1b2441318SGreg Kroah-Hartman // SPDX-License-Identifier: GPL-2.0 2d475a507SRichard Weinberger #include "ubifs.h" 3d475a507SRichard Weinberger 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 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 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 27d475a507SRichard Weinberger static unsigned int ubifs_crypt_max_namelen(struct inode *inode) 28d475a507SRichard Weinberger { 29d475a507SRichard Weinberger if (S_ISLNK(inode->i_mode)) 30d475a507SRichard Weinberger return UBIFS_MAX_INO_DATA; 31d475a507SRichard Weinberger else 32d475a507SRichard Weinberger return UBIFS_MAX_NLEN; 33d475a507SRichard Weinberger } 34d475a507SRichard Weinberger 357799953bSRichard Weinberger int ubifs_encrypt(const struct inode *inode, struct ubifs_data_node *dn, 367799953bSRichard Weinberger unsigned int in_len, unsigned int *out_len, int block) 377799953bSRichard Weinberger { 387799953bSRichard Weinberger struct ubifs_info *c = inode->i_sb->s_fs_info; 397799953bSRichard Weinberger void *p = &dn->data; 407799953bSRichard Weinberger struct page *ret; 417799953bSRichard Weinberger unsigned int pad_len = round_up(in_len, UBIFS_CIPHER_BLOCK_SIZE); 427799953bSRichard Weinberger 437799953bSRichard Weinberger ubifs_assert(pad_len <= *out_len); 447799953bSRichard Weinberger dn->compr_size = cpu_to_le16(in_len); 457799953bSRichard Weinberger 467799953bSRichard Weinberger /* pad to full block cipher length */ 477799953bSRichard Weinberger if (pad_len != in_len) 487799953bSRichard Weinberger memset(p + in_len, 0, pad_len - in_len); 497799953bSRichard Weinberger 507799953bSRichard Weinberger ret = fscrypt_encrypt_page(inode, virt_to_page(&dn->data), pad_len, 517799953bSRichard Weinberger offset_in_page(&dn->data), block, GFP_NOFS); 527799953bSRichard Weinberger if (IS_ERR(ret)) { 537799953bSRichard Weinberger ubifs_err(c, "fscrypt_encrypt_page failed: %ld", PTR_ERR(ret)); 547799953bSRichard Weinberger return PTR_ERR(ret); 557799953bSRichard Weinberger } 567799953bSRichard Weinberger *out_len = pad_len; 577799953bSRichard Weinberger 587799953bSRichard Weinberger return 0; 597799953bSRichard Weinberger } 607799953bSRichard Weinberger 617799953bSRichard Weinberger int ubifs_decrypt(const struct inode *inode, struct ubifs_data_node *dn, 627799953bSRichard Weinberger unsigned int *out_len, int block) 637799953bSRichard Weinberger { 647799953bSRichard Weinberger struct ubifs_info *c = inode->i_sb->s_fs_info; 657799953bSRichard Weinberger int err; 667799953bSRichard Weinberger unsigned int clen = le16_to_cpu(dn->compr_size); 677799953bSRichard Weinberger unsigned int dlen = *out_len; 687799953bSRichard Weinberger 697799953bSRichard Weinberger if (clen <= 0 || clen > UBIFS_BLOCK_SIZE || clen > dlen) { 707799953bSRichard Weinberger ubifs_err(c, "bad compr_size: %i", clen); 717799953bSRichard Weinberger return -EINVAL; 727799953bSRichard Weinberger } 737799953bSRichard Weinberger 747799953bSRichard Weinberger ubifs_assert(dlen <= UBIFS_BLOCK_SIZE); 757799953bSRichard Weinberger err = fscrypt_decrypt_page(inode, virt_to_page(&dn->data), dlen, 767799953bSRichard Weinberger offset_in_page(&dn->data), block); 777799953bSRichard Weinberger if (err) { 787799953bSRichard Weinberger ubifs_err(c, "fscrypt_decrypt_page failed: %i", err); 797799953bSRichard Weinberger return err; 807799953bSRichard Weinberger } 817799953bSRichard Weinberger *out_len = clen; 827799953bSRichard Weinberger 837799953bSRichard Weinberger return 0; 847799953bSRichard Weinberger } 857799953bSRichard Weinberger 866f69f0edSEric Biggers const struct fscrypt_operations ubifs_crypt_operations = { 8738588668SRichard Weinberger .flags = FS_CFLG_OWN_PAGES, 88a5d431efSEric Biggers .key_prefix = "ubifs:", 89d475a507SRichard Weinberger .get_context = ubifs_crypt_get_context, 90d475a507SRichard Weinberger .set_context = ubifs_crypt_set_context, 911ee77870SRichard Weinberger .is_encrypted = __ubifs_crypt_is_encrypted, 92d475a507SRichard Weinberger .empty_dir = ubifs_crypt_empty_dir, 93d475a507SRichard Weinberger .max_namelen = ubifs_crypt_max_namelen, 94d475a507SRichard Weinberger }; 95