* [PATCH 1/4] ext4 crypto: optimize filename encryption
@ 2015-05-05 15:18 Theodore Ts'o
2015-05-05 15:18 ` [PATCH 2/4] ext4 crypto: don't allocate a page when encrypting/decrypting file names Theodore Ts'o
` (2 more replies)
0 siblings, 3 replies; 4+ messages in thread
From: Theodore Ts'o @ 2015-05-05 15:18 UTC (permalink / raw)
To: Ext4 Developers List; +Cc: mhalcrow, savagaon, Theodore Ts'o
Encrypt the filename as soon it is passed in by the user. This avoids
our needing to encrypt the filename 2 or 3 times while in the process
of creating a filename.
Similarly, when looking up a directory entry, encrypt the filename
early, or if the encryption key is not available, base-64 decode the
file syystem so that the hash value and the last 16 bytes of the
encrypted filename is available in the new struct ext4_filename data
structure.
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
---
fs/ext4/crypto_fname.c | 155 +++++++++++---------------
fs/ext4/ext4.h | 63 +++++++----
fs/ext4/inline.c | 31 +++---
fs/ext4/namei.c | 294 ++++++++++++++++++-------------------------------
4 files changed, 230 insertions(+), 313 deletions(-)
diff --git a/fs/ext4/crypto_fname.c b/fs/ext4/crypto_fname.c
index fded02f..ad5e328 100644
--- a/fs/ext4/crypto_fname.c
+++ b/fs/ext4/crypto_fname.c
@@ -611,109 +611,82 @@ int ext4_fname_usr_to_disk(struct ext4_fname_crypto_ctx *ctx,
return -EACCES;
}
-/*
- * Calculate the htree hash from a filename from user space
- */
-int ext4_fname_usr_to_hash(struct ext4_fname_crypto_ctx *ctx,
- const struct qstr *iname,
- struct dx_hash_info *hinfo)
+int ext4_fname_setup_filename(struct inode *dir, const struct qstr *iname,
+ int lookup, struct ext4_filename *fname)
{
- struct ext4_str tmp;
- int ret = 0;
- char buf[EXT4_FNAME_CRYPTO_DIGEST_SIZE+1];
+ struct ext4_fname_crypto_ctx *ctx;
+ int ret = 0, bigname = 0;
+
+ memset(fname, 0, sizeof(struct ext4_filename));
+ fname->usr_fname = iname;
- if (!ctx ||
+ ctx = ext4_get_fname_crypto_ctx(dir, EXT4_NAME_LEN);
+ if (IS_ERR(ctx))
+ return PTR_ERR(ctx);
+ if ((ctx == NULL) ||
((iname->name[0] == '.') &&
((iname->len == 1) ||
((iname->name[1] == '.') && (iname->len == 2))))) {
- ext4fs_dirhash(iname->name, iname->len, hinfo);
- return 0;
+ fname->disk_name.name = (unsigned char *) iname->name;
+ fname->disk_name.len = iname->len;
+ goto out;
}
-
- if (!ctx->has_valid_key && iname->name[0] == '_') {
- if (iname->len != 33)
- return -ENOENT;
- ret = digest_decode(iname->name+1, iname->len, buf);
- if (ret != 24)
- return -ENOENT;
- memcpy(&hinfo->hash, buf, 4);
- memcpy(&hinfo->minor_hash, buf + 4, 4);
- return 0;
+ if (ctx->has_valid_key) {
+ ret = ext4_fname_crypto_alloc_buffer(ctx, iname->len,
+ &fname->crypto_buf);
+ if (ret < 0)
+ goto out;
+ ret = ext4_fname_encrypt(ctx, iname, &fname->crypto_buf);
+ if (ret < 0)
+ goto out;
+ fname->disk_name.name = fname->crypto_buf.name;
+ fname->disk_name.len = fname->crypto_buf.len;
+ ret = 0;
+ goto out;
}
-
- if (!ctx->has_valid_key && iname->name[0] != '_') {
- if (iname->len > 43)
- return -ENOENT;
- ret = digest_decode(iname->name, iname->len, buf);
- ext4fs_dirhash(buf, ret, hinfo);
- return 0;
+ if (!lookup) {
+ ret = -EACCES;
+ goto out;
}
- /* First encrypt the plaintext name */
- ret = ext4_fname_crypto_alloc_buffer(ctx, iname->len, &tmp);
- if (ret < 0)
- return ret;
-
- ret = ext4_fname_encrypt(ctx, iname, &tmp);
- if (ret >= 0) {
- ext4fs_dirhash(tmp.name, tmp.len, hinfo);
- ret = 0;
+ /* We don't have the key and we are doing a lookup; decode the
+ * user-supplied name
+ */
+ if (iname->name[0] == '_')
+ bigname = 1;
+ if ((bigname && (iname->len != 33)) ||
+ (!bigname && (iname->len > 43))) {
+ ret = -ENOENT;
}
-
- ext4_fname_crypto_free_buffer(&tmp);
+ fname->crypto_buf.name = kmalloc(32, GFP_KERNEL);
+ if (fname->crypto_buf.name == NULL) {
+ ret = -ENOMEM;
+ goto out;
+ }
+ ret = digest_decode(iname->name + bigname, iname->len - bigname,
+ fname->crypto_buf.name);
+ if (ret < 0) {
+ ret = -ENOENT;
+ goto out;
+ }
+ fname->crypto_buf.len = ret;
+ if (bigname) {
+ memcpy(&fname->hinfo.hash, fname->crypto_buf.name, 4);
+ memcpy(&fname->hinfo.minor_hash, fname->crypto_buf.name + 4, 4);
+ } else {
+ fname->disk_name.name = fname->crypto_buf.name;
+ fname->disk_name.len = fname->crypto_buf.len;
+ }
+ ret = 0;
+out:
+ ext4_put_fname_crypto_ctx(&ctx);
return ret;
}
-int ext4_fname_match(struct ext4_fname_crypto_ctx *ctx, struct ext4_str *cstr,
- int len, const char * const name,
- struct ext4_dir_entry_2 *de)
+void ext4_fname_free_filename(struct ext4_filename *fname)
{
- int ret = -ENOENT;
- int bigname = (*name == '_');
-
- if (ctx->has_valid_key) {
- if (cstr->name == NULL) {
- struct qstr istr;
-
- ret = ext4_fname_crypto_alloc_buffer(ctx, len, cstr);
- if (ret < 0)
- goto errout;
- istr.name = name;
- istr.len = len;
- ret = ext4_fname_encrypt(ctx, &istr, cstr);
- if (ret < 0)
- goto errout;
- }
- } else {
- if (cstr->name == NULL) {
- cstr->name = kmalloc(32, GFP_KERNEL);
- if (cstr->name == NULL)
- return -ENOMEM;
- if ((bigname && (len != 33)) ||
- (!bigname && (len > 43)))
- goto errout;
- ret = digest_decode(name+bigname, len-bigname,
- cstr->name);
- if (ret < 0) {
- ret = -ENOENT;
- goto errout;
- }
- cstr->len = ret;
- }
- if (bigname) {
- if (de->name_len < 16)
- return 0;
- ret = memcmp(de->name + de->name_len - 16,
- cstr->name + 8, 16);
- return (ret == 0) ? 1 : 0;
- }
- }
- if (de->name_len != cstr->len)
- return 0;
- ret = memcmp(de->name, cstr->name, cstr->len);
- return (ret == 0) ? 1 : 0;
-errout:
- kfree(cstr->name);
- cstr->name = NULL;
- return ret;
+ kfree(fname->crypto_buf.name);
+ fname->crypto_buf.name = NULL;
+ fname->usr_fname = NULL;
+ fname->disk_name.name = NULL;
}
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 009a059..6bdd69e 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -1838,6 +1838,17 @@ struct dx_hash_info
*/
#define HASH_NB_ALWAYS 1
+struct ext4_filename {
+ const struct qstr *usr_fname;
+ struct ext4_str disk_name;
+ struct dx_hash_info hinfo;
+#ifdef CONFIG_EXT4_FS_ENCRYPTION
+ struct ext4_str crypto_buf;
+#endif
+};
+
+#define fname_name(p) ((p)->disk_name.name)
+#define fname_len(p) ((p)->disk_name.len)
/*
* Describe an inode's exact location on disk and in memory
@@ -2098,21 +2109,16 @@ int ext4_fname_disk_to_usr(struct ext4_fname_crypto_ctx *ctx,
int ext4_fname_usr_to_disk(struct ext4_fname_crypto_ctx *ctx,
const struct qstr *iname,
struct ext4_str *oname);
-int ext4_fname_usr_to_hash(struct ext4_fname_crypto_ctx *ctx,
- const struct qstr *iname,
- struct dx_hash_info *hinfo);
int ext4_fname_crypto_namelen_on_disk(struct ext4_fname_crypto_ctx *ctx,
u32 namelen);
-int ext4_fname_match(struct ext4_fname_crypto_ctx *ctx, struct ext4_str *cstr,
- int len, const char * const name,
- struct ext4_dir_entry_2 *de);
-
-
#ifdef CONFIG_EXT4_FS_ENCRYPTION
void ext4_put_fname_crypto_ctx(struct ext4_fname_crypto_ctx **ctx);
struct ext4_fname_crypto_ctx *ext4_get_fname_crypto_ctx(struct inode *inode,
u32 max_len);
void ext4_fname_crypto_free_buffer(struct ext4_str *crypto_str);
+int ext4_fname_setup_filename(struct inode *dir, const struct qstr *iname,
+ int lookup, struct ext4_filename *fname);
+void ext4_fname_free_filename(struct ext4_filename *fname);
#else
static inline
void ext4_put_fname_crypto_ctx(struct ext4_fname_crypto_ctx **ctx) { }
@@ -2123,6 +2129,16 @@ struct ext4_fname_crypto_ctx *ext4_get_fname_crypto_ctx(struct inode *inode,
return NULL;
}
static inline void ext4_fname_crypto_free_buffer(struct ext4_str *p) { }
+static inline int ext4_fname_setup_filename(struct inode *dir,
+ const struct qstr *iname,
+ int lookup, struct ext4_filename *fname)
+{
+ fname->usr_fname = iname;
+ fname->disk_name.name = (unsigned char *) iname->name;
+ fname->disk_name.len = iname->len;
+ return 0;
+}
+static inline void ext4_fname_free_filename(struct ext4_filename *fname) { }
#endif
@@ -2156,14 +2172,13 @@ extern void ext4_htree_free_dir_info(struct dir_private_info *p);
extern int ext4_find_dest_de(struct inode *dir, struct inode *inode,
struct buffer_head *bh,
void *buf, int buf_size,
- const char *name, int namelen,
+ struct ext4_filename *fname,
struct ext4_dir_entry_2 **dest_de);
int ext4_insert_dentry(struct inode *dir,
- struct inode *inode,
- struct ext4_dir_entry_2 *de,
- int buf_size,
- const struct qstr *iname,
- const char *name, int namelen);
+ struct inode *inode,
+ struct ext4_dir_entry_2 *de,
+ int buf_size,
+ struct ext4_filename *fname);
static inline void ext4_update_dx_flag(struct inode *inode)
{
if (!EXT4_HAS_COMPAT_FEATURE(inode->i_sb,
@@ -2317,13 +2332,14 @@ extern int ext4_orphan_add(handle_t *, struct inode *);
extern int ext4_orphan_del(handle_t *, struct inode *);
extern int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash,
__u32 start_minor_hash, __u32 *next_hash);
-extern int search_dir(struct buffer_head *bh,
- char *search_buf,
- int buf_size,
- struct inode *dir,
- const struct qstr *d_name,
- unsigned int offset,
- struct ext4_dir_entry_2 **res_dir);
+extern int ext4_search_dir(struct buffer_head *bh,
+ char *search_buf,
+ int buf_size,
+ struct inode *dir,
+ struct ext4_filename *fname,
+ const struct qstr *d_name,
+ unsigned int offset,
+ struct ext4_dir_entry_2 **res_dir);
extern int ext4_generic_delete_entry(handle_t *handle,
struct inode *dir,
struct ext4_dir_entry_2 *de_del,
@@ -2768,7 +2784,9 @@ extern int ext4_da_write_inline_data_begin(struct address_space *mapping,
extern int ext4_da_write_inline_data_end(struct inode *inode, loff_t pos,
unsigned len, unsigned copied,
struct page *page);
-extern int ext4_try_add_inline_entry(handle_t *handle, struct dentry *dentry,
+extern int ext4_try_add_inline_entry(handle_t *handle,
+ struct ext4_filename *fname,
+ struct dentry *dentry,
struct inode *inode);
extern int ext4_try_create_inline_dir(handle_t *handle,
struct inode *parent,
@@ -2782,6 +2800,7 @@ extern int htree_inlinedir_to_tree(struct file *dir_file,
__u32 start_hash, __u32 start_minor_hash,
int *has_inline_data);
extern struct buffer_head *ext4_find_inline_entry(struct inode *dir,
+ struct ext4_filename *fname,
const struct qstr *d_name,
struct ext4_dir_entry_2 **res_dir,
int *has_inline_data);
diff --git a/fs/ext4/inline.c b/fs/ext4/inline.c
index 095c7a2..cd944a7 100644
--- a/fs/ext4/inline.c
+++ b/fs/ext4/inline.c
@@ -995,20 +995,18 @@ void ext4_show_inline_dir(struct inode *dir, struct buffer_head *bh,
* and -EEXIST if directory entry already exists.
*/
static int ext4_add_dirent_to_inline(handle_t *handle,
+ struct ext4_filename *fname,
struct dentry *dentry,
struct inode *inode,
struct ext4_iloc *iloc,
void *inline_start, int inline_size)
{
struct inode *dir = d_inode(dentry->d_parent);
- const char *name = dentry->d_name.name;
- int namelen = dentry->d_name.len;
int err;
struct ext4_dir_entry_2 *de;
- err = ext4_find_dest_de(dir, inode, iloc->bh,
- inline_start, inline_size,
- name, namelen, &de);
+ err = ext4_find_dest_de(dir, inode, iloc->bh, inline_start,
+ inline_size, fname, &de);
if (err)
return err;
@@ -1016,8 +1014,7 @@ static int ext4_add_dirent_to_inline(handle_t *handle,
err = ext4_journal_get_write_access(handle, iloc->bh);
if (err)
return err;
- ext4_insert_dentry(dir, inode, de, inline_size, &dentry->d_name,
- name, namelen);
+ ext4_insert_dentry(dir, inode, de, inline_size, fname);
ext4_show_inline_dir(dir, iloc->bh, inline_start, inline_size);
@@ -1248,8 +1245,8 @@ out:
* If succeeds, return 0. If not, extended the inline dir and copied data to
* the new created block.
