96 lines
2.7 KiB
C
96 lines
2.7 KiB
C
// SPDX-License-Identifier: GPL-2.0
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#include "ubifs.h"
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static int ubifs_crypt_get_context(struct inode *inode, void *ctx, size_t len)
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{
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return ubifs_xattr_get(inode, UBIFS_XATTR_NAME_ENCRYPTION_CONTEXT,
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ctx, len);
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}
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static int ubifs_crypt_set_context(struct inode *inode, const void *ctx,
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size_t len, void *fs_data)
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{
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/*
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* Creating an encryption context is done unlocked since we
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* operate on a new inode which is not visible to other users
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* at this point. So, no need to check whether inode is locked.
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*/
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return ubifs_xattr_set(inode, UBIFS_XATTR_NAME_ENCRYPTION_CONTEXT,
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ctx, len, 0, false);
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}
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static bool ubifs_crypt_empty_dir(struct inode *inode)
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{
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return ubifs_check_dir_empty(inode) == 0;
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}
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/**
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* ubifs_encrypt - Encrypt data.
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* @inode: inode which refers to the data node
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* @dn: data node to encrypt
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* @in_len: length of data to be compressed
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* @out_len: allocated memory size for the data area of @dn
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* @block: logical block number of the block
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*
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* This function encrypt a possibly-compressed data in the data node.
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* The encrypted data length will store in @out_len.
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*/
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int ubifs_encrypt(const struct inode *inode, struct ubifs_data_node *dn,
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unsigned int in_len, unsigned int *out_len, int block)
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{
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struct ubifs_info *c = inode->i_sb->s_fs_info;
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void *p = &dn->data;
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unsigned int pad_len = round_up(in_len, UBIFS_CIPHER_BLOCK_SIZE);
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int err;
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ubifs_assert(c, pad_len <= *out_len);
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dn->compr_size = cpu_to_le16(in_len);
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/* pad to full block cipher length */
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if (pad_len != in_len)
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memset(p + in_len, 0, pad_len - in_len);
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err = fscrypt_encrypt_block_inplace(inode, virt_to_page(p), pad_len,
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offset_in_page(p), block, GFP_NOFS);
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if (err) {
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ubifs_err(c, "fscrypt_encrypt_block_inplace() failed: %d", err);
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return err;
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}
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*out_len = pad_len;
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return 0;
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}
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int ubifs_decrypt(const struct inode *inode, struct ubifs_data_node *dn,
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unsigned int *out_len, int block)
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{
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struct ubifs_info *c = inode->i_sb->s_fs_info;
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int err;
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unsigned int clen = le16_to_cpu(dn->compr_size);
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unsigned int dlen = *out_len;
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if (clen <= 0 || clen > UBIFS_BLOCK_SIZE || clen > dlen) {
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ubifs_err(c, "bad compr_size: %i", clen);
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return -EINVAL;
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}
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ubifs_assert(c, dlen <= UBIFS_BLOCK_SIZE);
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err = fscrypt_decrypt_block_inplace(inode, virt_to_page(&dn->data),
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dlen, offset_in_page(&dn->data),
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block);
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if (err) {
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ubifs_err(c, "fscrypt_decrypt_block_inplace() failed: %d", err);
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return err;
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}
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*out_len = clen;
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return 0;
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}
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const struct fscrypt_operations ubifs_crypt_operations = {
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.legacy_key_prefix = "ubifs:",
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.get_context = ubifs_crypt_get_context,
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.set_context = ubifs_crypt_set_context,
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.empty_dir = ubifs_crypt_empty_dir,
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};
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