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ubifs: Implement encrypt/decrypt for all IO
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Signed-off-by: Richard Weinberger <[email protected]>
Signed-off-by: David Gstir <[email protected]>
Signed-off-by: Richard Weinberger <[email protected]>
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@richardweinberger
richardweinberger committed Dec 12, 2016
1 parent 1ee7787 commit 7799953
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Showing 5 changed files with 152 additions and 28 deletions.
51 changes: 51 additions & 0 deletions fs/ubifs/crypto.c
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Original file line number Diff line number Diff line change
Expand Up @@ -35,6 +35,57 @@ static int ubifs_key_prefix(struct inode *inode, u8 **key)
return sizeof(prefix) - 1;
}

int ubifs_encrypt(const struct inode *inode, struct ubifs_data_node *dn,
unsigned int in_len, unsigned int *out_len, int block)
{
struct ubifs_info *c = inode->i_sb->s_fs_info;
void *p = &dn->data;
struct page *ret;
unsigned int pad_len = round_up(in_len, UBIFS_CIPHER_BLOCK_SIZE);

ubifs_assert(pad_len <= *out_len);
dn->compr_size = cpu_to_le16(in_len);

/* pad to full block cipher length */
if (pad_len != in_len)
memset(p + in_len, 0, pad_len - in_len);

ret = fscrypt_encrypt_page(inode, virt_to_page(&dn->data), pad_len,
offset_in_page(&dn->data), block, GFP_NOFS);
if (IS_ERR(ret)) {
ubifs_err(c, "fscrypt_encrypt_page failed: %ld", PTR_ERR(ret));
return PTR_ERR(ret);
}
*out_len = pad_len;

return 0;
}

int ubifs_decrypt(const struct inode *inode, struct ubifs_data_node *dn,
unsigned int *out_len, int block)
{
struct ubifs_info *c = inode->i_sb->s_fs_info;
int err;
unsigned int clen = le16_to_cpu(dn->compr_size);
unsigned int dlen = *out_len;

if (clen <= 0 || clen > UBIFS_BLOCK_SIZE || clen > dlen) {
ubifs_err(c, "bad compr_size: %i", clen);
return -EINVAL;
}

ubifs_assert(dlen <= UBIFS_BLOCK_SIZE);
err = fscrypt_decrypt_page(inode, virt_to_page(&dn->data), dlen,
offset_in_page(&dn->data), block);
if (err) {
ubifs_err(c, "fscrypt_decrypt_page failed: %i", err);
return err;
}
*out_len = clen;

return 0;
}

struct fscrypt_operations ubifs_crypt_operations = {
.flags = FS_CFLG_INPLACE_ENCRYPTION,
.get_context = ubifs_crypt_get_context,
Expand Down
14 changes: 14 additions & 0 deletions fs/ubifs/file.c
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Original file line number Diff line number Diff line change
Expand Up @@ -78,6 +78,13 @@ static int read_block(struct inode *inode, void *addr, unsigned int block,
goto dump;

dlen = le32_to_cpu(dn->ch.len) - UBIFS_DATA_NODE_SZ;

if (ubifs_crypt_is_encrypted(inode)) {
err = ubifs_decrypt(inode, dn, &dlen, block);
if (err)
goto dump;
}

out_len = UBIFS_BLOCK_SIZE;
err = ubifs_decompress(c, &dn->data, dlen, addr, &out_len,
le16_to_cpu(dn->compr_type));
Expand Down Expand Up @@ -650,6 +657,13 @@ static int populate_page(struct ubifs_info *c, struct page *page,

dlen = le32_to_cpu(dn->ch.len) - UBIFS_DATA_NODE_SZ;
out_len = UBIFS_BLOCK_SIZE;

if (ubifs_crypt_is_encrypted(inode)) {
err = ubifs_decrypt(inode, dn, &dlen, page_block);
if (err)
goto out_err;
}

err = ubifs_decompress(c, &dn->data, dlen, addr, &out_len,
le16_to_cpu(dn->compr_type));
if (err || len != out_len)
Expand Down
78 changes: 54 additions & 24 deletions fs/ubifs/journal.c
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Original file line number Diff line number Diff line change
Expand Up @@ -688,14 +688,18 @@ int ubifs_jnl_write_data(struct ubifs_info *c, const struct inode *inode,
const union ubifs_key *key, const void *buf, int len)
{
struct ubifs_data_node *data;
int err, lnum, offs, compr_type, out_len;
int err, lnum, offs, compr_type, out_len, compr_len;
int dlen = COMPRESSED_DATA_NODE_BUF_SZ, allocated = 1;
struct ubifs_inode *ui = ubifs_inode(inode);
bool encrypted = ubifs_crypt_is_encrypted(inode);