*/
-int ext4_try_add_inline_entry(handle_t *handle, struct dentry *dentry,
- struct inode *inode)
+int ext4_try_add_inline_entry(handle_t *handle, struct ext4_filename *fname,
+ struct dentry *dentry, struct inode *inode)
{
int ret, inline_size;
void *inline_start;
@@ -1268,7 +1265,7 @@ int ext4_try_add_inline_entry(handle_t *handle, struct dentry *dentry,
EXT4_INLINE_DOTDOT_SIZE;
inline_size = EXT4_MIN_INLINE_DATA_SIZE - EXT4_INLINE_DOTDOT_SIZE;
- ret = ext4_add_dirent_to_inline(handle, dentry, inode, &iloc,
+ ret = ext4_add_dirent_to_inline(handle, fname, dentry, inode, &iloc,
inline_start, inline_size);
if (ret != -ENOSPC)
goto out;
@@ -1289,8 +1286,9 @@ int ext4_try_add_inline_entry(handle_t *handle, struct dentry *dentry,
if (inline_size) {
inline_start = ext4_get_inline_xattr_pos(dir, &iloc);
- ret = ext4_add_dirent_to_inline(handle, dentry, inode, &iloc,
- inline_start, inline_size);
+ ret = ext4_add_dirent_to_inline(handle, fname, dentry,
+ inode, &iloc, inline_start,
+ inline_size);
if (ret != -ENOSPC)
goto out;
@@ -1611,6 +1609,7 @@ out:
}
struct buffer_head *ext4_find_inline_entry(struct inode *dir,
+ struct ext4_filename *fname,
const struct qstr *d_name,
struct ext4_dir_entry_2 **res_dir,
int *has_inline_data)
@@ -1632,8 +1631,8 @@ struct buffer_head *ext4_find_inline_entry(struct inode *dir,
inline_start = (void *)ext4_raw_inode(&iloc)->i_block +
EXT4_INLINE_DOTDOT_SIZE;
inline_size = EXT4_MIN_INLINE_DATA_SIZE - EXT4_INLINE_DOTDOT_SIZE;
- ret = search_dir(iloc.bh, inline_start, inline_size,
- dir, d_name, 0, res_dir);
+ ret = ext4_search_dir(iloc.bh, inline_start, inline_size,
+ dir, fname, d_name, 0, res_dir);
if (ret == 1)
goto out_find;
if (ret < 0)
@@ -1645,8 +1644,8 @@ struct buffer_head *ext4_find_inline_entry(struct inode *dir,
inline_start = ext4_get_inline_xattr_pos(dir, &iloc);
inline_size = ext4_get_inline_size(dir) - EXT4_MIN_INLINE_DATA_SIZE;
- ret = search_dir(iloc.bh, inline_start, inline_size,
- dir, d_name, 0, res_dir);
+ ret = ext4_search_dir(iloc.bh, inline_start, inline_size,
+ dir, fname, d_name, 0, res_dir);
if (ret == 1)
goto out_find;
diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
index 814f3be..56c60cb 100644
--- a/fs/ext4/namei.c
+++ b/fs/ext4/namei.c
@@ -248,7 +248,7 @@ static void dx_set_count(struct dx_entry *entries, unsigned value);
static void dx_set_limit(struct dx_entry *entries, unsigned value);
static unsigned dx_root_limit(struct inode *dir, unsigned infosize);
static unsigned dx_node_limit(struct inode *dir);
-static struct dx_frame *dx_probe(const struct qstr *d_name,
+static struct dx_frame *dx_probe(struct ext4_filename *fname,
struct inode *dir,
struct dx_hash_info *hinfo,
struct dx_frame *frame);
@@ -267,10 +267,10 @@ static int ext4_htree_next_block(struct inode *dir, __u32 hash,
struct dx_frame *frames,
__u32 *start_hash);
static struct buffer_head * ext4_dx_find_entry(struct inode *dir,
- const struct qstr *d_name,
+ struct ext4_filename *fname,
struct ext4_dir_entry_2 **res_dir);
-static int ext4_dx_add_entry(handle_t *handle, struct dentry *dentry,
- struct inode *inode);
+static int ext4_dx_add_entry(handle_t *handle, struct ext4_filename *fname,
+ struct dentry *dentry, struct inode *inode);
/* checksumming functions */
void initialize_dirent_tail(struct ext4_dir_entry_tail *t,
@@ -724,7 +724,7 @@ struct stats dx_show_entries(struct dx_hash_info *hinfo, struct inode *dir,
* back to userspace.
*/
static struct dx_frame *
-dx_probe(const struct qstr *d_name, struct inode *dir,
+dx_probe(struct ext4_filename *fname, struct inode *dir,
struct dx_hash_info *hinfo, struct dx_frame *frame_in)
{
unsigned count, indirect;
@@ -746,32 +746,14 @@ dx_probe(const struct qstr *d_name, struct inode *dir,
root->info.hash_version);
goto fail;
}
+ if (fname)
+ hinfo = &fname->hinfo;
hinfo->hash_version = root->info.hash_version;
if (hinfo->hash_version <= DX_HASH_TEA)
hinfo->hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
hinfo->seed = EXT4_SB(dir->i_sb)->s_hash_seed;
-#ifdef CONFIG_EXT4_FS_ENCRYPTION
- if (d_name) {
- struct ext4_fname_crypto_ctx *ctx = NULL;
- int res;
-
- /* Check if the directory is encrypted */
- ctx = ext4_get_fname_crypto_ctx(dir, EXT4_NAME_LEN);
- if (IS_ERR(ctx)) {
- ret_err = ERR_PTR(PTR_ERR(ctx));
- goto fail;
- }
- res = ext4_fname_usr_to_hash(ctx, d_name, hinfo);
- if (res < 0) {
- ret_err = ERR_PTR(res);
- goto fail;
- }
- ext4_put_fname_crypto_ctx(&ctx);
- }
-#else
- if (d_name)
- ext4fs_dirhash(d_name->name, d_name->len, hinfo);
-#endif
+ if (fname && fname_name(fname))
+ ext4fs_dirhash(fname_name(fname), fname_len(fname), hinfo);
hash = hinfo->hash;
if (root->info.unused_flags & 1) {
@@ -1155,12 +1137,13 @@ errout:
static inline int search_dirblock(struct buffer_head *bh,
struct inode *dir,
+ struct ext4_filename *fname,
const struct qstr *d_name,
unsigned int offset,
struct ext4_dir_entry_2 **res_dir)
{
- return search_dir(bh, bh->b_data, dir->i_sb->s_blocksize, dir,
- d_name, offset, res_dir);
+ return ext4_search_dir(bh, bh->b_data, dir->i_sb->s_blocksize, dir,
+ fname, d_name, offset, res_dir);
}
/*
@@ -1242,54 +1225,54 @@ static void dx_insert_block(struct dx_frame *frame, u32 hash, ext4_lblk_t block)
* `len <= EXT4_NAME_LEN' is guaranteed by caller.
* `de != NULL' is guaranteed by caller.
*/
-static inline int ext4_match(struct ext4_fname_crypto_ctx *ctx,
- struct ext4_str *fname_crypto_str,
- int len, const char * const name,
+static inline int ext4_match(struct ext4_filename *fname,
struct ext4_dir_entry_2 *de)
{
- int res;
+ const void *name = fname_name(fname);
+ u32 len = fname_len(fname);
if (!de->inode)
return 0;
#ifdef CONFIG_EXT4_FS_ENCRYPTION
- if (ctx)
- return ext4_fname_match(ctx, fname_crypto_str, len, name, de);
+ if (unlikely(!name)) {
+ if (fname->usr_fname->name[0] == '_') {
+ int ret;
+ if (de->name_len < 16)
+ return 0;
+ ret = memcmp(de->name + de->name_len - 16,
+ fname->crypto_buf.name + 8, 16);
+ return (ret == 0) ? 1 : 0;
+ }
+ name = fname->crypto_buf.name;
+ len = fname->crypto_buf.len;
+ }
#endif
- if (len != de->name_len)
+ if (de->name_len != len)
return 0;
- res = memcmp(name, de->name, len);
- return (res == 0) ? 1 : 0;
+ return (memcmp(de->name, name, len) == 0) ? 1 : 0;
}
/*
* Returns 0 if not found, -1 on failure, and 1 on success
*/
-int search_dir(struct buffer_head *bh, char *search_buf, int buf_size,
- struct inode *dir, const struct qstr *d_name,
- unsigned int offset, struct ext4_dir_entry_2 **res_dir)
+int ext4_search_dir(struct buffer_head *bh, char *search_buf, int buf_size,
+ struct inode *dir, struct ext4_filename *fname,
+ const struct qstr *d_name,
+ unsigned int offset, struct ext4_dir_entry_2 **res_dir)
{
struct ext4_dir_entry_2 * de;
char * dlimit;
int de_len;
- const char *name = d_name->name;
- int namelen = d_name->len;
- struct ext4_fname_crypto_ctx *ctx = NULL;
- struct ext4_str fname_crypto_str = {.name = NULL, .len = 0};
int res;
- ctx = ext4_get_fname_crypto_ctx(dir, EXT4_NAME_LEN);
- if (IS_ERR(ctx))
- return -1;
-
de = (struct ext4_dir_entry_2 *)search_buf;
dlimit = search_buf + buf_size;
while ((char *) de < dlimit) {
/* this code is executed quadratically often */
/* do minimal checking `by hand' */
if ((char *) de + de->name_len <= dlimit) {
- res = ext4_match(ctx, &fname_crypto_str, namelen,
- name, de);
+ res = ext4_match(fname, de);
if (res < 0) {
res = -1;
goto return_result;
@@ -1322,8 +1305,6 @@ int search_dir(struct buffer_head *bh, char *search_buf, int buf_size,
res = 0;
return_result:
- ext4_put_fname_crypto_ctx(&ctx);
- ext4_fname_crypto_free_buffer(&fname_crypto_str);
return res;
}
@@ -1370,7 +1351,8 @@ static struct buffer_head * ext4_find_entry (struct inode *dir,
buffer */
int num = 0;
ext4_lblk_t nblocks;
- int i, namelen;
+ int i, namelen, retval;
+ struct ext4_filename fname;
*res_dir = NULL;
sb = dir->i_sb;
@@ -1378,14 +1360,18 @@ static struct buffer_head * ext4_find_entry (struct inode *dir,
if (namelen > EXT4_NAME_LEN)
return NULL;
+ retval = ext4_fname_setup_filename(dir, d_name, 1, &fname);
+ if (retval)
+ return ERR_PTR(retval);
+
if (ext4_has_inline_data(dir)) {
int has_inline_data = 1;
- ret = ext4_find_inline_entry(dir, d_name, res_dir,
+ ret = ext4_find_inline_entry(dir, &fname, d_name, res_dir,
&has_inline_data);
if (has_inline_data) {
if (inlined)
*inlined = 1;
- return ret;
+ goto cleanup_and_exit;
}
}
@@ -1400,14 +1386,14 @@ static struct buffer_head * ext4_find_entry (struct inode *dir,
goto restart;
}
if (is_dx(dir)) {
- bh = ext4_dx_find_entry(dir, d_name, res_dir);
+ ret = ext4_dx_find_entry(dir, &fname, res_dir);
/*
* On success, or if the error was file not found,
* return. Otherwise, fall back to doing a search the
* old fashioned way.
