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// SPDX-License-Identifier: GPL-2.0
#include "ubifs.h"
static int ubifs_crypt_get_context(struct inode *inode, void *ctx, size_t len)
{
return ubifs_xattr_get(inode, UBIFS_XATTR_NAME_ENCRYPTION_CONTEXT,
ctx, len);
}
static int ubifs_crypt_set_context(struct inode *inode, const void *ctx,
size_t len, void *fs_data)
{
/*
* Creating an encryption context is done unlocked since we
* operate on a new inode which is not visible to other users
* at this point. So, no need to check whether inode is locked.
*/
return ubifs_xattr_set(inode, UBIFS_XATTR_NAME_ENCRYPTION_CONTEXT,
ctx, len, 0, false);
}
static bool ubifs_crypt_empty_dir(struct inode *inode)
{
return ubifs_check_dir_empty(inode) == 0;
}
/**
* ubifs_encrypt - Encrypt data.
* @inode: inode which refers to the data node
* @dn: data node to encrypt
* @in_len: length of data to be compressed
* @out_len: allocated memory size for the data area of @dn
* @block: logical block number of the block
*
* This function encrypt a possibly-compressed data in the data node.
* The encrypted data length will store in @out_len.
*/
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;
unsigned int pad_len = round_up(in_len, UBIFS_CIPHER_BLOCK_SIZE);
int err;
ubifs_assert(c, 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);
err = fscrypt_encrypt_block_inplace(inode, virt_to_page(p), pad_len,
offset_in_page(p), block, GFP_NOFS);
if (err) {
ubifs_err(c, "fscrypt_encrypt_block_inplace() failed: %d", err);
return err;
}
*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(c, dlen <= UBIFS_BLOCK_SIZE);
err = fscrypt_decrypt_block_inplace(inode, virt_to_page(&dn->data),
dlen, offset_in_page(&dn->data),
block);
if (err) {
ubifs_err(c, "fscrypt_decrypt_block_inplace() failed: %d", err);
return err;
}
*out_len = clen;
return 0;
}
const struct fscrypt_operations ubifs_crypt_operations = {
.flags = FS_CFLG_OWN_PAGES,
.key_prefix = "ubifs:",
.get_context = ubifs_crypt_get_context,
.set_context = ubifs_crypt_set_context,
.empty_dir = ubifs_crypt_empty_dir,
};
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