[linux.git] / fs / ubifs / crypto.c

// 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,
};
Commit	Line	Data
b2441318	1	// SPDX-License-Identifier: GPL-2.0
d475a507 RW	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	{
d8db5b1c XL	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	*/
d475a507	18	return ubifs_xattr_set(inode, UBIFS_XATTR_NAME_ENCRYPTION_CONTEXT,
d8db5b1c	19	ctx, len, 0, false);
d475a507 RW	20	}
	21
	22	static bool ubifs_crypt_empty_dir(struct inode *inode)
	23	{
	24	return ubifs_check_dir_empty(inode) == 0;
	25	}
	26
7799953b RW	27	int ubifs_encrypt(const struct inode inode, struct ubifs_data_node dn,
	28	unsigned int in_len, unsigned int *out_len, int block)
	29	{
	30	struct ubifs_info *c = inode->i_sb->s_fs_info;
	31	void *p = &dn->data;
7799953b	32	unsigned int pad_len = round_up(in_len, UBIFS_CIPHER_BLOCK_SIZE);
03569f2f	33	int err;
7799953b	34
6eb61d58	35	ubifs_assert(c, pad_len <= *out_len);
7799953b RW	36	dn->compr_size = cpu_to_le16(in_len);
	37
	38	/* pad to full block cipher length */
	39	if (pad_len != in_len)
	40	memset(p + in_len, 0, pad_len - in_len);
	41
03569f2f EB	42	err = fscrypt_encrypt_block_inplace(inode, virt_to_page(p), pad_len,
	43	offset_in_page(p), block, GFP_NOFS);
	44	if (err) {
	45	ubifs_err(c, "fscrypt_encrypt_block_inplace() failed: %d", err);
	46	return err;
7799953b RW	47	}
	48	*out_len = pad_len;
	49
	50	return 0;
	51	}
	52
	53	int ubifs_decrypt(const struct inode inode, struct ubifs_data_node dn,
	54	unsigned int *out_len, int block)
	55	{
	56	struct ubifs_info *c = inode->i_sb->s_fs_info;
	57	int err;
	58	unsigned int clen = le16_to_cpu(dn->compr_size);
	59	unsigned int dlen = *out_len;
	60
	61	if (clen <= 0 \|\| clen > UBIFS_BLOCK_SIZE \|\| clen > dlen) {
	62	ubifs_err(c, "bad compr_size: %i", clen);
	63	return -EINVAL;
	64	}
	65
6eb61d58	66	ubifs_assert(c, dlen <= UBIFS_BLOCK_SIZE);
41adbcb7 EB	67	err = fscrypt_decrypt_block_inplace(inode, virt_to_page(&dn->data),
	68	dlen, offset_in_page(&dn->data),
	69	block);
7799953b	70	if (err) {
41adbcb7	71	ubifs_err(c, "fscrypt_decrypt_block_inplace() failed: %d", err);
7799953b RW	72	return err;
	73	}
	74	*out_len = clen;
	75
	76	return 0;
	77	}
	78
6f69f0ed	79	const struct fscrypt_operations ubifs_crypt_operations = {
38588668	80	.flags = FS_CFLG_OWN_PAGES,
a5d431ef	81	.key_prefix = "ubifs:",
d475a507 RW	82	.get_context = ubifs_crypt_get_context,
d475a507 RW	83	.set_context = ubifs_crypt_set_context,
d475a507	84	.empty_dir = ubifs_crypt_empty_dir,
e12ee683	85	.max_namelen = UBIFS_MAX_NLEN,
d475a507	86	};