*/
- if (!IS_ERR(bh) || PTR_ERR(bh) != ERR_BAD_DX_DIR)
- return bh;
+ if (!IS_ERR(ret) || PTR_ERR(ret) != ERR_BAD_DX_DIR)
+ goto cleanup_and_exit;
dxtrace(printk(KERN_DEBUG "ext4_find_entry: dx failed, "
"falling back\n"));
}
@@ -1438,8 +1424,10 @@ restart:
num++;
bh = ext4_getblk(NULL, dir, b++, 0);
if (unlikely(IS_ERR(bh))) {
- if (ra_max == 0)
- return bh;
+ if (ra_max == 0) {
+ ret = bh;
+ goto cleanup_and_exit;
+ }
break;
}
bh_use[ra_max] = bh;
@@ -1469,7 +1457,7 @@ restart:
goto next;
}
set_buffer_verified(bh);
- i = search_dirblock(bh, dir, d_name,
+ i = search_dirblock(bh, dir, &fname, d_name,
block << EXT4_BLOCK_SIZE_BITS(sb), res_dir);
if (i == 1) {
EXT4_I(dir)->i_dir_start_lookup = block;
@@ -1500,15 +1488,17 @@ cleanup_and_exit:
/* Clean up the read-ahead blocks */
for (; ra_ptr < ra_max; ra_ptr++)
brelse(bh_use[ra_ptr]);
+ ext4_fname_free_filename(&fname);
return ret;
}
-static struct buffer_head * ext4_dx_find_entry(struct inode *dir, const struct qstr *d_name,
- struct ext4_dir_entry_2 **res_dir)
+static struct buffer_head * ext4_dx_find_entry(struct inode *dir,
+ struct ext4_filename *fname,
+ struct ext4_dir_entry_2 **res_dir)
{
struct super_block * sb = dir->i_sb;
- struct dx_hash_info hinfo;
struct dx_frame frames[2], *frame;
+ const struct qstr *d_name = fname->usr_fname;
struct buffer_head *bh;
ext4_lblk_t block;
int retval;
@@ -1516,7 +1506,7 @@ static struct buffer_head * ext4_dx_find_entry(struct inode *dir, const struct q
#ifdef CONFIG_EXT4_FS_ENCRYPTION
*res_dir = NULL;
#endif
- frame = dx_probe(d_name, dir, &hinfo, frames);
+ frame = dx_probe(fname, dir, NULL, frames);
if (IS_ERR(frame))
return (struct buffer_head *) frame;
do {
@@ -1525,7 +1515,7 @@ static struct buffer_head * ext4_dx_find_entry(struct inode *dir, const struct q
if (IS_ERR(bh))
goto errout;
- retval = search_dirblock(bh, dir, d_name,
+ retval = search_dirblock(bh, dir, fname, d_name,
block << EXT4_BLOCK_SIZE_BITS(sb),
res_dir);
if (retval == 1)
@@ -1537,7 +1527,7 @@ static struct buffer_head * ext4_dx_find_entry(struct inode *dir, const struct q
}
/* Check to see if we should continue to search */
- retval = ext4_htree_next_block(dir, hinfo.hash, frame,
+ retval = ext4_htree_next_block(dir, fname->hinfo.hash, frame,
frames, NULL);
if (retval < 0) {
ext4_warning(sb,
@@ -1796,32 +1786,16 @@ journal_error:
int ext4_find_dest_de(struct inode *dir, struct inode *inode,
struct buffer_head *bh,
void *buf, int buf_size,
- const char *name, int namelen,
+ struct ext4_filename *fname,
struct ext4_dir_entry_2 **dest_de)
{
struct ext4_dir_entry_2 *de;
- unsigned short reclen = EXT4_DIR_REC_LEN(namelen);
+ unsigned short reclen = EXT4_DIR_REC_LEN(fname_len(fname));
int nlen, rlen;
unsigned int offset = 0;
char *top;
- struct ext4_fname_crypto_ctx *ctx = NULL;
- struct ext4_str fname_crypto_str = {.name = NULL, .len = 0};
int res;
- ctx = ext4_get_fname_crypto_ctx(dir, EXT4_NAME_LEN);
- if (IS_ERR(ctx))
- return -1;
-
- if (ctx != NULL) {
- /* Calculate record length needed to store the entry */
- res = ext4_fname_crypto_namelen_on_disk(ctx, namelen);
- if (res < 0) {
- ext4_put_fname_crypto_ctx(&ctx);
- return res;
- }
- reclen = EXT4_DIR_REC_LEN(res);
- }
-
de = (struct ext4_dir_entry_2 *)buf;
top = buf + buf_size - reclen;
while ((char *) de <= top) {
@@ -1831,7 +1805,7 @@ int ext4_find_dest_de(struct inode *dir, struct inode *inode,
goto return_result;
}
/* Provide crypto context and crypto buffer to ext4 match */
- res = ext4_match(ctx, &fname_crypto_str, namelen, name, de);
+ res = ext4_match(fname, de);
if (res < 0)
goto return_result;
if (res > 0) {
@@ -1853,8 +1827,6 @@ int ext4_find_dest_de(struct inode *dir, struct inode *inode,
res = 0;
}
return_result:
- ext4_put_fname_crypto_ctx(&ctx);
- ext4_fname_crypto_free_buffer(&fname_crypto_str);
return res;
}
@@ -1862,39 +1834,10 @@ int ext4_insert_dentry(struct inode *dir,
struct inode *inode,
struct ext4_dir_entry_2 *de,
int buf_size,
- const struct qstr *iname,
- const char *name, int namelen)
+ struct ext4_filename *fname)
{
int nlen, rlen;
- struct ext4_fname_crypto_ctx *ctx = NULL;
- struct ext4_str fname_crypto_str = {.name = NULL, .len = 0};
- struct ext4_str tmp_str;
- int res;
-
- ctx = ext4_get_fname_crypto_ctx(dir, EXT4_NAME_LEN);
- if (IS_ERR(ctx))
- return -EIO;
- /* By default, the input name would be written to the disk */
- tmp_str.name = (unsigned char *)name;
- tmp_str.len = namelen;
- if (ctx != NULL) {
- /* Directory is encrypted */
- res = ext4_fname_crypto_alloc_buffer(ctx, EXT4_NAME_LEN,
- &fname_crypto_str);
- if (res < 0) {
- ext4_put_fname_crypto_ctx(&ctx);
- return -ENOMEM;
- }
- res = ext4_fname_usr_to_disk(ctx, iname, &fname_crypto_str);
- if (res < 0) {
- ext4_put_fname_crypto_ctx(&ctx);
- ext4_fname_crypto_free_buffer(&fname_crypto_str);
- return res;
- }
- tmp_str.name = fname_crypto_str.name;
- tmp_str.len = fname_crypto_str.len;
- }
nlen = EXT4_DIR_REC_LEN(de->name_len);
rlen = ext4_rec_len_from_disk(de->rec_len, buf_size);
@@ -1908,11 +1851,8 @@ int ext4_insert_dentry(struct inode *dir,
de->file_type = EXT4_FT_UNKNOWN;
de->inode = cpu_to_le32(inode->i_ino);
ext4_set_de_type(inode->i_sb, de, inode->i_mode);
- de->name_len = tmp_str.len;
-
- memcpy(de->name, tmp_str.name, tmp_str.len);
- ext4_put_fname_crypto_ctx(&ctx);
- ext4_fname_crypto_free_buffer(&fname_crypto_str);
+ de->name_len = fname_len(fname);
+ memcpy(de->name, fname_name(fname), fname_len(fname));
return 0;
}
@@ -1924,13 +1864,11 @@ int ext4_insert_dentry(struct inode *dir,
* space. It will return -ENOSPC if no space is available, and -EIO
* and -EEXIST if directory entry already exists.
*/
-static int add_dirent_to_buf(handle_t *handle, struct dentry *dentry,
+static int add_dirent_to_buf(handle_t *handle, struct ext4_filename *fname,
+ struct inode *dir,
struct inode *inode, struct ext4_dir_entry_2 *de,
struct buffer_head *bh)
{
- struct inode *dir = d_inode(dentry->d_parent);
- const char *name = dentry->d_name.name;
- int namelen = dentry->d_name.len;
unsigned int blocksize = dir->i_sb->s_blocksize;
int csum_size = 0;
int err;
@@ -1939,9 +1877,8 @@ static int add_dirent_to_buf(handle_t *handle, struct dentry *dentry,
csum_size = sizeof(struct ext4_dir_entry_tail);
if (!de) {
- err = ext4_find_dest_de(dir, inode,
- bh, bh->b_data, blocksize - csum_size,
- name, namelen, &de);
+ err = ext4_find_dest_de(dir, inode, bh, bh->b_data,
+ blocksize - csum_size, fname, &de);
if (err)
return err;
}
@@ -1954,8 +1891,7 @@ static int add_dirent_to_buf(handle_t *handle, struct dentry *dentry,
/* By now the buffer is marked for journaling. Due to crypto operations,
* the following function call may fail */
- err = ext4_insert_dentry(dir, inode, de, blocksize, &dentry->d_name,
- name, namelen);
+ err = ext4_insert_dentry(dir, inode, de, blocksize, fname);
if (err < 0)
return err;
@@ -1985,17 +1921,11 @@ static int add_dirent_to_buf(handle_t *handle, struct dentry *dentry,
* This converts a one block unindexed directory to a 3 block indexed
* directory, and adds the dentry to the indexed directory.
*/
-static int make_indexed_dir(handle_t *handle, struct dentry *dentry,
+static int make_indexed_dir(handle_t *handle, struct ext4_filename *fname,
+ struct dentry *dentry,
struct inode *inode, struct buffer_head *bh)
{
struct inode *dir = d_inode(dentry->d_parent);
-#ifdef CONFIG_EXT4_FS_ENCRYPTION
- struct ext4_fname_crypto_ctx *ctx = NULL;
- int res;
-#else
- const char *name = dentry->d_name.name;
- int namelen = dentry->d_name.len;
-#endif
struct buffer_head *bh2;
struct dx_root *root;
struct dx_frame frames[2], *frame;
@@ -2006,17 +1936,10 @@ static int make_indexed_dir(handle_t *handle, struct dentry *dentry,
unsigned len;
int retval;
unsigned blocksize;
- struct dx_hash_info hinfo;
ext4_lblk_t block;
struct fake_dirent *fde;
int csum_size = 0;
-#ifdef CONFIG_EXT4_FS_ENCRYPTION
- ctx = ext4_get_fname_crypto_ctx(dir, EXT4_NAME_LEN);
- if (IS_ERR(ctx))
- return PTR_ERR(ctx);
-#endif
-
if (ext4_has_metadata_csum(inode->i_sb))
csum_size = sizeof(struct ext4_dir_entry_tail);
@@ -2078,22 +2001,12 @@ static int make_indexed_dir(handle_t *handle, struct dentry *dentry,
dx_set_limit(entries, dx_root_limit(dir, sizeof(root->info)));
/* Initialize as for dx_probe */
- hinfo.hash_version = root->info.hash_version;
- if (hinfo.hash_version <= DX_HASH_TEA)
- hinfo.hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
- hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
-#ifdef CONFIG_EXT4_FS_ENCRYPTION
- res = ext4_fname_usr_to_hash(ctx, &dentry->d_name, &hinfo);
- if (res < 0) {
- ext4_put_fname_crypto_ctx(&ctx);
- ext4_mark_inode_dirty(handle, dir);
- brelse(bh);
- return res;
- }
- ext4_put_fname_crypto_ctx(&ctx);
-#else
- ext4fs_dirhash(name, namelen, &hinfo);
-#endif
+ fname->hinfo.hash_version = root->info.hash_version;
+ if (fname->hinfo.hash_version <= DX_HASH_TEA)
+ fname->hinfo.hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
+ fname->hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
+ ext4fs_dirhash(fname_name(fname), fname_len(fname), &fname->hinfo);
+
memset(frames, 0, sizeof(frames));
frame = frames;
frame->entries = entries;
@@ -2108,14 +2021,14 @@ static int make_indexed_dir(handle_t *handle, struct dentry *dentry,
if (retval)
goto out_frames;
- de = do_split(handle,dir, &bh, frame, &hinfo);
+ de = do_split(handle,dir, &bh, frame, &fname->hinfo);
if (IS_ERR(de)) {
retval = PTR_ERR(de);
goto out_frames;
}
dx_release(frames);
- retval = add_dirent_to_buf(handle, dentry, inode, de, bh);
+ retval = add_dirent_to_buf(handle, fname, dir, inode, de, bh);
brelse(bh);
return retval;
out_frames:
@@ -2147,6 +2060,7 @@ static int ext4_add_entry(handle_t *handle, struct dentry *dentry,
struct ext4_dir_entry_2 *de;
struct ext4_dir_entry_tail *t;
struct super_block *sb;
+ struct ext4_filename fname;
int retval;
int dx_fallback=0;
unsigned blocksize;
@@ -2161,10 +2075,15 @@ static int ext4_add_entry(handle_t *handle, struct dentry *dentry,
if (!dentry->d_name.len)
return -EINVAL;
+ retval = ext4_fname_setup_filename(dir, &dentry->d_name, 0, &fname);
+ if (retval)
+ return retval;
+
if (ext4_has_inline_data(dir)) {
- retval = ext4_try_add_inline_entry(handle, dentry, inode);
+ retval = ext4_try_add_inline_entry(handle, &fname,
+ dentry, inode);
if (retval < 0)
- return retval;
+ goto out;
if (retval == 1) {
retval = 0;
goto out;
@@ -2172,7 +2091,7 @@ static int ext4_add_entry(handle_t *handle, struct dentry *dentry,
}
if (is_dx(dir)) {
- retval = ext4_dx_add_entry(handle, dentry, inode);
+ retval = ext4_dx_add_entry(handle, &fname, dentry, inode);
if (!retval || (retval != ERR_BAD_DX_DIR))
goto out;
ext4_clear_inode_flag(dir, EXT4_INODE_INDEX);
@@ -2182,24 +2101,31 @@ static int ext4_add_entry(handle_t *handle, struct dentry *dentry,
blocks = dir->i_size >> sb->s_blocksize_bits;
for (block = 0; block < blocks; block++) {
bh = ext4_read_dirblock(dir, block, DIRENT);
- if (IS_ERR(bh))
- return PTR_ERR(bh);
-
- retval = add_dirent_to_buf(handle, dentry, inode, NULL, bh);
+ if (IS_ERR(bh)) {
+ retval = PTR_ERR(bh);
+ bh = NULL;
+ goto out;
+ }
+ retval = add_dirent_to_buf(handle, &fname, dir, inode,
+ NULL, bh);
if (retval != -ENOSPC)
goto out;
if (blocks == 1 && !dx_fallback &&
EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_DIR_INDEX)) {
