Adding upstream version 6.1.76.upstream/6.1.76upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 666 insertions, 0 deletions

diff --git a/fs/crypto/fscrypt_private.h b/fs/crypto/fscrypt_private.h
new file mode 100644
index 000000000..d5f68a0c5
--- /dev/null
+++ b/fs/crypto/fscrypt_private.h
@@ -0,0 +1,666 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * fscrypt_private.h
+ *
+ * Copyright (C) 2015, Google, Inc.
+ *
+ * Originally written by Michael Halcrow, Ildar Muslukhov, and Uday Savagaonkar.
+ * Heavily modified since then.
+ */
+
+#ifndef _FSCRYPT_PRIVATE_H
+#define _FSCRYPT_PRIVATE_H
+
+#include <linux/fscrypt.h>
+#include <linux/siphash.h>
+#include <crypto/hash.h>
+#include <linux/blk-crypto.h>
+
+#define CONST_STRLEN(str)	(sizeof(str) - 1)
+
+#define FSCRYPT_FILE_NONCE_SIZE	16
+
+/*
+ * Minimum size of an fscrypt master key.  Note: a longer key will be required
+ * if ciphers with a 256-bit security strength are used.  This is just the
+ * absolute minimum, which applies when only 128-bit encryption is used.
+ */
+#define FSCRYPT_MIN_KEY_SIZE	16
+
+#define FSCRYPT_CONTEXT_V1	1
+#define FSCRYPT_CONTEXT_V2	2
+
+/* Keep this in sync with include/uapi/linux/fscrypt.h */
+#define FSCRYPT_MODE_MAX	FSCRYPT_MODE_AES_256_HCTR2
+
+struct fscrypt_context_v1 {
+	u8 version; /* FSCRYPT_CONTEXT_V1 */
+	u8 contents_encryption_mode;
+	u8 filenames_encryption_mode;
+	u8 flags;
+	u8 master_key_descriptor[FSCRYPT_KEY_DESCRIPTOR_SIZE];
+	u8 nonce[FSCRYPT_FILE_NONCE_SIZE];
+};
+
+struct fscrypt_context_v2 {
+	u8 version; /* FSCRYPT_CONTEXT_V2 */
+	u8 contents_encryption_mode;
+	u8 filenames_encryption_mode;
+	u8 flags;
+	u8 __reserved[4];
+	u8 master_key_identifier[FSCRYPT_KEY_IDENTIFIER_SIZE];
+	u8 nonce[FSCRYPT_FILE_NONCE_SIZE];
+};
+
+/*
+ * fscrypt_context - the encryption context of an inode
+ *
+ * This is the on-disk equivalent of an fscrypt_policy, stored alongside each
+ * encrypted file usually in a hidden extended attribute.  It contains the
+ * fields from the fscrypt_policy, in order to identify the encryption algorithm
+ * and key with which the file is encrypted.  It also contains a nonce that was
+ * randomly generated by fscrypt itself; this is used as KDF input or as a tweak
+ * to cause different files to be encrypted differently.
+ */
+union fscrypt_context {
+	u8 version;
+	struct fscrypt_context_v1 v1;
+	struct fscrypt_context_v2 v2;
+};
+
+/*
+ * Return the size expected for the given fscrypt_context based on its version
+ * number, or 0 if the context version is unrecognized.
+ */
+static inline int fscrypt_context_size(const union fscrypt_context *ctx)
+{
+	switch (ctx->version) {
+	case FSCRYPT_CONTEXT_V1:
+		BUILD_BUG_ON(sizeof(ctx->v1) != 28);
+		return sizeof(ctx->v1);
+	case FSCRYPT_CONTEXT_V2:
+		BUILD_BUG_ON(sizeof(ctx->v2) != 40);
+		return sizeof(ctx->v2);
+	}
+	return 0;
+}
+
+/* Check whether an fscrypt_context has a recognized version number and size */
+static inline bool fscrypt_context_is_valid(const union fscrypt_context *ctx,
+					    int ctx_size)
+{
+	return ctx_size >= 1 && ctx_size == fscrypt_context_size(ctx);
+}
+
+/* Retrieve the context's nonce, assuming the context was already validated */
+static inline const u8 *fscrypt_context_nonce(const union fscrypt_context *ctx)
+{
+	switch (ctx->version) {
+	case FSCRYPT_CONTEXT_V1:
+		return ctx->v1.nonce;
+	case FSCRYPT_CONTEXT_V2:
+		return ctx->v2.nonce;
+	}
+	WARN_ON(1);
+	return NULL;
+}
+
+union fscrypt_policy {
+	u8 version;
+	struct fscrypt_policy_v1 v1;
+	struct fscrypt_policy_v2 v2;
+};
+
+/*
+ * Return the size expected for the given fscrypt_policy based on its version
+ * number, or 0 if the policy version is unrecognized.
