1b2441318SGreg Kroah-Hartman // SPDX-License-Identifier: GPL-2.0
2d475a507SRichard Weinberger #include "ubifs.h"
3d475a507SRichard Weinberger
ubifs_crypt_get_context(struct inode * inode,void * ctx,size_t len)4d475a507SRichard Weinberger static int ubifs_crypt_get_context(struct inode *inode, void *ctx, size_t len)
5d475a507SRichard Weinberger {
6d475a507SRichard Weinberger return ubifs_xattr_get(inode, UBIFS_XATTR_NAME_ENCRYPTION_CONTEXT,
7d475a507SRichard Weinberger ctx, len);
8d475a507SRichard Weinberger }
9d475a507SRichard Weinberger
ubifs_crypt_set_context(struct inode * inode,const void * ctx,size_t len,void * fs_data)10d475a507SRichard Weinberger static int ubifs_crypt_set_context(struct inode *inode, const void *ctx,
11d475a507SRichard Weinberger size_t len, void *fs_data)
12d475a507SRichard Weinberger {
13d8db5b1cSXiaolei Li /*
14d8db5b1cSXiaolei Li * Creating an encryption context is done unlocked since we
15d8db5b1cSXiaolei Li * operate on a new inode which is not visible to other users
16d8db5b1cSXiaolei Li * at this point. So, no need to check whether inode is locked.
17d8db5b1cSXiaolei Li */
18d475a507SRichard Weinberger return ubifs_xattr_set(inode, UBIFS_XATTR_NAME_ENCRYPTION_CONTEXT,
19d8db5b1cSXiaolei Li ctx, len, 0, false);
20d475a507SRichard Weinberger }
21d475a507SRichard Weinberger
ubifs_crypt_empty_dir(struct inode * inode)22d475a507SRichard Weinberger static bool ubifs_crypt_empty_dir(struct inode *inode)
23d475a507SRichard Weinberger {
24d475a507SRichard Weinberger return ubifs_check_dir_empty(inode) == 0;
25d475a507SRichard Weinberger }
26d475a507SRichard Weinberger
27*713346caSZhaoLong Wang /**
28*713346caSZhaoLong Wang * ubifs_encrypt - Encrypt data.
29*713346caSZhaoLong Wang * @inode: inode which refers to the data node
30*713346caSZhaoLong Wang * @dn: data node to encrypt
31*713346caSZhaoLong Wang * @in_len: length of data to be compressed
32*713346caSZhaoLong Wang * @out_len: allocated memory size for the data area of @dn
33*713346caSZhaoLong Wang * @block: logical block number of the block
34*713346caSZhaoLong Wang *
35*713346caSZhaoLong Wang * This function encrypt a possibly-compressed data in the data node.
36*713346caSZhaoLong Wang * The encrypted data length will store in @out_len.
37*713346caSZhaoLong Wang */
ubifs_encrypt(const struct inode * inode,struct ubifs_data_node * dn,unsigned int in_len,unsigned int * out_len,int block)387799953bSRichard Weinberger int ubifs_encrypt(const struct inode *inode, struct ubifs_data_node *dn,
397799953bSRichard Weinberger unsigned int in_len, unsigned int *out_len, int block)
407799953bSRichard Weinberger {
417799953bSRichard Weinberger struct ubifs_info *c = inode->i_sb->s_fs_info;
427799953bSRichard Weinberger void *p = &dn->data;
437799953bSRichard Weinberger unsigned int pad_len = round_up(in_len, UBIFS_CIPHER_BLOCK_SIZE);
4403569f2fSEric Biggers int err;
457799953bSRichard Weinberger
466eb61d58SRichard Weinberger ubifs_assert(c, pad_len <= *out_len);
477799953bSRichard Weinberger dn->compr_size = cpu_to_le16(in_len);
487799953bSRichard Weinberger
497799953bSRichard Weinberger /* pad to full block cipher length */
507799953bSRichard Weinberger if (pad_len != in_len)
517799953bSRichard Weinberger memset(p + in_len, 0, pad_len - in_len);
527799953bSRichard Weinberger
5303569f2fSEric Biggers err = fscrypt_encrypt_block_inplace(inode, virt_to_page(p), pad_len,
5403569f2fSEric Biggers offset_in_page(p), block, GFP_NOFS);
5503569f2fSEric Biggers if (err) {
5603569f2fSEric Biggers ubifs_err(c, "fscrypt_encrypt_block_inplace() failed: %d", err);
5703569f2fSEric Biggers return err;
587799953bSRichard Weinberger }
597799953bSRichard Weinberger *out_len = pad_len;
607799953bSRichard Weinberger
617799953bSRichard Weinberger return 0;
627799953bSRichard Weinberger }
637799953bSRichard Weinberger
ubifs_decrypt(const struct inode * inode,struct ubifs_data_node * dn,unsigned int * out_len,int block)647799953bSRichard Weinberger int ubifs_decrypt(const struct inode *inode, struct ubifs_data_node *dn,
657799953bSRichard Weinberger unsigned int *out_len, int block)
667799953bSRichard Weinberger {
677799953bSRichard Weinberger struct ubifs_info *c = inode->i_sb->s_fs_info;
687799953bSRichard Weinberger int err;
697799953bSRichard Weinberger unsigned int clen = le16_to_cpu(dn->compr_size);
707799953bSRichard Weinberger unsigned int dlen = *out_len;
717799953bSRichard Weinberger
727799953bSRichard Weinberger if (clen <= 0 || clen > UBIFS_BLOCK_SIZE || clen > dlen) {
737799953bSRichard Weinberger ubifs_err(c, "bad compr_size: %i", clen);
747799953bSRichard Weinberger return -EINVAL;
757799953bSRichard Weinberger }
767799953bSRichard Weinberger
776eb61d58SRichard Weinberger ubifs_assert(c, dlen <= UBIFS_BLOCK_SIZE);
7841adbcb7SEric Biggers err = fscrypt_decrypt_block_inplace(inode, virt_to_page(&dn->data),
7941adbcb7SEric Biggers dlen, offset_in_page(&dn->data),
8041adbcb7SEric Biggers block);
817799953bSRichard Weinberger if (err) {
8241adbcb7SEric Biggers ubifs_err(c, "fscrypt_decrypt_block_inplace() failed: %d", err);
837799953bSRichard Weinberger return err;
847799953bSRichard Weinberger }
857799953bSRichard Weinberger *out_len = clen;
867799953bSRichard Weinberger
877799953bSRichard Weinberger return 0;
887799953bSRichard Weinberger }
897799953bSRichard Weinberger
906f69f0edSEric Biggers const struct fscrypt_operations ubifs_crypt_operations = {
9138588668SRichard Weinberger .flags = FS_CFLG_OWN_PAGES,
92a5d431efSEric Biggers .key_prefix = "ubifs:",
93d475a507SRichard Weinberger .get_context = ubifs_crypt_get_context,
94d475a507SRichard Weinberger .set_context = ubifs_crypt_set_context,
95d475a507SRichard Weinberger .empty_dir = ubifs_crypt_empty_dir,
96d475a507SRichard Weinberger };
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