- retval = make_indexed_dir(handle, dentry, inode, bh);
+ retval = make_indexed_dir(handle, &fname, dentry,
+ inode, bh);
bh = NULL; /* make_indexed_dir releases bh */
goto out;
}
brelse(bh);
}
bh = ext4_append(handle, dir, &block);
- if (IS_ERR(bh))
- return PTR_ERR(bh);
+ if (IS_ERR(bh)) {
+ retval = PTR_ERR(bh);
+ bh = NULL;
+ goto out;
+ }
de = (struct ext4_dir_entry_2 *) bh->b_data;
de->inode = 0;
de->rec_len = ext4_rec_len_to_disk(blocksize - csum_size, blocksize);
@@ -2209,8 +2135,9 @@ static int ext4_add_entry(handle_t *handle, struct dentry *dentry,
initialize_dirent_tail(t, blocksize);
}
- retval = add_dirent_to_buf(handle, dentry, inode, de, bh);
+ retval = add_dirent_to_buf(handle, &fname, dir, inode, de, bh);
out:
+ ext4_fname_free_filename(&fname);
brelse(bh);
if (retval == 0)
ext4_set_inode_state(inode, EXT4_STATE_NEWENTRY);
@@ -2220,19 +2147,18 @@ out:
/*
* Returns 0 for success, or a negative error value
*/
-static int ext4_dx_add_entry(handle_t *handle, struct dentry *dentry,
- struct inode *inode)
+static int ext4_dx_add_entry(handle_t *handle, struct ext4_filename *fname,
+ struct dentry *dentry, struct inode *inode)
{
struct dx_frame frames[2], *frame;
struct dx_entry *entries, *at;
- struct dx_hash_info hinfo;
struct buffer_head *bh;
struct inode *dir = d_inode(dentry->d_parent);
struct super_block *sb = dir->i_sb;
struct ext4_dir_entry_2 *de;
int err;
- frame = dx_probe(&dentry->d_name, dir, &hinfo, frames);
+ frame = dx_probe(fname, dir, NULL, frames);
if (IS_ERR(frame))
return PTR_ERR(frame);
entries = frame->entries;
@@ -2249,7 +2175,7 @@ static int ext4_dx_add_entry(handle_t *handle, struct dentry *dentry,
if (err)
goto journal_error;
- err = add_dirent_to_buf(handle, dentry, inode, NULL, bh);
+ err = add_dirent_to_buf(handle, fname, dir, inode, NULL, bh);
if (err != -ENOSPC)
goto cleanup;
@@ -2345,12 +2271,12 @@ static int ext4_dx_add_entry(handle_t *handle, struct dentry *dentry,
goto cleanup;
}
}
- de = do_split(handle, dir, &bh, frame, &hinfo);
+ de = do_split(handle, dir, &bh, frame, &fname->hinfo);
if (IS_ERR(de)) {
err = PTR_ERR(de);
goto cleanup;
}
- err = add_dirent_to_buf(handle, dentry, inode, de, bh);
+ err = add_dirent_to_buf(handle, fname, dir, inode, de, bh);
goto cleanup;
journal_error:
--
2.3.0
^ permalink raw reply related [flat|nested] 4+ messages in thread
* [PATCH 2/4] ext4 crypto: don't allocate a page when encrypting/decrypting file names
2015-05-05 15:18 [PATCH 1/4] ext4 crypto: optimize filename encryption Theodore Ts'o
@ 2015-05-05 15:18 ` Theodore Ts'o
2015-05-05 15:18 ` [PATCH 3/4] ext4 crypto: separate kernel and userspace structure for the key Theodore Ts'o
2015-05-05 15:18 ` [PATCH 4/4] ext4 crypto: reorganize how we store keys in the inode Theodore Ts'o
2 siblings, 0 replies; 4+ messages in thread
From: Theodore Ts'o @ 2015-05-05 15:18 UTC (permalink / raw)
To: Ext4 Developers List; +Cc: mhalcrow, savagaon, Theodore Ts'o
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
---
fs/ext4/crypto_fname.c | 72 ++++++++++++++------------------------------------
fs/ext4/dir.c | 3 +++
fs/ext4/ext4_crypto.h | 2 --
fs/ext4/namei.c | 4 +++
fs/ext4/symlink.c | 1 +
5 files changed, 28 insertions(+), 54 deletions(-)
diff --git a/fs/ext4/crypto_fname.c b/fs/ext4/crypto_fname.c
index ad5e328..23d7f1d 100644
--- a/fs/ext4/crypto_fname.c
+++ b/fs/ext4/crypto_fname.c
@@ -65,9 +65,9 @@ static int ext4_fname_encrypt(struct ext4_fname_crypto_ctx *ctx,
struct crypto_ablkcipher *tfm = ctx->ctfm;
int res = 0;
char iv[EXT4_CRYPTO_BLOCK_SIZE];
- struct scatterlist sg[1];
+ struct scatterlist src_sg, dst_sg;
int padding = 4 << (ctx->flags & EXT4_POLICY_FLAGS_PAD_MASK);
- char *workbuf;
+ char *workbuf, buf[32], *alloc_buf = NULL;
if (iname->len <= 0 || iname->len > ctx->lim)
return -EIO;
@@ -78,20 +78,27 @@ static int ext4_fname_encrypt(struct ext4_fname_crypto_ctx *ctx,
ciphertext_len = (ciphertext_len > ctx->lim)
? ctx->lim : ciphertext_len;
+ if (ciphertext_len <= sizeof(buf)) {
+ workbuf = buf;
+ } else {
+ alloc_buf = kmalloc(ciphertext_len, GFP_NOFS);
+ if (!alloc_buf)
+ return -ENOMEM;
+ workbuf = alloc_buf;
+ }
+
/* Allocate request */
req = ablkcipher_request_alloc(tfm, GFP_NOFS);
if (!req) {
printk_ratelimited(
KERN_ERR "%s: crypto_request_alloc() failed\n", __func__);
+ kfree(alloc_buf);
return -ENOMEM;
}
ablkcipher_request_set_callback(req,
CRYPTO_TFM_REQ_MAY_BACKLOG | CRYPTO_TFM_REQ_MAY_SLEEP,
ext4_dir_crypt_complete, &ecr);
- /* Map the workpage */
- workbuf = kmap(ctx->workpage);
-
/* Copy the input */
memcpy(workbuf, iname->name, iname->len);
if (iname->len < ciphertext_len)
@@ -101,21 +108,16 @@ static int ext4_fname_encrypt(struct ext4_fname_crypto_ctx *ctx,
memset(iv, 0, EXT4_CRYPTO_BLOCK_SIZE);
/* Create encryption request */
- sg_init_table(sg, 1);
- sg_set_page(sg, ctx->workpage, PAGE_SIZE, 0);
- ablkcipher_request_set_crypt(req, sg, sg, ciphertext_len, iv);
+ sg_init_one(&src_sg, workbuf, ciphertext_len);
+ sg_init_one(&dst_sg, oname->name, ciphertext_len);
+ ablkcipher_request_set_crypt(req, &src_sg, &dst_sg, ciphertext_len, iv);
res = crypto_ablkcipher_encrypt(req);
if (res == -EINPROGRESS || res == -EBUSY) {
BUG_ON(req->base.data != &ecr);
wait_for_completion(&ecr.completion);
res = ecr.res;
}
- if (res >= 0) {
- /* Copy the result to output */
- memcpy(oname->name, workbuf, ciphertext_len);
- res = ciphertext_len;
- }
- kunmap(ctx->workpage);
+ kfree(alloc_buf);
ablkcipher_request_free(req);
if (res < 0) {
printk_ratelimited(
@@ -139,11 +141,10 @@ static int ext4_fname_decrypt(struct ext4_fname_crypto_ctx *ctx,
struct ext4_str tmp_in[2], tmp_out[1];
struct ablkcipher_request *req = NULL;
DECLARE_EXT4_COMPLETION_RESULT(ecr);
- struct scatterlist sg[1];
+ struct scatterlist src_sg, dst_sg;
struct crypto_ablkcipher *tfm = ctx->ctfm;
int res = 0;
char iv[EXT4_CRYPTO_BLOCK_SIZE];
- char *workbuf;
if (iname->len <= 0 || iname->len > ctx->lim)
return -EIO;
@@ -163,31 +164,19 @@ static int ext4_fname_decrypt(struct ext4_fname_crypto_ctx *ctx,
CRYPTO_TFM_REQ_MAY_BACKLOG | CRYPTO_TFM_REQ_MAY_SLEEP,
ext4_dir_crypt_complete, &ecr);
- /* Map the workpage */
- workbuf = kmap(ctx->workpage);
-
- /* Copy the input */
- memcpy(workbuf, iname->name, iname->len);
-
/* Initialize IV */
memset(iv, 0, EXT4_CRYPTO_BLOCK_SIZE);
/* Create encryption request */
- sg_init_table(sg, 1);
- sg_set_page(sg, ctx->workpage, PAGE_SIZE, 0);
- ablkcipher_request_set_crypt(req, sg, sg, iname->len, iv);
+ sg_init_one(&src_sg, iname->name, iname->len);
+ sg_init_one(&dst_sg, oname->name, oname->len);
+ ablkcipher_request_set_crypt(req, &src_sg, &dst_sg, iname->len, iv);
res = crypto_ablkcipher_decrypt(req);
if (res == -EINPROGRESS || res == -EBUSY) {
BUG_ON(req->base.data != &ecr);
wait_for_completion(&ecr.completion);
res = ecr.res;
}
- if (res >= 0) {
- /* Copy the result to output */
- memcpy(oname->name, workbuf, iname->len);
- res = iname->len;
- }
- kunmap(ctx->workpage);
ablkcipher_request_free(req);
if (res < 0) {
printk_ratelimited(
@@ -267,8 +256,6 @@ void ext4_free_fname_crypto_ctx(struct ext4_fname_crypto_ctx *ctx)
crypto_free_ablkcipher(ctx->ctfm);
if (ctx->htfm && !IS_ERR(ctx->htfm))
crypto_free_hash(ctx->htfm);
- if (ctx->workpage && !IS_ERR(ctx->workpage))
- __free_page(ctx->workpage);
kfree(ctx);
}
@@ -322,7 +309,6 @@ struct ext4_fname_crypto_ctx *ext4_alloc_fname_crypto_ctx(
ctx->ctfm_key_is_ready = 0;
ctx->ctfm = NULL;
ctx->htfm = NULL;
- ctx->workpage = NULL;
return ctx;
}
@@ -390,24 +376,6 @@ struct ext4_fname_crypto_ctx *ext4_get_fname_crypto_ctx(
ext4_put_fname_crypto_ctx(&ctx);
return ERR_PTR(-ENOMEM);
}
- if (ctx->workpage == NULL)
- ctx->workpage = alloc_page(GFP_NOFS);
- if (IS_ERR(ctx->workpage)) {
- res = PTR_ERR(ctx->workpage);
- printk(
- KERN_DEBUG "%s: error (%d) allocating work page\n",
- __func__, res);
- ctx->workpage = NULL;
- ext4_put_fname_crypto_ctx(&ctx);
- return ERR_PTR(res);
- }
- if (ctx->workpage == NULL) {
- printk(
- KERN_DEBUG "%s: could not allocate work page\n",
- __func__);
- ext4_put_fname_crypto_ctx(&ctx);
- return ERR_PTR(-ENOMEM);
- }
ctx->lim = max_ciphertext_len;
crypto_ablkcipher_clear_flags(ctx->ctfm, ~0);
crypto_tfm_set_flags(crypto_ablkcipher_tfm(ctx->ctfm),
diff --git a/fs/ext4/dir.c b/fs/ext4/dir.c
index 5665d82..d799d5d 100644
--- a/fs/ext4/dir.c
+++ b/fs/ext4/dir.c
@@ -247,9 +247,12 @@ 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;
+
/* Directory is encrypted */
err = ext4_fname_disk_to_usr(enc_ctx,
NULL, de, &fname_crypto_str);
+ fname_crypto_str.len = save_len;
if (err < 0)
goto errout;
if (!dir_emit(ctx,
diff --git a/fs/ext4/ext4_crypto.h b/fs/ext4/ext4_crypto.h
index d75159c..552424a 100644
--- a/fs/ext4/ext4_crypto.h
+++ b/fs/ext4/ext4_crypto.h
@@ -123,10 +123,8 @@ struct ext4_str {
struct ext4_fname_crypto_ctx {
u32 lim;
- char tmp_buf[EXT4_CRYPTO_BLOCK_SIZE];
struct crypto_ablkcipher *ctfm;
struct crypto_hash *htfm;
- struct page *workpage;
struct ext4_encryption_key key;
unsigned flags : 8;
unsigned has_valid_key : 1;
diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
index 56c60cb..b340643 100644
--- a/fs/ext4/namei.c
+++ b/fs/ext4/namei.c
@@ -998,6 +998,8 @@ static int htree_dirblock_to_tree(struct file *dir_file,
hinfo->hash, hinfo->minor_hash, de,
&tmp_str);
} else {
+ int save_len = fname_crypto_str.len;
+
/* Directory is encrypted */
err = ext4_fname_disk_to_usr(ctx, hinfo, de,
&fname_crypto_str);
@@ -1008,6 +1010,7 @@ static int htree_dirblock_to_tree(struct file *dir_file,
err = ext4_htree_store_dirent(dir_file,
hinfo->hash, hinfo->minor_hash, de,
&fname_crypto_str);
+ fname_crypto_str.len = save_len;
}
if (err != 0) {
count = err;
@@ -3126,6 +3129,7 @@ static int ext4_symlink(struct inode *dir,
istr.name = (const unsigned char *) symname;
istr.len = len;
ostr.name = sd->encrypted_path;
+ ostr.len = disk_link.len;
err = ext4_fname_usr_to_disk(ctx, &istr, &ostr);
ext4_put_fname_crypto_ctx(&ctx);
if (err < 0)
diff --git a/fs/ext4/symlink.c b/fs/ext4/symlink.c
index 187b789..ca65d45 100644
--- a/fs/ext4/symlink.c
+++ b/fs/ext4/symlink.c
@@ -74,6 +74,7 @@ static void *ext4_follow_link(struct dentry *dentry, struct nameidata *nd)
goto errout;
}
pstr.name = paddr;
+ pstr.len = plen;
res = _ext4_fname_disk_to_usr(ctx, NULL, &cstr, &pstr);
if (res < 0)
goto errout;
--
2.3.0
^ permalink raw reply related [flat|nested] 4+ messages in thread
* [PATCH 3/4] ext4 crypto: separate kernel and userspace structure for the key
2015-05-05 15:18 [PATCH 1/4] ext4 crypto: optimize filename encryption Theodore Ts'o
2015-05-05 15:18 ` [PATCH 2/4] ext4 crypto: don't allocate a page when encrypting/decrypting file names Theodore Ts'o
@ 2015-05-05 15:18 ` Theodore Ts'o
2015-05-05 15:18 ` [PATCH 4/4] ext4 crypto: reorganize how we store keys in the inode Theodore Ts'o
2 siblings, 0 replies; 4+ messages in thread
From: Theodore Ts'o @ 2015-05-05 15:18 UTC (permalink / raw)
To: Ext4 Developers List; +Cc: mhalcrow, savagaon, Theodore Ts'o
Use struct ext4_encryption_key only for the master key passed via the
kernel keyring.
For internal kernel space users, we now use struct ext4_crypt_info.
This will allow us to put information from the policy structure so we
can cache it and avoid needing to constantly looking up the extended
attribute. We will do this in a spearate patch. This patch is mostly
mechnical to make it easier for patch review.
