@@ -24,3 +24,9 @@ config FS_ENCRYPTION_ALGS
select CRYPTO_SHA256
select CRYPTO_SHA512
select CRYPTO_XTS
+
+config FS_ENCRYPTION_INLINE_CRYPT
+ bool "Enable fscrypt to use inline crypto"
+ depends on FS_ENCRYPTION && BLK_INLINE_ENCRYPTION
+ help
+ Enable fscrypt to use inline encryption hardware if available.
@@ -11,3 +11,4 @@ fscrypto-y := crypto.o \
policy.o
fscrypto-$(CONFIG_BLOCK) += bio.o
+fscrypto-$(CONFIG_FS_ENCRYPTION_INLINE_CRYPT) += inline_crypt.o
@@ -41,6 +41,52 @@ void fscrypt_decrypt_bio(struct bio *bio)
}
EXPORT_SYMBOL(fscrypt_decrypt_bio);
+static int fscrypt_zeroout_range_inline_crypt(const struct inode *inode,
+ pgoff_t lblk, sector_t pblk,
+ unsigned int len)
+{
+ const unsigned int blockbits = inode->i_blkbits;
+ const unsigned int blocks_per_page = 1 << (PAGE_SHIFT - blockbits);
+ struct bio *bio;
+ int ret, err = 0;
+ int num_pages = 0;
+
+ /* This always succeeds since __GFP_DIRECT_RECLAIM is set. */
+ bio = bio_alloc(GFP_NOFS, BIO_MAX_PAGES);
+
+ while (len) {
+ unsigned int blocks_this_page = min(len, blocks_per_page);
+ unsigned int bytes_this_page = blocks_this_page << blockbits;
+
+ if (num_pages == 0) {
+ fscrypt_set_bio_crypt_ctx(bio, inode, lblk, GFP_NOFS);
+ bio_set_dev(bio, inode->i_sb->s_bdev);
+ bio->bi_iter.bi_sector =
+ pblk << (blockbits - SECTOR_SHIFT);
+ bio_set_op_attrs(bio, REQ_OP_WRITE, 0);
+ }
+ ret = bio_add_page(bio, ZERO_PAGE(0), bytes_this_page, 0);
+ if (WARN_ON(ret != bytes_this_page)) {
+ err = -EIO;
+ goto out;
+ }
+ num_pages++;
+ len -= blocks_this_page;
+ lblk += blocks_this_page;
+ pblk += blocks_this_page;
+ if (num_pages == BIO_MAX_PAGES || !len) {
+ err = submit_bio_wait(bio);
+ if (err)
+ goto out;
+ bio_reset(bio);
+ num_pages = 0;
+ }
+ }
+out:
+ bio_put(bio);
+ return err;
+}
+
/**
* fscrypt_zeroout_range() - zero out a range of blocks in an encrypted file
* @inode: the file's inode
@@ -75,6 +121,10 @@ int fscrypt_zeroout_range(const struct inode *inode, pgoff_t lblk,
if (len == 0)
return 0;
+ if (fscrypt_inode_uses_inline_crypto(inode))
+ return fscrypt_zeroout_range_inline_crypt(inode, lblk, pblk,
+ len);
+
BUILD_BUG_ON(ARRAY_SIZE(pages) > BIO_MAX_PAGES);
nr_pages = min_t(unsigned int, ARRAY_SIZE(pages),
(len + blocks_per_page - 1) >> blocks_per_page_bits);
@@ -95,7 +95,7 @@ int fscrypt_crypt_block(const struct inode *inode, fscrypt_direction_t rw,
DECLARE_CRYPTO_WAIT(wait);
struct scatterlist dst, src;
struct fscrypt_info *ci = inode->i_crypt_info;
- struct crypto_skcipher *tfm = ci->ci_ctfm;
+ struct crypto_skcipher *tfm = ci->ci_key.tfm;
int res = 0;
if (WARN_ON_ONCE(len <= 0))
@@ -117,7 +117,7 @@ int fscrypt_fname_encrypt(const struct inode *inode, const struct qstr *iname,
struct skcipher_request *req = NULL;
DECLARE_CRYPTO_WAIT(wait);
const struct fscrypt_info *ci = inode->i_crypt_info;
- struct crypto_skcipher *tfm = ci->ci_ctfm;
+ struct crypto_skcipher *tfm = ci->ci_key.tfm;
union fscrypt_iv iv;
struct scatterlist sg;
int res;
@@ -170,7 +170,7 @@ static int fname_decrypt(const struct inode *inode,
DECLARE_CRYPTO_WAIT(wait);
struct scatterlist src_sg, dst_sg;
const struct fscrypt_info *ci = inode->i_crypt_info;
- struct crypto_skcipher *tfm = ci->ci_ctfm;
+ struct crypto_skcipher *tfm = ci->ci_key.tfm;
union fscrypt_iv iv;
int res;
@@ -14,6 +14,7 @@
#include <linux/fscrypt.h>
#include <linux/siphash.h>
#include <crypto/hash.h>
+#include <linux/blk-crypto.h>
#define CONST_STRLEN(str) (sizeof(str) - 1)
@@ -166,6 +167,20 @@ struct fscrypt_symlink_data {
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 fscrypt_blk_crypto_key *blk_key;
+#endif
+};
+
/*
* fscrypt_info - the "encryption key" for an inode
*
@@ -175,12 +190,20 @@ struct fscrypt_symlink_data {
*/
struct fscrypt_info {
- /* The actual crypto transform used for encryption and decryption */
- struct crypto_skcipher *ci_ctfm;
+ /* The key in a form prepared for actual encryption/decryption */
+ struct fscrypt_prepared_key ci_key;
/* True if the 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.
