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-rw-r--r--fs/ubifs/crypto.c86
1 files changed, 86 insertions, 0 deletions
diff --git a/fs/ubifs/crypto.c b/fs/ubifs/crypto.c
new file mode 100644
index 000000000..22be7aeb9
--- /dev/null
+++ b/fs/ubifs/crypto.c
@@ -0,0 +1,86 @@
+// SPDX-License-Identifier: GPL-2.0
+#include "ubifs.h"
+
+static int ubifs_crypt_get_context(struct inode *inode, void *ctx, size_t len)
+{
+ return ubifs_xattr_get(inode, UBIFS_XATTR_NAME_ENCRYPTION_CONTEXT,
+ ctx, len);
+}
+
+static int ubifs_crypt_set_context(struct inode *inode, const void *ctx,
+ size_t len, void *fs_data)
+{
+ /*
+ * Creating an encryption context is done unlocked since we
+ * operate on a new inode which is not visible to other users
+ * at this point. So, no need to check whether inode is locked.
+ */
+ return ubifs_xattr_set(inode, UBIFS_XATTR_NAME_ENCRYPTION_CONTEXT,
+ ctx, len, 0, false);
+}
+
+static bool ubifs_crypt_empty_dir(struct inode *inode)
+{
+ return ubifs_check_dir_empty(inode) == 0;
+}
+
+int ubifs_encrypt(const struct inode *inode, struct ubifs_data_node *dn,
+ unsigned int in_len, unsigned int *out_len, int block)
+{
+ struct ubifs_info *c = inode->i_sb->s_fs_info;
+ void *p = &dn->data;
+ unsigned int pad_len = round_up(in_len, UBIFS_CIPHER_BLOCK_SIZE);
+ int err;
+
+ ubifs_assert(c, pad_len <= *out_len);
+ dn->compr_size = cpu_to_le16(in_len);
+
+ /* pad to full block cipher length */
+ if (pad_len != in_len)
+ memset(p + in_len, 0, pad_len - in_len);
+
+ err = fscrypt_encrypt_block_inplace(inode, virt_to_page(p), pad_len,
+ offset_in_page(p), block, GFP_NOFS);
+ if (err) {
+ ubifs_err(c, "fscrypt_encrypt_block_inplace() failed: %d", err);
+ return err;
+ }
+ *out_len = pad_len;
+
+ return 0;
+}
+
+int ubifs_decrypt(const struct inode *inode, struct ubifs_data_node *dn,
+ unsigned int *out_len, int block)
+{
+ struct ubifs_info *c = inode->i_sb->s_fs_info;
+ int err;
+ unsigned int clen = le16_to_cpu(dn->compr_size);
+ unsigned int dlen = *out_len;
+
+ if (clen <= 0 || clen > UBIFS_BLOCK_SIZE || clen > dlen) {
+ ubifs_err(c, "bad compr_size: %i", clen);
+ return -EINVAL;
+ }
+
+ ubifs_assert(c, dlen <= UBIFS_BLOCK_SIZE);
+ err = fscrypt_decrypt_block_inplace(inode, virt_to_page(&dn->data),
+ dlen, offset_in_page(&dn->data),
+ block);
+ if (err) {
+ ubifs_err(c, "fscrypt_decrypt_block_inplace() failed: %d", err);
+ return err;
+ }
+ *out_len = clen;
+
+ return 0;
+}
+
+const struct fscrypt_operations ubifs_crypt_operations = {
+ .flags = FS_CFLG_OWN_PAGES,
+ .key_prefix = "ubifs:",
+ .get_context = ubifs_crypt_get_context,
+ .set_context = ubifs_crypt_set_context,
+ .empty_dir = ubifs_crypt_empty_dir,
+ .max_namelen = UBIFS_MAX_NLEN,
+};