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
---
fs/ext4/crypto.c | 18 +++++++++---------
fs/ext4/crypto_fname.c | 33 ++++++++++-----------------------
fs/ext4/crypto_key.c | 21 +++++++++++----------
fs/ext4/ext4.h | 2 +-
fs/ext4/ext4_crypto.h | 15 +++++++++++----
fs/ext4/super.c | 2 +-
6 files changed, 43 insertions(+), 48 deletions(-)
diff --git a/fs/ext4/crypto.c b/fs/ext4/crypto.c
index 8ff1527..918200e 100644
--- a/fs/ext4/crypto.c
+++ b/fs/ext4/crypto.c
@@ -118,7 +118,7 @@ struct ext4_crypto_ctx *ext4_get_crypto_ctx(struct inode *inode)
struct ext4_crypto_ctx *ctx = NULL;
int res = 0;
unsigned long flags;
- struct ext4_encryption_key *key = &EXT4_I(inode)->i_encryption_key;
+ struct ext4_crypt_info *ci = &EXT4_I(inode)->i_crypt_info;
if (!ext4_read_workqueue)
ext4_init_crypto();
@@ -152,14 +152,14 @@ struct ext4_crypto_ctx *ext4_get_crypto_ctx(struct inode *inode)
/* Allocate a new Crypto API context if we don't already have
* one or if it isn't the right mode. */
- BUG_ON(key->mode == EXT4_ENCRYPTION_MODE_INVALID);
- if (ctx->tfm && (ctx->mode != key->mode)) {
+ BUG_ON(ci->ci_mode == EXT4_ENCRYPTION_MODE_INVALID);
+ if (ctx->tfm && (ctx->mode != ci->ci_mode)) {
crypto_free_tfm(ctx->tfm);
ctx->tfm = NULL;
ctx->mode = EXT4_ENCRYPTION_MODE_INVALID;
}
if (!ctx->tfm) {
- switch (key->mode) {
+ switch (ci->ci_mode) {
case EXT4_ENCRYPTION_MODE_AES_256_XTS:
ctx->tfm = crypto_ablkcipher_tfm(
crypto_alloc_ablkcipher("xts(aes)", 0, 0));
@@ -177,9 +177,9 @@ struct ext4_crypto_ctx *ext4_get_crypto_ctx(struct inode *inode)
ctx->tfm = NULL;
goto out;
}
- ctx->mode = key->mode;
+ ctx->mode = ci->ci_mode;
}
- BUG_ON(key->size != ext4_encryption_key_size(key->mode));
+ BUG_ON(ci->ci_size != ext4_encryption_key_size(ci->ci_mode));
/* There shouldn't be a bounce page attached to the crypto
* context at this point. */
@@ -322,7 +322,7 @@ static int ext4_page_crypto(struct ext4_crypto_ctx *ctx,
int res = 0;
BUG_ON(!ctx->tfm);
- BUG_ON(ctx->mode != ei->i_encryption_key.mode);
+ BUG_ON(ctx->mode != ei->i_crypt_info.ci_mode);
if (ctx->mode != EXT4_ENCRYPTION_MODE_AES_256_XTS) {
printk_ratelimited(KERN_ERR
@@ -334,8 +334,8 @@ static int ext4_page_crypto(struct ext4_crypto_ctx *ctx,
crypto_ablkcipher_clear_flags(atfm, ~0);
crypto_tfm_set_flags(ctx->tfm, CRYPTO_TFM_REQ_WEAK_KEY);
- res = crypto_ablkcipher_setkey(atfm, ei->i_encryption_key.raw,
- ei->i_encryption_key.size);
+ res = crypto_ablkcipher_setkey(atfm, ei->i_crypt_info.ci_raw,
+ ei->i_crypt_info.ci_size);
if (res) {
printk_ratelimited(KERN_ERR
"%s: crypto_ablkcipher_setkey() failed\n",
diff --git a/fs/ext4/crypto_fname.c b/fs/ext4/crypto_fname.c
index 23d7f1d..d9f08dd 100644
--- a/fs/ext4/crypto_fname.c
+++ b/fs/ext4/crypto_fname.c
@@ -278,33 +278,24 @@ void ext4_put_fname_crypto_ctx(struct ext4_fname_crypto_ctx **ctx)
}
/**
- * ext4_search_fname_crypto_ctx() -
- */
-static struct ext4_fname_crypto_ctx *ext4_search_fname_crypto_ctx(
- const struct ext4_encryption_key *key)
-{
- return NULL;
-}
-
-/**
* ext4_alloc_fname_crypto_ctx() -
*/
struct ext4_fname_crypto_ctx *ext4_alloc_fname_crypto_ctx(
- const struct ext4_encryption_key *key)
+ const struct ext4_crypt_info *ci)
{
struct ext4_fname_crypto_ctx *ctx;
ctx = kmalloc(sizeof(struct ext4_fname_crypto_ctx), GFP_NOFS);
if (ctx == NULL)
return ERR_PTR(-ENOMEM);
- if (key->mode == EXT4_ENCRYPTION_MODE_INVALID) {
+ if (ci->ci_mode == EXT4_ENCRYPTION_MODE_INVALID) {
/* This will automatically set key mode to invalid
* As enum for ENCRYPTION_MODE_INVALID is zero */
- memset(&ctx->key, 0, sizeof(ctx->key));
+ memset(&ctx->ci, 0, sizeof(ctx->ci));
} else {
- memcpy(&ctx->key, key, sizeof(struct ext4_encryption_key));
+ memcpy(&ctx->ci, ci, sizeof(struct ext4_crypt_info));
}
- ctx->has_valid_key = (EXT4_ENCRYPTION_MODE_INVALID == key->mode)
+ ctx->has_valid_key = (EXT4_ENCRYPTION_MODE_INVALID == ci->ci_mode)
? 0 : 1;
ctx->ctfm_key_is_ready = 0;
ctx->ctfm = NULL;
@@ -335,21 +326,17 @@ struct ext4_fname_crypto_ctx *ext4_get_fname_crypto_ctx(
if (!ext4_has_encryption_key(inode))
ext4_generate_encryption_key(inode);
- /* Get a crypto context based on the key.
- * A new context is allocated if no context matches the requested key.
- */
- ctx = ext4_search_fname_crypto_ctx(&(ei->i_encryption_key));
- if (ctx == NULL)
- ctx = ext4_alloc_fname_crypto_ctx(&(ei->i_encryption_key));
+ /* Get a crypto context based on the key. */
+ ctx = ext4_alloc_fname_crypto_ctx(&(ei->i_crypt_info));
if (IS_ERR(ctx))
return ctx;
ctx->flags = ei->i_crypt_policy_flags;
if (ctx->has_valid_key) {
- if (ctx->key.mode != EXT4_ENCRYPTION_MODE_AES_256_CTS) {
+ if (ctx->ci.ci_mode != EXT4_ENCRYPTION_MODE_AES_256_CTS) {
printk_once(KERN_WARNING
"ext4: unsupported key mode %d\n",
- ctx->key.mode);
+ ctx->ci.ci_mode);
return ERR_PTR(-ENOKEY);
}
@@ -389,7 +376,7 @@ struct ext4_fname_crypto_ctx *ext4_get_fname_crypto_ctx(
* are pretty weak,
* we directly use the inode master key */
res = crypto_ablkcipher_setkey(ctx->ctfm,
- ctx->key.raw, ctx->key.size);
+ ctx->ci.ci_raw, ctx->ci.ci_size);
if (res) {
ext4_put_fname_crypto_ctx(&ctx);
return ERR_PTR(-EIO);
diff --git a/fs/ext4/crypto_key.c b/fs/ext4/crypto_key.c
index 52170d0..ec6635d 100644
--- a/fs/ext4/crypto_key.c
+++ b/fs/ext4/crypto_key.c
@@ -91,7 +91,7 @@ out:
int ext4_generate_encryption_key(struct inode *inode)
{
struct ext4_inode_info *ei = EXT4_I(inode);
- struct ext4_encryption_key *crypt_key = &ei->i_encryption_key;
+ struct ext4_crypt_info *crypt_info = &ei->i_crypt_info;
char full_key_descriptor[EXT4_KEY_DESC_PREFIX_SIZE +
(EXT4_KEY_DESCRIPTOR_SIZE * 2) + 1];
struct key *keyring_key = NULL;
@@ -112,17 +112,17 @@ int ext4_generate_encryption_key(struct inode *inode)
ei->i_crypt_policy_flags = ctx.flags;
if (S_ISREG(inode->i_mode))
- crypt_key->mode = ctx.contents_encryption_mode;
+ crypt_info->ci_mode = ctx.contents_encryption_mode;
else if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode))
- crypt_key->mode = ctx.filenames_encryption_mode;
+ crypt_info->ci_mode = ctx.filenames_encryption_mode;
else {
printk(KERN_ERR "ext4 crypto: Unsupported inode type.\n");
BUG();
}
- crypt_key->size = ext4_encryption_key_size(crypt_key->mode);
- BUG_ON(!crypt_key->size);
+ crypt_info->ci_size = ext4_encryption_key_size(crypt_info->ci_mode);
+ BUG_ON(!crypt_info->ci_size);
if (DUMMY_ENCRYPTION_ENABLED(sbi)) {
- memset(crypt_key->raw, 0x42, EXT4_AES_256_XTS_KEY_SIZE);
+ memset(crypt_info->ci_raw, 0x42, EXT4_AES_256_XTS_KEY_SIZE);
goto out;
}
memcpy(full_key_descriptor, EXT4_KEY_DESC_PREFIX,
@@ -148,19 +148,20 @@ int ext4_generate_encryption_key(struct inode *inode)
BUILD_BUG_ON(EXT4_AES_128_ECB_KEY_SIZE !=
EXT4_KEY_DERIVATION_NONCE_SIZE);
BUG_ON(master_key->size != EXT4_AES_256_XTS_KEY_SIZE);
- res = ext4_derive_key_aes(ctx.nonce, master_key->raw, crypt_key->raw);
+ res = ext4_derive_key_aes(ctx.nonce, master_key->raw,
+ crypt_info->ci_raw);
out:
if (keyring_key)
key_put(keyring_key);
if (res < 0)
- crypt_key->mode = EXT4_ENCRYPTION_MODE_INVALID;
+ crypt_info->ci_mode = EXT4_ENCRYPTION_MODE_INVALID;
return res;
}
int ext4_has_encryption_key(struct inode *inode)
{
struct ext4_inode_info *ei = EXT4_I(inode);
- struct ext4_encryption_key *crypt_key = &ei->i_encryption_key;
+ struct ext4_crypt_info *crypt_info = &ei->i_crypt_info;
- return (crypt_key->mode != EXT4_ENCRYPTION_MODE_INVALID);
+ return (crypt_info->ci_mode != EXT4_ENCRYPTION_MODE_INVALID);
}
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 6bdd69e..e3671c2 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -955,7 +955,7 @@ struct ext4_inode_info {
#ifdef CONFIG_EXT4_FS_ENCRYPTION
/* Encryption params */
- struct ext4_encryption_key i_encryption_key;
+ struct ext4_crypt_info i_crypt_info;
#endif
};
diff --git a/fs/ext4/ext4_crypto.h b/fs/ext4/ext4_crypto.h
index 552424a..deecbe8 100644
--- a/fs/ext4/ext4_crypto.h
+++ b/fs/ext4/ext4_crypto.h
@@ -66,10 +66,17 @@ struct ext4_encryption_context {
#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 {
- uint32_t mode;
- char raw[EXT4_MAX_KEY_SIZE];
- uint32_t size;
+ __u32 mode;
+ char raw[EXT4_MAX_KEY_SIZE];
+ __u32 size;
+} __attribute__((__packed__));
+
+struct ext4_crypt_info {
+ unsigned char ci_mode;
+ unsigned char ci_size;
+ char ci_raw[EXT4_MAX_KEY_SIZE];
};
#define EXT4_CTX_REQUIRES_FREE_ENCRYPT_FL 0x00000001
@@ -125,7 +132,7 @@ struct ext4_fname_crypto_ctx {
u32 lim;
struct crypto_ablkcipher *ctfm;
struct crypto_hash *htfm;
- struct ext4_encryption_key key;
+ struct ext4_crypt_info ci;
unsigned flags : 8;
unsigned has_valid_key : 1;
unsigned ctfm_key_is_ready : 1;
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index f06d058..a9ebe3d 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -877,7 +877,7 @@ static struct inode *ext4_alloc_inode(struct super_block *sb)
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_encryption_key.mode = EXT4_ENCRYPTION_MODE_INVALID;
+ ei->i_crypt_info.ci_mode = EXT4_ENCRYPTION_MODE_INVALID;
#endif
return &ei->vfs_inode;
--
2.3.0
^ permalink raw reply related [flat|nested] 4+ messages in thread
* [PATCH 4/4] ext4 crypto: reorganize how we store keys in the inode
2015-05-05 15:18 [PATCH 1/4] ext4 crypto: optimize filename encryption Theodore Ts'o
2015-05-05 15:18 ` [PATCH 2/4] ext4 crypto: don't allocate a page when encrypting/decrypting file names Theodore Ts'o
2015-05-05 15:18 ` [PATCH 3/4] ext4 crypto: separate kernel and userspace structure for the key Theodore Ts'o
@ 2015-05-05 15:18 ` Theodore Ts'o
2 siblings, 0 replies; 4+ messages in thread
From: Theodore Ts'o @ 2015-05-05 15:18 UTC (permalink / raw)
To: Ext4 Developers List; +Cc: mhalcrow, savagaon, Theodore Ts'o
This is a pretty massive patch which does a number of different things:
1) The per-inode encryption information is now stored in an allocated
data structure, ext4_crypt_info, instead of directly in the node.
This reduces the size usage of an in-memory inode when it is not
using encryption.
2) We drop the ext4_fname_crypto_ctx entirely, and use the per-inode
encryption structure instead. This remove an unnecessary memory
allocation and free for the fname_crypto_ctx as well as allowing us
to reuse the ctfm in a directory for multiple lookups and file
creations.
3) We also cache the inode's policy information in the ext4_crypt_info
structure so we don't have to continually read it out of the
extended attributes.
4) We now keep the keyring key in the inode's encryption structure
instead of releasing it after we are done using it to derive the
per-inode key. This allows us to test to see if the key has been
revoked; if it has, we prevent the use of the derived key and free
it.
5) When an inode is released (or when the derived key is freed), we
will use memset_explicit() to zero out the derived key, so it's not
left hanging around in memory. This implies that when a user logs
out, it is important to first revoke the key, and then unlink it,
and then finally, to use "echo 3 > /proc/sys/vm/drop_caches" to
release any decrypted pages and dcache entries from the system
caches.
6) All this, and we also shrink the number of lines of code by around
100. :-)
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
---
fs/ext4/crypto.c | 9 +-
fs/ext4/crypto_fname.c | 284 +++++++++++++-----------------------------------
fs/ext4/crypto_key.c | 74 ++++++++++---
fs/ext4/crypto_policy.c | 76 +++++++------
fs/ext4/dir.c | 21 ++--
fs/ext4/ext4.h | 40 ++++---
fs/ext4/ext4_crypto.h | 16 +--
fs/ext4/file.c | 4 +-
fs/ext4/namei.c | 42 +++----
fs/ext4/super.c | 5 +-
fs/ext4/symlink.c | 15 +--
11 files changed, 240 insertions(+), 346 deletions(-)
diff --git a/fs/ext4/crypto.c b/fs/ext4/crypto.c
index 918200e..3a25aa4 100644
--- a/fs/ext4/crypto.c
+++ b/fs/ext4/crypto.c
@@ -118,8 +118,9 @@ struct ext4_crypto_ctx *ext4_get_crypto_ctx(struct inode *inode)
struct ext4_crypto_ctx *ctx = NULL;
int res = 0;
unsigned long flags;
- struct ext4_crypt_info *ci = &EXT4_I(inode)->i_crypt_info;
+ struct ext4_crypt_info *ci = EXT4_I(inode)->i_crypt_info;
+ BUG_ON(ci == NULL);
if (!ext4_read_workqueue)
ext4_init_crypto();
@@ -322,7 +323,7 @@ static int ext4_page_crypto(struct ext4_crypto_ctx *ctx,
int res = 0;
BUG_ON(!ctx->tfm);
- BUG_ON(ctx->mode != ei->i_crypt_info.ci_mode);
+ BUG_ON(ctx->mode != ei->i_crypt_info->ci_mode);
if (ctx->mode != EXT4_ENCRYPTION_MODE_AES_256_XTS) {
printk_ratelimited(KERN_ERR
@@ -334,8 +335,8 @@ static int ext4_page_crypto(struct ext4_crypto_ctx *ctx,
crypto_ablkcipher_clear_flags(atfm, ~0);
crypto_tfm_set_flags(ctx->tfm, CRYPTO_TFM_REQ_WEAK_KEY);
- res = crypto_ablkcipher_setkey(atfm, ei->i_crypt_info.ci_raw,
- ei->i_crypt_info.ci_size);
+ res = crypto_ablkcipher_setkey(atfm, ei->i_crypt_info->ci_raw,
+ ei->i_crypt_info->ci_size);
if (res) {
printk_ratelimited(KERN_ERR
"%s: crypto_ablkcipher_setkey() failed\n",
diff --git a/fs/ext4/crypto_fname.c b/fs/ext4/crypto_fname.c
index d9f08dd..374d0e7 100644
--- a/fs/ext4/crypto_fname.c
+++ b/fs/ext4/crypto_fname.c
@@ -48,6 +48,12 @@ bool ext4_valid_filenames_enc_mode(uint32_t mode)
return (mode == EXT4_ENCRYPTION_MODE_AES_256_CTS);
}
+static unsigned max_name_len(struct inode *inode)
+{
+ return S_ISLNK(inode->i_mode) ? inode->i_sb->s_blocksize :
+ EXT4_NAME_LEN;
+}
+
/**
* ext4_fname_encrypt() -
*
@@ -55,28 +61,30 @@ bool ext4_valid_filenames_enc_mode(uint32_t mode)
* ciphertext. Errors are returned as negative numbers. We trust the caller to
* allocate sufficient memory to oname string.