@@ -205,7 +228,7 @@ struct fscrypt_info {
/*
* If non-NULL, then encryption is done using the master key directly
- * and ci_ctfm will equal ci_direct_key->dk_ctfm.
+ * and ci_key will equal ci_direct_key->dk_key.
*/
struct fscrypt_direct_key *ci_direct_key;
@@ -258,6 +281,7 @@ union fscrypt_iv {
u8 nonce[FS_KEY_DERIVATION_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,
@@ -300,6 +324,76 @@ extern int fscrypt_hkdf_expand(const struct fscrypt_hkdf *hkdf, u8 context,
extern void fscrypt_destroy_hkdf(struct fscrypt_hkdf *hkdf);
+/* inline_crypt.c */
+#ifdef CONFIG_FS_ENCRYPTION_INLINE_CRYPT
+extern void fscrypt_select_encryption_impl(struct fscrypt_info *ci);
+
+static inline bool
+fscrypt_using_inline_encryption(const struct fscrypt_info *ci)
+{
+ return ci->ci_inlinecrypt;
+}
+
+extern int fscrypt_prepare_inline_crypt_key(
+ struct fscrypt_prepared_key *prep_key,
+ const u8 *raw_key,
+ const struct fscrypt_info *ci);
+
+extern void fscrypt_destroy_inline_crypt_key(
+ 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 READ_ONCE() here pairs with the smp_store_release() in
+ * fscrypt_prepare_key(). (This only matters for the per-mode keys,
+ * which are shared by multiple inodes.)
+ */
+ if (fscrypt_using_inline_encryption(ci))
+ return READ_ONCE(prep_key->blk_key) != NULL;
+ return READ_ONCE(prep_key->tfm) != NULL;
+}
+
+#else /* CONFIG_FS_ENCRYPTION_INLINE_CRYPT */
+
+static inline void fscrypt_select_encryption_impl(struct fscrypt_info *ci)
+{
+}
+
+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 fscrypt_prepared_key *prep_key)
+{
+}
+
+static inline bool
+fscrypt_is_key_prepared(struct fscrypt_prepared_key *prep_key,
+ const struct fscrypt_info *ci)
+{
+ return READ_ONCE(prep_key->tfm) != NULL;
+}
+#endif /* !CONFIG_FS_ENCRYPTION_INLINE_CRYPT */
+
/* keyring.c */
/*
@@ -389,14 +483,11 @@ struct fscrypt_master_key {
struct list_head mk_decrypted_inodes;
spinlock_t mk_decrypted_inodes_lock;
- /* Crypto API transforms for DIRECT_KEY policies, allocated on-demand */
- struct crypto_skcipher *mk_direct_tfms[__FSCRYPT_MODE_MAX + 1];
+ /* Per-mode keys for DIRECT_KEY policies, allocated on-demand */
+ struct fscrypt_prepared_key mk_direct_keys[__FSCRYPT_MODE_MAX + 1];
- /*
- * Crypto API transforms for filesystem-layer implementation of
- * IV_INO_LBLK_64 policies, allocated on-demand.
- */
- struct crypto_skcipher *mk_iv_ino_lblk_64_tfms[__FSCRYPT_MODE_MAX + 1];
+ /* Per-mode keys for IV_INO_LBLK_64 policies, allocated on-demand */
+ struct fscrypt_prepared_key mk_iv_ino_lblk_64_keys[__FSCRYPT_MODE_MAX + 1];
} __randomize_layout;
@@ -453,13 +544,16 @@ struct fscrypt_mode {
int keysize;
int ivsize;
int logged_impl_name;
+ enum blk_crypto_mode_num blk_crypto_mode;
};
extern struct fscrypt_mode fscrypt_modes[];
-extern struct crypto_skcipher *
-fscrypt_allocate_skcipher(struct fscrypt_mode *mode, const u8 *raw_key,
- const struct inode *inode);
+extern int fscrypt_prepare_key(struct fscrypt_prepared_key *prep_key,
+ const u8 *raw_key,
+ const struct fscrypt_info *ci);
+
+extern void fscrypt_destroy_prepared_key(struct fscrypt_prepared_key *prep_key);
extern int fscrypt_set_per_file_enc_key(struct fscrypt_info *ci,
const u8 *raw_key);
new file mode 100644
@@ -0,0 +1,365 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Inline encryption support for fscrypt
+ *
+ * Copyright 2019 Google LLC
+ */
+
+/*
+ * With "inline encryption", the block layer handles the decryption/encryption
+ * as part of the bio, instead of the filesystem doing the crypto itself via
+ * crypto API. See Documentation/block/inline-encryption.rst. fscrypt still
+ * provides the key and IV to use.
