE +
(EXT4_KEY_DESCRIPTOR_SIZE * 2) + 1];
struct key *keyring_key = NULL;
struct ext4_encryption_key *master_key;
struct ext4_encryption_context ctx;
const struct user_key_payload *ukp;
struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
struct crypto_skcipher *ctfm;
const char *cipher_str;
char raw_key[EXT4_MAX_KEY_SIZE];
char mode;
int res;
if (!ext4_read_workqueue) {
res = ext4_init_crypto();
if (res)
return res;
}
retry:
crypt_info = ACCESS_ONCE(ei->i_crypt_info);
if (crypt_info) {
if (!crypt_info->ci_keyring_key ||
key_validate(crypt_info->ci_keyring_key) == 0)
return 0;
ext4_free_encryption_info(inode, crypt_info);
goto retry;
}
res = ext4_xattr_get(inode, EXT4_XATTR_INDEX_ENCRYPTION,
EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
&ctx, sizeof(ctx));
if (res < 0) {
if (!DUMMY_ENCRYPTION_ENABLED(sbi))
return res;
ctx.contents_encryption_mode = EXT4_ENCRYPTION_MODE_AES_256_XTS;
ctx.filenames_encryption_mode =
EXT4_ENCRYPTION_MODE_AES_256_CTS;
ctx.flags = 0;
} else if (res != sizeof(ctx))
return -EINVAL;
res = 0;
crypt_info = kmem_cache_alloc(ext4_crypt_info_cachep, GFP_KERNEL);
if (!crypt_info)
return -ENOMEM;
crypt_info->ci_flags = ctx.flags;
crypt_info->ci_data_mode = ctx.contents_encryption_mode;
crypt_info->ci_filename_mode = ctx.filenames_encryption_mode;
crypt_info->ci_ctfm = NULL;
crypt_info->ci_keyring_key = NULL;
memcpy(crypt_info->ci_master_key, ctx.master_key_descriptor,
sizeof(crypt_info->ci_master_key));
if (S_ISREG(inode->i_mode))
mode = crypt_info->ci_data_mode;
else if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode))
mode = crypt_info->ci_filename_mode;
else
BUG();
switch (mode) {
case EXT4_ENCRYPTION_MODE_AES_256_XTS:
cipher_str = "xts(aes)";
break;
case EXT4_ENCRYPTION_MODE_AES_256_CTS:
cipher_str = "cts(cbc(aes))";
break;
default:
printk_once(KERN_WARNING
"ext4: unsupported key mode %d (ino %u)\n",
mode, (unsigned) inode->i_ino);
res = -ENOKEY;
goto out;
}
if (DUMMY_ENCRYPTION_ENABLED(sbi)) {
memset(raw_key, 0x42, EXT4_AES_256_XTS_KEY_SIZE);
goto got_key;
}
memcpy(full_key_descriptor, EXT4_KEY_DESC_PREFIX,
EXT4_KEY_DESC_PREFIX_SIZE);
sprintf(full_key_descriptor + EXT4_KEY_DESC_PREFIX_SIZE,
"%*phN", EXT4_KEY_DESCRIPTOR_SIZE,
ctx.master_key_descriptor);
full_key_descriptor[EXT4_KEY_DESC_PREFIX_SIZE +
(2 * EXT4_KEY_DESCRIPTOR_SIZE)] = '\0';
keyring_key = request_key(&key_type_logon, full_key_descriptor, NULL);
if (IS_ERR(keyring_key)) {
res = PTR_ERR(keyring_key);
keyring_key = NULL;
goto out;
}
crypt_info->ci_keyring_key = keyring_key;
if (keyring_key->type != &key_type_logon) {
printk_once(KERN_WARNING
"ext4: key type must be logon\n");
res = -ENOKEY;
goto out;
}
down_read(&keyring_key->sem);
ukp = user_key_payload(keyring_key);
if (ukp->datalen != sizeof(struct ext4_encryption_key)) {
res = -EINVAL;
up_read(&keyring_key->sem);
goto out;
}
master_key = (struct ext4_encryption_key *)ukp->data;
BUILD_BUG_ON(EXT4_AES_128_ECB_KEY_SIZE !=
EXT4_KEY_DERIVATION_NONCE_SIZE);
if (master_key->size != EXT4_AES_256_XTS_KEY_SIZE) {
printk_once(KERN_WARNING
"ext4: key size incorrect: %d\n",
master_key->size);
res = -ENOKEY;
up_read(&keyring_key->sem);
goto out;
}
res = ext4_derive_key_aes(ctx.nonce, master_key->raw,
raw_key);
up_read(&keyring_key->sem);
if (res)
goto out;
got_key:
ctfm = crypto_alloc_skcipher(cipher_str, 0, 0);
if (!ctfm || IS_ERR(ctfm)) {
res = ctfm ? PTR_ERR(ctfm) : -ENOMEM;
printk(KERN_DEBUG
"%s: error %d (inode %u) allocating crypto tfm\n",
__func__, res, (unsigned) inode->i_ino);
goto out;
}
crypt_info->ci_ctfm = ctfm;
crypto_skcipher_clear_flags(ctfm, ~0);
crypto_tfm_set_flags(crypto_skcipher_tfm(ctfm),
CRYPTO_TFM_REQ_WEAK_KEY);
res = crypto_skcipher_setkey(ctfm, raw_key,
ext4_encryption_key_size(mode));
if (res)
goto out;
memzero_explicit(raw_key, sizeof(raw_key));
if (cmpxchg(&ei->i_crypt_info, NULL, crypt_info) != NULL) {
ext4_free_crypt_info(crypt_info);
goto retry;
}
return 0;
out:
if (res == -ENOKEY)
res = 0;
ext4_free_crypt_info(crypt_info);
memzero_explicit(raw_key, sizeof(raw_key));
return res;
}
int ext4_has_encryption_key(struct inode *inode)
{
struct ext4_inode_info *ei = EXT4_I(inode);
return (ei->i_crypt_info != NULL);
}
fs/ext4/crypto_policy.c deleted 100644 → 0
View file @ ff0031d8
/*
* linux/fs/ext4/crypto_policy.c
*
* Copyright (C) 2015, Google, Inc.
