[linux-2.6-block.git] / fs / crypto / fscrypt_private.h

/* SPDX-License-Identifier: GPL-2.0 */
/*
 * fscrypt_private.h
 *
 * Copyright (C) 2015, Google, Inc.
 *
 * This contains encryption key functions.
 *
 * Written by Michael Halcrow, Ildar Muslukhov, and Uday Savagaonkar, 2015.
 */

#ifndef _FSCRYPT_PRIVATE_H
#define _FSCRYPT_PRIVATE_H

#define __FS_HAS_ENCRYPTION 1
#include <linux/fscrypt.h>
#include <crypto/hash.h>

/* Encryption parameters */
#define FS_IV_SIZE			16
#define FS_KEY_DERIVATION_NONCE_SIZE	16

/**
 * Encryption context for inode
 *
 * Protector format:
 *  1 byte: Protector format (1 = this version)
 *  1 byte: File contents encryption mode
 *  1 byte: File names encryption mode
 *  1 byte: Flags
 *  8 bytes: Master Key descriptor
 *  16 bytes: Encryption Key derivation nonce
 */
struct fscrypt_context {
	u8 format;
	u8 contents_encryption_mode;
	u8 filenames_encryption_mode;
	u8 flags;
	u8 master_key_descriptor[FS_KEY_DESCRIPTOR_SIZE];
	u8 nonce[FS_KEY_DERIVATION_NONCE_SIZE];
} __packed;

#define FS_ENCRYPTION_CONTEXT_FORMAT_V1		1

/**
 * For encrypted symlinks, the ciphertext length is stored at the beginning
 * of the string in little-endian format.
 */
struct fscrypt_symlink_data {
	__le16 len;
	char encrypted_path[1];
} __packed;

/*
 * A pointer to this structure is stored in the file system's in-core
 * representation of an inode.
 */
struct fscrypt_info {
	u8 ci_data_mode;
	u8 ci_filename_mode;
	u8 ci_flags;
	struct crypto_skcipher *ci_ctfm;
	struct crypto_cipher *ci_essiv_tfm;
	u8 ci_master_key[FS_KEY_DESCRIPTOR_SIZE];
};

typedef enum {
	FS_DECRYPT = 0,
	FS_ENCRYPT,
} fscrypt_direction_t;

#define FS_CTX_REQUIRES_FREE_ENCRYPT_FL		0x00000001
#define FS_CTX_HAS_BOUNCE_BUFFER_FL		0x00000002

static inline bool fscrypt_valid_enc_modes(u32 contents_mode,
					   u32 filenames_mode)
{
	if (contents_mode == FS_ENCRYPTION_MODE_AES_128_CBC &&
	    filenames_mode == FS_ENCRYPTION_MODE_AES_128_CTS)
		return true;

	if (contents_mode == FS_ENCRYPTION_MODE_AES_256_XTS &&
	    filenames_mode == FS_ENCRYPTION_MODE_AES_256_CTS)
		return true;

	if (contents_mode == FS_ENCRYPTION_MODE_SPECK128_256_XTS &&
	    filenames_mode == FS_ENCRYPTION_MODE_SPECK128_256_CTS)
		return true;

	return false;
}

/* crypto.c */
extern struct kmem_cache *fscrypt_info_cachep;
extern int fscrypt_initialize(unsigned int cop_flags);
extern int fscrypt_do_page_crypto(const struct inode *inode,
				  fscrypt_direction_t rw, u64 lblk_num,
				  struct page *src_page,
				  struct page *dest_page,
				  unsigned int len, unsigned int offs,
				  gfp_t gfp_flags);
extern struct page *fscrypt_alloc_bounce_page(struct fscrypt_ctx *ctx,
					      gfp_t gfp_flags);
extern const struct dentry_operations fscrypt_d_ops;

extern void __printf(3, 4) __cold
fscrypt_msg(struct super_block *sb, const char *level, const char *fmt, ...);

#define fscrypt_warn(sb, fmt, ...)		\
	fscrypt_msg(sb, KERN_WARNING, fmt, ##__VA_ARGS__)
#define fscrypt_err(sb, fmt, ...)		\
	fscrypt_msg(sb, KERN_ERR, fmt, ##__VA_ARGS__)

/* fname.c */
extern int fname_encrypt(struct inode *inode, const struct qstr *iname,
			 u8 *out, unsigned int olen);
extern bool fscrypt_fname_encrypted_size(const struct inode *inode,
					 u32 orig_len, u32 max_len,
					 u32 *encrypted_len_ret);

/* keyinfo.c */
extern void __exit fscrypt_essiv_cleanup(void);