+ */
+static inline int fscrypt_policy_size(const union fscrypt_policy *policy)
+{
+	switch (policy->version) {
+	case FSCRYPT_POLICY_V1:
+		return sizeof(policy->v1);
+	case FSCRYPT_POLICY_V2:
+		return sizeof(policy->v2);
+	}
+	return 0;
+}
+
+/* Return the contents encryption mode of a valid encryption policy */
+static inline u8
+fscrypt_policy_contents_mode(const union fscrypt_policy *policy)
+{
+	switch (policy->version) {
+	case FSCRYPT_POLICY_V1:
+		return policy->v1.contents_encryption_mode;
+	case FSCRYPT_POLICY_V2:
+		return policy->v2.contents_encryption_mode;
+	}
+	BUG();
+}
+
+/* Return the filenames encryption mode of a valid encryption policy */
+static inline u8
+fscrypt_policy_fnames_mode(const union fscrypt_policy *policy)
+{
+	switch (policy->version) {
+	case FSCRYPT_POLICY_V1:
+		return policy->v1.filenames_encryption_mode;
+	case FSCRYPT_POLICY_V2:
+		return policy->v2.filenames_encryption_mode;
+	}
+	BUG();
+}
+
+/* Return the flags (FSCRYPT_POLICY_FLAG*) of a valid encryption policy */
+static inline u8
+fscrypt_policy_flags(const union fscrypt_policy *policy)
+{
+	switch (policy->version) {
+	case FSCRYPT_POLICY_V1:
+		return policy->v1.flags;
+	case FSCRYPT_POLICY_V2:
+		return policy->v2.flags;
+	}
+	BUG();
+}
+
+/*
+ * 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;
+
+/**
+ * struct fscrypt_prepared_key - a key prepared for actual encryption/decryption
+ * @tfm: crypto API transform object
+ * @blk_key: key for blk-crypto
+ *
+ * Normally only one of the fields will be non-NULL.
+ */
+struct fscrypt_prepared_key {
+	struct crypto_skcipher *tfm;
+#ifdef CONFIG_FS_ENCRYPTION_INLINE_CRYPT
+	struct blk_crypto_key *blk_key;
+#endif
+};
+
+/*
+ * fscrypt_info - the "encryption key" for an inode
+ *
+ * When an encrypted file's key is made available, an instance of this struct is
+ * allocated and stored in ->i_crypt_info.  Once created, it remains until the
+ * inode is evicted.
+ */
+struct fscrypt_info {
+
+	/* The key in a form prepared for actual encryption/decryption */
+	struct fscrypt_prepared_key ci_enc_key;
+
+	/* True if ci_enc_key should be freed when this fscrypt_info is freed */
+	bool ci_owns_key;
+
+#ifdef CONFIG_FS_ENCRYPTION_INLINE_CRYPT
+	/*
+	 * True if this inode will use inline encryption (blk-crypto) instead of
+	 * the traditional filesystem-layer encryption.
+	 */
+	bool ci_inlinecrypt;
+#endif
+
+	/*
+	 * Encryption mode used for this inode.  It corresponds to either the
+	 * contents or filenames encryption mode, depending on the inode type.
+	 */
+	struct fscrypt_mode *ci_mode;
+
+	/* Back-pointer to the inode */
+	struct inode *ci_inode;
+
+	/*
+	 * The master key with which this inode was unlocked (decrypted).  This
+	 * will be NULL if the master key was found in a process-subscribed
+	 * keyring rather than in the filesystem-level keyring.
+	 */
+	struct fscrypt_master_key *ci_master_key;
+
+	/*
+	 * Link in list of inodes that were unlocked with the master key.
+	 * Only used when ->ci_master_key is set.
+	 */
+	struct list_head ci_master_key_link;
+
+	/*
+	 * If non-NULL, then encryption is done using the master key directly
+	 * and ci_enc_key will equal ci_direct_key->dk_key.
