f2fs crypto: declare some definitions for f2fs encryption feature
This definitions will be used by inode and superblock for encyption.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
diff --git a/fs/f2fs/f2fs_crypto.h b/fs/f2fs/f2fs_crypto.h
new file mode 100644
index 0000000..3323266
--- /dev/null
+++ b/fs/f2fs/f2fs_crypto.h
@@ -0,0 +1,147 @@
+/*
+ * 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)
+{
+ return (l + sizeof(struct f2fs_encrypted_symlink_data) - 1);
+}
+#endif /* _F2FS_CRYPTO_H */