1 /* SPDX-License-Identifier: GPL-2.0 */ 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 15 #define __FS_HAS_ENCRYPTION 1 16 #include <linux/fscrypt.h> 17 #include <crypto/hash.h> 18 19 /* Encryption parameters */ 20 #define FS_IV_SIZE 16 21 #define FS_AES_128_ECB_KEY_SIZE 16 22 #define FS_AES_128_CBC_KEY_SIZE 16 23 #define FS_AES_128_CTS_KEY_SIZE 16 24 #define FS_AES_256_GCM_KEY_SIZE 32 25 #define FS_AES_256_CBC_KEY_SIZE 32 26 #define FS_AES_256_CTS_KEY_SIZE 32 27 #define FS_AES_256_XTS_KEY_SIZE 64 28 29 #define FS_KEY_DERIVATION_NONCE_SIZE 16 30 31 /** 32 * Encryption context for inode 33 * 34 * Protector format: 35 * 1 byte: Protector format (1 = this version) 36 * 1 byte: File contents encryption mode 37 * 1 byte: File names encryption mode 38 * 1 byte: Flags 39 * 8 bytes: Master Key descriptor 40 * 16 bytes: Encryption Key derivation nonce 41 */ 42 struct fscrypt_context { 43 u8 format; 44 u8 contents_encryption_mode; 45 u8 filenames_encryption_mode; 46 u8 flags; 47 u8 master_key_descriptor[FS_KEY_DESCRIPTOR_SIZE]; 48 u8 nonce[FS_KEY_DERIVATION_NONCE_SIZE]; 49 } __packed; 50 51 #define FS_ENCRYPTION_CONTEXT_FORMAT_V1 1 52 53 /* 54 * A pointer to this structure is stored in the file system's in-core 55 * representation of an inode. 56 */ 57 struct fscrypt_info { 58 u8 ci_data_mode; 59 u8 ci_filename_mode; 60 u8 ci_flags; 61 struct crypto_skcipher *ci_ctfm; 62 struct crypto_cipher *ci_essiv_tfm; 63 u8 ci_master_key[FS_KEY_DESCRIPTOR_SIZE]; 64 }; 65 66 typedef enum { 67 FS_DECRYPT = 0, 68 FS_ENCRYPT, 69 } fscrypt_direction_t; 70 71 #define FS_CTX_REQUIRES_FREE_ENCRYPT_FL 0x00000001 72 #define FS_CTX_HAS_BOUNCE_BUFFER_FL 0x00000002 73 74 /* crypto.c */ 75 extern int fscrypt_initialize(unsigned int cop_flags); 76 extern struct workqueue_struct *fscrypt_read_workqueue; 77 extern int fscrypt_do_page_crypto(const struct inode *inode, 78 fscrypt_direction_t rw, u64 lblk_num, 79 struct page *src_page, 80 struct page *dest_page, 81 unsigned int len, unsigned int offs, 82 gfp_t gfp_flags); 83 extern struct page *fscrypt_alloc_bounce_page(struct fscrypt_ctx *ctx, 84 gfp_t gfp_flags); 85 86 /* keyinfo.c */ 87 extern void __exit fscrypt_essiv_cleanup(void); 88 89 #endif /* _FSCRYPT_PRIVATE_H */ 90