[03/18] f2fs crypto: declare some definitions for f2fs encryption feature

Message ID	1431145253-2019-3-git-send-email-jaegeuk@kernel.org (mailing list archive)
State	New, archived
Headers	show Return-Path: <linux-fsdevel-owner@kernel.org> From: Jaegeuk Kim <jaegeuk@kernel.org> To: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net Cc: Jaegeuk Kim <jaegeuk@kernel.org> Subject: [PATCH 03/18] f2fs crypto: declare some definitions for f2fs encryption feature Date: Fri, 8 May 2015 21:20:38 -0700 Message-Id: <1431145253-2019-3-git-send-email-jaegeuk@kernel.org> In-Reply-To: <1431145253-2019-1-git-send-email-jaegeuk@kernel.org> References: <1431145253-2019-1-git-send-email-jaegeuk@kernel.org> Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk

diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h index 477e65f..c3c4deb 100644 --- a/fs/f2fs/f2fs.h +++ b/fs/f2fs/f2fs.h @@ -70,6 +70,8 @@ struct f2fs_mount_info { unsigned int opt; }; +#define F2FS_FEATURE_ENCRYPT 0x0001 + #define F2FS_HAS_FEATURE(sb, mask) \ ((F2FS_SB(sb)->raw_super->feature & cpu_to_le32(mask)) != 0) #define F2FS_SET_FEATURE(sb, mask) \ @@ -346,6 +348,7 @@ struct f2fs_map_blocks { */ #define FADVISE_COLD_BIT 0x01 #define FADVISE_LOST_PINO_BIT 0x02 +#define FADVISE_ENCRYPT_BIT 0x04 #define file_is_cold(inode) is_file(inode, FADVISE_COLD_BIT) #define file_wrong_pino(inode) is_file(inode, FADVISE_LOST_PINO_BIT) @@ -353,6 +356,16 @@ struct f2fs_map_blocks { #define file_lost_pino(inode) set_file(inode, FADVISE_LOST_PINO_BIT) #define file_clear_cold(inode) clear_file(inode, FADVISE_COLD_BIT) #define file_got_pino(inode) clear_file(inode, FADVISE_LOST_PINO_BIT) +#define file_is_encrypt(inode) is_file(inode, FADVISE_ENCRYPT_BIT) +#define file_set_encrypt(inode) set_file(inode, FADVISE_ENCRYPT_BIT) +#define file_clear_encrypt(inode) clear_file(inode, FADVISE_ENCRYPT_BIT) + +/* Encryption algorithms */ +#define F2FS_ENCRYPTION_MODE_INVALID 0 +#define F2FS_ENCRYPTION_MODE_AES_256_XTS 1 +#define F2FS_ENCRYPTION_MODE_AES_256_GCM 2 +#define F2FS_ENCRYPTION_MODE_AES_256_CBC 3 +#define F2FS_ENCRYPTION_MODE_AES_256_CTS 4 #define DEF_DIR_LEVEL 0 @@ -380,6 +393,11 @@ struct f2fs_inode_info { struct radix_tree_root inmem_root; /* radix tree for inmem pages */ struct list_head inmem_pages; /* inmemory pages managed by f2fs */ struct mutex inmem_lock; /* lock for inmemory pages */ + +#ifdef CONFIG_F2FS_FS_ENCRYPTION + /* Encryption params */ + struct f2fs_crypt_info *i_crypt_info; +#endif }; static inline void get_extent_info(struct extent_info *ext, @@ -1891,4 +1909,40 @@ void f2fs_delete_inline_entry(struct f2fs_dir_entry *, struct page *, struct inode *, struct inode *); bool f2fs_empty_inline_dir(struct inode *); int f2fs_read_inline_dir(struct file *, struct dir_context *); + +/* + * crypto support + */ +static inline int f2fs_encrypted_inode(struct inode *inode) +{ +#ifdef CONFIG_F2FS_FS_ENCRYPTION + return file_is_encrypt(inode); +#else + return 0; +#endif +} + +static inline void f2fs_set_encrypted_inode(struct inode *inode) +{ +#ifdef CONFIG_F2FS_FS_ENCRYPTION + file_set_encrypt(inode); +#endif +} + +static inline bool f2fs_bio_encrypted(struct bio *bio) +{ +#ifdef CONFIG_F2FS_FS_ENCRYPTION + return unlikely(bio->bi_private != NULL); +#else + return false; +#endif +} + +static inline int f2fs_sb_has_crypto(struct super_block *sb) +{ +#ifdef CONFIG_F2FS_FS_ENCRYPTION + return F2FS_HAS_FEATURE(sb, F2FS_FEATURE_ENCRYPT); +#else + return 0; +#endif #endif diff --git a/fs/f2fs/f2fs_crypto.h b/fs/f2fs/f2fs_crypto.h new file mode 100644 index 0000000..cfc37c1 --- /dev/null +++ b/fs/f2fs/f2fs_crypto.h @@ -0,0 +1,149 @@ +/* + * linux/fs/f2fs/f2fs_crypto.h + * + * Copied from linux/fs/ext4/ext4_crypto.h + * + * Copyright (C) 2015, Google, Inc. + * + * This contains encryption header content for f2fs + * + * Written by Michael Halcrow, 2015. + * Modified by Jaegeuk Kim, 2015. + */ +#ifndef _F2FS_CRYPTO_H +#define _F2FS_CRYPTO_H + +#include <linux/fs.h> + +#define F2FS_KEY_DESCRIPTOR_SIZE 8 + +/* Policy provided via an ioctl on the topmost directory */ +struct f2fs_encryption_policy { + char version; + char