+	 */
+	struct fscrypt_direct_key *ci_direct_key;
+
+	/*
+	 * This inode's hash key for filenames.  This is a 128-bit SipHash-2-4
+	 * key.  This is only set for directories that use a keyed dirhash over
+	 * the plaintext filenames -- currently just casefolded directories.
+	 */
+	siphash_key_t ci_dirhash_key;
+	bool ci_dirhash_key_initialized;
+
+	/* The encryption policy used by this inode */
+	union fscrypt_policy ci_policy;
+
+	/* This inode's nonce, copied from the fscrypt_context */
+	u8 ci_nonce[FSCRYPT_FILE_NONCE_SIZE];
+
+	/* Hashed inode number.  Only set for IV_INO_LBLK_32 */
+	u32 ci_hashed_ino;
+};
+
+typedef enum {
+	FS_DECRYPT = 0,
+	FS_ENCRYPT,
+} fscrypt_direction_t;
+
+/* crypto.c */
+extern struct kmem_cache *fscrypt_info_cachep;
+int fscrypt_initialize(unsigned int cop_flags);
+int fscrypt_crypt_block(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);
+struct page *fscrypt_alloc_bounce_page(gfp_t gfp_flags);
+
+void __printf(3, 4) __cold
+fscrypt_msg(const struct inode *inode, const char *level, const char *fmt, ...);
+
+#define fscrypt_warn(inode, fmt, ...)		\
+	fscrypt_msg((inode), KERN_WARNING, fmt, ##__VA_ARGS__)
+#define fscrypt_err(inode, fmt, ...)		\
+	fscrypt_msg((inode), KERN_ERR, fmt, ##__VA_ARGS__)
+
+#define FSCRYPT_MAX_IV_SIZE	32
+
+union fscrypt_iv {
+	struct {
+		/* logical block number within the file */
+		__le64 lblk_num;
+
+		/* per-file nonce; only set in DIRECT_KEY mode */
+		u8 nonce[FSCRYPT_FILE_NONCE_SIZE];
+	};
+	u8 raw[FSCRYPT_MAX_IV_SIZE];
+	__le64 dun[FSCRYPT_MAX_IV_SIZE / sizeof(__le64)];
+};
+
+void fscrypt_generate_iv(union fscrypt_iv *iv, u64 lblk_num,
+			 const struct fscrypt_info *ci);
+
+/* fname.c */
+bool __fscrypt_fname_encrypted_size(const union fscrypt_policy *policy,
+				    u32 orig_len, u32 max_len,
+				    u32 *encrypted_len_ret);
+
+/* hkdf.c */
+struct fscrypt_hkdf {
+	struct crypto_shash *hmac_tfm;
+};
+
+int fscrypt_init_hkdf(struct fscrypt_hkdf *hkdf, const u8 *master_key,
+		      unsigned int master_key_size);
+
+/*
+ * The list of contexts in which fscrypt uses HKDF.  These values are used as
+ * the first byte of the HKDF application-specific info string to guarantee that
+ * info strings are never repeated between contexts.  This ensures that all HKDF
+ * outputs are unique and cryptographically isolated, i.e. knowledge of one
+ * output doesn't reveal another.
+ */
+#define HKDF_CONTEXT_KEY_IDENTIFIER	1 /* info=<empty>		*/
+#define HKDF_CONTEXT_PER_FILE_ENC_KEY	2 /* info=file_nonce		*/
+#define HKDF_CONTEXT_DIRECT_KEY		3 /* info=mode_num		*/
+#define HKDF_CONTEXT_IV_INO_LBLK_64_KEY	4 /* info=mode_num||fs_uuid	*/
+#define HKDF_CONTEXT_DIRHASH_KEY	5 /* info=file_nonce		*/
+#define HKDF_CONTEXT_IV_INO_LBLK_32_KEY	6 /* info=mode_num||fs_uuid	*/
+#define HKDF_CONTEXT_INODE_HASH_KEY	7 /* info=<empty>		*/
+
+int fscrypt_hkdf_expand(const struct fscrypt_hkdf *hkdf, u8 context,
+			const u8 *info, unsigned int infolen,
+			u8 *okm, unsigned int okmlen);
+
+void fscrypt_destroy_hkdf(struct fscrypt_hkdf *hkdf);
+
+/* inline_crypt.c */
+#ifdef CONFIG_FS_ENCRYPTION_INLINE_CRYPT
+int fscrypt_select_encryption_impl(struct fscrypt_info *ci);
+
+static inline bool
+fscrypt_using_inline_encryption(const struct fscrypt_info *ci)
+{
+	return ci->ci_inlinecrypt;
+}
+
+int fscrypt_prepare_inline_crypt_key(struct fscrypt_prepared_key *prep_key,
+				     const u8 *raw_key,
+				     const struct fscrypt_info *ci);
+
+void fscrypt_destroy_inline_crypt_key(struct super_block *sb,
+				      struct fscrypt_prepared_key *prep_key);
+
+/*
+ * Check whether the crypto transform or blk-crypto key has been allocated in
+ * @prep_key, depending on which encryption implementation the file will use.
