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1// SPDX-License-Identifier: GPL-2.02#include "ubifs.h"3 4static 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 10static 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 we15 * operate on a new inode which is not visible to other users16 * 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 22static 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 node30 * @dn: data node to encrypt31 * @in_len: length of data to be compressed32 * @out_len: allocated memory size for the data area of @dn33 * @block: logical block number of the block34 *35 * This function encrypt a possibly-compressed data in the data node.36 * The encrypted data length will store in @out_len.37 */38int 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 64int 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 90const 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