+ */
+
+#include <linux/blk-crypto.h>
+#include <linux/blkdev.h>
+#include <linux/buffer_head.h>
+#include <linux/sched/mm.h>
+
+#include "fscrypt_private.h"
+
+struct fscrypt_blk_crypto_key {
+ struct blk_crypto_key base;
+ int num_devs;
+ struct request_queue *devs[];
+};
+
+static int fscrypt_get_num_devices(struct super_block *sb)
+{
+ if (sb->s_cop->get_num_devices)
+ return sb->s_cop->get_num_devices(sb);
+ return 1;
+}
+
+static void fscrypt_get_devices(struct super_block *sb, int num_devs,
+ struct request_queue **devs)
+{
+ if (num_devs == 1)
+ devs[0] = bdev_get_queue(sb->s_bdev);
+ else
+ sb->s_cop->get_devices(sb, devs);
+}
+
+static unsigned int fscrypt_get_dun_bytes(const struct fscrypt_info *ci)
+{
+ unsigned int dun_bytes = 8;
+
+ if (fscrypt_policy_flags(&ci->ci_policy) &
+ FSCRYPT_POLICY_FLAG_DIRECT_KEY)
+ dun_bytes += FS_KEY_DERIVATION_NONCE_SIZE;
+
+ return dun_bytes;
+}
+
+/* Enable inline encryption for this file if supported. */
+void fscrypt_select_encryption_impl(struct fscrypt_info *ci)
+{
+ const struct inode *inode = ci->ci_inode;
+ struct super_block *sb = inode->i_sb;
+ struct blk_crypto_config crypto_cfg;
+ int num_devs;
+ struct request_queue **devs;
+ int i;
+
+ /* The file must need contents encryption, not filenames encryption */
+ if (!fscrypt_needs_contents_encryption(inode))
+ return;
+
+ /* The crypto mode must be valid */
+ if (ci->ci_mode->blk_crypto_mode == BLK_ENCRYPTION_MODE_INVALID)
+ return;
+
+ /* The filesystem must be mounted with -o inlinecrypt */
+ if (!(sb->s_flags & SB_INLINECRYPT))
+ return;
+
+ /*
+ * blk-crypto must support the crypto configuration we'll use for the
+ * inode on all devices in the sb
+ */
+ crypto_cfg.crypto_mode = ci->ci_mode->blk_crypto_mode;
+ crypto_cfg.data_unit_size = sb->s_blocksize;
+ crypto_cfg.dun_bytes = fscrypt_get_dun_bytes(ci);
+ num_devs = fscrypt_get_num_devices(sb);
+ devs = kmalloc_array(num_devs, sizeof(*devs), GFP_NOFS);
+ if (!devs)
+ return;
+ fscrypt_get_devices(sb, num_devs, devs);
+
+ for (i = 0; i < num_devs; i++) {
+ if (!blk_crypto_config_supported(devs[i], &crypto_cfg))
+ goto out_free_devs;
+ }
+
+ ci->ci_inlinecrypt = true;
+out_free_devs:
+ kfree(devs);
+}
+
+int fscrypt_prepare_inline_crypt_key(struct fscrypt_prepared_key *prep_key,
+ const u8 *raw_key,
+ const struct fscrypt_info *ci)
+{
+ const struct inode *inode = ci->ci_inode;
+ struct super_block *sb = inode->i_sb;
+ enum blk_crypto_mode_num crypto_mode = ci->ci_mode->blk_crypto_mode;
+ int num_devs = fscrypt_get_num_devices(sb);
+ int queue_refs = 0;
+ struct fscrypt_blk_crypto_key *blk_key;
+ int err;
+ int i;
+ unsigned int flags;
+
+ blk_key = kzalloc(struct_size(blk_key, devs, num_devs), GFP_NOFS);
+ if (!blk_key)
+ return -ENOMEM;
+
+ blk_key->num_devs = num_devs;
+ fscrypt_get_devices(sb, num_devs, blk_key->devs);
+
+ err = blk_crypto_init_key(&blk_key->base, raw_key, crypto_mode,
+ fscrypt_get_dun_bytes(ci), sb->s_blocksize);
+ if (err) {
+ fscrypt_err(inode, "error %d initializing blk-crypto key", err);
+ goto fail;
+ }
+
+ /*
+ * We have to start using blk-crypto on all the filesystem's devices.