dbg_jnlk(key, "ino %lu, blk %u, len %d, key ",
(unsigned long)key_inum(c, key), key_block(c, key), len);
ubifs_assert(len <= UBIFS_BLOCK_SIZE);

if (encrypted)
dlen += UBIFS_CIPHER_BLOCK_SIZE;

data = kmalloc(dlen, GFP_NOFS | __GFP_NOWARN);
if (!data) {
/*
Expand All @@ -720,9 +724,18 @@ int ubifs_jnl_write_data(struct ubifs_info *c, const struct inode *inode,
else
compr_type = ui->compr_type;

out_len = dlen - UBIFS_DATA_NODE_SZ;
ubifs_compress(c, buf, len, &data->data, &out_len, &compr_type);
ubifs_assert(out_len <= UBIFS_BLOCK_SIZE);
out_len = compr_len = dlen - UBIFS_DATA_NODE_SZ;
ubifs_compress(c, buf, len, &data->data, &compr_len, &compr_type);
ubifs_assert(compr_len <= UBIFS_BLOCK_SIZE);

if (encrypted) {
err = ubifs_encrypt(inode, data, compr_len, &out_len, key_block(c, key));
if (err)
goto out_free;

} else {
data->compr_size = 0;
}

dlen = UBIFS_DATA_NODE_SZ + out_len;
data->compr_type = cpu_to_le16(compr_type);
Expand Down Expand Up @@ -1241,31 +1254,55 @@ int ubifs_jnl_rename(struct ubifs_info *c, const struct inode *old_dir,
}

/**
* recomp_data_node - re-compress a truncated data node.
* truncate_data_node - re-compress/encrypt a truncated data node.
* @c: UBIFS file-system description object
* @inode: inode which referes to the data node
* @block: data block number
* @dn: data node to re-compress
* @new_len: new length
*
* This function is used when an inode is truncated and the last data node of
* the inode has to be re-compressed and re-written.
* the inode has to be re-compressed/encrypted and re-written.
*/
static int recomp_data_node(const struct ubifs_info *c,
struct ubifs_data_node *dn, int *new_len)
static int truncate_data_node(const struct ubifs_info *c, const struct inode *inode,
unsigned int block, struct ubifs_data_node *dn,
int *new_len)
{
void *buf;
int err, len, compr_type, out_len;
int err, dlen, compr_type, out_len, old_dlen;

out_len = le32_to_cpu(dn->size);
buf = kmalloc(out_len * WORST_COMPR_FACTOR, GFP_NOFS);
if (!buf)
return -ENOMEM;

len = le32_to_cpu(dn->ch.len) - UBIFS_DATA_NODE_SZ;
dlen = old_dlen = le32_to_cpu(dn->ch.len) - UBIFS_DATA_NODE_SZ;
compr_type = le16_to_cpu(dn->compr_type);
err = ubifs_decompress(c, &dn->data, len, buf, &out_len, compr_type);
if (err)
goto out;

ubifs_compress(c, buf, *new_len, &dn->data, &out_len, &compr_type);
if (ubifs_crypt_is_encrypted(inode)) {
err = ubifs_decrypt(inode, dn, &dlen, block);
if (err)
goto out;
}

if (compr_type != UBIFS_COMPR_NONE) {
err = ubifs_decompress(c, &dn->data, dlen, buf, &out_len, compr_type);
if (err)
goto out;

ubifs_compress(c, buf, *new_len, &dn->data, &out_len, &compr_type);
}

if (ubifs_crypt_is_encrypted(inode)) {
err = ubifs_encrypt(inode, dn, out_len, &old_dlen, block);
if (err)
goto out;

