1 // SPDX-License-Identifier: GPL-2.0 2 #include "ubifs.h" 3 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 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 22 static bool ubifs_crypt_empty_dir(struct inode *inode) 23 { 24 return ubifs_check_dir_empty(inode) == 0; 25 } 26 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 unsigned int pad_len = round_up(in_len, UBIFS_CIPHER_BLOCK_SIZE); 33 int err; 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 err = fscrypt_encrypt_block_inplace(inode, virt_to_page(p), pad_len, 43 offset_in_page(p), block, GFP_NOFS); 44 if (err) { 45 ubifs_err(c, "fscrypt_encrypt_block_inplace() failed: %d", err); 46 return err; 47 } 48 *out_len = pad_len; 49 50 return 0; 51 } 52 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_block_inplace(inode, virt_to_page(&dn->data), 68 dlen, offset_in_page(&dn->data), 69 block); 70 if (err) { 71 ubifs_err(c, "fscrypt_decrypt_block_inplace() failed: %d", err); 72 return err; 73 } 74 *out_len = clen; 75 76 return 0; 77 } 78 79 const struct fscrypt_operations ubifs_crypt_operations = { 80 .flags = FS_CFLG_OWN_PAGES, 81 .key_prefix = "ubifs:", 82 .get_context = ubifs_crypt_get_context, 83 .set_context = ubifs_crypt_set_context, 84 .empty_dir = ubifs_crypt_empty_dir, 85 }; 86