Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / fs / ext4 / ext4_crypto.h

diff --git a/kernel/fs/ext4/ext4_crypto.h b/kernel/fs/ext4/ext4_crypto.h
new file mode 100644 (file)
index 0000000..d75159c
--- /dev/null
+++ b/kernel/fs/ext4/ext4_crypto.h
@@ -0,0 +1,156 @@
+/*
+ * linux/fs/ext4/ext4_crypto.h
+ *
+ * Copyright (C) 2015, Google, Inc.
+ *
+ * This contains encryption header content for ext4
+ *
+ * Written by Michael Halcrow, 2015.
+ */
+
+#ifndef _EXT4_CRYPTO_H
+#define _EXT4_CRYPTO_H
+
+#include <linux/fs.h>
+
+#define EXT4_KEY_DESCRIPTOR_SIZE 8
+
+/* Policy provided via an ioctl on the topmost directory */
+struct ext4_encryption_policy {
+       char version;
+       char contents_encryption_mode;
+       char filenames_encryption_mode;
+       char flags;
+       char master_key_descriptor[EXT4_KEY_DESCRIPTOR_SIZE];
+} __attribute__((__packed__));
+
+#define EXT4_ENCRYPTION_CONTEXT_FORMAT_V1 1
+#define EXT4_KEY_DERIVATION_NONCE_SIZE 16
+
+#define EXT4_POLICY_FLAGS_PAD_4                0x00
+#define EXT4_POLICY_FLAGS_PAD_8                0x01
+#define EXT4_POLICY_FLAGS_PAD_16       0x02
+#define EXT4_POLICY_FLAGS_PAD_32       0x03
+#define EXT4_POLICY_FLAGS_PAD_MASK     0x03
+#define EXT4_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: Reserved
+ *  8 bytes: Master Key descriptor
+ *  16 bytes: Encryption Key derivation nonce
+ */
+struct ext4_encryption_context {
+       char format;
+       char contents_encryption_mode;
+       char filenames_encryption_mode;
+       char flags;
+       char master_key_descriptor[EXT4_KEY_DESCRIPTOR_SIZE];
+       char nonce[EXT4_KEY_DERIVATION_NONCE_SIZE];
+} __attribute__((__packed__));
+
+/* Encryption parameters */
+#define EXT4_XTS_TWEAK_SIZE 16
+#define EXT4_AES_128_ECB_KEY_SIZE 16
+#define EXT4_AES_256_GCM_KEY_SIZE 32
+#define EXT4_AES_256_CBC_KEY_SIZE 32
+#define EXT4_AES_256_CTS_KEY_SIZE 32
+#define EXT4_AES_256_XTS_KEY_SIZE 64
+#define EXT4_MAX_KEY_SIZE 64
+
+#define EXT4_KEY_DESC_PREFIX "ext4:"
+#define EXT4_KEY_DESC_PREFIX_SIZE 5
+
+struct ext4_encryption_key {
+       uint32_t mode;
+       char raw[EXT4_MAX_KEY_SIZE];
+       uint32_t size;
+};
+
+#define EXT4_CTX_REQUIRES_FREE_ENCRYPT_FL             0x00000001
+#define EXT4_BOUNCE_PAGE_REQUIRES_FREE_ENCRYPT_FL     0x00000002
+
+struct ext4_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 ext4_completion_result {
+       struct completion completion;
+       int res;
+};
+
+#define DECLARE_EXT4_COMPLETION_RESULT(ecr) \
+       struct ext4_completion_result ecr = { \
+               COMPLETION_INITIALIZER((ecr).completion), 0 }
+
+static inline int ext4_encryption_key_size(int mode)
+{
+       switch (mode) {
+       case EXT4_ENCRYPTION_MODE_AES_256_XTS:
+               return EXT4_AES_256_XTS_KEY_SIZE;
+       case EXT4_ENCRYPTION_MODE_AES_256_GCM:
+               return EXT4_AES_256_GCM_KEY_SIZE;
+       case EXT4_ENCRYPTION_MODE_AES_256_CBC:
+               return EXT4_AES_256_CBC_KEY_SIZE;
+       case EXT4_ENCRYPTION_MODE_AES_256_CTS:
+               return EXT4_AES_256_CTS_KEY_SIZE;
+       default:
+               BUG();
+       }
+       return 0;
+}
+
+#define EXT4_FNAME_NUM_SCATTER_ENTRIES 4
+#define EXT4_CRYPTO_BLOCK_SIZE         16
+#define EXT4_FNAME_CRYPTO_DIGEST_SIZE  32
+
+struct ext4_str {
+       unsigned char *name;
+       u32 len;
+};
+
+struct ext4_fname_crypto_ctx {
+       u32 lim;
+       char tmp_buf[EXT4_CRYPTO_BLOCK_SIZE];
+       struct crypto_ablkcipher *ctfm;
+       struct crypto_hash *htfm;
+       struct page *workpage;
+       struct ext4_encryption_key key;
+       unsigned flags : 8;
+       unsigned has_valid_key : 1;
+       unsigned ctfm_key_is_ready : 1;
+};
+
+/**
+ * For encrypted symlinks, the ciphertext length is stored at the beginning
+ * of the string in little-endian format.
+ */
+struct ext4_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 < EXT4_CRYPTO_BLOCK_SIZE)
+               l = EXT4_CRYPTO_BLOCK_SIZE;
+       return (l + sizeof(struct ext4_encrypted_symlink_data) - 1);
+}
+
+#endif /* _EXT4_CRYPTO_H */