out_len = old_dlen;
} else {
dn->compr_size = 0;
}

ubifs_assert(out_len <= UBIFS_BLOCK_SIZE);
dn->compr_type = cpu_to_le16(compr_type);
dn->size = cpu_to_le32(*new_len);
Expand Down Expand Up @@ -1337,16 +1374,9 @@ int ubifs_jnl_truncate(struct ubifs_info *c, const struct inode *inode,
if (le32_to_cpu(dn->size) <= dlen)
dlen = 0; /* Nothing to do */
else {
int compr_type = le16_to_cpu(dn->compr_type);

if (compr_type != UBIFS_COMPR_NONE) {
err = recomp_data_node(c, dn, &dlen);
if (err)
goto out_free;
} else {
dn->size = cpu_to_le32(dlen);
dlen += UBIFS_DATA_NODE_SZ;
}
err = truncate_data_node(c, inode, blk, dn, &dlen);
if (err)
goto out_free;
}
}
}
Expand Down
6 changes: 4 additions & 2 deletions fs/ubifs/super.c
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Original file line number Diff line number Diff line change
Expand Up @@ -1210,7 +1210,8 @@ static int mount_ubifs(struct ubifs_info *c)
bu_init(c);

if (!c->ro_mount) {
c->write_reserve_buf = kmalloc(COMPRESSED_DATA_NODE_BUF_SZ,
c->write_reserve_buf = kmalloc(COMPRESSED_DATA_NODE_BUF_SZ + \
UBIFS_CIPHER_BLOCK_SIZE,
GFP_KERNEL);
if (!c->write_reserve_buf)
goto out_free;
Expand Down Expand Up @@ -1623,7 +1624,8 @@ static int ubifs_remount_rw(struct ubifs_info *c)
goto out;
}

c->write_reserve_buf = kmalloc(COMPRESSED_DATA_NODE_BUF_SZ, GFP_KERNEL);
c->write_reserve_buf = kmalloc(COMPRESSED_DATA_NODE_BUF_SZ + \
UBIFS_CIPHER_BLOCK_SIZE, GFP_KERNEL);
if (!c->write_reserve_buf) {
err = -ENOMEM;
goto out;
Expand Down
31 changes: 29 additions & 2 deletions fs/ubifs/ubifs.h
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Original file line number Diff line number Diff line change
Expand Up @@ -135,6 +135,12 @@
*/
#define WORST_COMPR_FACTOR 2

#ifdef CONFIG_UBIFS_FS_ENCRYPTION
#define UBIFS_CIPHER_BLOCK_SIZE FS_CRYPTO_BLOCK_SIZE
#else
#define UBIFS_CIPHER_BLOCK_SIZE 0
#endif

/*
* How much memory is needed for a buffer where we compress a data node.
*/
Expand Down Expand Up @@ -1774,8 +1780,6 @@ void ubifs_compress(const struct ubifs_info *c, const void *in_buf, int in_len,
int ubifs_decompress(const struct ubifs_info *c, const void *buf, int len,
void *out, int *out_len, int compr_type);

extern struct fscrypt_operations ubifs_crypt_operations;

#include "debug.h"
#include "misc.h"
#include "key.h"
Expand Down Expand Up @@ -1803,8 +1807,31 @@ extern struct fscrypt_operations ubifs_crypt_operations;
#define fscrypt_fname_free_buffer fscrypt_notsupp_fname_free_buffer
#define fscrypt_fname_disk_to_usr fscrypt_notsupp_fname_disk_to_usr
#define fscrypt_fname_usr_to_disk fscrypt_notsupp_fname_usr_to_disk
static inline int ubifs_encrypt(const struct inode *inode,
struct ubifs_data_node *dn,
unsigned int in_len, unsigned int *out_len,
int block)
{
ubifs_assert(0);
return -EOPNOTSUPP;
}
static inline int ubifs_decrypt(const struct inode *inode,
struct ubifs_data_node *dn,
unsigned int *out_len, int block)
{
ubifs_assert(0);
return -EOPNOTSUPP;
}
#else
/* crypto.c */
int ubifs_encrypt(const struct inode *inode, struct ubifs_data_node *dn,
unsigned int in_len, unsigned int *out_len, int block);
int ubifs_decrypt(const struct inode *inode, struct ubifs_data_node *dn,
unsigned int *out_len, int block);
#endif

extern struct fscrypt_operations ubifs_crypt_operations;

static inline bool __ubifs_crypt_is_encrypted(struct inode *inode)
{
struct ubifs_inode *ui = ubifs_inode(inode);
Expand Down

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