#endif /* _FSCRYPT_PRIVATE_H */
Commit	Line	Data
b2441318	1	/* SPDX-License-Identifier: GPL-2.0 */
3325bea5 TT	2	/*
	3	* fscrypt_private.h
	4	*
	5	* Copyright (C) 2015, Google, Inc.
	6	*
	7	* This contains encryption key functions.
	8	*
	9	* Written by Michael Halcrow, Ildar Muslukhov, and Uday Savagaonkar, 2015.
	10	*/
	11
	12	#ifndef _FSCRYPT_PRIVATE_H
	13	#define _FSCRYPT_PRIVATE_H
	14
734f0d24 DC	15	#define __FS_HAS_ENCRYPTION 1
734f0d24 DC	16	#include <linux/fscrypt.h>
b7e7cf7a	17	#include <crypto/hash.h>
3325bea5	18
cc4e0df0	19	/* Encryption parameters */
b7e7cf7a	20	#define FS_IV_SIZE 16
11b8818e	21	#define FS_KEY_DERIVATION_NONCE_SIZE 16
cc4e0df0 TT	22
	23	/**
	24	* Encryption context for inode
	25	*
	26	* Protector format:
	27	* 1 byte: Protector format (1 = this version)
	28	* 1 byte: File contents encryption mode
	29	* 1 byte: File names encryption mode
	30	* 1 byte: Flags
	31	* 8 bytes: Master Key descriptor
	32	* 16 bytes: Encryption Key derivation nonce
	33	*/
	34	struct fscrypt_context {
	35	u8 format;
	36	u8 contents_encryption_mode;
	37	u8 filenames_encryption_mode;
	38	u8 flags;
	39	u8 master_key_descriptor[FS_KEY_DESCRIPTOR_SIZE];
	40	u8 nonce[FS_KEY_DERIVATION_NONCE_SIZE];
	41	} __packed;
	42
	43	#define FS_ENCRYPTION_CONTEXT_FORMAT_V1 1
	44
0eaab5b1 EB	45	/**
	46	* For encrypted symlinks, the ciphertext length is stored at the beginning
	47	* of the string in little-endian format.
	48	*/
	49	struct fscrypt_symlink_data {
	50	__le16 len;
	51	char encrypted_path[1];
	52	} __packed;
	53
cc4e0df0 TT	54	/*
	55	* A pointer to this structure is stored in the file system's in-core
	56	* representation of an inode.
	57	*/
	58	struct fscrypt_info {
	59	u8 ci_data_mode;
	60	u8 ci_filename_mode;
	61	u8 ci_flags;
	62	struct crypto_skcipher *ci_ctfm;
b7e7cf7a	63	struct crypto_cipher *ci_essiv_tfm;
cc4e0df0 TT	64	u8 ci_master_key[FS_KEY_DESCRIPTOR_SIZE];
	65	};
	66
58ae7468 RW	67	typedef enum {
	68	FS_DECRYPT = 0,
	69	FS_ENCRYPT,
	70	} fscrypt_direction_t;
	71
cc4e0df0	72	#define FS_CTX_REQUIRES_FREE_ENCRYPT_FL 0x00000001
6a34e4d2	73	#define FS_CTX_HAS_BOUNCE_BUFFER_FL 0x00000002
cc4e0df0	74
bb8179e5 EB	75	static inline bool fscrypt_valid_enc_modes(u32 contents_mode,
	76	u32 filenames_mode)
	77	{
	78	if (contents_mode == FS_ENCRYPTION_MODE_AES_128_CBC &&
	79	filenames_mode == FS_ENCRYPTION_MODE_AES_128_CTS)
	80	return true;
	81
	82	if (contents_mode == FS_ENCRYPTION_MODE_AES_256_XTS &&
	83	filenames_mode == FS_ENCRYPTION_MODE_AES_256_CTS)
	84	return true;
	85
12d28f79 EB	86	if (contents_mode == FS_ENCRYPTION_MODE_SPECK128_256_XTS &&
	87	filenames_mode == FS_ENCRYPTION_MODE_SPECK128_256_CTS)
	88	return true;
	89
bb8179e5 EB	90	return false;
	91	}
	92
b98701df	93	/* crypto.c */
e4de782a	94	extern struct kmem_cache *fscrypt_info_cachep;
58ae7468	95	extern int fscrypt_initialize(unsigned int cop_flags);
58ae7468 RW	96	extern int fscrypt_do_page_crypto(const struct inode *inode,
	97	fscrypt_direction_t rw, u64 lblk_num,
	98	struct page *src_page,
	99	struct page *dest_page,
	100	unsigned int len, unsigned int offs,
	101	gfp_t gfp_flags);
	102	extern struct page fscrypt_alloc_bounce_page(struct fscrypt_ctx ctx,
	103	gfp_t gfp_flags);
54222025	104	extern const struct dentry_operations fscrypt_d_ops;
b98701df	105
544d08fd EB	106	extern void __printf(3, 4) __cold
	107	fscrypt_msg(struct super_block sb, const char level, const char *fmt, ...);
	108
	109	#define fscrypt_warn(sb, fmt, ...) \
	110	fscrypt_msg(sb, KERN_WARNING, fmt, ##__VA_ARGS__)
	111	#define fscrypt_err(sb, fmt, ...) \
	112	fscrypt_msg(sb, KERN_ERR, fmt, ##__VA_ARGS__)
	113
76e81d6d	114	/* fname.c */
50c961de EB	115	extern int fname_encrypt(struct inode inode, const struct qstr iname,
50c961de EB	116	u8 *out, unsigned int olen);
b9db0b4a EB	117	extern bool fscrypt_fname_encrypted_size(const struct inode *inode,
	118	u32 orig_len, u32 max_len,
	119	u32 *encrypted_len_ret);
76e81d6d	120
b7e7cf7a DW	121	/* keyinfo.c */
	122	extern void __exit fscrypt_essiv_cleanup(void);
	123
3325bea5	124	#endif /* _FSCRYPT_PRIVATE_H */