+ * We also have to save all the request_queue's for later so that the
+ * key can be evicted from them. This is needed because some keys
+ * aren't destroyed until after the filesystem was already unmounted
+ * (namely, the per-mode keys in struct fscrypt_master_key).
+ */
+ for (i = 0; i < num_devs; i++) {
+ if (!blk_get_queue(blk_key->devs[i])) {
+ fscrypt_err(inode, "couldn't get request_queue");
+ err = -EAGAIN;
+ goto fail;
+ }
+ queue_refs++;
+
+ flags = memalloc_nofs_save();
+ err = blk_crypto_start_using_key(&blk_key->base,
+ blk_key->devs[i]);
+ memalloc_nofs_restore(flags);
+ if (err) {
+ fscrypt_err(inode,
+ "error %d starting to use blk-crypto", err);
+ goto fail;
+ }
+ }
+ /*
+ * Pairs with READ_ONCE() in fscrypt_is_key_prepared(). (Only matters
+ * for the per-mode keys, which are shared by multiple inodes.)
+ */
+ smp_store_release(&prep_key->blk_key, blk_key);
+ return 0;
+
+fail:
+ for (i = 0; i < queue_refs; i++)
+ blk_put_queue(blk_key->devs[i]);
+ kzfree(blk_key);
+ return err;
+}
+
+void fscrypt_destroy_inline_crypt_key(struct fscrypt_prepared_key *prep_key)
+{
+ struct fscrypt_blk_crypto_key *blk_key = prep_key->blk_key;
+ int i;
+
+ if (blk_key) {
+ for (i = 0; i < blk_key->num_devs; i++) {
+ blk_crypto_evict_key(blk_key->devs[i], &blk_key->base);
+ blk_put_queue(blk_key->devs[i]);
+ }
+ kzfree(blk_key);
+ }
+}
+
+/**
+ * fscrypt_inode_uses_inline_crypto - test whether an inode uses inline
+ * encryption
+ * @inode: an inode
+ *
+ * Return: true if the inode requires file contents encryption and if the
+ * encryption should be done in the block layer via blk-crypto rather
+ * than in the filesystem layer.
+ */
+bool fscrypt_inode_uses_inline_crypto(const struct inode *inode)
+{
+ return fscrypt_needs_contents_encryption(inode) &&
+ inode->i_crypt_info->ci_inlinecrypt;
+}
+EXPORT_SYMBOL_GPL(fscrypt_inode_uses_inline_crypto);
+
+/**
+ * fscrypt_inode_uses_fs_layer_crypto - test whether an inode uses fs-layer
+ * encryption
+ * @inode: an inode
+ *
+ * Return: true if the inode requires file contents encryption and if the
+ * encryption should be done in the filesystem layer rather than in the
+ * block layer via blk-crypto.
+ */
+bool fscrypt_inode_uses_fs_layer_crypto(const struct inode *inode)
+{
+ return fscrypt_needs_contents_encryption(inode) &&
+ !inode->i_crypt_info->ci_inlinecrypt;
+}
+EXPORT_SYMBOL_GPL(fscrypt_inode_uses_fs_layer_crypto);
+
+static void fscrypt_generate_dun(const struct fscrypt_info *ci, u64 lblk_num,
+ u64 dun[BLK_CRYPTO_DUN_ARRAY_SIZE])
+{
+ union fscrypt_iv iv;
+ int i;
+
+ fscrypt_generate_iv(&iv, lblk_num, ci);
+
+ BUILD_BUG_ON(FSCRYPT_MAX_IV_SIZE > BLK_CRYPTO_MAX_IV_SIZE);
+ memset(dun, 0, BLK_CRYPTO_MAX_IV_SIZE);
+ for (i = 0; i < ci->ci_mode->ivsize/sizeof(dun[0]); i++)
+ dun[i] = le64_to_cpu(iv.dun[i]);
+}
+
+/**
+ * fscrypt_set_bio_crypt_ctx - prepare a file contents bio for inline encryption
+ * @bio: a bio which will eventually be submitted to the file
+ * @inode: the file's inode
+ * @first_lblk: the first file logical block number in the I/O
+ * @gfp_mask: memory allocation flags - these must be a waiting mask so that
+ * bio_crypt_set_ctx can't fail.
+ *
+ * If the contents of the file should be encrypted (or decrypted) with inline
+ * encryption, then assign the appropriate encryption context to the bio.
+ *
+ * Normally the bio should be newly allocated (i.e. no pages added yet), as
+ * otherwise fscrypt_mergeable_bio() won't work as intended.
+ *
+ * The encryption context will be freed automatically when the bio is freed.