*
* This contains encryption policy functions for ext4
*
* Written by Michael Halcrow, 2015.
*/
#include <linux/random.h>
#include <linux/string.h>
#include <linux/types.h>
#include "ext4_jbd2.h"
#include "ext4.h"
#include "xattr.h"
static int ext4_inode_has_encryption_context(struct inode *inode)
{
int res = ext4_xattr_get(inode, EXT4_XATTR_INDEX_ENCRYPTION,
EXT4_XATTR_NAME_ENCRYPTION_CONTEXT, NULL, 0);
return (res > 0);
}
/*
* check whether the policy is consistent with the encryption context
* for the inode
*/
static int ext4_is_encryption_context_consistent_with_policy(
struct inode *inode, const struct ext4_encryption_policy *policy)
{
struct ext4_encryption_context ctx;
int res = ext4_xattr_get(inode, EXT4_XATTR_INDEX_ENCRYPTION,
EXT4_XATTR_NAME_ENCRYPTION_CONTEXT, &ctx,
sizeof(ctx));
if (res != sizeof(ctx))
return 0;
return (memcmp(ctx.master_key_descriptor, policy->master_key_descriptor,
EXT4_KEY_DESCRIPTOR_SIZE) == 0 &&
(ctx.flags ==
policy->flags) &&
(ctx.contents_encryption_mode ==
policy->contents_encryption_mode) &&
(ctx.filenames_encryption_mode ==
policy->filenames_encryption_mode));
}
static int ext4_create_encryption_context_from_policy(
struct inode *inode, const struct ext4_encryption_policy *policy)
{
struct ext4_encryption_context ctx;
handle_t *handle;
int res, res2;
res = ext4_convert_inline_data(inode);
if (res)
return res;
ctx.format = EXT4_ENCRYPTION_CONTEXT_FORMAT_V1;
memcpy(ctx.master_key_descriptor, policy->master_key_descriptor,
EXT4_KEY_DESCRIPTOR_SIZE);
if (!ext4_valid_contents_enc_mode(policy->contents_encryption_mode)) {
printk(KERN_WARNING
"%s: Invalid contents encryption mode %d\n", __func__,
policy->contents_encryption_mode);
return -EINVAL;
}
if (!ext4_valid_filenames_enc_mode(policy->filenames_encryption_mode)) {
printk(KERN_WARNING
"%s: Invalid filenames encryption mode %d\n", __func__,
policy->filenames_encryption_mode);
return -EINVAL;
}
if (policy->flags & ~EXT4_POLICY_FLAGS_VALID)
return -EINVAL;
ctx.contents_encryption_mode = policy->contents_encryption_mode;
ctx.filenames_encryption_mode = policy->filenames_encryption_mode;
ctx.flags = policy->flags;
BUILD_BUG_ON(sizeof(ctx.nonce) != EXT4_KEY_DERIVATION_NONCE_SIZE);
get_random_bytes(ctx.nonce, EXT4_KEY_DERIVATION_NONCE_SIZE);
handle = ext4_journal_start(inode, EXT4_HT_MISC,
ext4_jbd2_credits_xattr(inode));
if (IS_ERR(handle))
return PTR_ERR(handle);
res = ext4_xattr_set(inode, EXT4_XATTR_INDEX_ENCRYPTION,
EXT4_XATTR_NAME_ENCRYPTION_CONTEXT, &ctx,
sizeof(ctx), 0);
if (!res) {
ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
res = ext4_mark_inode_dirty(handle, inode);
if (res)
EXT4_ERROR_INODE(inode, "Failed to mark inode dirty");
}
res2 = ext4_journal_stop(handle);
if (!res)
res = res2;
return res;
}
int ext4_process_policy(const struct ext4_encryption_policy *policy,
struct inode *inode)
{
if (policy->version != 0)
return -EINVAL;
if (!ext4_inode_has_encryption_context(inode)) {
if (!S_ISDIR(inode->i_mode))
return -EINVAL;
if (!ext4_empty_dir(inode))
return -ENOTEMPTY;
return ext4_create_encryption_context_from_policy(inode,
policy);
}
if (ext4_is_encryption_context_consistent_with_policy(inode, policy))
return 0;
printk(KERN_WARNING "%s: Policy inconsistent with encryption context\n",
__func__);
return -EINVAL;
}
int ext4_get_policy(struct inode *inode, struct ext4_encryption_policy *policy)
{
struct ext4_encryption_context ctx;
int res = ext4_xattr_get(inode, EXT4_XATTR_INDEX_ENCRYPTION,
EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
&ctx, sizeof(ctx));
if (res != sizeof(ctx))
return -ENOENT;
if (ctx.format != EXT4_ENCRYPTION_CONTEXT_FORMAT_V1)
return -EINVAL;
policy->version = 0;
policy->contents_encryption_mode = ctx.contents_encryption_mode;
policy->filenames_encryption_mode = ctx.filenames_encryption_mode;
policy->flags = ctx.flags;
memcpy(&policy->master_key_descriptor, ctx.master_key_descriptor,
EXT4_KEY_DESCRIPTOR_SIZE);
return 0;
}
int ext4_is_child_context_consistent_with_parent(struct inode *parent,
struct inode *child)
{
struct ext4_crypt_info *parent_ci, *child_ci;
int res;
if ((parent == NULL) || (child == NULL)) {
pr_err("parent %p child %p\n", parent, child);
WARN_ON(1); /* Should never happen */
return 0;
}
/* no restrictions if the parent directory is not encrypted */
if (!ext4_encrypted_inode(parent))
return 1;
/* if the child directory is not encrypted, this is always a problem */
