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 14 #include <linux/fscrypt_supp.h> 15 #include <crypto/hash.h> 16 17 /* Encryption parameters */ 18 #define FS_IV_SIZE 16 19 #define FS_AES_128_ECB_KEY_SIZE 16 20 #define FS_AES_128_CBC_KEY_SIZE 16 21 #define FS_AES_128_CTS_KEY_SIZE 16 22 #define FS_AES_256_GCM_KEY_SIZE 32 23 #define FS_AES_256_CBC_KEY_SIZE 32 24 #define FS_AES_256_CTS_KEY_SIZE 32 25 #define FS_AES_256_XTS_KEY_SIZE 64 26 27 #define FS_KEY_DERIVATION_NONCE_SIZE 16 28 29 /** 30 * Encryption context for inode 31 * 32 * Protector format: 33 * 1 byte: Protector format (1 = this version) 34 * 1 byte: File contents encryption mode 35 * 1 byte: File names encryption mode 36 * 1 byte: Flags 37 * 8 bytes: Master Key descriptor 38 * 16 bytes: Encryption Key derivation nonce 39 */ 40 struct fscrypt_context { 41 u8 format; 42 u8 contents_encryption_mode; 43 u8 filenames_encryption_mode; 44 u8 flags; 45 u8 master_key_descriptor[FS_KEY_DESCRIPTOR_SIZE]; 46 u8 nonce[FS_KEY_DERIVATION_NONCE_SIZE]; 47 } __packed; 48 49 #define FS_ENCRYPTION_CONTEXT_FORMAT_V1 1 50 51 /* 52 * A pointer to this structure is stored in the file system's in-core 53 * representation of an inode. 54 */ 55 struct fscrypt_info { 56 u8 ci_data_mode; 57 u8 ci_filename_mode; 58 u8 ci_flags; 59 struct crypto_skcipher *ci_ctfm; 60 struct crypto_cipher *ci_essiv_tfm; 61 u8 ci_master_key[FS_KEY_DESCRIPTOR_SIZE]; 62 }; 63 64 typedef enum { 65 FS_DECRYPT = 0, 66 FS_ENCRYPT, 67 } fscrypt_direction_t; 68 69 #define FS_CTX_REQUIRES_FREE_ENCRYPT_FL 0x00000001 70 #define FS_CTX_HAS_BOUNCE_BUFFER_FL 0x00000002 71 72 struct fscrypt_completion_result { 73 struct completion completion; 74 int res; 75 }; 76 77 #define DECLARE_FS_COMPLETION_RESULT(ecr) \ 78 struct fscrypt_completion_result ecr = { \ 79 COMPLETION_INITIALIZER_ONSTACK((ecr).completion), 0 } 80 81 82 /* crypto.c */ 83 extern int fscrypt_initialize(unsigned int cop_flags); 84 extern struct workqueue_struct *fscrypt_read_workqueue; 85 extern int fscrypt_do_page_crypto(const struct inode *inode, 86 fscrypt_direction_t rw, u64 lblk_num, 87 struct page *src_page, 88 struct page *dest_page, 89 unsigned int len, unsigned int offs, 90 gfp_t gfp_flags); 91 extern struct page *fscrypt_alloc_bounce_page(struct fscrypt_ctx *ctx, 92 gfp_t gfp_flags); 93 94 /* keyinfo.c */ 95 extern void __exit fscrypt_essiv_cleanup(void); 96 97 #endif /* _FSCRYPT_PRIVATE_H */ 98