+ */
+void fscrypt_set_bio_crypt_ctx(struct bio *bio, const struct inode *inode,
+ u64 first_lblk, gfp_t gfp_mask)
+{
+ const struct fscrypt_info *ci = inode->i_crypt_info;
+ u64 dun[BLK_CRYPTO_DUN_ARRAY_SIZE];
+
+ if (!fscrypt_inode_uses_inline_crypto(inode))
+ return;
+
+ fscrypt_generate_dun(ci, first_lblk, dun);
+ bio_crypt_set_ctx(bio, &ci->ci_key.blk_key->base, dun, gfp_mask);
+}
+EXPORT_SYMBOL_GPL(fscrypt_set_bio_crypt_ctx);
+
+/* Extract the inode and logical block number from a buffer_head. */
+static bool bh_get_inode_and_lblk_num(const struct buffer_head *bh,
+ const struct inode **inode_ret,
+ u64 *lblk_num_ret)
+{
+ struct page *page = bh->b_page;
+ const struct address_space *mapping;
+ const struct inode *inode;
+
+ /*
+ * The ext4 journal (jbd2) can submit a buffer_head it directly created
+ * for a non-pagecache page. fscrypt doesn't care about these.
+ */
+ mapping = page_mapping(page);
+ if (!mapping)
+ return false;
+ inode = mapping->host;
+
+ *inode_ret = inode;
+ *lblk_num_ret = ((u64)page->index << (PAGE_SHIFT - inode->i_blkbits)) +
+ (bh_offset(bh) >> inode->i_blkbits);
+ return true;
+}
+
+/**
+ * fscrypt_set_bio_crypt_ctx_bh - prepare a file contents bio for inline
+ * encryption
+ * @bio: a bio which will eventually be submitted to the file
+ * @first_bh: the first buffer_head for which I/O will be submitted
+ * @gfp_mask: memory allocation flags
+ *
+ * Same as fscrypt_set_bio_crypt_ctx(), except this takes a buffer_head instead
+ * of an inode and block number directly.
+ */
+void fscrypt_set_bio_crypt_ctx_bh(struct bio *bio,
+ const struct buffer_head *first_bh,
+ gfp_t gfp_mask)
+{
+ const struct inode *inode;
+ u64 first_lblk;
+
+ if (bh_get_inode_and_lblk_num(first_bh, &inode, &first_lblk))
+ fscrypt_set_bio_crypt_ctx(bio, inode, first_lblk, gfp_mask);
+}
+EXPORT_SYMBOL_GPL(fscrypt_set_bio_crypt_ctx_bh);
+
+/**
+ * fscrypt_mergeable_bio - test whether data can be added to a bio
+ * @bio: the bio being built up
+ * @inode: the inode for the next part of the I/O
+ * @next_lblk: the next file logical block number in the I/O
+ *
+ * When building a bio which may contain data which should undergo inline
+ * encryption (or decryption) via fscrypt, filesystems should call this function
+ * to ensure that the resulting bio contains only logically contiguous data.
+ * This will return false if the next part of the I/O cannot be merged with the
+ * bio because either the encryption key would be different or the encryption
+ * data unit numbers would be discontiguous.
+ *
+ * fscrypt_set_bio_crypt_ctx() must have already been called on the bio.
+ *
+ * Return: true iff the I/O is mergeable
+ */
+bool fscrypt_mergeable_bio(struct bio *bio, const struct inode *inode,
+ u64 next_lblk)
+{
+ const struct bio_crypt_ctx *bc = bio->bi_crypt_context;
+ u64 next_dun[BLK_CRYPTO_DUN_ARRAY_SIZE];
+
+ if (!!bc != fscrypt_inode_uses_inline_crypto(inode))
+ return false;
+ if (!bc)
+ return true;
+
+ /*
+ * Comparing the key pointers is good enough, as all I/O for each key
+ * uses the same pointer. I.e., there's currently no need to support
+ * merging requests where the keys are the same but the pointers differ.
+ */
+ if (bc->bc_key != &inode->i_crypt_info->ci_key.blk_key->base)
+ return false;
+
+ fscrypt_generate_dun(inode->i_crypt_info, next_lblk, next_dun);
+ return bio_crypt_dun_is_contiguous(bc, bio->bi_iter.bi_size, next_dun);
+}
+EXPORT_SYMBOL_GPL(fscrypt_mergeable_bio);
+
+/**
+ * fscrypt_mergeable_bio_bh - test whether data can be added to a bio
+ * @bio: the bio being built up
+ * @next_bh: the next buffer_head for which I/O will be submitted
+ *
+ * Same as fscrypt_mergeable_bio(), except this takes a buffer_head instead of
+ * an inode and block number directly.
