1 files changed, 97 insertions, 0 deletions
diff --git a/fs/ubifs/crypto.c b/fs/ubifs/crypto.c
new file mode 100644
index 000000000000..3402720f2b28
--- /dev/null
+++ b/fs/ubifs/crypto.c
@@ -0,0 +1,97 @@
+#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)
+{
+	return ubifs_xattr_set(inode, UBIFS_XATTR_NAME_ENCRYPTION_CONTEXT,
+			       ctx, len, 0);
+}
+
+static bool ubifs_crypt_empty_dir(struct inode *inode)
+{
+	return ubifs_check_dir_empty(inode) == 0;
+}
+
+static unsigned int ubifs_crypt_max_namelen(struct inode *inode)
+{
+	if (S_ISLNK(inode->i_mode))
+		return UBIFS_MAX_INO_DATA;
+	else
+		return UBIFS_MAX_NLEN;
+}
+
+static int ubifs_key_prefix(struct inode *inode, u8 **key)
+{
+	static char prefix[] = "ubifs:";
+
+	*key = prefix;
+
+	return sizeof(prefix) - 1;
+}
+
+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;
+	struct page *ret;
+	unsigned int pad_len = round_up(in_len, UBIFS_CIPHER_BLOCK_SIZE);
+
+	ubifs_assert(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);
+
+	ret = fscrypt_encrypt_page(inode, virt_to_page(&dn->data), pad_len,
+			offset_in_page(&dn->data), block, GFP_NOFS);
+	if (IS_ERR(ret)) {
+		ubifs_err(c, "fscrypt_encrypt_page failed: %ld", PTR_ERR(ret));
+		return PTR_ERR(ret);
+	}
+	*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(dlen <= UBIFS_BLOCK_SIZE);
+	err = fscrypt_decrypt_page(inode, virt_to_page(&dn->data), dlen,
+			offset_in_page(&dn->data), block);
+	if (err) {
+		ubifs_err(c, "fscrypt_decrypt_page failed: %i", err);
+		return err;
+	}
+	*out_len = clen;
+
+	return 0;
+}
+
+struct fscrypt_operations ubifs_crypt_operations = {
+	.flags			= FS_CFLG_OWN_PAGES,
+	.get_context		= ubifs_crypt_get_context,
+	.set_context		= ubifs_crypt_set_context,
+	.is_encrypted		= __ubifs_crypt_is_encrypted,
+	.empty_dir		= ubifs_crypt_empty_dir,
+	.max_namelen		= ubifs_crypt_max_namelen,
+	.key_prefix		= ubifs_key_prefix,
+};