contents_encryption_mode; + char filenames_encryption_mode; + char flags; + char master_key_descriptor[F2FS_KEY_DESCRIPTOR_SIZE]; +} __attribute__((__packed__)); + +#define F2FS_ENCRYPTION_CONTEXT_FORMAT_V1 1 +#define F2FS_KEY_DERIVATION_NONCE_SIZE 16 + +#define F2FS_POLICY_FLAGS_PAD_4 0x00 +#define F2FS_POLICY_FLAGS_PAD_8 0x01 +#define F2FS_POLICY_FLAGS_PAD_16 0x02 +#define F2FS_POLICY_FLAGS_PAD_32 0x03 +#define F2FS_POLICY_FLAGS_PAD_MASK 0x03 +#define F2FS_POLICY_FLAGS_VALID 0x03 + +/** + * 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 f2fs_encryption_context { + char format; + char contents_encryption_mode; + char filenames_encryption_mode; + char flags; + char master_key_descriptor[F2FS_KEY_DESCRIPTOR_SIZE]; + char nonce[F2FS_KEY_DERIVATION_NONCE_SIZE]; +} __attribute__((__packed__)); + +/* Encryption parameters */ +#define F2FS_XTS_TWEAK_SIZE 16 +#define F2FS_AES_128_ECB_KEY_SIZE 16 +#define F2FS_AES_256_GCM_KEY_SIZE 32 +#define F2FS_AES_256_CBC_KEY_SIZE 32 +#define F2FS_AES_256_CTS_KEY_SIZE 32 +#define F2FS_AES_256_XTS_KEY_SIZE 64 +#define F2FS_MAX_KEY_SIZE 64 + +struct f2fs_encryption_key { + __u32 mode; + char raw[F2FS_MAX_KEY_SIZE]; + __u32 size; +} __attribute__((__packed__)); + +struct f2fs_crypt_info { + unsigned char ci_mode; + unsigned char ci_size; + char ci_data_mode; + char ci_filename_mode; + char ci_flags; + struct crypto_ablkcipher *ci_ctfm; + struct key *ci_keyring_key; + char ci_raw[F2FS_MAX_KEY_SIZE]; + char ci_master_key[F2FS_KEY_DESCRIPTOR_SIZE]; +}; + +#define F2FS_CTX_REQUIRES_FREE_ENCRYPT_FL 0x00000001 +#define F2FS_BOUNCE_PAGE_REQUIRES_FREE_ENCRYPT_FL 0x00000002 + +struct f2fs_crypto_ctx { + struct crypto_tfm *tfm; /* Crypto API context */ + struct page *bounce_page; /* Ciphertext page on write path */ + struct page *control_page; /* Original page on write path */ + struct bio *bio; /* The bio for this context */ + struct work_struct work; /* Work queue for read complete path */ + struct list_head free_list; /* Free list */ + int flags; /* Flags */ + int mode; /* Encryption mode for tfm */ +}; + +struct f2fs_completion_result { + struct completion completion; + int res; +}; + +#define DECLARE_F2FS_COMPLETION_RESULT(ecr) \ + struct f2fs_completion_result ecr = { \ + COMPLETION_INITIALIZER((ecr).completion), 0 } + +static inline int f2fs_encryption_key_size(int mode) +{ + switch (mode) { + case F2FS_ENCRYPTION_MODE_AES_256_XTS: + return F2FS_AES_256_XTS_KEY_SIZE; + case F2FS_ENCRYPTION_MODE_AES_256_GCM: + return F2FS_AES_256_GCM_KEY_SIZE; + case F2FS_ENCRYPTION_MODE_AES_256_CBC: + return F2FS_AES_256_CBC_KEY_SIZE; + case F2FS_ENCRYPTION_MODE_AES_256_CTS: + return F2FS_AES_256_CTS_KEY_SIZE; + default: + BUG(); + } + return 0; +} + +#define F2FS_FNAME_NUM_SCATTER_ENTRIES 4 +#define F2FS_CRYPTO_BLOCK_SIZE 16 +#define F2FS_FNAME_CRYPTO_DIGEST_SIZE 32 + +/** + * For encrypted symlinks, the ciphertext length is stored at the beginning + * of the string in little-endian format. + */ +struct f2fs_encrypted_symlink_data { + __le16 len; + char encrypted_path[1]; +} __attribute__((__packed__)); + +/** + * This function is used to calculate the disk space required to + * store a filename of length l in encrypted symlink format. + */ +static inline u32 encrypted_symlink_data_len(u32 l) +{ + if (l < F2FS_CRYPTO_BLOCK_SIZE) + l = F2FS_CRYPTO_BLOCK_SIZE; + return (l + sizeof(struct f2fs_encrypted_symlink_data) - 1); +} +#endif /* _F2FS_CRYPTO_H */ diff --git a/include/linux/f2fs_fs.h b/include/linux/f2fs_fs.h index d44e97f..920408a 100644 --- a/include/linux/f2fs_fs.h +++ b/include/linux/f2fs_fs.h @@ -91,7 +91,9 @@ struct f2fs_super_block { __u8 version[VERSION_LEN]; /* the kernel version */ __u8 init_version[VERSION_LEN]; /* the initial kernel version */ __le32 feature; /* defined features */ - __u8 reserved[888]; /* valid reserved region */ + __u8 encryption_level; /* versioning level for encryption */ + __u8 encrypt_pw_salt[16]; /* Salt used for string2key algorithm */ + __u8 reserved[871]; /* valid reserved region */ } __packed; /*

[03/18] f2fs crypto: declare some definitions for f2fs encryption feature

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