Release 4.16 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_AES_128_ECB_KEY_SIZE		16

#define FS_AES_128_CBC_KEY_SIZE		16

#define FS_AES_128_CTS_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_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;

	return false;
}

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Eric Biggers
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1
100.00%

/* crypto.c */
extern struct kmem_cache *fscrypt_info_cachep;
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);

/* 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 */
Overall Contributors
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CommitProp
Theodore Y. Ts'o
114
34.44%
3
20.00%
Eric Biggers
110
33.23%
6
40.00%
Richard Weinberger
71
21.45%
1
6.67%
Daniel Walter
26
7.85%
1
6.67%
Dave Chinner
5
1.51%
1
6.67%
David Gstir
4
1.21%
2
13.33%
Greg Kroah-Hartman
1
0.30%
1
6.67%
Total
331
100.00%
15
100.00%
Directory: fs/crypto

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