*/
-static int ext4_fname_encrypt(struct ext4_fname_crypto_ctx *ctx,
+static int ext4_fname_encrypt(struct inode *inode,
const struct qstr *iname,
struct ext4_str *oname)
{
u32 ciphertext_len;
struct ablkcipher_request *req = NULL;
DECLARE_EXT4_COMPLETION_RESULT(ecr);
- struct crypto_ablkcipher *tfm = ctx->ctfm;
+ struct ext4_crypt_info *ci = EXT4_I(inode)->i_crypt_info;
+ struct crypto_ablkcipher *tfm = ci->ci_ctfm;
int res = 0;
char iv[EXT4_CRYPTO_BLOCK_SIZE];
struct scatterlist src_sg, dst_sg;
- int padding = 4 << (ctx->flags & EXT4_POLICY_FLAGS_PAD_MASK);
+ int padding = 4 << (ci->ci_flags & EXT4_POLICY_FLAGS_PAD_MASK);
char *workbuf, buf[32], *alloc_buf = NULL;
+ unsigned lim = max_name_len(inode);
- if (iname->len <= 0 || iname->len > ctx->lim)
+ if (iname->len <= 0 || iname->len > lim)
return -EIO;
ciphertext_len = (iname->len < EXT4_CRYPTO_BLOCK_SIZE) ?
EXT4_CRYPTO_BLOCK_SIZE : iname->len;
ciphertext_len = ext4_fname_crypto_round_up(ciphertext_len, padding);
- ciphertext_len = (ciphertext_len > ctx->lim)
- ? ctx->lim : ciphertext_len;
+ ciphertext_len = (ciphertext_len > lim)
+ ? lim : ciphertext_len;
if (ciphertext_len <= sizeof(buf)) {
workbuf = buf;
@@ -134,7 +142,7 @@ static int ext4_fname_encrypt(struct ext4_fname_crypto_ctx *ctx,
* Errors are returned as negative numbers.
* We trust the caller to allocate sufficient memory to oname string.
*/
-static int ext4_fname_decrypt(struct ext4_fname_crypto_ctx *ctx,
+static int ext4_fname_decrypt(struct inode *inode,
const struct ext4_str *iname,
struct ext4_str *oname)
{
@@ -142,11 +150,13 @@ static int ext4_fname_decrypt(struct ext4_fname_crypto_ctx *ctx,
struct ablkcipher_request *req = NULL;
DECLARE_EXT4_COMPLETION_RESULT(ecr);
struct scatterlist src_sg, dst_sg;
- struct crypto_ablkcipher *tfm = ctx->ctfm;
+ struct ext4_crypt_info *ci = EXT4_I(inode)->i_crypt_info;
+ struct crypto_ablkcipher *tfm = ci->ci_ctfm;
int res = 0;
char iv[EXT4_CRYPTO_BLOCK_SIZE];
+ unsigned lim = max_name_len(inode);
- if (iname->len <= 0 || iname->len > ctx->lim)
+ if (iname->len <= 0 || iname->len > lim)
return -EIO;
tmp_in[0].name = iname->name;
@@ -242,171 +252,50 @@ static int digest_decode(const char *src, int len, char *dst)
return cp - dst;
}
-/**
- * ext4_free_fname_crypto_ctx() -
- *
- * Frees up a crypto context.
- */
-void ext4_free_fname_crypto_ctx(struct ext4_fname_crypto_ctx *ctx)
-{
- if (ctx == NULL || IS_ERR(ctx))
- return;
-
- if (ctx->ctfm && !IS_ERR(ctx->ctfm))
- crypto_free_ablkcipher(ctx->ctfm);
- if (ctx->htfm && !IS_ERR(ctx->htfm))
- crypto_free_hash(ctx->htfm);
- kfree(ctx);
-}
-
-/**
- * ext4_put_fname_crypto_ctx() -
- *
- * Return: The crypto context onto free list. If the free list is above a
- * threshold, completely frees up the context, and returns the memory.
- *
- * TODO: Currently we directly free the crypto context. Eventually we should
- * add code it to return to free list. Such an approach will increase
- * efficiency of directory lookup.
- */
-void ext4_put_fname_crypto_ctx(struct ext4_fname_crypto_ctx **ctx)
+int ext4_setup_fname_crypto(struct inode *inode)
{
- if (*ctx == NULL || IS_ERR(*ctx))
- return;
- ext4_free_fname_crypto_ctx(*ctx);
- *ctx = NULL;
-}
-
-/**
- * ext4_alloc_fname_crypto_ctx() -
- */
-struct ext4_fname_crypto_ctx *ext4_alloc_fname_crypto_ctx(
- const struct ext4_crypt_info *ci)
-{
- struct ext4_fname_crypto_ctx *ctx;
-
- ctx = kmalloc(sizeof(struct ext4_fname_crypto_ctx), GFP_NOFS);
- if (ctx == NULL)
- return ERR_PTR(-ENOMEM);
- if (ci->ci_mode == EXT4_ENCRYPTION_MODE_INVALID) {
- /* This will automatically set key mode to invalid
- * As enum for ENCRYPTION_MODE_INVALID is zero */
- memset(&ctx->ci, 0, sizeof(ctx->ci));
- } else {
- memcpy(&ctx->ci, ci, sizeof(struct ext4_crypt_info));
- }
- ctx->has_valid_key = (EXT4_ENCRYPTION_MODE_INVALID == ci->ci_mode)
- ? 0 : 1;
- ctx->ctfm_key_is_ready = 0;
- ctx->ctfm = NULL;
- ctx->htfm = NULL;
- return ctx;
-}
-
-/**
- * ext4_get_fname_crypto_ctx() -
- *
- * Allocates a free crypto context and initializes it to hold
- * the crypto material for the inode.
- *
- * Return: NULL if not encrypted. Error value on error. Valid pointer otherwise.
- */
-struct ext4_fname_crypto_ctx *ext4_get_fname_crypto_ctx(
- struct inode *inode, u32 max_ciphertext_len)
-{
- struct ext4_fname_crypto_ctx *ctx;
struct ext4_inode_info *ei = EXT4_I(inode);
+ struct ext4_crypt_info *ci = ei->i_crypt_info;
+ struct crypto_ablkcipher *ctfm;
int res;
/* Check if the crypto policy is set on the inode */
res = ext4_encrypted_inode(inode);
if (res == 0)
- return NULL;
-
- if (!ext4_has_encryption_key(inode))
- ext4_generate_encryption_key(inode);
-
- /* Get a crypto context based on the key. */
- ctx = ext4_alloc_fname_crypto_ctx(&(ei->i_crypt_info));
- if (IS_ERR(ctx))
- return ctx;
-
- ctx->flags = ei->i_crypt_policy_flags;
- if (ctx->has_valid_key) {
- if (ctx->ci.ci_mode != EXT4_ENCRYPTION_MODE_AES_256_CTS) {
- printk_once(KERN_WARNING
- "ext4: unsupported key mode %d\n",
- ctx->ci.ci_mode);
- return ERR_PTR(-ENOKEY);
- }
+ return 0;
- /* As a first cut, we will allocate new tfm in every call.
- * later, we will keep the tfm around, in case the key gets
- * re-used */
- if (ctx->ctfm == NULL) {
- ctx->ctfm = crypto_alloc_ablkcipher("cts(cbc(aes))",
- 0, 0);
- }
- if (IS_ERR(ctx->ctfm)) {
- res = PTR_ERR(ctx->ctfm);
- printk(
- KERN_DEBUG "%s: error (%d) allocating crypto tfm\n",
- __func__, res);
- ctx->ctfm = NULL;
- ext4_put_fname_crypto_ctx(&ctx);
- return ERR_PTR(res);
- }
- if (ctx->ctfm == NULL) {
- printk(
- KERN_DEBUG "%s: could not allocate crypto tfm\n",
- __func__);
- ext4_put_fname_crypto_ctx(&ctx);
- return ERR_PTR(-ENOMEM);
- }
- ctx->lim = max_ciphertext_len;
- crypto_ablkcipher_clear_flags(ctx->ctfm, ~0);
- crypto_tfm_set_flags(crypto_ablkcipher_tfm(ctx->ctfm),
- CRYPTO_TFM_REQ_WEAK_KEY);
-
- /* If we are lucky, we will get a context that is already
- * set up with the right key. Else, we will have to
- * set the key */
- if (!ctx->ctfm_key_is_ready) {
- /* Since our crypto objectives for filename encryption
- * are pretty weak,
- * we directly use the inode master key */
- res = crypto_ablkcipher_setkey(ctx->ctfm,
- ctx->ci.ci_raw, ctx->ci.ci_size);
- if (res) {
- ext4_put_fname_crypto_ctx(&ctx);
- return ERR_PTR(-EIO);
- }
- ctx->ctfm_key_is_ready = 1;
- } else {
- /* In the current implementation, key should never be
- * marked "ready" for a context that has just been
- * allocated. So we should never reach here */
- BUG();
- }
- }
- if (ctx->htfm == NULL)
- ctx->htfm = crypto_alloc_hash("sha256", 0, CRYPTO_ALG_ASYNC);
- if (IS_ERR(ctx->htfm)) {
- res = PTR_ERR(ctx->htfm);
- printk(KERN_DEBUG "%s: error (%d) allocating hash tfm\n",
- __func__, res);
- ctx->htfm = NULL;
- ext4_put_fname_crypto_ctx(&ctx);
- return ERR_PTR(res);
+ res = ext4_get_encryption_info(inode);
+ if (res < 0)
+ return res;
+ ci = ei->i_crypt_info;
+
+ if (!ci || ci->ci_ctfm)
+ return 0;
+
+ if (ci->ci_mode != EXT4_ENCRYPTION_MODE_AES_256_CTS) {
+ printk_once(KERN_WARNING "ext4: unsupported key mode %d\n",
+ ci->ci_mode);
+ return -ENOKEY;
}
- if (ctx->htfm == NULL) {
- printk(KERN_DEBUG "%s: could not allocate hash tfm\n",
- __func__);
- ext4_put_fname_crypto_ctx(&ctx);
- return ERR_PTR(-ENOMEM);
+
+ ctfm = crypto_alloc_ablkcipher("cts(cbc(aes))", 0, 0);
+ if (!ctfm || IS_ERR(ctfm)) {
+ res = ctfm ? PTR_ERR(ctfm) : -ENOMEM;
+ printk(KERN_DEBUG "%s: error (%d) allocating crypto tfm\n",
+ __func__, res);
+ return res;
}
+ crypto_ablkcipher_clear_flags(ctfm, ~0);
+ crypto_tfm_set_flags(crypto_ablkcipher_tfm(ctfm),
+ CRYPTO_TFM_REQ_WEAK_KEY);
- return ctx;
+ res = crypto_ablkcipher_setkey(ctfm, ci->ci_raw, ci->ci_size);
+ if (res) {
+ crypto_free_ablkcipher(ctfm);
+ return -EIO;
+ }
+ ci->ci_ctfm = ctfm;
+ return 0;
}
/**
@@ -420,40 +309,20 @@ u32 ext4_fname_crypto_round_up(u32 size, u32 blksize)
}
/**
- * ext4_fname_crypto_namelen_on_disk() -
- */
-int ext4_fname_crypto_namelen_on_disk(struct ext4_fname_crypto_ctx *ctx,
- u32 namelen)
-{
- u32 ciphertext_len;
- int padding = 4 << (ctx->flags & EXT4_POLICY_FLAGS_PAD_MASK);
-
- if (ctx == NULL)
- return -EIO;
- if (!(ctx->has_valid_key))
- return -EACCES;
- ciphertext_len = (namelen < EXT4_CRYPTO_BLOCK_SIZE) ?
- EXT4_CRYPTO_BLOCK_SIZE : namelen;
- ciphertext_len = ext4_fname_crypto_round_up(ciphertext_len, padding);
- ciphertext_len = (ciphertext_len > ctx->lim)
- ? ctx->lim : ciphertext_len;
- return (int) ciphertext_len;
-}
-
-/**
* ext4_fname_crypto_alloc_obuff() -
*
* Allocates an output buffer that is sufficient for the crypto operation
* specified by the context and the direction.