if (!ext4_encrypted_inode(child))
return 0;
res = ext4_get_encryption_info(parent);
if (res)
return 0;
res = ext4_get_encryption_info(child);
if (res)
return 0;
parent_ci = EXT4_I(parent)->i_crypt_info;
child_ci = EXT4_I(child)->i_crypt_info;
if (!parent_ci && !child_ci)
return 1;
if (!parent_ci || !child_ci)
return 0;
return (memcmp(parent_ci->ci_master_key,
child_ci->ci_master_key,
EXT4_KEY_DESCRIPTOR_SIZE) == 0 &&
(parent_ci->ci_data_mode == child_ci->ci_data_mode) &&
(parent_ci->ci_filename_mode == child_ci->ci_filename_mode) &&
(parent_ci->ci_flags == child_ci->ci_flags));
}
/**
* ext4_inherit_context() - Sets a child context from its parent
* @parent: Parent inode from which the context is inherited.
* @child: Child inode that inherits the context from @parent.
*
* Return: Zero on success, non-zero otherwise
*/
int ext4_inherit_context(struct inode *parent, struct inode *child)
{
struct ext4_encryption_context ctx;
struct ext4_crypt_info *ci;
int res;
res = ext4_get_encryption_info(parent);
if (res < 0)
return res;
ci = EXT4_I(parent)->i_crypt_info;
if (ci == NULL)
return -ENOKEY;
ctx.format = EXT4_ENCRYPTION_CONTEXT_FORMAT_V1;
if (DUMMY_ENCRYPTION_ENABLED(EXT4_SB(parent->i_sb))) {
ctx.contents_encryption_mode = EXT4_ENCRYPTION_MODE_AES_256_XTS;
ctx.filenames_encryption_mode =
EXT4_ENCRYPTION_MODE_AES_256_CTS;
ctx.flags = 0;
memset(ctx.master_key_descriptor, 0x42,
EXT4_KEY_DESCRIPTOR_SIZE);
res = 0;
} else {
ctx.contents_encryption_mode = ci->ci_data_mode;
ctx.filenames_encryption_mode = ci->ci_filename_mode;
ctx.flags = ci->ci_flags;
memcpy(ctx.master_key_descriptor, ci->ci_master_key,
EXT4_KEY_DESCRIPTOR_SIZE);
}
get_random_bytes(ctx.nonce, EXT4_KEY_DERIVATION_NONCE_SIZE);
res = ext4_xattr_set(child, EXT4_XATTR_INDEX_ENCRYPTION,
EXT4_XATTR_NAME_ENCRYPTION_CONTEXT, &ctx,
sizeof(ctx), 0);
if (!res) {
ext4_set_inode_flag(child, EXT4_INODE_ENCRYPT);
ext4_clear_inode_state(child, EXT4_STATE_MAY_INLINE_DATA);
res = ext4_get_encryption_info(child);
}
return res;
}
fs/ext4/dir.c
View file @ a7550b30
......@@ -109,10 +109,10 @@ static int ext4_readdir(struct file *file, struct dir_context *ctx)
struct super_block *sb = inode->i_sb;
struct buffer_head *bh = NULL;
int dir_has_error = 0;
struct ext4_str fname_crypto_str = {.name = NULL, .len = 0};
struct fscrypt_str fstr = FSTR_INIT(NULL, 0);
if (ext4_encrypted_inode(inode)) {
err = ext4_get_encryption_info(inode);
err = fscrypt_get_encryption_info(inode);
if (err && err != -ENOKEY)
return err;
}
......@@ -139,8 +139,7 @@ static int ext4_readdir(struct file *file, struct dir_context *ctx)
}
if (ext4_encrypted_inode(inode)) {
err = ext4_fname_crypto_alloc_buffer(inode, EXT4_NAME_LEN,
&fname_crypto_str);
err = fscrypt_fname_alloc_buffer(inode, EXT4_NAME_LEN, &fstr);
if (err < 0)
return err;
}
......@@ -253,16 +252,19 @@ static int ext4_readdir(struct file *file, struct dir_context *ctx)
get_dtype(sb, de->file_type)))
goto done;
} else {
int save_len = fname_crypto_str.len;
int save_len = fstr.len;
struct fscrypt_str de_name =
FSTR_INIT(de->name,
de->name_len);
/* Directory is encrypted */
err = ext4_fname_disk_to_usr(inode,
NULL, de, &fname_crypto_str);
fname_crypto_str.len = save_len;
err = fscrypt_fname_disk_to_usr(inode,
0, 0, &de_name, &fstr);
fstr.len = save_len;
if (err < 0)
goto errout;
if (!dir_emit(ctx,
fname_crypto_str.name, err,
fstr.name, err,
le32_to_cpu(de->inode),
get_dtype(sb, de->file_type)))
goto done;
......@@ -281,7 +283,7 @@ static int ext4_readdir(struct file *file, struct dir_context *ctx)
err = 0;
errout:
#ifdef CONFIG_EXT4_FS_ENCRYPTION
ext4_fname_crypto_free_buffer(&fname_crypto_str);
fscrypt_fname_free_buffer(&fstr);
#endif
brelse(bh);
return err;
......@@ -432,7 +434,7 @@ void ext4_htree_free_dir_info(struct dir_private_info *p)
int ext4_htree_store_dirent(struct file *dir_file, __u32 hash,
__u32 minor_hash,
struct ext4_dir_entry_2 *dirent,
struct ext4_str *ent_name)
struct fscrypt_str *ent_name)
{
struct rb_node **p, *parent = NULL;
struct fname *fname, *new_fn;
......@@ -609,7 +611,7 @@ static int ext4_dx_readdir(struct file *file, struct dir_context *ctx)
static int ext4_dir_open(struct inode * inode, struct file * filp)
{
if (ext4_encrypted_inode(inode))
return ext4_get_encryption_info(inode) ? -EACCES : 0;
return fscrypt_get_encryption_info(inode) ? -EACCES : 0;
return 0;
}
......