+ *
+ * Return: true iff the I/O is mergeable
+ */
+bool fscrypt_mergeable_bio_bh(struct bio *bio,
+ const struct buffer_head *next_bh)
+{
+ const struct inode *inode;
+ u64 next_lblk;
+
+ if (!bh_get_inode_and_lblk_num(next_bh, &inode, &next_lblk))
+ return !bio->bi_crypt_context;
+
+ return fscrypt_mergeable_bio(bio, inode, next_lblk);
+}
+EXPORT_SYMBOL_GPL(fscrypt_mergeable_bio_bh);
@@ -44,8 +44,8 @@ static void free_master_key(struct fscrypt_master_key *mk)
wipe_master_key_secret(&mk->mk_secret);
for (i = 0; i <= __FSCRYPT_MODE_MAX; i++) {
- crypto_free_skcipher(mk->mk_direct_tfms[i]);
- crypto_free_skcipher(mk->mk_iv_ino_lblk_64_tfms[i]);
+ fscrypt_destroy_prepared_key(&mk->mk_direct_keys[i]);
+ fscrypt_destroy_prepared_key(&mk->mk_iv_ino_lblk_64_keys[i]);
}
key_put(mk->mk_users);
@@ -19,6 +19,7 @@ struct fscrypt_mode fscrypt_modes[] = {
.cipher_str = "xts(aes)",
.keysize = 64,
.ivsize = 16,
+ .blk_crypto_mode = BLK_ENCRYPTION_MODE_AES_256_XTS,
},
[FSCRYPT_MODE_AES_256_CTS] = {
.friendly_name = "AES-256-CTS-CBC",
@@ -31,6 +32,7 @@ struct fscrypt_mode fscrypt_modes[] = {
.cipher_str = "essiv(cbc(aes),sha256)",
.keysize = 16,
.ivsize = 16,
+ .blk_crypto_mode = BLK_ENCRYPTION_MODE_AES_128_CBC_ESSIV,
},
[FSCRYPT_MODE_AES_128_CTS] = {
.friendly_name = "AES-128-CTS-CBC",
@@ -43,6 +45,7 @@ struct fscrypt_mode fscrypt_modes[] = {
.cipher_str = "adiantum(xchacha12,aes)",
.keysize = 32,
.ivsize = 32,
+ .blk_crypto_mode = BLK_ENCRYPTION_MODE_ADIANTUM,
},
};
@@ -62,9 +65,9 @@ select_encryption_mode(const union fscrypt_policy *policy,
}
/* Create a symmetric cipher object for the given encryption mode and key */
-struct crypto_skcipher *fscrypt_allocate_skcipher(struct fscrypt_mode *mode,
- const u8 *raw_key,
- const struct inode *inode)
+static struct crypto_skcipher *
+fscrypt_allocate_skcipher(struct fscrypt_mode *mode, const u8 *raw_key,
+ const struct inode *inode)
{
struct crypto_skcipher *tfm;
int err;
@@ -107,30 +110,55 @@ struct crypto_skcipher *fscrypt_allocate_skcipher(struct fscrypt_mode *mode,
return ERR_PTR(err);
}
-/* Given a per-file encryption key, set up the file's crypto transform object */
-int fscrypt_set_per_file_enc_key(struct fscrypt_info *ci, const u8 *raw_key)
+/*
+ * Prepare the crypto transform object or blk-crypto key in @prep_key, given the
+ * raw key, encryption mode, and flag indicating which encryption implementation
+ * (fs-layer or blk-crypto) will be used.
+ */
+int fscrypt_prepare_key(struct fscrypt_prepared_key *prep_key,
+ const u8 *raw_key, const struct fscrypt_info *ci)
{
struct crypto_skcipher *tfm;
+ if (fscrypt_using_inline_encryption(ci))
+ return fscrypt_prepare_inline_crypt_key(prep_key, raw_key, ci);
+
tfm = fscrypt_allocate_skcipher(ci->ci_mode, raw_key, ci->ci_inode);
if (IS_ERR(tfm))
return PTR_ERR(tfm);
+ /*
+ * Pairs with READ_ONCE() in fscrypt_is_key_prepared(). (Only matters
+ * for the per-mode keys, which are shared by multiple inodes.)
