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 /** 28 * ubifs_encrypt - Encrypt data. 29 * @inode: inode which refers to the data node 30 * @dn: data node to encrypt 31 * @in_len: length of data to be compressed 32 * @out_len: allocated memory size for the data area of @dn 33 * @block: logical block number of the block 34 * 35 * This function encrypt a possibly-compressed data in the data node. 36 * The encrypted data length will store in @out_len. 37 */ 38 int ubifs_encrypt(const struct inode *inode, struct ubifs_data_node *dn, 39 unsigned int in_len, unsigned int *out_len, int block) 40 { 41 struct ubifs_info *c = inode->i_sb->s_fs_info; 42 void *p = &dn->data; 43 unsigned int pad_len = round_up(in_len, UBIFS_CIPHER_BLOCK_SIZE); 44 int err; 45 46 ubifs_assert(c, pad_len <= *out_len); 47 dn->compr_size = cpu_to_le16(in_len); 48 49 /* pad to full block cipher length */ 50 if (pad_len != in_len) 51 memset(p + in_len, 0, pad_len - in_len); 52 53 err = fscrypt_encrypt_block_inplace(inode, virt_to_page(p), pad_len, 54 offset_in_page(p), block, GFP_NOFS); 55 if (err) { 56 ubifs_err(c, "fscrypt_encrypt_block_inplace() failed: %d", err); 57 return err; 58 } 59 *out_len = pad_len; 60 61 return 0; 62 } 63 64 int ubifs_decrypt(const struct inode *inode, struct ubifs_data_node *dn, 65 unsigned int *out_len, int block) 66 { 67 struct ubifs_info *c = inode->i_sb->s_fs_info; 68 int err; 69 unsigned int clen = le16_to_cpu(dn->compr_size); 70 unsigned int dlen = *out_len; 71 72 if (clen <= 0 || clen > UBIFS_BLOCK_SIZE || clen > dlen) { 73 ubifs_err(c, "bad compr_size: %i", clen); 74 return -EINVAL; 75 } 76 77 ubifs_assert(c, dlen <= UBIFS_BLOCK_SIZE); 78 err = fscrypt_decrypt_block_inplace(inode, virt_to_page(&dn->data), 79 dlen, offset_in_page(&dn->data), 80 block); 81 if (err) { 82 ubifs_err(c, "fscrypt_decrypt_block_inplace() failed: %d", err); 83 return err; 84 } 85 *out_len = clen; 86 87 return 0; 88 } 89 90 const struct fscrypt_operations ubifs_crypt_operations = { 91 .legacy_key_prefix = "ubifs:", 92 .get_context = ubifs_crypt_get_context, 93 .set_context = ubifs_crypt_set_context, 94 .empty_dir = ubifs_crypt_empty_dir, 95 }; 96