1 files changed, 122 insertions, 0 deletions
diff --git a/fs/crypto/fscrypt_private.h b/fs/crypto/fscrypt_private.h
new file mode 100644
index 000000000000..c73962a3c59f
--- /dev/null
+++ b/fs/crypto/fscrypt_private.h
@@ -0,0 +1,122 @@
+/*
+ * 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;
+
+	if (contents_mode == FS_ENCRYPTION_MODE_SPECK128_256_XTS &&
+	    filenames_mode == FS_ENCRYPTION_MODE_SPECK128_256_CTS)
+		return true;
+
+	return false;
+}
+
+/* crypto.c */
+extern struct kmem_cache *fscrypt_info_cachep;
+extern int fscrypt_initialize(unsigned int cop_flags);
+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 */