+ */
+ smp_store_release(&prep_key->tfm, tfm);
+ return 0;
+}
+
+/* Destroy a crypto transform object and/or blk-crypto key. */
+void fscrypt_destroy_prepared_key(struct fscrypt_prepared_key *prep_key)
+{
+ crypto_free_skcipher(prep_key->tfm);
+ fscrypt_destroy_inline_crypt_key(prep_key);
+}
- ci->ci_ctfm = tfm;
+/* Given a per-file encryption key, set up the file's crypto transform object */
+int fscrypt_set_per_file_enc_key(struct fscrypt_info *ci, const u8 *raw_key)
+{
ci->ci_owns_key = true;
- return 0;
+ return fscrypt_prepare_key(&ci->ci_key, raw_key, ci);
}
static int setup_per_mode_enc_key(struct fscrypt_info *ci,
struct fscrypt_master_key *mk,
- struct crypto_skcipher **tfms,
+ struct fscrypt_prepared_key *keys,
u8 hkdf_context, bool include_fs_uuid)
{
+ static DEFINE_MUTEX(mode_key_setup_mutex);
const struct inode *inode = ci->ci_inode;
const struct super_block *sb = inode->i_sb;
struct fscrypt_mode *mode = ci->ci_mode;
const u8 mode_num = mode - fscrypt_modes;
- struct crypto_skcipher *tfm, *prev_tfm;
+ struct fscrypt_prepared_key *prep_key;
u8 mode_key[FSCRYPT_MAX_KEY_SIZE];
u8 hkdf_info[sizeof(mode_num) + sizeof(sb->s_uuid)];
unsigned int hkdf_infolen = 0;
@@ -139,10 +167,16 @@ static int setup_per_mode_enc_key(struct fscrypt_info *ci,
if (WARN_ON(mode_num > __FSCRYPT_MODE_MAX))
return -EINVAL;
- /* pairs with cmpxchg() below */
- tfm = READ_ONCE(tfms[mode_num]);
- if (likely(tfm != NULL))
- goto done;
+ prep_key = &keys[mode_num];
+ if (fscrypt_is_key_prepared(prep_key, ci)) {
+ ci->ci_key = *prep_key;
+ return 0;
+ }
+
+ mutex_lock(&mode_key_setup_mutex);
+
+ if (fscrypt_is_key_prepared(prep_key, ci))
+ goto done_unlock;
BUILD_BUG_ON(sizeof(mode_num) != 1);
BUILD_BUG_ON(sizeof(sb->s_uuid) != 16);
@@ -157,21 +191,17 @@ static int setup_per_mode_enc_key(struct fscrypt_info *ci,
hkdf_context, hkdf_info, hkdf_infolen,
mode_key, mode->keysize);
if (err)
- return err;
- tfm = fscrypt_allocate_skcipher(mode, mode_key, inode);
+ goto out_unlock;
+ err = fscrypt_prepare_key(prep_key, mode_key, ci);
memzero_explicit(mode_key, mode->keysize);
- if (IS_ERR(tfm))
- return PTR_ERR(tfm);
-
- /* pairs with READ_ONCE() above */
- prev_tfm = cmpxchg(&tfms[mode_num], NULL, tfm);
- if (prev_tfm != NULL) {
- crypto_free_skcipher(tfm);
- tfm = prev_tfm;
- }
-done:
- ci->ci_ctfm = tfm;
- return 0;
+ if (err)
+ goto out_unlock;
+done_unlock:
+ ci->ci_key = *prep_key;
+ err = 0;
+out_unlock:
+ mutex_unlock(&mode_key_setup_mutex);
+ return err;
}
int fscrypt_derive_dirhash_key(struct fscrypt_info *ci,
@@ -203,7 +233,7 @@ static int fscrypt_setup_v2_file_key(struct fscrypt_info *ci,
* encryption key. This ensures that the master key is
* consistently used only for HKDF, avoiding key reuse issues.
*/
- err = setup_per_mode_enc_key(ci, mk, mk->mk_direct_tfms,
+ err = setup_per_mode_enc_key(ci, mk, mk->mk_direct_keys,
HKDF_CONTEXT_DIRECT_KEY, false);
} else if (ci->ci_policy.v2.flags &
FSCRYPT_POLICY_FLAG_IV_INO_LBLK_64) {
@@ -213,7 +243,7 @@ static int fscrypt_setup_v2_file_key(struct fscrypt_info *ci,
* the IVs. This format is optimized for use with inline
* encryption hardware compliant with the UFS or eMMC standards.
*/
- err = setup_per_mode_enc_key(ci, mk, mk->mk_iv_ino_lblk_64_tfms,
+ err = setup_per_mode_enc_key(ci, mk, mk->mk_iv_ino_lblk_64_keys,
HKDF_CONTEXT_IV_INO_LBLK_64_KEY,
true);
} else {
@@ -261,6 +291,8 @@ static int setup_file_encryption_key(struct fscrypt_info *ci,
struct fscrypt_key_specifier mk_spec;
int err;
+ fscrypt_select_encryption_impl(ci);
+
switch (ci->ci_policy.version) {
case FSCRYPT_POLICY_V1:
mk_spec.type = FSCRYPT_KEY_SPEC_TYPE_DESCRIPTOR;
@@ -353,7 +385,7 @@ static void put_crypt_info(struct fscrypt_info *ci)
if (ci->ci_direct_key)
fscrypt_put_direct_key(ci->ci_direct_key);
else if (ci->ci_owns_key)
- crypto_free_skcipher(ci->ci_ctfm);
