mkfs.ubifs: Move fscrypt definitions and functions out of mkfs.ubifs.c

Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>
Signed-off-by: Richard Weinberger <richard@nod.at>

1 files changed, 112 insertions, 0 deletions

diff --git a/ubifs-utils/mkfs.ubifs/fscrypt.h b/ubifs-utils/mkfs.ubifs/fscrypt.h
new file mode 100644
index 0000000..b6fb6d1
--- /dev/null
+++ b/ubifs-utils/mkfs.ubifs/fscrypt.h
@@ -0,0 +1,112 @@
+/*
+ * Copyright (C) 2017 sigma star gmbh
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published by
+ * the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, write to the Free Software Foundation, Inc., 51
+ * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ *
+ * Authors: Richard Weinberger <richard@sigma-star.at>
+ *          David Oberhollenzer <david.oberhollenzer@sigma-star.at>
+ */
+
+#ifndef FSCRYPT_H
+#define FSCRYPT_H
+
+
+#include "mkfs.ubifs.h"
+#include <sys/types.h>
+#include "crypto.h"
+
+
+#ifndef FS_KEY_DESCRIPTOR_SIZE
+#define FS_KEY_DESCRIPTOR_SIZE  8
+#endif
+#define FS_ENCRYPTION_CONTEXT_FORMAT_V1 1
+#define FS_KEY_DERIVATION_NONCE_SIZE	16
+
+#ifndef FS_ENCRYPTION_MODE_AES_128_CBC
+#define FS_ENCRYPTION_MODE_AES_128_CBC 5
+#endif
+
+#ifndef FS_ENCRYPTION_MODE_AES_128_CTS
+#define FS_ENCRYPTION_MODE_AES_128_CTS 6
+#endif
+
+#ifndef FS_POLICY_FLAGS_VALID
+#define FS_POLICY_FLAGS_PAD_4		0x00
+#define FS_POLICY_FLAGS_PAD_8		0x01
+#define FS_POLICY_FLAGS_PAD_16		0x02
+#define FS_POLICY_FLAGS_PAD_32		0x03
+#define FS_POLICY_FLAGS_PAD_MASK	0x03
+#define FS_POLICY_FLAGS_VALID		0x03
+#endif
+
+#define FS_CRYPTO_BLOCK_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];
+} __attribute__((packed));
+
+/**
+ * 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];
+} __attribute__((packed));
+
+
+#ifndef FS_MAX_KEY_SIZE
+#define FS_MAX_KEY_SIZE	64
+#endif
+
+unsigned char *calc_fscrypt_subkey(struct fscrypt_context *fctx);
+
+struct fscrypt_context *inherit_fscrypt_context(struct fscrypt_context *fctx);
+
+void free_fscrypt_context(struct fscrypt_context *fctx);
+
+void print_fscrypt_master_key_descriptor(struct fscrypt_context *fctx);
+
+unsigned int fscrypt_fname_encrypted_size(struct fscrypt_context *fctx,
+					  unsigned int ilen);
+
+int encrypt_path(void **outbuf, void *data, unsigned int data_len,
+		 unsigned int max_namelen, struct fscrypt_context *fctx);
+
+int encrypt_data_node(struct fscrypt_context *fctx, unsigned int block_no,
+		      struct ubifs_data_node *dn, size_t length);
+
+struct fscrypt_context *init_fscrypt_context(const char *cipher_name,
+					     unsigned int flags,
+					     const char *key_file,
+					     const char *key_descriptor);
+
+#endif /* FSCRYPT_H */
+