+ */
+static inline bool
+fscrypt_is_key_prepared(struct fscrypt_prepared_key *prep_key,
+			const struct fscrypt_info *ci)
+{
+	/*
+	 * The two smp_load_acquire()'s here pair with the smp_store_release()'s
+	 * in fscrypt_prepare_inline_crypt_key() and fscrypt_prepare_key().
+	 * I.e., in some cases (namely, if this prep_key is a per-mode
+	 * encryption key) another task can publish blk_key or tfm concurrently,
+	 * executing a RELEASE barrier.  We need to use smp_load_acquire() here
+	 * to safely ACQUIRE the memory the other task published.
+	 */
+	if (fscrypt_using_inline_encryption(ci))
+		return smp_load_acquire(&prep_key->blk_key) != NULL;
+	return smp_load_acquire(&prep_key->tfm) != NULL;
+}
+
+#else /* CONFIG_FS_ENCRYPTION_INLINE_CRYPT */
+
+static inline int fscrypt_select_encryption_impl(struct fscrypt_info *ci)
+{
+	return 0;
+}
+
+static inline bool
+fscrypt_using_inline_encryption(const struct fscrypt_info *ci)
+{
+	return false;
+}
+
+static inline int
+fscrypt_prepare_inline_crypt_key(struct fscrypt_prepared_key *prep_key,
+				 const u8 *raw_key,
+				 const struct fscrypt_info *ci)
+{
+	WARN_ON(1);
+	return -EOPNOTSUPP;
+}
+
+static inline void
+fscrypt_destroy_inline_crypt_key(struct super_block *sb,
+				 struct fscrypt_prepared_key *prep_key)
+{
+}
+
+static inline bool
+fscrypt_is_key_prepared(struct fscrypt_prepared_key *prep_key,
+			const struct fscrypt_info *ci)
+{
+	return smp_load_acquire(&prep_key->tfm) != NULL;
+}
+#endif /* !CONFIG_FS_ENCRYPTION_INLINE_CRYPT */
+
+/* keyring.c */
+
+/*
+ * fscrypt_master_key_secret - secret key material of an in-use master key
+ */
+struct fscrypt_master_key_secret {
+
+	/*
+	 * For v2 policy keys: HKDF context keyed by this master key.
+	 * For v1 policy keys: not set (hkdf.hmac_tfm == NULL).
+	 */
+	struct fscrypt_hkdf	hkdf;
+
+	/*
+	 * Size of the raw key in bytes.  This remains set even if ->raw was
+	 * zeroized due to no longer being needed.  I.e. we still remember the
+	 * size of the key even if we don't need to remember the key itself.
+	 */
+	u32			size;
+
+	/* For v1 policy keys: the raw key.  Wiped for v2 policy keys. */
+	u8			raw[FSCRYPT_MAX_KEY_SIZE];
+
+} __randomize_layout;
+
+/*
+ * fscrypt_master_key - an in-use master key
+ *
+ * This represents a master encryption key which has been added to the
+ * filesystem and can be used to "unlock" the encrypted files which were
+ * encrypted with it.
+ */
+struct fscrypt_master_key {
+
+	/*
+	 * Back-pointer to the super_block of the filesystem to which this
+	 * master key has been added.  Only valid if ->mk_active_refs > 0.
+	 */
+	struct super_block			*mk_sb;
+
+	/*
+	 * Link in ->mk_sb->s_master_keys->key_hashtable.
+	 * Only valid if ->mk_active_refs > 0.
+	 */
+	struct hlist_node			mk_node;
+
+	/* Semaphore that protects ->mk_secret and ->mk_users */
+	struct rw_semaphore			mk_sem;
+
+	/*
+	 * Active and structural reference counts.  An active ref guarantees
+	 * that the struct continues to exist, continues to be in the keyring
+	 * ->mk_sb->s_master_keys, and that any embedded subkeys (e.g.
