[mirror_ubuntu-focal-kernel.git] / fs / crypto / fscrypt_private.h

/*
 * 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

#include <linux/fscrypt_supp.h>

#define FS_FNAME_CRYPTO_DIGEST_SIZE	32

/* Encryption parameters */
#define FS_XTS_TWEAK_SIZE		16
#define FS_AES_128_ECB_KEY_SIZE		16
#define FS_AES_256_GCM_KEY_SIZE		32
#define FS_AES_256_CBC_KEY_SIZE		32
#define FS_AES_256_CTS_KEY_SIZE		32
#define FS_AES_256_XTS_KEY_SIZE		64
#define FS_MAX_KEY_SIZE			64

#define FS_KEY_DESC_PREFIX		"fscrypt:"
#define FS_KEY_DESC_PREFIX_SIZE		8

#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

/* This is passed in from userspace into the kernel keyring */
struct fscrypt_key {
	u32 mode;
	u8 raw[FS_MAX_KEY_SIZE];
	u32 size;
} __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;
	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

struct fscrypt_completion_result {
	struct completion completion;
	int res;
};

#define DECLARE_FS_COMPLETION_RESULT(ecr) \
	struct fscrypt_completion_result ecr = { \
		COMPLETION_INITIALIZER_ONSTACK((ecr).completion), 0 }


/* crypto.c */
extern int fscrypt_initialize(unsigned int cop_flags);
extern struct workqueue_struct *fscrypt_read_workqueue;
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);

#endif /* _FSCRYPT_PRIVATE_H */
Commit	Line	Data
3325bea5 TT	1	/*
	2	* fscrypt_private.h
	3	*
	4	* Copyright (C) 2015, Google, Inc.
	5	*
	6	* This contains encryption key functions.
	7	*
	8	* Written by Michael Halcrow, Ildar Muslukhov, and Uday Savagaonkar, 2015.
	9	*/
	10
	11	#ifndef _FSCRYPT_PRIVATE_H
	12	#define _FSCRYPT_PRIVATE_H
	13
46f47e48	14	#include <linux/fscrypt_supp.h>
3325bea5	15
cc4e0df0 TT	16	#define FS_FNAME_CRYPTO_DIGEST_SIZE 32
	17
	18	/* Encryption parameters */
	19	#define FS_XTS_TWEAK_SIZE 16
	20	#define FS_AES_128_ECB_KEY_SIZE 16
	21	#define FS_AES_256_GCM_KEY_SIZE 32
	22	#define FS_AES_256_CBC_KEY_SIZE 32
	23	#define FS_AES_256_CTS_KEY_SIZE 32
	24	#define FS_AES_256_XTS_KEY_SIZE 64
	25	#define FS_MAX_KEY_SIZE 64
	26
	27	#define FS_KEY_DESC_PREFIX "fscrypt:"
	28	#define FS_KEY_DESC_PREFIX_SIZE 8
	29
	30	#define FS_KEY_DERIVATION_NONCE_SIZE 16
	31
	32	/**
	33	* Encryption context for inode
	34	*
	35	* Protector format:
	36	* 1 byte: Protector format (1 = this version)
	37	* 1 byte: File contents encryption mode
	38	* 1 byte: File names encryption mode
	39	* 1 byte: Flags
	40	* 8 bytes: Master Key descriptor
	41	* 16 bytes: Encryption Key derivation nonce
	42	*/
	43	struct fscrypt_context {
	44	u8 format;
	45	u8 contents_encryption_mode;
	46	u8 filenames_encryption_mode;
	47	u8 flags;
	48	u8 master_key_descriptor[FS_KEY_DESCRIPTOR_SIZE];
	49	u8 nonce[FS_KEY_DERIVATION_NONCE_SIZE];
	50	} __packed;
	51
	52	#define FS_ENCRYPTION_CONTEXT_FORMAT_V1 1
	53
	54	/* This is passed in from userspace into the kernel keyring */
	55	struct fscrypt_key {
	56	u32 mode;
	57	u8 raw[FS_MAX_KEY_SIZE];
	58	u32 size;
	59	} __packed;
	60
	61	/*
	62	* A pointer to this structure is stored in the file system's in-core
	63	* representation of an inode.
	64	*/
	65	struct fscrypt_info {
	66	u8 ci_data_mode;
	67	u8 ci_filename_mode;
	68	u8 ci_flags;
	69	struct crypto_skcipher *ci_ctfm;
cc4e0df0 TT	70	u8 ci_master_key[FS_KEY_DESCRIPTOR_SIZE];
	71	};
	72
58ae7468 RW	73	typedef enum {
	74	FS_DECRYPT = 0,
	75	FS_ENCRYPT,
	76	} fscrypt_direction_t;
	77
cc4e0df0	78	#define FS_CTX_REQUIRES_FREE_ENCRYPT_FL 0x00000001
6a34e4d2	79	#define FS_CTX_HAS_BOUNCE_BUFFER_FL 0x00000002
cc4e0df0 TT	80
	81	struct fscrypt_completion_result {
	82	struct completion completion;
	83	int res;
	84	};
	85
	86	#define DECLARE_FS_COMPLETION_RESULT(ecr) \
	87	struct fscrypt_completion_result ecr = { \
b14c8e6a	88	COMPLETION_INITIALIZER_ONSTACK((ecr).completion), 0 }
cc4e0df0 TT	89
cc4e0df0 TT	90
b98701df	91	/* crypto.c */
58ae7468 RW	92	extern int fscrypt_initialize(unsigned int cop_flags);
	93	extern struct workqueue_struct *fscrypt_read_workqueue;
	94	extern int fscrypt_do_page_crypto(const struct inode *inode,
	95	fscrypt_direction_t rw, u64 lblk_num,
	96	struct page *src_page,
	97	struct page *dest_page,
	98	unsigned int len, unsigned int offs,
	99	gfp_t gfp_flags);
	100	extern struct page fscrypt_alloc_bounce_page(struct fscrypt_ctx ctx,
	101	gfp_t gfp_flags);
b98701df	102
3325bea5	103	#endif /* _FSCRYPT_PRIVATE_H */