fs/ext4/ext4.h
View file @ a7550b30
This diff is collapsed.
fs/ext4/ext4_crypto.h deleted 100644 → 0
View file @ ff0031d8
/*
* linux/fs/ext4/ext4_crypto.h
*
* Copyright (C) 2015, Google, Inc.
*
* This contains encryption header content for ext4
*
* Written by Michael Halcrow, 2015.
*/
#ifndef _EXT4_CRYPTO_H
#define _EXT4_CRYPTO_H
#include <linux/fs.h>
#define EXT4_KEY_DESCRIPTOR_SIZE 8
/* Policy provided via an ioctl on the topmost directory */
struct ext4_encryption_policy {
char version;
char contents_encryption_mode;
char filenames_encryption_mode;
char flags;
char master_key_descriptor[EXT4_KEY_DESCRIPTOR_SIZE];
} __attribute__((__packed__));
#define EXT4_ENCRYPTION_CONTEXT_FORMAT_V1 1
#define EXT4_KEY_DERIVATION_NONCE_SIZE 16
#define EXT4_POLICY_FLAGS_PAD_4 0x00
#define EXT4_POLICY_FLAGS_PAD_8 0x01
#define EXT4_POLICY_FLAGS_PAD_16 0x02
#define EXT4_POLICY_FLAGS_PAD_32 0x03
#define EXT4_POLICY_FLAGS_PAD_MASK 0x03
#define EXT4_POLICY_FLAGS_VALID 0x03
/**
* Encryption context for inode
*
* Protector format:
* 1 byte: Protector format (1 = this version)
* 1 byte: File contents encryption mode
* 1 byte: File names encryption mode
* 1 byte: Reserved
* 8 bytes: Master Key descriptor
* 16 bytes: Encryption Key derivation nonce
*/
struct ext4_encryption_context {
char format;
char contents_encryption_mode;
char filenames_encryption_mode;
char flags;
char master_key_descriptor[EXT4_KEY_DESCRIPTOR_SIZE];
char nonce[EXT4_KEY_DERIVATION_NONCE_SIZE];
} __attribute__((__packed__));
/* Encryption parameters */
#define EXT4_XTS_TWEAK_SIZE 16
#define EXT4_AES_128_ECB_KEY_SIZE 16
#define EXT4_AES_256_GCM_KEY_SIZE 32
#define EXT4_AES_256_CBC_KEY_SIZE 32
#define EXT4_AES_256_CTS_KEY_SIZE 32
#define EXT4_AES_256_XTS_KEY_SIZE 64
#define EXT4_MAX_KEY_SIZE 64
#define EXT4_KEY_DESC_PREFIX "ext4:"
#define EXT4_KEY_DESC_PREFIX_SIZE 5
/* This is passed in from userspace into the kernel keyring */
struct ext4_encryption_key {
__u32 mode;
char raw[EXT4_MAX_KEY_SIZE];
__u32 size;
} __attribute__((__packed__));
struct ext4_crypt_info {
char ci_data_mode;
char ci_filename_mode;
char ci_flags;
struct crypto_skcipher *ci_ctfm;
struct key *ci_keyring_key;
char ci_master_key[EXT4_KEY_DESCRIPTOR_SIZE];
};
#define EXT4_CTX_REQUIRES_FREE_ENCRYPT_FL 0x00000001
#define EXT4_WRITE_PATH_FL 0x00000002
struct ext4_crypto_ctx {
union {
struct {
struct page *bounce_page; /* Ciphertext page */
struct page *control_page; /* Original page */
} w;
struct {
struct bio *bio;
struct work_struct work;
} r;
struct list_head free_list; /* Free list */
};
char flags; /* Flags */
char mode; /* Encryption mode for tfm */
};
struct ext4_completion_result {
struct completion completion;
int res;
};
#define DECLARE_EXT4_COMPLETION_RESULT(ecr) \
struct ext4_completion_result ecr = { \
COMPLETION_INITIALIZER((ecr).completion), 0 }
static inline int ext4_encryption_key_size(int mode)
{
switch (mode) {
case EXT4_ENCRYPTION_MODE_AES_256_XTS:
return EXT4_AES_256_XTS_KEY_SIZE;
case EXT4_ENCRYPTION_MODE_AES_256_GCM:
return EXT4_AES_256_GCM_KEY_SIZE;
case EXT4_ENCRYPTION_MODE_AES_256_CBC:
return EXT4_AES_256_CBC_KEY_SIZE;
case EXT4_ENCRYPTION_MODE_AES_256_CTS:
return EXT4_AES_256_CTS_KEY_SIZE;
default:
BUG();
}
return 0;
}
#define EXT4_FNAME_NUM_SCATTER_ENTRIES 4
#define EXT4_CRYPTO_BLOCK_SIZE 16
#define EXT4_FNAME_CRYPTO_DIGEST_SIZE 32
struct ext4_str {
unsigned char *name;
u32 len;
};
/**
* For encrypted symlinks, the ciphertext length is stored at the beginning
* of the string in little-endian format.