+ fscrypt_destroy_prepared_key(&ci->ci_key);
key = ci->ci_master_key;
if (key) {
@@ -146,7 +146,7 @@ struct fscrypt_direct_key {
struct hlist_node dk_node;
refcount_t dk_refcount;
const struct fscrypt_mode *dk_mode;
- struct crypto_skcipher *dk_ctfm;
+ struct fscrypt_prepared_key dk_key;
u8 dk_descriptor[FSCRYPT_KEY_DESCRIPTOR_SIZE];
u8 dk_raw[FSCRYPT_MAX_KEY_SIZE];
};
@@ -154,7 +154,7 @@ struct fscrypt_direct_key {
static void free_direct_key(struct fscrypt_direct_key *dk)
{
if (dk) {
- crypto_free_skcipher(dk->dk_ctfm);
+ fscrypt_destroy_prepared_key(&dk->dk_key);
kzfree(dk);
}
}
@@ -199,6 +199,8 @@ find_or_insert_direct_key(struct fscrypt_direct_key *to_insert,
continue;
if (ci->ci_mode != dk->dk_mode)
continue;
+ if (!fscrypt_is_key_prepared(&dk->dk_key, ci))
+ continue;
if (crypto_memneq(raw_key, dk->dk_raw, ci->ci_mode->keysize))
continue;
/* using existing tfm with same (descriptor, mode, raw_key) */
@@ -231,13 +233,9 @@ fscrypt_get_direct_key(const struct fscrypt_info *ci, const u8 *raw_key)
return ERR_PTR(-ENOMEM);
refcount_set(&dk->dk_refcount, 1);
dk->dk_mode = ci->ci_mode;
- dk->dk_ctfm = fscrypt_allocate_skcipher(ci->ci_mode, raw_key,
- ci->ci_inode);
- if (IS_ERR(dk->dk_ctfm)) {
- err = PTR_ERR(dk->dk_ctfm);
- dk->dk_ctfm = NULL;
+ err = fscrypt_prepare_key(&dk->dk_key, raw_key, ci);
+ if (err)
goto err_free_dk;
- }
memcpy(dk->dk_descriptor, ci->ci_policy.v1.master_key_descriptor,
FSCRYPT_KEY_DESCRIPTOR_SIZE);
memcpy(dk->dk_raw, raw_key, ci->ci_mode->keysize);
@@ -259,7 +257,7 @@ static int setup_v1_file_key_direct(struct fscrypt_info *ci,
if (IS_ERR(dk))
return PTR_ERR(dk);
ci->ci_direct_key = dk;
- ci->ci_ctfm = dk->dk_ctfm;
+ ci->ci_key = dk->dk_key;
return 0;
}
@@ -64,6 +64,9 @@ struct fscrypt_operations {
bool (*has_stable_inodes)(struct super_block *sb);
void (*get_ino_and_lblk_bits)(struct super_block *sb,
int *ino_bits_ret, int *lblk_bits_ret);
+ int (*get_num_devices)(struct super_block *sb);
+ void (*get_devices)(struct super_block *sb,
+ struct request_queue **devs);
};
static inline bool fscrypt_has_encryption_key(const struct inode *inode)
@@ -503,6 +506,60 @@ static inline void fscrypt_set_ops(struct super_block *sb,
#endif /* !CONFIG_FS_ENCRYPTION */
+/* inline_crypt.c */
+#ifdef CONFIG_FS_ENCRYPTION_INLINE_CRYPT
+extern bool fscrypt_inode_uses_inline_crypto(const struct inode *inode);
+
+extern bool fscrypt_inode_uses_fs_layer_crypto(const struct inode *inode);
+
+extern void fscrypt_set_bio_crypt_ctx(struct bio *bio,
+ const struct inode *inode,
+ u64 first_lblk, gfp_t gfp_mask);
+
+extern void fscrypt_set_bio_crypt_ctx_bh(struct bio *bio,
+ const struct buffer_head *first_bh,
+ gfp_t gfp_mask);
+
+extern bool fscrypt_mergeable_bio(struct bio *bio, const struct inode *inode,
+ u64 next_lblk);
+
+extern bool fscrypt_mergeable_bio_bh(struct bio *bio,
+ const struct buffer_head *next_bh);
+
+#else /* CONFIG_FS_ENCRYPTION_INLINE_CRYPT */
+static inline bool fscrypt_inode_uses_inline_crypto(const struct inode *inode)
+{
+ return false;
+}
+
+static inline bool fscrypt_inode_uses_fs_layer_crypto(const struct inode *inode)
+{
+ return fscrypt_needs_contents_encryption(inode);
+}
+
+static inline void fscrypt_set_bio_crypt_ctx(struct bio *bio,
+ const struct inode *inode,
+ u64 first_lblk, gfp_t gfp_mask) { }
+
+static inline void fscrypt_set_bio_crypt_ctx_bh(
+ struct bio *bio,
+ const struct buffer_head *first_bh,
+ gfp_t gfp_mask) { }
+
+static inline bool fscrypt_mergeable_bio(struct bio *bio,
+ const struct inode *inode,
+ u64 next_lblk)
+{
+ return true;
+}
+
+static inline bool fscrypt_mergeable_bio_bh(struct bio *bio,
+ const struct buffer_head *next_bh)
+{
+ return true;
+}
+#endif /* !CONFIG_FS_ENCRYPTION_INLINE_CRYPT */
+
/**
* fscrypt_require_key - require an inode's encryption key
* @inode: the inode we need the key for