Merge tag 'fscrypt_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/fscrypt (58f587cb) · Commits · 戴 / test

fs/crypto/Kconfig

+1 −0

Original line number	Diff line number	Diff line
		@@ -7,6 +7,7 @@ config FS_ENCRYPTION
		select CRYPTO_XTS
		select CRYPTO_CTS
		select CRYPTO_CTR
		select CRYPTO_SHA256
		select KEYS
		help
		Enable encryption of files and directories. This

fs/crypto/crypto.c

+16 −7

Original line number	Diff line number	Diff line
		@@ -26,6 +26,7 @@
		#include <linux/ratelimit.h>
		#include <linux/dcache.h>
		#include <linux/namei.h>
		#include <crypto/aes.h>
		#include "fscrypt_private.h"

		static unsigned int num_prealloc_crypto_pages = 32;
		@@ -147,8 +148,8 @@ int fscrypt_do_page_crypto(const struct inode *inode, fscrypt_direction_t rw,
		{
		struct {
		__le64 index;
		u8 padding[FS_XTS_TWEAK_SIZE - sizeof(__le64)];
		} xts_tweak;
		u8 padding[FS_IV_SIZE - sizeof(__le64)];
		} iv;
		struct skcipher_request *req = NULL;
		DECLARE_FS_COMPLETION_RESULT(ecr);
		struct scatterlist dst, src;
		@@ -158,6 +159,16 @@ int fscrypt_do_page_crypto(const struct inode *inode, fscrypt_direction_t rw,

		BUG_ON(len == 0);

		BUILD_BUG_ON(sizeof(iv) != FS_IV_SIZE);
		BUILD_BUG_ON(AES_BLOCK_SIZE != FS_IV_SIZE);
		iv.index = cpu_to_le64(lblk_num);
		memset(iv.padding, 0, sizeof(iv.padding));

		if (ci->ci_essiv_tfm != NULL) {
		crypto_cipher_encrypt_one(ci->ci_essiv_tfm, (u8 *)&iv,
		(u8 *)&iv);
		}

		req = skcipher_request_alloc(tfm, gfp_flags);
		if (!req) {
		printk_ratelimited(KERN_ERR
		@@ -170,15 +181,11 @@ int fscrypt_do_page_crypto(const struct inode *inode, fscrypt_direction_t rw,
		req, CRYPTO_TFM_REQ_MAY_BACKLOG \| CRYPTO_TFM_REQ_MAY_SLEEP,
		page_crypt_complete, &ecr);

		BUILD_BUG_ON(sizeof(xts_tweak) != FS_XTS_TWEAK_SIZE);
		xts_tweak.index = cpu_to_le64(lblk_num);
		memset(xts_tweak.padding, 0, sizeof(xts_tweak.padding));

		sg_init_table(&dst, 1);
		sg_set_page(&dst, dest_page, len, offs);
		sg_init_table(&src, 1);
		sg_set_page(&src, src_page, len, offs);
		skcipher_request_set_crypt(req, &src, &dst, len, &xts_tweak);
		skcipher_request_set_crypt(req, &src, &dst, len, &iv);
		if (rw == FS_DECRYPT)
		res = crypto_skcipher_decrypt(req);
		else
		@@ -477,6 +484,8 @@ static void __exit fscrypt_exit(void)
		destroy_workqueue(fscrypt_read_workqueue);
		kmem_cache_destroy(fscrypt_ctx_cachep);
		kmem_cache_destroy(fscrypt_info_cachep);

		fscrypt_essiv_cleanup();
		}
		module_exit(fscrypt_exit);

fs/crypto/fname.c

+0 −9

Original line number	Diff line number	Diff line
		@@ -453,12 +453,3 @@ errout:
		return ret;
		}
		EXPORT_SYMBOL(fscrypt_setup_filename);

		void fscrypt_free_filename(struct fscrypt_name *fname)
		{
		kfree(fname->crypto_buf.name);
		fname->crypto_buf.name = NULL;
		fname->usr_fname = NULL;
		fname->disk_name.name = NULL;
		}
		EXPORT_SYMBOL(fscrypt_free_filename);

fs/crypto/fscrypt_private.h

+8 −1

Original line number	Diff line number	Diff line
		@@ -12,10 +12,13 @@
		#define _FSCRYPT_PRIVATE_H