*/
struct ext4_encrypted_symlink_data {
__le16 len;
char encrypted_path[1];
} __attribute__((__packed__));
/**
* This function is used to calculate the disk space required to
* store a filename of length l in encrypted symlink format.
*/
static inline u32 encrypted_symlink_data_len(u32 l)
{
if (l < EXT4_CRYPTO_BLOCK_SIZE)
l = EXT4_CRYPTO_BLOCK_SIZE;
return (l + sizeof(struct ext4_encrypted_symlink_data) - 1);
}
#endif /* _EXT4_CRYPTO_H */
fs/ext4/file.c
View file @ a7550b30
......@@ -303,10 +303,10 @@ static int ext4_file_mmap(struct file *file, struct vm_area_struct *vma)
struct inode *inode = file->f_mapping->host;
if (ext4_encrypted_inode(inode)) {
int err = ext4_get_encryption_info(inode);
int err = fscrypt_get_encryption_info(inode);
if (err)
return 0;
if (ext4_encryption_info(inode) == NULL)
if (!fscrypt_has_encryption_key(inode))
return -ENOKEY;
}
file_accessed(file);
......@@ -362,16 +362,16 @@ static int ext4_file_open(struct inode * inode, struct file * filp)
}
}
if (ext4_encrypted_inode(inode)) {
ret = ext4_get_encryption_info(inode);
ret = fscrypt_get_encryption_info(inode);
if (ret)
return -EACCES;
if (ext4_encryption_info(inode) == NULL)
if (!fscrypt_has_encryption_key(inode))
return -ENOKEY;
}
dir = dget_parent(file_dentry(filp));
if (ext4_encrypted_inode(d_inode(dir)) &&
!ext4_is_child_context_consistent_with_parent(d_inode(dir), inode)) {
!fscrypt_has_permitted_context(d_inode(dir), inode)) {
ext4_warning(inode->i_sb,
"Inconsistent encryption contexts: %lu/%lu",
(unsigned long) d_inode(dir)->i_ino,
......
fs/ext4/ialloc.c
View file @ a7550b30
......@@ -767,10 +767,10 @@ struct inode *__ext4_new_inode(handle_t *handle, struct inode *dir,
if ((ext4_encrypted_inode(dir) ||
DUMMY_ENCRYPTION_ENABLED(EXT4_SB(dir->i_sb))) &&
(S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode))) {
err = ext4_get_encryption_info(dir);
err = fscrypt_get_encryption_info(dir);
if (err)
return ERR_PTR(err);
if (ext4_encryption_info(dir) == NULL)
if (!fscrypt_has_encryption_key(dir))
return ERR_PTR(-EPERM);
if (!handle)
nblocks += EXT4_DATA_TRANS_BLOCKS(dir->i_sb);
......@@ -1115,7 +1115,8 @@ struct inode *__ext4_new_inode(handle_t *handle, struct inode *dir,
}
if (encrypt) {
err = ext4_inherit_context(dir, inode);
/* give pointer to avoid set_context with journal ops. */
err = fscrypt_inherit_context(dir, inode, &encrypt, true);
if (err)
goto fail_free_drop;
}
......
fs/ext4/inline.c
View file @ a7550b30
......@@ -1326,7 +1326,7 @@ int htree_inlinedir_to_tree(struct file *dir_file,
struct ext4_iloc iloc;
void *dir_buf = NULL;
struct ext4_dir_entry_2 fake;
struct ext4_str tmp_str;
struct fscrypt_str tmp_str;
ret = ext4_get_inode_loc(inode, &iloc);
if (ret)
......@@ -1739,20 +1739,20 @@ ext4_get_inline_entry(struct inode *inode,
return (struct ext4_dir_entry_2 *)(inline_pos + offset);
}
int empty_inline_dir(struct inode *dir, int *has_inline_data)
bool empty_inline_dir(struct inode *dir, int *has_inline_data)
{
int err, inline_size;
struct ext4_iloc iloc;
void *inline_pos;
unsigned int offset;
struct ext4_dir_entry_2 *de;
int ret = 1;
bool ret = true;
err = ext4_get_inode_loc(dir, &iloc);
if (err) {
EXT4_ERROR_INODE(dir, "error %d getting inode %lu block",
err, dir->i_ino);
return 1;
return true;
}
down_read(&EXT4_I(dir)->xattr_sem);
......@@ -1766,7 +1766,7 @@ int empty_inline_dir(struct inode *dir, int *has_inline_data)
ext4_warning(dir->i_sb,
"bad inline directory (dir #%lu) - no `..'",
dir->i_ino);
ret = 1;
ret = true;
goto out;
}
......@@ -1784,11 +1784,11 @@ int empty_inline_dir(struct inode *dir, int *has_inline_data)
dir->i_ino, le32_to_cpu(de->inode),
le16_to_cpu(de->rec_len), de->name_len,
inline_size);
ret = 1;
ret = true;
goto out;
}
if (le32_to_cpu(de->inode)) {
ret = 0;
ret = false;
goto out;
}
offset += ext4_rec_len_from_disk(de->rec_len, inline_size);
......