*/
-int ext4_fname_crypto_alloc_buffer(struct ext4_fname_crypto_ctx *ctx,
+int ext4_fname_crypto_alloc_buffer(struct inode *inode,
u32 ilen, struct ext4_str *crypto_str)
{
unsigned int olen;
- int padding = 4 << (ctx->flags & EXT4_POLICY_FLAGS_PAD_MASK);
+ int padding = 16;
+ struct ext4_crypt_info *ci = EXT4_I(inode)->i_crypt_info;
- if (!ctx)
- return -EIO;
+ if (ci)
+ padding = 4 << (ci->ci_flags & EXT4_POLICY_FLAGS_PAD_MASK);
if (padding < EXT4_CRYPTO_BLOCK_SIZE)
padding = EXT4_CRYPTO_BLOCK_SIZE;
olen = ext4_fname_crypto_round_up(ilen, padding);
@@ -484,7 +353,7 @@ void ext4_fname_crypto_free_buffer(struct ext4_str *crypto_str)
/**
* ext4_fname_disk_to_usr() - converts a filename from disk space to user space
*/
-int _ext4_fname_disk_to_usr(struct ext4_fname_crypto_ctx *ctx,
+int _ext4_fname_disk_to_usr(struct inode *inode,
struct dx_hash_info *hinfo,
const struct ext4_str *iname,
struct ext4_str *oname)
@@ -492,8 +361,6 @@ int _ext4_fname_disk_to_usr(struct ext4_fname_crypto_ctx *ctx,
char buf[24];
int ret;
- if (ctx == NULL)
- return -EIO;
if (iname->len < 3) {
/*Check for . and .. */
if (iname->name[0] == '.' && iname->name[iname->len-1] == '.') {
@@ -503,8 +370,8 @@ int _ext4_fname_disk_to_usr(struct ext4_fname_crypto_ctx *ctx,
return oname->len;
}
}
- if (ctx->has_valid_key)
- return ext4_fname_decrypt(ctx, iname, oname);
+ if (EXT4_I(inode)->i_crypt_info)
+ return ext4_fname_decrypt(inode, iname, oname);
if (iname->len <= EXT4_FNAME_CRYPTO_DIGEST_SIZE) {
ret = digest_encode(iname->name, iname->len, oname->name);
@@ -523,7 +390,7 @@ int _ext4_fname_disk_to_usr(struct ext4_fname_crypto_ctx *ctx,
return ret + 1;
}
-int ext4_fname_disk_to_usr(struct ext4_fname_crypto_ctx *ctx,
+int ext4_fname_disk_to_usr(struct inode *inode,
struct dx_hash_info *hinfo,
const struct ext4_dir_entry_2 *de,
struct ext4_str *oname)
@@ -531,21 +398,20 @@ int ext4_fname_disk_to_usr(struct ext4_fname_crypto_ctx *ctx,
struct ext4_str iname = {.name = (unsigned char *) de->name,
.len = de->name_len };
- return _ext4_fname_disk_to_usr(ctx, hinfo, &iname, oname);
+ return _ext4_fname_disk_to_usr(inode, hinfo, &iname, oname);
}
/**
* ext4_fname_usr_to_disk() - converts a filename from user space to disk space
*/
-int ext4_fname_usr_to_disk(struct ext4_fname_crypto_ctx *ctx,
+int ext4_fname_usr_to_disk(struct inode *inode,
const struct qstr *iname,
struct ext4_str *oname)
{
int res;
+ struct ext4_crypt_info *ci = EXT4_I(inode)->i_crypt_info;
- if (ctx == NULL)
- return -EIO;
if (iname->len < 3) {
/*Check for . and .. */
if (iname->name[0] == '.' &&
@@ -556,8 +422,8 @@ int ext4_fname_usr_to_disk(struct ext4_fname_crypto_ctx *ctx,
return oname->len;
}
}
- if (ctx->has_valid_key) {
- res = ext4_fname_encrypt(ctx, iname, oname);
+ if (ci) {
+ res = ext4_fname_encrypt(inode, iname, oname);
return res;
}
/* Without a proper key, a user is not allowed to modify the filenames
@@ -569,16 +435,13 @@ int ext4_fname_usr_to_disk(struct ext4_fname_crypto_ctx *ctx,
int ext4_fname_setup_filename(struct inode *dir, const struct qstr *iname,
int lookup, struct ext4_filename *fname)
{
- struct ext4_fname_crypto_ctx *ctx;
+ struct ext4_crypt_info *ci;
int ret = 0, bigname = 0;
memset(fname, 0, sizeof(struct ext4_filename));
fname->usr_fname = iname;
- ctx = ext4_get_fname_crypto_ctx(dir, EXT4_NAME_LEN);
- if (IS_ERR(ctx))
- return PTR_ERR(ctx);
- if ((ctx == NULL) ||
+ if (!ext4_encrypted_inode(dir) ||
((iname->name[0] == '.') &&
((iname->len == 1) ||
((iname->name[1] == '.') && (iname->len == 2))))) {
@@ -586,12 +449,16 @@ int ext4_fname_setup_filename(struct inode *dir, const struct qstr *iname,
fname->disk_name.len = iname->len;
goto out;
}
- if (ctx->has_valid_key) {
- ret = ext4_fname_crypto_alloc_buffer(ctx, iname->len,
+ ret = ext4_setup_fname_crypto(dir);
+ if (ret)
+ return ret;
+ ci = EXT4_I(dir)->i_crypt_info;
+ if (ci) {
+ ret = ext4_fname_crypto_alloc_buffer(dir, iname->len,
&fname->crypto_buf);
if (ret < 0)
goto out;
- ret = ext4_fname_encrypt(ctx, iname, &fname->crypto_buf);
+ ret = ext4_fname_encrypt(dir, iname, &fname->crypto_buf);
if (ret < 0)
goto out;
fname->disk_name.name = fname->crypto_buf.name;
@@ -634,7 +501,6 @@ int ext4_fname_setup_filename(struct inode *dir, const struct qstr *iname,
}
ret = 0;
out:
- ext4_put_fname_crypto_ctx(&ctx);
return ret;
}
diff --git a/fs/ext4/crypto_key.c b/fs/ext4/crypto_key.c
index ec6635d..0075e43 100644
--- a/fs/ext4/crypto_key.c
+++ b/fs/ext4/crypto_key.c
@@ -84,14 +84,26 @@ out:
return res;
}
-/**
- * ext4_generate_encryption_key() - generates an encryption key
- * @inode: The inode to generate the encryption key for.
- */
-int ext4_generate_encryption_key(struct inode *inode)
+void ext4_free_encryption_info(struct inode *inode)
+{
+ struct ext4_inode_info *ei = EXT4_I(inode);
+ struct ext4_crypt_info *ci = ei->i_crypt_info;
+
+ if (!ci)
+ return;
+
+ if (ci->ci_keyring_key)
+ key_put(ci->ci_keyring_key);
+ crypto_free_ablkcipher(ci->ci_ctfm);
+ memzero_explicit(&ci->ci_raw, sizeof(ci->ci_raw));
+ kfree(ci);
+ ei->i_crypt_info = NULL;
+}
+
+int _ext4_get_encryption_info(struct inode *inode)
{
struct ext4_inode_info *ei = EXT4_I(inode);
- struct ext4_crypt_info *crypt_info = &ei->i_crypt_info;
+ 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;
@@ -99,18 +111,40 @@ int ext4_generate_encryption_key(struct inode *inode)
struct ext4_encryption_context ctx;
struct user_key_payload *ukp;
struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
- int res = ext4_xattr_get(inode, EXT4_XATTR_INDEX_ENCRYPTION,
- EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
- &ctx, sizeof(ctx));
+ int res;
- if (res != sizeof(ctx)) {
- if (res > 0)
- res = -EINVAL;
- goto out;
+ if (ei->i_crypt_info) {
+ if (!ei->i_crypt_info->ci_keyring_key ||
+ key_validate(ei->i_crypt_info->ci_keyring_key) == 0)
+ return 0;
+ ext4_free_encryption_info(inode);
}
+
+ 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 = kmalloc(sizeof(struct ext4_crypt_info), GFP_KERNEL);
+ if (!crypt_info)
+ return -ENOMEM;
+
ei->i_crypt_policy_flags = ctx.flags;
+ 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;
+ memcpy(crypt_info->ci_master_key, ctx.master_key_descriptor,
+ sizeof(crypt_info->ci_master_key));
if (S_ISREG(inode->i_mode))
crypt_info->ci_mode = ctx.contents_encryption_mode;
else if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode))
@@ -151,17 +185,23 @@ int ext4_generate_encryption_key(struct inode *inode)
res = ext4_derive_key_aes(ctx.nonce, master_key->raw,
crypt_info->ci_raw);
out:
+ if (res < 0) {
+ if (res == -ENOKEY)
+ res = 0;
+ kfree(crypt_info);
+ } else {
+ ei->i_crypt_info = crypt_info;
+ crypt_info->ci_keyring_key = keyring_key;
+ keyring_key = NULL;
+ }
if (keyring_key)
key_put(keyring_key);
- if (res < 0)
- crypt_info->ci_mode = EXT4_ENCRYPTION_MODE_INVALID;
return res;
}
int ext4_has_encryption_key(struct inode *inode)
{
struct ext4_inode_info *ei = EXT4_I(inode);
- struct ext4_crypt_info *crypt_info = &ei->i_crypt_info;
- return (crypt_info->ci_mode != EXT4_ENCRYPTION_MODE_INVALID);
+ return (ei->i_crypt_info != NULL);
}
diff --git a/fs/ext4/crypto_policy.c b/fs/ext4/crypto_policy.c
index a6d6291..370d3aa 100644
--- a/fs/ext4/crypto_policy.c
+++ b/fs/ext4/crypto_policy.c
@@ -126,7 +126,7 @@ int ext4_get_policy(struct inode *inode, struct ext4_encryption_policy *policy)
int ext4_is_child_context_consistent_with_parent(struct inode *parent,
struct inode *child)
{
- struct ext4_encryption_context parent_ctx, child_ctx;
+ struct ext4_crypt_info *parent_ci, *child_ci;
int res;
if ((parent == NULL) || (child == NULL)) {
@@ -136,26 +136,28 @@ int ext4_is_child_context_consistent_with_parent(struct inode *parent,
/* no restrictions if the parent directory is not encrypted */
if (!ext4_encrypted_inode(parent))
return 1;
- res = ext4_xattr_get(parent, EXT4_XATTR_INDEX_ENCRYPTION,
- EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
- &parent_ctx, sizeof(parent_ctx));
- if (res != sizeof(parent_ctx))
- return 0;
/* if the child directory is not encrypted, this is always a problem */
if (!ext4_encrypted_inode(child))
return 0;
- res = ext4_xattr_get(child, EXT4_XATTR_INDEX_ENCRYPTION,
- EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
- &child_ctx, sizeof(child_ctx));
- if (res != sizeof(child_ctx))
+ 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_ctx.master_key_descriptor,
- child_ctx.master_key_descriptor,
+
+ return (memcmp(parent_ci->ci_master_key,
+ child_ci->ci_master_key,
EXT4_KEY_DESCRIPTOR_SIZE) == 0 &&
- (parent_ctx.contents_encryption_mode ==
- child_ctx.contents_encryption_mode) &&
- (parent_ctx.filenames_encryption_mode ==
- child_ctx.filenames_encryption_mode));
+ (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));
}
/**
@@ -168,31 +170,37 @@ int ext4_is_child_context_consistent_with_parent(struct inode *parent,
int ext4_inherit_context(struct inode *parent, struct inode *child)
{
struct ext4_encryption_context ctx;
- int res = ext4_xattr_get(parent, EXT4_XATTR_INDEX_ENCRYPTION,
- EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
- &ctx, sizeof(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;
+ BUG_ON(ci == NULL);
- if (res != sizeof(ctx)) {
- if (DUMMY_ENCRYPTION_ENABLED(EXT4_SB(parent->i_sb))) {
- ctx.format = EXT4_ENCRYPTION_CONTEXT_FORMAT_V1;
- 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 {
- goto out;
- }
+ 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);
-out:
if (!res)
ext4_set_inode_flag(child, EXT4_INODE_ENCRYPT);
return res;
+
}
diff --git a/fs/ext4/dir.c b/fs/ext4/dir.c
index d799d5d..28cb94f 100644
--- a/fs/ext4/dir.c
+++ b/fs/ext4/dir.c
@@ -110,7 +110,6 @@ 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_fname_crypto_ctx *enc_ctx = NULL;
struct ext4_str fname_crypto_str = {.name = NULL, .len = 0};
if (is_dx_dir(inode)) {
@@ -134,16 +133,14 @@ static int ext4_readdir(struct file *file, struct dir_context *ctx)
return err;
}
- enc_ctx = ext4_get_fname_crypto_ctx(inode, EXT4_NAME_LEN);
- if (IS_ERR(enc_ctx))
- return PTR_ERR(enc_ctx);
- if (enc_ctx) {
- err = ext4_fname_crypto_alloc_buffer(enc_ctx, EXT4_NAME_LEN,
+ err = ext4_setup_fname_crypto(inode);
+ if (err)
+ return err;
+ if (ext4_encrypted_inode(inode)) {
+ err = ext4_fname_crypto_alloc_buffer(inode, EXT4_NAME_LEN,
&fname_crypto_str);
- if (err < 0) {
- ext4_put_fname_crypto_ctx(&enc_ctx);
+ if (err < 0)
return err;
- }
}
offset = ctx->pos & (sb->s_blocksize - 1);
@@ -239,8 +236,7 @@ static int ext4_readdir(struct file *file, struct dir_context *ctx)
offset += ext4_rec_len_from_disk(de->rec_len,
sb->s_blocksize);
if (le32_to_cpu(de->inode)) {
- if (enc_ctx == NULL) {
- /* Directory is not encrypted */
+ if (!ext4_encrypted_inode(inode)) {
if (!dir_emit(ctx, de->name,
de->name_len,
le32_to_cpu(de->inode),
@@ -250,7 +246,7 @@ static int ext4_readdir(struct file *file, struct dir_context *ctx)
int save_len = fname_crypto_str.len;
/* Directory is encrypted */
- err = ext4_fname_disk_to_usr(enc_ctx,
+ err = ext4_fname_disk_to_usr(inode,
NULL, de, &fname_crypto_str);
fname_crypto_str.len = save_len;
if (err < 0)
@@ -275,7 +271,6 @@ done:
err = 0;
errout:
#ifdef CONFIG_EXT4_FS_ENCRYPTION
- ext4_put_fname_crypto_ctx(&enc_ctx);
ext4_fname_crypto_free_buffer(&fname_crypto_str);
#endif
brelse(bh);
