[mirror_ubuntu-zesty-kernel.git] / fs / ubifs / crypto.c

#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,
};
Commit	Line	Data
d475a507 RW	1	#include "ubifs.h"
	2
	3	static int ubifs_crypt_get_context(struct inode inode, void ctx, size_t len)
	4	{
	5	return ubifs_xattr_get(inode, UBIFS_XATTR_NAME_ENCRYPTION_CONTEXT,
	6	ctx, len);
	7	}
	8
	9	static int ubifs_crypt_set_context(struct inode inode, const void ctx,
	10	size_t len, void *fs_data)
	11	{
	12	return ubifs_xattr_set(inode, UBIFS_XATTR_NAME_ENCRYPTION_CONTEXT,
	13	ctx, len, 0);
	14	}
	15
	16	static bool ubifs_crypt_empty_dir(struct inode *inode)
	17	{
	18	return ubifs_check_dir_empty(inode) == 0;
	19	}
	20
	21	static unsigned int ubifs_crypt_max_namelen(struct inode *inode)
	22	{
	23	if (S_ISLNK(inode->i_mode))
	24	return UBIFS_MAX_INO_DATA;
	25	else
	26	return UBIFS_MAX_NLEN;
	27	}
	28
	29	static int ubifs_key_prefix(struct inode inode, u8 *key)
	30	{
	31	static char prefix[] = "ubifs:";
	32
	33	*key = prefix;
	34
	35	return sizeof(prefix) - 1;
	36	}
	37
7799953b RW	38	int 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	struct page *ret;
	44	unsigned int pad_len = round_up(in_len, UBIFS_CIPHER_BLOCK_SIZE);
	45
	46	ubifs_assert(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	ret = fscrypt_encrypt_page(inode, virt_to_page(&dn->data), pad_len,
	54	offset_in_page(&dn->data), block, GFP_NOFS);
	55	if (IS_ERR(ret)) {
	56	ubifs_err(c, "fscrypt_encrypt_page failed: %ld", PTR_ERR(ret));
	57	return PTR_ERR(ret);
	58	}
	59	*out_len = pad_len;
	60
	61	return 0;
	62	}
	63
	64	int 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(dlen <= UBIFS_BLOCK_SIZE);
	78	err = fscrypt_decrypt_page(inode, virt_to_page(&dn->data), dlen,
	79	offset_in_page(&dn->data), block);
	80	if (err) {
	81	ubifs_err(c, "fscrypt_decrypt_page failed: %i", err);
	82	return err;
	83	}
	84	*out_len = clen;
	85
	86	return 0;
	87	}
	88
d475a507	89	struct fscrypt_operations ubifs_crypt_operations = {
38588668	90	.flags = FS_CFLG_OWN_PAGES,
d475a507 RW	91	.get_context = ubifs_crypt_get_context,
d475a507 RW	92	.set_context = ubifs_crypt_set_context,
1ee77870	93	.is_encrypted = __ubifs_crypt_is_encrypted,
d475a507 RW	94	.empty_dir = ubifs_crypt_empty_dir,
	95	.max_namelen = ubifs_crypt_max_namelen,
	96	.key_prefix = ubifs_key_prefix,
	97	};