fs/ext4/inode.c
View file @ a7550b30
......@@ -392,7 +392,7 @@ int ext4_issue_zeroout(struct inode *inode, ext4_lblk_t lblk, ext4_fsblk_t pblk,
int ret;
if (ext4_encrypted_inode(inode))
return ext4_encrypted_zeroout(inode, lblk, pblk, len);
return fscrypt_zeroout_range(inode, lblk, pblk, len);
ret = sb_issue_zeroout(inode->i_sb, pblk, len, GFP_NOFS);
if (ret > 0)
......@@ -1158,7 +1158,7 @@ static int ext4_block_write_begin(struct page *page, loff_t pos, unsigned len,
if (unlikely(err))
page_zero_new_buffers(page, from, to);
else if (decrypt)
err = ext4_decrypt(page);
err = fscrypt_decrypt_page(page);
return err;
}
#endif
......@@ -3735,9 +3735,9 @@ static int __ext4_block_zero_page_range(handle_t *handle,
if (S_ISREG(inode->i_mode) &&
ext4_encrypted_inode(inode)) {
/* We expect the key to be set. */
BUG_ON(!ext4_has_encryption_key(inode));
BUG_ON(!fscrypt_has_encryption_key(inode));
BUG_ON(blocksize != PAGE_SIZE);
WARN_ON_ONCE(ext4_decrypt(page));
WARN_ON_ONCE(fscrypt_decrypt_page(page));
}
}
if (ext4_should_journal_data(inode)) {
......
fs/ext4/ioctl.c
View file @ a7550b30
......@@ -770,19 +770,13 @@ long ext4_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
return ext4_ext_precache(inode);
case EXT4_IOC_SET_ENCRYPTION_POLICY: {
#ifdef CONFIG_EXT4_FS_ENCRYPTION
struct ext4_encryption_policy policy;
int err = 0;
struct fscrypt_policy policy;
if (copy_from_user(&policy,
(struct ext4_encryption_policy __user *)arg,
sizeof(policy))) {
err = -EFAULT;
goto encryption_policy_out;
}
err = ext4_process_policy(&policy, inode);
encryption_policy_out:
return err;
(struct fscrypt_policy __user *)arg,
sizeof(policy)))
return -EFAULT;
return fscrypt_process_policy(inode, &policy);
#else
return -EOPNOTSUPP;
#endif
......@@ -825,12 +819,12 @@ long ext4_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
}
case EXT4_IOC_GET_ENCRYPTION_POLICY: {
#ifdef CONFIG_EXT4_FS_ENCRYPTION
struct ext4_encryption_policy policy;
struct fscrypt_policy policy;
int err = 0;
if (!ext4_encrypted_inode(inode))
return -ENOENT;
err = ext4_get_policy(inode, &policy);
err = fscrypt_get_policy(inode, &policy);
if (err)
return err;
if (copy_to_user((void __user *)arg, &policy, sizeof(policy)))
......
fs/ext4/namei.c
View file @ a7550b30
This diff is collapsed.
fs/ext4/page-io.c
View file @ a7550b30
......@@ -24,6 +24,7 @@
#include <linux/slab.h>
#include <linux/mm.h>
#include <linux/backing-dev.h>
#include <linux/fscrypto.h>
#include "ext4_jbd2.h"
#include "xattr.h"
......@@ -67,7 +68,6 @@ static void ext4_finish_bio(struct bio *bio)
struct page *page = bvec->bv_page;
#ifdef CONFIG_EXT4_FS_ENCRYPTION
struct page *data_page = NULL;
struct ext4_crypto_ctx *ctx = NULL;
#endif
struct buffer_head *bh, *head;
unsigned bio_start = bvec->bv_offset;
......@@ -82,8 +82,7 @@ static void ext4_finish_bio(struct bio *bio)
if (!page->mapping) {
/* The bounce data pages are unmapped. */
data_page = page;
ctx = (struct ext4_crypto_ctx *)page_private(data_page);
page = ctx->w.control_page;
fscrypt_pullback_bio_page(&page, false);
}
#endif
......@@ -113,8 +112,8 @@ static void ext4_finish_bio(struct bio *bio)
local_irq_restore(flags);
if (!under_io) {
#ifdef CONFIG_EXT4_FS_ENCRYPTION
if (ctx)
ext4_restore_control_page(data_page);
if (data_page)
fscrypt_restore_control_page(data_page);
#endif
end_page_writeback(page);
}
......@@ -472,7 +471,7 @@ int ext4_bio_write_page(struct ext4_io_submit *io,
gfp_t gfp_flags = GFP_NOFS;
retry_encrypt:
data_page = ext4_encrypt(inode, page, gfp_flags);
data_page = fscrypt_encrypt_page(inode, page, gfp_flags);
if (IS_ERR(data_page)) {
ret = PTR_ERR(data_page);
if (ret == -ENOMEM && wbc->sync_mode == WB_SYNC_ALL) {
......@@ -510,7 +509,7 @@ int ext4_bio_write_page(struct ext4_io_submit *io,
if (ret) {
out:
if (data_page)
ext4_restore_control_page(data_page);
fscrypt_restore_control_page(data_page);
printk_ratelimited(KERN_ERR "%s: ret = %d\n", __func__, ret);
redirty_page_for_writepage(wbc, page);
do {
......
fs/ext4/readpage.c
View file @ a7550b30
......@@ -46,37 +46,6 @@
#include "ext4.h"
/*
* Call ext4_decrypt on every single page, reusing the encryption
* context.
