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 static unsigned int ubifs_crypt_max_namelen(struct inode *inode) 28 { 29 if (S_ISLNK(inode->i_mode)) 30 return UBIFS_MAX_INO_DATA; 31 else 32 return UBIFS_MAX_NLEN; 33 } 34 35 int ubifs_encrypt(const struct inode *inode, struct ubifs_data_node *dn, 36 unsigned int in_len, unsigned int *out_len, int block) 37 { 38 struct ubifs_info *c = inode->i_sb->s_fs_info; 39 void *p = &dn->data; 40 struct page *ret; 41 unsigned int pad_len = round_up(in_len, UBIFS_CIPHER_BLOCK_SIZE); 42 43 ubifs_assert(pad_len <= *out_len); 44 dn->compr_size = cpu_to_le16(in_len); 45 46 /* pad to full block cipher length */ 47 if (pad_len != in_len) 48 memset(p + in_len, 0, pad_len - in_len); 49 50 ret = fscrypt_encrypt_page(inode, virt_to_page(&dn->data), pad_len, 51 offset_in_page(&dn->data), block, GFP_NOFS); 52 if (IS_ERR(ret)) { 53 ubifs_err(c, "fscrypt_encrypt_page failed: %ld", PTR_ERR(ret)); 54 return PTR_ERR(ret); 55 } 56 *out_len = pad_len; 57 58 return 0; 59 } 60 61 int ubifs_decrypt(const struct inode *inode, struct ubifs_data_node *dn, 62 unsigned int *out_len, int block) 63 { 64 struct ubifs_info *c = inode->i_sb->s_fs_info; 65 int err; 66 unsigned int clen = le16_to_cpu(dn->compr_size); 67 unsigned int dlen = *out_len; 68 69 if (clen <= 0 || clen > UBIFS_BLOCK_SIZE || clen > dlen) { 70 ubifs_err(c, "bad compr_size: %i", clen); 71 return -EINVAL; 72 } 73 74 ubifs_assert(dlen <= UBIFS_BLOCK_SIZE); 75 err = fscrypt_decrypt_page(inode, virt_to_page(&dn->data), dlen, 76 offset_in_page(&dn->data), block); 77 if (err) { 78 ubifs_err(c, "fscrypt_decrypt_page failed: %i", err); 79 return err; 80 } 81 *out_len = clen; 82 83 return 0; 84 } 85 86 const struct fscrypt_operations ubifs_crypt_operations = { 87 .flags = FS_CFLG_OWN_PAGES, 88 .key_prefix = "ubifs:", 89 .get_context = ubifs_crypt_get_context, 90 .set_context = ubifs_crypt_set_context, 91 .empty_dir = ubifs_crypt_empty_dir, 92 .max_namelen = ubifs_crypt_max_namelen, 93 }; 94