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index e3671c2..4ffaa02 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -955,7 +955,7 @@ struct ext4_inode_info {
#ifdef CONFIG_EXT4_FS_ENCRYPTION
/* Encryption params */
- struct ext4_crypt_info i_crypt_info;
+ struct ext4_crypt_info *i_crypt_info;
#endif
};
@@ -2096,37 +2096,30 @@ static inline int ext4_sb_has_crypto(struct super_block *sb)
/* crypto_fname.c */
bool ext4_valid_filenames_enc_mode(uint32_t mode);
u32 ext4_fname_crypto_round_up(u32 size, u32 blksize);
-int ext4_fname_crypto_alloc_buffer(struct ext4_fname_crypto_ctx *ctx,
+int ext4_fname_crypto_alloc_buffer(struct inode *inode,
u32 ilen, struct ext4_str *crypto_str);
-int _ext4_fname_disk_to_usr(struct ext4_fname_crypto_ctx *ctx,
+int _ext4_fname_disk_to_usr(struct inode *inode,
struct dx_hash_info *hinfo,
const struct ext4_str *iname,
struct ext4_str *oname);
-int ext4_fname_disk_to_usr(struct ext4_fname_crypto_ctx *ctx,
+int ext4_fname_disk_to_usr(struct inode *inode,
struct dx_hash_info *hinfo,
const struct ext4_dir_entry_2 *de,
struct ext4_str *oname);
-int ext4_fname_usr_to_disk(struct ext4_fname_crypto_ctx *ctx,
+int ext4_fname_usr_to_disk(struct inode *inode,
const struct qstr *iname,
struct ext4_str *oname);
-int ext4_fname_crypto_namelen_on_disk(struct ext4_fname_crypto_ctx *ctx,
- u32 namelen);
#ifdef CONFIG_EXT4_FS_ENCRYPTION
-void ext4_put_fname_crypto_ctx(struct ext4_fname_crypto_ctx **ctx);
-struct ext4_fname_crypto_ctx *ext4_get_fname_crypto_ctx(struct inode *inode,
- u32 max_len);
+int ext4_setup_fname_crypto(struct inode *inode);
void ext4_fname_crypto_free_buffer(struct ext4_str *crypto_str);
int ext4_fname_setup_filename(struct inode *dir, const struct qstr *iname,
int lookup, struct ext4_filename *fname);
void ext4_fname_free_filename(struct ext4_filename *fname);
#else
static inline
-void ext4_put_fname_crypto_ctx(struct ext4_fname_crypto_ctx **ctx) { }
-static inline
-struct ext4_fname_crypto_ctx *ext4_get_fname_crypto_ctx(struct inode *inode,
- u32 max_len)
+int ext4_setup_fname_crypto(struct inode *inode)
{
- return NULL;
+ return 0;
}
static inline void ext4_fname_crypto_free_buffer(struct ext4_str *p) { }
static inline int ext4_fname_setup_filename(struct inode *dir,
@@ -2143,10 +2136,25 @@ static inline void ext4_fname_free_filename(struct ext4_filename *fname) { }
/* crypto_key.c */
-int ext4_generate_encryption_key(struct inode *inode);
+void ext4_free_encryption_info(struct inode *inode);
+int _ext4_get_encryption_info(struct inode *inode);
#ifdef CONFIG_EXT4_FS_ENCRYPTION
int ext4_has_encryption_key(struct inode *inode);
+
+static inline int ext4_get_encryption_info(struct inode *inode)
+{
+ struct ext4_crypt_info *ci = EXT4_I(inode)->i_crypt_info;
+
+ if (!ci ||
+ (ci->ci_keyring_key &&
+ (ci->ci_keyring_key->flags & ((1 << KEY_FLAG_INVALIDATED) |
+ (1 << KEY_FLAG_REVOKED) |
+ (1 << KEY_FLAG_DEAD)))))
+ return _ext4_get_encryption_info(inode);
+ return 0;
+}
+
#else
static inline int ext4_has_encryption_key(struct inode *inode)
{
diff --git a/fs/ext4/ext4_crypto.h b/fs/ext4/ext4_crypto.h
index deecbe8..d29687c 100644
--- a/fs/ext4/ext4_crypto.h
+++ b/fs/ext4/ext4_crypto.h
@@ -76,7 +76,13 @@ struct ext4_encryption_key {
struct ext4_crypt_info {
unsigned char ci_mode;
unsigned char ci_size;
+ char ci_data_mode;
+ char ci_filename_mode;
+ char ci_flags;
+ struct crypto_ablkcipher *ci_ctfm;
+ struct key *ci_keyring_key;
char ci_raw[EXT4_MAX_KEY_SIZE];
+ char ci_master_key[EXT4_KEY_DESCRIPTOR_SIZE];
};
#define EXT4_CTX_REQUIRES_FREE_ENCRYPT_FL 0x00000001
@@ -128,16 +134,6 @@ struct ext4_str {
u32 len;
};
-struct ext4_fname_crypto_ctx {
- u32 lim;
- struct crypto_ablkcipher *ctfm;
- struct crypto_hash *htfm;
- struct ext4_crypt_info ci;
- unsigned flags : 8;
- unsigned has_valid_key : 1;
- unsigned ctfm_key_is_ready : 1;
-};
-
/**
* For encrypted symlinks, the ciphertext length is stored at the beginning
* of the string in little-endian format.
diff --git a/fs/ext4/file.c b/fs/ext4/file.c
index 0613c25..875ca6b 100644
--- a/fs/ext4/file.c
+++ b/fs/ext4/file.c
@@ -223,7 +223,7 @@ 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_generate_encryption_key(inode);
+ int err = ext4_get_encryption_info(inode);
if (err)
return 0;
}
@@ -289,7 +289,7 @@ static int ext4_file_open(struct inode * inode, struct file * filp)
}
ret = dquot_file_open(inode, filp);
if (!ret && ext4_encrypted_inode(inode)) {
- ret = ext4_generate_encryption_key(inode);
+ ret = ext4_get_encryption_info(inode);
if (ret)
ret = -EACCES;
}
diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
index b340643..9bed99f 100644
--- a/fs/ext4/namei.c
+++ b/fs/ext4/namei.c
@@ -607,17 +607,14 @@ static struct stats dx_show_leaf(struct inode *dir,
char *name;
struct ext4_str fname_crypto_str
= {.name = NULL, .len = 0};
- struct ext4_fname_crypto_ctx *ctx = NULL;
int res;
name = de->name;
len = de->name_len;
- ctx = ext4_get_fname_crypto_ctx(dir,
- EXT4_NAME_LEN);
- if (IS_ERR(ctx)) {
- printk(KERN_WARNING "Error acquiring"
- " crypto ctxt--skipping crypto\n");
- ctx = NULL;
+ res = ext4_setup_fname_crypto(dir);
+ if (res) {
+ printk(KERN_WARNING "Error setting up"
+ " fname crypto: %d\n", res);
}
if (ctx == NULL) {
/* Directory is not encrypted */
@@ -637,7 +634,6 @@ static struct stats dx_show_leaf(struct inode *dir,
"allocating crypto "
"buffer--skipping "
"crypto\n");
- ext4_put_fname_crypto_ctx(&ctx);
ctx = NULL;
}
res = ext4_fname_disk_to_usr(ctx, NULL, de,
@@ -658,7 +654,6 @@ static struct stats dx_show_leaf(struct inode *dir,
printk("%*.s:(E)%x.%u ", len, name,
h.hash, (unsigned) ((char *) de
- base));
- ext4_put_fname_crypto_ctx(&ctx);
ext4_fname_crypto_free_buffer(
&fname_crypto_str);
}
@@ -944,7 +939,6 @@ static int htree_dirblock_to_tree(struct file *dir_file,
struct buffer_head *bh;
struct ext4_dir_entry_2 *de, *top;
int err = 0, count = 0;
- struct ext4_fname_crypto_ctx *ctx = NULL;
struct ext4_str fname_crypto_str = {.name = NULL, .len = 0}, tmp_str;
dxtrace(printk(KERN_INFO "In htree dirblock_to_tree: block %lu\n",
@@ -959,17 +953,15 @@ static int htree_dirblock_to_tree(struct file *dir_file,
EXT4_DIR_REC_LEN(0));
#ifdef CONFIG_EXT4_FS_ENCRYPTION
/* Check if the directory is encrypted */
- ctx = ext4_get_fname_crypto_ctx(dir, EXT4_NAME_LEN);
- if (IS_ERR(ctx)) {
- err = PTR_ERR(ctx);
+ err = ext4_setup_fname_crypto(dir);
+ if (err) {
brelse(bh);
return err;
}
- if (ctx != NULL) {
- err = ext4_fname_crypto_alloc_buffer(ctx, EXT4_NAME_LEN,
+ if (ext4_encrypted_inode(dir)) {
+ err = ext4_fname_crypto_alloc_buffer(dir, EXT4_NAME_LEN,
&fname_crypto_str);
if (err < 0) {
- ext4_put_fname_crypto_ctx(&ctx);
brelse(bh);
return err;
}
@@ -990,8 +982,7 @@ static int htree_dirblock_to_tree(struct file *dir_file,
continue;
if (de->inode == 0)
continue;
- if (ctx == NULL) {
- /* Directory is not encrypted */
+ if (!ext4_encrypted_inode(dir)) {
tmp_str.name = de->name;
tmp_str.len = de->name_len;
err = ext4_htree_store_dirent(dir_file,
@@ -1001,7 +992,7 @@ static int htree_dirblock_to_tree(struct file *dir_file,
int save_len = fname_crypto_str.len;
/* Directory is encrypted */
- err = ext4_fname_disk_to_usr(ctx, hinfo, de,
+ err = ext4_fname_disk_to_usr(dir, hinfo, de,
&fname_crypto_str);
if (err < 0) {
count = err;
@@ -1021,7 +1012,6 @@ static int htree_dirblock_to_tree(struct file *dir_file,
errout:
brelse(bh);
#ifdef CONFIG_EXT4_FS_ENCRYPTION
- ext4_put_fname_crypto_ctx(&ctx);
ext4_fname_crypto_free_buffer(&fname_crypto_str);
#endif
return count;
@@ -3107,7 +3097,6 @@ static int ext4_symlink(struct inode *dir,
}
if (encryption_required) {
- struct ext4_fname_crypto_ctx *ctx = NULL;
struct qstr istr;
struct ext4_str ostr;
@@ -3119,19 +3108,14 @@ static int ext4_symlink(struct inode *dir,
err = ext4_inherit_context(dir, inode);
if (err)
goto err_drop_inode;
- ctx = ext4_get_fname_crypto_ctx(inode,
- inode->i_sb->s_blocksize);
- if (IS_ERR_OR_NULL(ctx)) {
- /* We just set the policy, so ctx should not be NULL */
- err = (ctx == NULL) ? -EIO : PTR_ERR(ctx);
+ err = ext4_setup_fname_crypto(inode);
+ if (err)
goto err_drop_inode;
- }
istr.name = (const unsigned char *) symname;
istr.len = len;
ostr.name = sd->encrypted_path;
ostr.len = disk_link.len;
- err = ext4_fname_usr_to_disk(ctx, &istr, &ostr);
- ext4_put_fname_crypto_ctx(&ctx);
+ err = ext4_fname_usr_to_disk(inode, &istr, &ostr);
if (err < 0)
goto err_drop_inode;
sd->len = cpu_to_le16(ostr.len);
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index a9ebe3d..1850553 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -877,9 +877,8 @@ static struct inode *ext4_alloc_inode(struct super_block *sb)
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.ci_mode = EXT4_ENCRYPTION_MODE_INVALID;
+ ei->i_crypt_info = NULL;
#endif
-
return &ei->vfs_inode;
}
@@ -956,6 +955,8 @@ void ext4_clear_inode(struct inode *inode)
jbd2_free_inode(EXT4_I(inode)->jinode);
EXT4_I(inode)->jinode = NULL;
}
+ if (EXT4_I(inode)->i_crypt_info)
+ ext4_free_encryption_info(inode);
}
static struct inode *ext4_nfs_get_inode(struct super_block *sb,
diff --git a/fs/ext4/symlink.c b/fs/ext4/symlink.c
index ca65d45..3287088 100644
--- a/fs/ext4/symlink.c
+++ b/fs/ext4/symlink.c
@@ -29,7 +29,6 @@ static void *ext4_follow_link(struct dentry *dentry, struct nameidata *nd)
char *caddr, *paddr = NULL;
struct ext4_str cstr, pstr;
struct inode *inode = d_inode(dentry);
- struct ext4_fname_crypto_ctx *ctx = NULL;
struct ext4_encrypted_symlink_data *sd;
loff_t size = min_t(loff_t, i_size_read(inode), PAGE_SIZE - 1);
int res;
@@ -38,19 +37,17 @@ static void *ext4_follow_link(struct dentry *dentry, struct nameidata *nd)
if (!ext4_encrypted_inode(inode))
return page_follow_link_light(dentry, nd);
- ctx = ext4_get_fname_crypto_ctx(inode, inode->i_sb->s_blocksize);
- if (IS_ERR(ctx))
- return ctx;
+ res = ext4_setup_fname_crypto(inode);
+ if (res)
+ return ERR_PTR(res);
if (ext4_inode_is_fast_symlink(inode)) {
caddr = (char *) EXT4_I(inode)->i_data;
max_size = sizeof(EXT4_I(inode)->i_data);
} else {
cpage = read_mapping_page(inode->i_mapping, 0, NULL);
- if (IS_ERR(cpage)) {
- ext4_put_fname_crypto_ctx(&ctx);
+ if (IS_ERR(cpage))
return cpage;
- }
caddr = kmap(cpage);
caddr[size] = 0;
}
@@ -75,21 +72,19 @@ static void *ext4_follow_link(struct dentry *dentry, struct nameidata *nd)
}
pstr.name = paddr;
pstr.len = plen;
- res = _ext4_fname_disk_to_usr(ctx, NULL, &cstr, &pstr);
+ res = _ext4_fname_disk_to_usr(inode, NULL, &cstr, &pstr);
if (res < 0)
goto errout;
/* Null-terminate the name */
if (res <= plen)
paddr[res] = '\0';
nd_set_link(nd, paddr);
- ext4_put_fname_crypto_ctx(&ctx);
if (cpage) {
kunmap(cpage);
page_cache_release(cpage);
}
return NULL;
errout:
- ext4_put_fname_crypto_ctx(&ctx);
if (cpage) {
kunmap(cpage);
page_cache_release(cpage);
--
2.3.0
^ permalink raw reply related [flat|nested] 4+ messages in thread
end of thread, other threads:[~2015-05-05 15:18 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2015-05-05 15:18 [PATCH 1/4] ext4 crypto: optimize filename encryption Theodore Ts'o
2015-05-05 15:18 ` [PATCH 2/4] ext4 crypto: don't allocate a page when encrypting/decrypting file names Theodore Ts'o
2015-05-05 15:18 ` [PATCH 3/4] ext4 crypto: separate kernel and userspace structure for the key Theodore Ts'o
2015-05-05 15:18 ` [PATCH 4/4] ext4 crypto: reorganize how we store keys in the inode Theodore Ts'o
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