*/
static void completion_pages(struct work_struct *work)
{
#ifdef CONFIG_EXT4_FS_ENCRYPTION
struct ext4_crypto_ctx *ctx =
container_of(work, struct ext4_crypto_ctx, r.work);
struct bio *bio = ctx->r.bio;
struct bio_vec *bv;
int i;
bio_for_each_segment_all(bv, bio, i) {
struct page *page = bv->bv_page;
int ret = ext4_decrypt(page);
if (ret) {
WARN_ON_ONCE(1);
SetPageError(page);
} else
SetPageUptodate(page);
unlock_page(page);
}
ext4_release_crypto_ctx(ctx);
bio_put(bio);
#else
BUG();
#endif
}
static inline bool ext4_bio_encrypted(struct bio *bio)
{
#ifdef CONFIG_EXT4_FS_ENCRYPTION
......@@ -104,14 +73,10 @@ static void mpage_end_io(struct bio *bio)
int i;
if (ext4_bio_encrypted(bio)) {
struct ext4_crypto_ctx *ctx = bio->bi_private;
if (bio->bi_error) {
ext4_release_crypto_ctx(ctx);
fscrypt_release_ctx(bio->bi_private);
} else {
INIT_WORK(&ctx->r.work, completion_pages);
ctx->r.bio = bio;
queue_work(ext4_read_workqueue, &ctx->r.work);
fscrypt_decrypt_bio_pages(bio->bi_private, bio);
return;
}
}
......@@ -274,11 +239,11 @@ int ext4_mpage_readpages(struct address_space *mapping,
bio = NULL;
}
if (bio == NULL) {
struct ext4_crypto_ctx *ctx = NULL;
struct fscrypt_ctx *ctx = NULL;
if (ext4_encrypted_inode(inode) &&
S_ISREG(inode->i_mode)) {
ctx = ext4_get_crypto_ctx(inode, GFP_NOFS);
ctx = fscrypt_get_ctx(inode, GFP_NOFS);
if (IS_ERR(ctx))
goto set_error_page;
}
......@@ -286,7 +251,7 @@ int ext4_mpage_readpages(struct address_space *mapping,
min_t(int, nr_pages, BIO_MAX_PAGES));
if (!bio) {
if (ctx)
ext4_release_crypto_ctx(ctx);
fscrypt_release_ctx(ctx);
goto set_error_page;
}
bio->bi_bdev = bdev;
......
fs/ext4/super.c
View file @ a7550b30
......@@ -945,9 +945,6 @@ static struct inode *ext4_alloc_inode(struct super_block *sb)
ei->i_datasync_tid = 0;
atomic_set(&ei->i_unwritten, 0);
INIT_WORK(&ei->i_rsv_conversion_work, ext4_end_io_rsv_work);
#ifdef CONFIG_EXT4_FS_ENCRYPTION
ei->i_crypt_info = NULL;
#endif
return &ei->vfs_inode;
}
......@@ -1026,8 +1023,7 @@ void ext4_clear_inode(struct inode *inode)
EXT4_I(inode)->jinode = NULL;
}
#ifdef CONFIG_EXT4_FS_ENCRYPTION
if (EXT4_I(inode)->i_crypt_info)
ext4_free_encryption_info(inode, EXT4_I(inode)->i_crypt_info);
fscrypt_put_encryption_info(inode, NULL);
#endif
}
......@@ -1094,6 +1090,90 @@ static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
return try_to_free_buffers(page);
}
#ifdef CONFIG_EXT4_FS_ENCRYPTION
static int ext4_get_context(struct inode *inode, void *ctx, size_t len)
{
return ext4_xattr_get(inode, EXT4_XATTR_INDEX_ENCRYPTION,
EXT4_XATTR_NAME_ENCRYPTION_CONTEXT, ctx, len);
}
static int ext4_key_prefix(struct inode *inode, u8 **key)
{
*key = EXT4_SB(inode->i_sb)->key_prefix;
return EXT4_SB(inode->i_sb)->key_prefix_size;
}
static int ext4_prepare_context(struct inode *inode)
{
return ext4_convert_inline_data(inode);
}
static int ext4_set_context(struct inode *inode, const void *ctx, size_t len,
void *fs_data)
{
handle_t *handle;
int res, res2;
/* fs_data is null when internally used. */
if (fs_data) {
res = ext4_xattr_set(inode, EXT4_XATTR_INDEX_ENCRYPTION,
EXT4_XATTR_NAME_ENCRYPTION_CONTEXT, ctx,
len, 0);
if (!res) {
ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
ext4_clear_inode_state(inode,
EXT4_STATE_MAY_INLINE_DATA);
}
return res;
}
handle = ext4_journal_start(inode, EXT4_HT_MISC,
ext4_jbd2_credits_xattr(inode));
if (IS_ERR(handle))
return PTR_ERR(handle);
res = ext4_xattr_set(inode, EXT4_XATTR_INDEX_ENCRYPTION,
EXT4_XATTR_NAME_ENCRYPTION_CONTEXT, ctx,
len, 0);
if (!res) {
ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
res = ext4_mark_inode_dirty(handle, inode);
if (res)
EXT4_ERROR_INODE(inode, "Failed to mark inode dirty");
}
res2 = ext4_journal_stop(handle);
if (!res)
res = res2;
return res;
}