+	 * ->mk_direct_keys) that have been prepared continue to exist.
+	 * A structural ref only guarantees that the struct continues to exist.
+	 *
+	 * There is one active ref associated with ->mk_secret being present,
+	 * and one active ref for each inode in ->mk_decrypted_inodes.
+	 *
+	 * There is one structural ref associated with the active refcount being
+	 * nonzero.  Finding a key in the keyring also takes a structural ref,
+	 * which is then held temporarily while the key is operated on.
+	 */
+	refcount_t				mk_active_refs;
+	refcount_t				mk_struct_refs;
+
+	struct rcu_head				mk_rcu_head;
+
+	/*
+	 * The secret key material.  After FS_IOC_REMOVE_ENCRYPTION_KEY is
+	 * executed, this is wiped and no new inodes can be unlocked with this
+	 * key; however, there may still be inodes in ->mk_decrypted_inodes
+	 * which could not be evicted.  As long as some inodes still remain,
+	 * FS_IOC_REMOVE_ENCRYPTION_KEY can be retried, or
+	 * FS_IOC_ADD_ENCRYPTION_KEY can add the secret again.
+	 *
+	 * While ->mk_secret is present, one ref in ->mk_active_refs is held.
+	 *
+	 * Locking: protected by ->mk_sem.  The manipulation of ->mk_active_refs
+	 *	    associated with this field is protected by ->mk_sem as well.
+	 */
+	struct fscrypt_master_key_secret	mk_secret;
+
+	/*
+	 * For v1 policy keys: an arbitrary key descriptor which was assigned by
+	 * userspace (->descriptor).
+	 *
+	 * For v2 policy keys: a cryptographic hash of this key (->identifier).
+	 */
+	struct fscrypt_key_specifier		mk_spec;
+
+	/*
+	 * Keyring which contains a key of type 'key_type_fscrypt_user' for each
+	 * user who has added this key.  Normally each key will be added by just
+	 * one user, but it's possible that multiple users share a key, and in
+	 * that case we need to keep track of those users so that one user can't
+	 * remove the key before the others want it removed too.
+	 *
+	 * This is NULL for v1 policy keys; those can only be added by root.
+	 *
+	 * Locking: protected by ->mk_sem.  (We don't just rely on the keyrings
+	 * subsystem semaphore ->mk_users->sem, as we need support for atomic
+	 * search+insert along with proper synchronization with ->mk_secret.)
+	 */
+	struct key		*mk_users;
+
+	/*
+	 * List of inodes that were unlocked using this key.  This allows the
+	 * inodes to be evicted efficiently if the key is removed.
+	 */
+	struct list_head	mk_decrypted_inodes;
+	spinlock_t		mk_decrypted_inodes_lock;
+
+	/*
+	 * Per-mode encryption keys for the various types of encryption policies
+	 * that use them.  Allocated and derived on-demand.
+	 */
+	struct fscrypt_prepared_key mk_direct_keys[FSCRYPT_MODE_MAX + 1];
+	struct fscrypt_prepared_key mk_iv_ino_lblk_64_keys[FSCRYPT_MODE_MAX + 1];
+	struct fscrypt_prepared_key mk_iv_ino_lblk_32_keys[FSCRYPT_MODE_MAX + 1];
+
+	/* Hash key for inode numbers.  Initialized only when needed. */
+	siphash_key_t		mk_ino_hash_key;
+	bool			mk_ino_hash_key_initialized;
+
+} __randomize_layout;
+
+static inline bool
+is_master_key_secret_present(const struct fscrypt_master_key_secret *secret)
+{
+	/*
+	 * The READ_ONCE() is only necessary for fscrypt_drop_inode().
+	 * fscrypt_drop_inode() runs in atomic context, so it can't take the key
+	 * semaphore and thus 'secret' can change concurrently which would be a
+	 * data race.  But fscrypt_drop_inode() only need to know whether the
+	 * secret *was* present at the time of check, so READ_ONCE() suffices.
