1 #include "ubifs.h" 2 3 static int ubifs_crypt_get_context(struct inode *inode, void *ctx, size_t len) 4 { 5 return ubifs_xattr_get(inode, UBIFS_XATTR_NAME_ENCRYPTION_CONTEXT, 6 ctx, len); 7 } 8 9 static int ubifs_crypt_set_context(struct inode *inode, const void *ctx, 10 size_t len, void *fs_data) 11 { 12 /* 13 * Creating an encryption context is done unlocked since we 14 * operate on a new inode which is not visible to other users 15 * at this point. So, no need to check whether inode is locked. 16 */ 17 return ubifs_xattr_set(inode, UBIFS_XATTR_NAME_ENCRYPTION_CONTEXT, 18 ctx, len, 0, false); 19 } 20 21 static bool ubifs_crypt_empty_dir(struct inode *inode) 22 { 23 return ubifs_check_dir_empty(inode) == 0; 24 } 25 26 static unsigned int ubifs_crypt_max_namelen(struct inode *inode) 27 { 28 if (S_ISLNK(inode->i_mode)) 29 return UBIFS_MAX_INO_DATA; 30 else 31 return UBIFS_MAX_NLEN; 32 } 33 34 int ubifs_encrypt(const struct inode *inode, struct ubifs_data_node *dn, 35 unsigned int in_len, unsigned int *out_len, int block) 36 { 37 struct ubifs_info *c = inode->i_sb->s_fs_info; 38 void *p = &dn->data; 39 struct page *ret; 40 unsigned int pad_len = round_up(in_len, UBIFS_CIPHER_BLOCK_SIZE); 41 42 ubifs_assert(pad_len <= *out_len); 43 dn->compr_size = cpu_to_le16(in_len); 44 45 /* pad to full block cipher length */ 46 if (pad_len != in_len) 47 memset(p + in_len, 0, pad_len - in_len); 48 49 ret = fscrypt_encrypt_page(inode, virt_to_page(&dn->data), pad_len, 50 offset_in_page(&dn->data), block, GFP_NOFS); 51 if (IS_ERR(ret)) { 52 ubifs_err(c, "fscrypt_encrypt_page failed: %ld", PTR_ERR(ret)); 53 return PTR_ERR(ret); 54 } 55 *out_len = pad_len; 56 57 return 0; 58 } 59 60 int ubifs_decrypt(const struct inode *inode, struct ubifs_data_node *dn, 61 unsigned int *out_len, int block) 62 { 63 struct ubifs_info *c = inode->i_sb->s_fs_info; 64 int err; 65 unsigned int clen = le16_to_cpu(dn->compr_size); 66 unsigned int dlen = *out_len; 67 68 if (clen <= 0 || clen > UBIFS_BLOCK_SIZE || clen > dlen) { 69 ubifs_err(c, "bad compr_size: %i", clen); 70 return -EINVAL; 71 } 72 73 ubifs_assert(dlen <= UBIFS_BLOCK_SIZE); 74 err = fscrypt_decrypt_page(inode, virt_to_page(&dn->data), dlen, 75 offset_in_page(&dn->data), block); 76 if (err) { 77 ubifs_err(c, "fscrypt_decrypt_page failed: %i", err); 78 return err; 79 } 80 *out_len = clen; 81 82 return 0; 83 } 84 85 const struct fscrypt_operations ubifs_crypt_operations = { 86 .flags = FS_CFLG_OWN_PAGES, 87 .key_prefix = "ubifs:", 88 .get_context = ubifs_crypt_get_context, 89 .set_context = ubifs_crypt_set_context, 90 .is_encrypted = __ubifs_crypt_is_encrypted, 91 .empty_dir = ubifs_crypt_empty_dir, 92 .max_namelen = ubifs_crypt_max_namelen, 93 }; 94