static int ext4_dummy_context(struct inode *inode)
{
return DUMMY_ENCRYPTION_ENABLED(EXT4_SB(inode->i_sb));
}
static unsigned ext4_max_namelen(struct inode *inode)
{
return S_ISLNK(inode->i_mode) ? inode->i_sb->s_blocksize :
EXT4_NAME_LEN;
}
static struct fscrypt_operations ext4_cryptops = {
.get_context = ext4_get_context,
.key_prefix = ext4_key_prefix,
.prepare_context = ext4_prepare_context,
.set_context = ext4_set_context,
.dummy_context = ext4_dummy_context,
.is_encrypted = ext4_encrypted_inode,
.empty_dir = ext4_empty_dir,
.max_namelen = ext4_max_namelen,
};
#else
static struct fscrypt_operations ext4_cryptops = {
.is_encrypted = ext4_encrypted_inode,
};
#endif
#ifdef CONFIG_QUOTA
static char *quotatypes[] = INITQFNAMES;
#define QTYPE2NAME(t) (quotatypes[t])
......@@ -3693,6 +3773,7 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
sb->s_op = &ext4_sops;
sb->s_export_op = &ext4_export_ops;
sb->s_xattr = ext4_xattr_handlers;
sb->s_cop = &ext4_cryptops;
#ifdef CONFIG_QUOTA
sb->dq_op = &ext4_quota_operations;
if (ext4_has_feature_quota(sb))
......@@ -4003,6 +4084,11 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
ratelimit_state_init(&sbi->s_msg_ratelimit_state, 5 * HZ, 10);
kfree(orig_data);
#ifdef CONFIG_EXT4_FS_ENCRYPTION
memcpy(sbi->key_prefix, EXT4_KEY_DESC_PREFIX,
EXT4_KEY_DESC_PREFIX_SIZE);
sbi->key_prefix_size = EXT4_KEY_DESC_PREFIX_SIZE;
#endif
return 0;
cantfind_ext4:
......@@ -5431,7 +5517,6 @@ static int __init ext4_init_fs(void)
static void __exit ext4_exit_fs(void)
{
ext4_exit_crypto();
ext4_destroy_lazyinit_thread();
unregister_as_ext2();
unregister_as_ext3();
......
fs/ext4/symlink.c
View file @ a7550b30
......@@ -22,23 +22,22 @@
#include "ext4.h"
#include "xattr.h"
#ifdef CONFIG_EXT4_FS_ENCRYPTION
static const char *ext4_encrypted_get_link(struct dentry *dentry,
struct inode *inode,
struct delayed_call *done)
{
struct page *cpage = NULL;
char *caddr, *paddr = NULL;
struct ext4_str cstr, pstr;
struct ext4_encrypted_symlink_data *sd;
struct fscrypt_str cstr, pstr;
struct fscrypt_symlink_data *sd;
loff_t size = min_t(loff_t, i_size_read(inode), PAGE_SIZE - 1);
int res;
u32 plen, max_size = inode->i_sb->s_blocksize;
u32 max_size = inode->i_sb->s_blocksize;
if (!dentry)
return ERR_PTR(-ECHILD);
res = ext4_get_encryption_info(inode);
res = fscrypt_get_encryption_info(inode);
if (res)
return ERR_PTR(res);
......@@ -54,30 +53,27 @@ static const char *ext4_encrypted_get_link(struct dentry *dentry,
}
/* Symlink is encrypted */
sd = (struct ext4_encrypted_symlink_data *)caddr;
sd = (struct fscrypt_symlink_data *)caddr;
cstr.name = sd->encrypted_path;
cstr.len = le16_to_cpu(sd->len);
if ((cstr.len +
sizeof(struct ext4_encrypted_symlink_data) - 1) >
max_size) {
if ((cstr.len + sizeof(struct fscrypt_symlink_data) - 1) > max_size) {
/* Symlink data on the disk is corrupted */
res = -EFSCORRUPTED;
goto errout;
}
plen = (cstr.len < EXT4_FNAME_CRYPTO_DIGEST_SIZE*2) ?
EXT4_FNAME_CRYPTO_DIGEST_SIZE*2 : cstr.len;
paddr = kmalloc(plen + 1, GFP_NOFS);
if (!paddr) {
res = -ENOMEM;
res = fscrypt_fname_alloc_buffer(inode, cstr.len, &pstr);
if (res)
goto errout;
}
pstr.name = paddr;
pstr.len = plen;
res = _ext4_fname_disk_to_usr(inode, NULL, &cstr, &pstr);
res = fscrypt_fname_disk_to_usr(inode, 0, 0, &cstr, &pstr);
if (res < 0)
goto errout;
paddr = pstr.name;
/* Null-terminate the name */
if (res <= plen)
if (res <= pstr.len)
paddr[res] = '\0';
if (cpage)
put_page(cpage);
......@@ -99,7 +95,6 @@ const struct inode_operations ext4_encrypted_symlink_inode_operations = {
.listxattr = ext4_listxattr,
.removexattr = generic_removexattr,
};
#endif
const struct inode_operations ext4_symlink_inode_operations = {
.readlink = generic_readlink,
......
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