1 // SPDX-License-Identifier: GPL-2.0
2 #include "ubifs.h"
3
ubifs_crypt_get_context(struct inode * inode,void * ctx,size_t len)4 static int ubifs_crypt_get_context(struct inode *inode, void *ctx, size_t len)
5 {
6 return ubifs_xattr_get(inode, UBIFS_XATTR_NAME_ENCRYPTION_CONTEXT,
7 ctx, len);
8 }
9
ubifs_crypt_set_context(struct inode * inode,const void * ctx,size_t len,void * fs_data)10 static int ubifs_crypt_set_context(struct inode *inode, const void *ctx,
11 size_t len, void *fs_data)
12 {
13 /*
14 * Creating an encryption context is done unlocked since we
15 * operate on a new inode which is not visible to other users
16 * at this point. So, no need to check whether inode is locked.
17 */
18 return ubifs_xattr_set(inode, UBIFS_XATTR_NAME_ENCRYPTION_CONTEXT,
19 ctx, len, 0, false);
20 }
21
ubifs_crypt_empty_dir(struct inode * inode)22 static bool ubifs_crypt_empty_dir(struct inode *inode)
23 {
24 return ubifs_check_dir_empty(inode) == 0;
25 }
26
ubifs_encrypt(const struct inode * inode,struct ubifs_data_node * dn,unsigned int in_len,unsigned int * out_len,int block)27 int ubifs_encrypt(const struct inode *inode, struct ubifs_data_node *dn,
28 unsigned int in_len, unsigned int *out_len, int block)
29 {
30 struct ubifs_info *c = inode->i_sb->s_fs_info;
31 void *p = &dn->data;
32 struct page *ret;
33 unsigned int pad_len = round_up(in_len, UBIFS_CIPHER_BLOCK_SIZE);
34
35 ubifs_assert(c, pad_len <= *out_len);
36 dn->compr_size = cpu_to_le16(in_len);
37
38 /* pad to full block cipher length */
39 if (pad_len != in_len)
40 memset(p + in_len, 0, pad_len - in_len);
41
42 ret = fscrypt_encrypt_page(inode, virt_to_page(&dn->data), pad_len,
43 offset_in_page(&dn->data), block, GFP_NOFS);
44 if (IS_ERR(ret)) {
45 ubifs_err(c, "fscrypt_encrypt_page failed: %ld", PTR_ERR(ret));
46 return PTR_ERR(ret);
47 }
48 *out_len = pad_len;
49
50 return 0;
51 }
52
ubifs_decrypt(const struct inode * inode,struct ubifs_data_node * dn,unsigned int * out_len,int block)53 int ubifs_decrypt(const struct inode *inode, struct ubifs_data_node *dn,
54 unsigned int *out_len, int block)
55 {
56 struct ubifs_info *c = inode->i_sb->s_fs_info;
57 int err;
58 unsigned int clen = le16_to_cpu(dn->compr_size);
59 unsigned int dlen = *out_len;
60
61 if (clen <= 0 || clen > UBIFS_BLOCK_SIZE || clen > dlen) {
62 ubifs_err(c, "bad compr_size: %i", clen);
63 return -EINVAL;
64 }
65
66 ubifs_assert(c, dlen <= UBIFS_BLOCK_SIZE);
67 err = fscrypt_decrypt_page(inode, virt_to_page(&dn->data), dlen,
68 offset_in_page(&dn->data), block);
69 if (err) {
70 ubifs_err(c, "fscrypt_decrypt_page failed: %i", err);
71 return err;
72 }
73 *out_len = clen;
74
75 return 0;
76 }
77
78 const struct fscrypt_operations ubifs_crypt_operations = {
79 .flags = FS_CFLG_OWN_PAGES,
80 .key_prefix = "ubifs:",
81 .get_context = ubifs_crypt_get_context,
82 .set_context = ubifs_crypt_set_context,
83 .empty_dir = ubifs_crypt_empty_dir,
84 .max_namelen = UBIFS_MAX_NLEN,
85 };
86