		#include <linux/fscrypt_supp.h>
		#include <crypto/hash.h>

		/* Encryption parameters */
		#define FS_XTS_TWEAK_SIZE 16
		#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
		@@ -54,6 +57,7 @@ struct fscrypt_info {
		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];
		};

		@@ -87,4 +91,7 @@ extern int fscrypt_do_page_crypto(const struct inode *inode,
		extern struct page fscrypt_alloc_bounce_page(struct fscrypt_ctx ctx,
		gfp_t gfp_flags);

		/* keyinfo.c */
		extern void __exit fscrypt_essiv_cleanup(void);

		#endif /* _FSCRYPT_PRIVATE_H */

fs/crypto/keyinfo.c

+135 −38

Original line number	Diff line number	Diff line
		@@ -10,8 +10,13 @@

		#include <keys/user-type.h>
		#include <linux/scatterlist.h>
		#include <linux/ratelimit.h>
		#include <crypto/aes.h>
		#include <crypto/sha.h>
		#include "fscrypt_private.h"

		static struct crypto_shash *essiv_hash_tfm;

		static void derive_crypt_complete(struct crypto_async_request *req, int rc)
		{
		struct fscrypt_completion_result *ecr = req->data;
		@@ -27,13 +32,13 @@ static void derive_crypt_complete(struct crypto_async_request *req, int rc)
		* derive_key_aes() - Derive a key using AES-128-ECB
		* @deriving_key: Encryption key used for derivation.
		* @source_key: Source key to which to apply derivation.
		* @derived_key: Derived key.
		* @derived_raw_key: Derived raw key.
		*
		* Return: Zero on success; non-zero otherwise.
		*/
		static int derive_key_aes(u8 deriving_key[FS_AES_128_ECB_KEY_SIZE],
		u8 source_key[FS_AES_256_XTS_KEY_SIZE],
		u8 derived_key[FS_AES_256_XTS_KEY_SIZE])
		const struct fscrypt_key *source_key,
		u8 derived_raw_key[FS_MAX_KEY_SIZE])
		{
		int res = 0;
		struct skcipher_request *req = NULL;
		@@ -60,10 +65,10 @@ static int derive_key_aes(u8 deriving_key[FS_AES_128_ECB_KEY_SIZE],
		if (res < 0)
		goto out;

		sg_init_one(&src_sg, source_key, FS_AES_256_XTS_KEY_SIZE);
		sg_init_one(&dst_sg, derived_key, FS_AES_256_XTS_KEY_SIZE);
		skcipher_request_set_crypt(req, &src_sg, &dst_sg,
		FS_AES_256_XTS_KEY_SIZE, NULL);
		sg_init_one(&src_sg, source_key->raw, source_key->size);
		sg_init_one(&dst_sg, derived_raw_key, source_key->size);
		skcipher_request_set_crypt(req, &src_sg, &dst_sg, source_key->size,
		NULL);
		res = crypto_skcipher_encrypt(req);
		if (res == -EINPROGRESS \|\| res == -EBUSY) {
		wait_for_completion(&ecr.completion);
		@@ -77,7 +82,7 @@ out:

		static int validate_user_key(struct fscrypt_info *crypt_info,
		struct fscrypt_context ctx, u8 raw_key,
		const char *prefix)
		const char *prefix, int min_keysize)
		{
		char *description;
		struct key *keyring_key;
		@@ -111,50 +116,60 @@ static int validate_user_key(struct fscrypt_info *crypt_info,
		master_key = (struct fscrypt_key *)ukp->data;
		BUILD_BUG_ON(FS_AES_128_ECB_KEY_SIZE != FS_KEY_DERIVATION_NONCE_SIZE);

		if (master_key->size != FS_AES_256_XTS_KEY_SIZE) {
		if (master_key->size < min_keysize \|\| master_key->size > FS_MAX_KEY_SIZE
		\|\| master_key->size % AES_BLOCK_SIZE != 0) {
		printk_once(KERN_WARNING
		"%s: key size incorrect: %d\n",
		__func__, master_key->size);
		res = -ENOKEY;
		goto out;
		}
		res = derive_key_aes(ctx->nonce, master_key->raw, raw_key);
		res = derive_key_aes(ctx->nonce, master_key, raw_key);
		out:
		up_read(&keyring_key->sem);
		key_put(keyring_key);
		return res;
		}

