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 277799953bSRichard Weinberger int ubifs_encrypt(const struct inode *inode, struct ubifs_data_node *dn, 287799953bSRichard Weinberger unsigned int in_len, unsigned int *out_len, int block) 297799953bSRichard Weinberger { 307799953bSRichard Weinberger struct ubifs_info *c = inode->i_sb->s_fs_info; 317799953bSRichard Weinberger void *p = &dn->data; 327799953bSRichard Weinberger unsigned int pad_len = round_up(in_len, UBIFS_CIPHER_BLOCK_SIZE); 3303569f2fSEric Biggers int err; 347799953bSRichard Weinberger 356eb61d58SRichard Weinberger ubifs_assert(c, pad_len <= *out_len); 367799953bSRichard Weinberger dn->compr_size = cpu_to_le16(in_len); 377799953bSRichard Weinberger 387799953bSRichard Weinberger /* pad to full block cipher length */ 397799953bSRichard Weinberger if (pad_len != in_len) 407799953bSRichard Weinberger memset(p + in_len, 0, pad_len - in_len); 417799953bSRichard Weinberger 4203569f2fSEric Biggers err = fscrypt_encrypt_block_inplace(inode, virt_to_page(p), pad_len, 4303569f2fSEric Biggers offset_in_page(p), block, GFP_NOFS); 4403569f2fSEric Biggers if (err) { 4503569f2fSEric Biggers ubifs_err(c, "fscrypt_encrypt_block_inplace() failed: %d", err); 4603569f2fSEric Biggers return err; 477799953bSRichard Weinberger } 487799953bSRichard Weinberger *out_len = pad_len; 497799953bSRichard Weinberger 507799953bSRichard Weinberger return 0; 517799953bSRichard Weinberger } 527799953bSRichard Weinberger 537799953bSRichard Weinberger int ubifs_decrypt(const struct inode *inode, struct ubifs_data_node *dn, 547799953bSRichard Weinberger unsigned int *out_len, int block) 557799953bSRichard Weinberger { 567799953bSRichard Weinberger struct ubifs_info *c = inode->i_sb->s_fs_info; 577799953bSRichard Weinberger int err; 587799953bSRichard Weinberger unsigned int clen = le16_to_cpu(dn->compr_size); 597799953bSRichard Weinberger unsigned int dlen = *out_len; 607799953bSRichard Weinberger 617799953bSRichard Weinberger if (clen <= 0 || clen > UBIFS_BLOCK_SIZE || clen > dlen) { 627799953bSRichard Weinberger ubifs_err(c, "bad compr_size: %i", clen); 637799953bSRichard Weinberger return -EINVAL; 647799953bSRichard Weinberger } 657799953bSRichard Weinberger 666eb61d58SRichard Weinberger ubifs_assert(c, dlen <= UBIFS_BLOCK_SIZE); 6741adbcb7SEric Biggers err = fscrypt_decrypt_block_inplace(inode, virt_to_page(&dn->data), 6841adbcb7SEric Biggers dlen, offset_in_page(&dn->data), 6941adbcb7SEric Biggers block); 707799953bSRichard Weinberger if (err) { 7141adbcb7SEric Biggers ubifs_err(c, "fscrypt_decrypt_block_inplace() failed: %d", err); 727799953bSRichard Weinberger return err; 737799953bSRichard Weinberger } 747799953bSRichard Weinberger *out_len = clen; 757799953bSRichard Weinberger 767799953bSRichard Weinberger return 0; 777799953bSRichard Weinberger } 787799953bSRichard Weinberger 796f69f0edSEric Biggers const struct fscrypt_operations ubifs_crypt_operations = { 8038588668SRichard Weinberger .flags = FS_CFLG_OWN_PAGES, 81a5d431efSEric Biggers .key_prefix = "ubifs:", 82d475a507SRichard Weinberger .get_context = ubifs_crypt_get_context, 83d475a507SRichard Weinberger .set_context = ubifs_crypt_set_context, 84d475a507SRichard Weinberger .empty_dir = ubifs_crypt_empty_dir, 85e12ee683SEric Biggers .max_namelen = UBIFS_MAX_NLEN, 86d475a507SRichard Weinberger }; 87