+	 */
+	return READ_ONCE(secret->size) != 0;
+}
+
+static inline const char *master_key_spec_type(
+				const struct fscrypt_key_specifier *spec)
+{
+	switch (spec->type) {
+	case FSCRYPT_KEY_SPEC_TYPE_DESCRIPTOR:
+		return "descriptor";
+	case FSCRYPT_KEY_SPEC_TYPE_IDENTIFIER:
+		return "identifier";
+	}
+	return "[unknown]";
+}
+
+static inline int master_key_spec_len(const struct fscrypt_key_specifier *spec)
+{
+	switch (spec->type) {
+	case FSCRYPT_KEY_SPEC_TYPE_DESCRIPTOR:
+		return FSCRYPT_KEY_DESCRIPTOR_SIZE;
+	case FSCRYPT_KEY_SPEC_TYPE_IDENTIFIER:
+		return FSCRYPT_KEY_IDENTIFIER_SIZE;
+	}
+	return 0;
+}
+
+void fscrypt_put_master_key(struct fscrypt_master_key *mk);
+
+void fscrypt_put_master_key_activeref(struct fscrypt_master_key *mk);
+
+struct fscrypt_master_key *
+fscrypt_find_master_key(struct super_block *sb,
+			const struct fscrypt_key_specifier *mk_spec);
+
+int fscrypt_get_test_dummy_key_identifier(
+			  u8 key_identifier[FSCRYPT_KEY_IDENTIFIER_SIZE]);
+
+int fscrypt_verify_key_added(struct super_block *sb,
+			     const u8 identifier[FSCRYPT_KEY_IDENTIFIER_SIZE]);
+
+int __init fscrypt_init_keyring(void);
+
+/* keysetup.c */
+
+struct fscrypt_mode {
+	const char *friendly_name;
+	const char *cipher_str;
+	int keysize;		/* key size in bytes */
+	int security_strength;	/* security strength in bytes */
+	int ivsize;		/* IV size in bytes */
+	int logged_cryptoapi_impl;
+	int logged_blk_crypto_native;
+	int logged_blk_crypto_fallback;
+	enum blk_crypto_mode_num blk_crypto_mode;
+};
+
+extern struct fscrypt_mode fscrypt_modes[];
+
+int fscrypt_prepare_key(struct fscrypt_prepared_key *prep_key,
+			const u8 *raw_key, const struct fscrypt_info *ci);
+
+void fscrypt_destroy_prepared_key(struct super_block *sb,
+				  struct fscrypt_prepared_key *prep_key);
+
+int fscrypt_set_per_file_enc_key(struct fscrypt_info *ci, const u8 *raw_key);
+
+int fscrypt_derive_dirhash_key(struct fscrypt_info *ci,
+			       const struct fscrypt_master_key *mk);
+
+void fscrypt_hash_inode_number(struct fscrypt_info *ci,
+			       const struct fscrypt_master_key *mk);
+
+int fscrypt_get_encryption_info(struct inode *inode, bool allow_unsupported);
+
+/**
+ * fscrypt_require_key() - require an inode's encryption key
+ * @inode: the inode we need the key for
+ *
+ * If the inode is encrypted, set up its encryption key if not already done.
+ * Then require that the key be present and return -ENOKEY otherwise.
+ *
+ * No locks are needed, and the key will live as long as the struct inode --- so
+ * it won't go away from under you.
+ *
+ * Return: 0 on success, -ENOKEY if the key is missing, or another -errno code
+ * if a problem occurred while setting up the encryption key.
+ */
+static inline int fscrypt_require_key(struct inode *inode)
+{
+	if (IS_ENCRYPTED(inode)) {
+		int err = fscrypt_get_encryption_info(inode, false);
+
+		if (err)
+			return err;
+		if (!fscrypt_has_encryption_key(inode))
+			return -ENOKEY;
+	}
+	return 0;
+}
+
+/* keysetup_v1.c */
+
+void fscrypt_put_direct_key(struct fscrypt_direct_key *dk);
+
+int fscrypt_setup_v1_file_key(struct fscrypt_info *ci,
+			      const u8 *raw_master_key);
+
+int fscrypt_setup_v1_file_key_via_subscribed_keyrings(struct fscrypt_info *ci);
+
+/* policy.c */
+
+bool fscrypt_policies_equal(const union fscrypt_policy *policy1,
+			    const union fscrypt_policy *policy2);
+int fscrypt_policy_to_key_spec(const union fscrypt_policy *policy,
+			       struct fscrypt_key_specifier *key_spec);
+bool fscrypt_supported_policy(const union fscrypt_policy *policy_u,
+			      const struct inode *inode);
+int fscrypt_policy_from_context(union fscrypt_policy *policy_u,
+				const union fscrypt_context *ctx_u,
+				int ctx_size);
+const union fscrypt_policy *fscrypt_policy_to_inherit(struct inode *dir);
+
+#endif /* _FSCRYPT_PRIVATE_H */