		static const struct {
		const char *cipher_str;
		int keysize;
		} available_modes[] = {
		[FS_ENCRYPTION_MODE_AES_256_XTS] = { "xts(aes)",
		FS_AES_256_XTS_KEY_SIZE },
		[FS_ENCRYPTION_MODE_AES_256_CTS] = { "cts(cbc(aes))",
		FS_AES_256_CTS_KEY_SIZE },
		[FS_ENCRYPTION_MODE_AES_128_CBC] = { "cbc(aes)",
		FS_AES_128_CBC_KEY_SIZE },
		[FS_ENCRYPTION_MODE_AES_128_CTS] = { "cts(cbc(aes))",
		FS_AES_128_CTS_KEY_SIZE },
		};

		static int determine_cipher_type(struct fscrypt_info ci, struct inode inode,
		const char *cipher_str_ret, int keysize_ret)
		{
		if (S_ISREG(inode->i_mode)) {
		if (ci->ci_data_mode == FS_ENCRYPTION_MODE_AES_256_XTS) {
		*cipher_str_ret = "xts(aes)";
		*keysize_ret = FS_AES_256_XTS_KEY_SIZE;
		return 0;
		}
		pr_warn_once("fscrypto: unsupported contents encryption mode "
		"%d for inode %lu\n",
		ci->ci_data_mode, inode->i_ino);
		return -ENOKEY;
		}
		u32 mode;

		if (S_ISDIR(inode->i_mode) \|\| S_ISLNK(inode->i_mode)) {
		if (ci->ci_filename_mode == FS_ENCRYPTION_MODE_AES_256_CTS) {
		*cipher_str_ret = "cts(cbc(aes))";
		*keysize_ret = FS_AES_256_CTS_KEY_SIZE;
		return 0;
		if (!fscrypt_valid_enc_modes(ci->ci_data_mode, ci->ci_filename_mode)) {
		pr_warn_ratelimited("fscrypt: inode %lu uses unsupported encryption modes (contents mode %d, filenames mode %d)\n",
		inode->i_ino,
		ci->ci_data_mode, ci->ci_filename_mode);
		return -EINVAL;
		}
		pr_warn_once("fscrypto: unsupported filenames encryption mode "
		"%d for inode %lu\n",
		ci->ci_filename_mode, inode->i_ino);
		return -ENOKEY;

		if (S_ISREG(inode->i_mode)) {
		mode = ci->ci_data_mode;
		} else if (S_ISDIR(inode->i_mode) \|\| S_ISLNK(inode->i_mode)) {
		mode = ci->ci_filename_mode;
		} else {
		WARN_ONCE(1, "fscrypt: filesystem tried to load encryption info for inode %lu, which is not encryptable (file type %d)\n",
		inode->i_ino, (inode->i_mode & S_IFMT));
		return -EINVAL;
		}

		pr_warn_once("fscrypto: unsupported file type %d for inode %lu\n",
		(inode->i_mode & S_IFMT), inode->i_ino);
		return -ENOKEY;
		*cipher_str_ret = available_modes[mode].cipher_str;
		*keysize_ret = available_modes[mode].keysize;
		return 0;
		}

		static void put_crypt_info(struct fscrypt_info *ci)
		@@ -163,9 +178,76 @@ static void put_crypt_info(struct fscrypt_info *ci)
		return;

		crypto_free_skcipher(ci->ci_ctfm);
		crypto_free_cipher(ci->ci_essiv_tfm);
		kmem_cache_free(fscrypt_info_cachep, ci);
		}

		static int derive_essiv_salt(const u8 key, int keysize, u8 salt)
		{
		struct crypto_shash *tfm = READ_ONCE(essiv_hash_tfm);

		/* init hash transform on demand */
		if (unlikely(!tfm)) {
		struct crypto_shash *prev_tfm;

		tfm = crypto_alloc_shash("sha256", 0, 0);
		if (IS_ERR(tfm)) {
		pr_warn_ratelimited("fscrypt: error allocating SHA-256 transform: %ld\n",
		PTR_ERR(tfm));
		return PTR_ERR(tfm);
		}
		prev_tfm = cmpxchg(&essiv_hash_tfm, NULL, tfm);
		if (prev_tfm) {
		crypto_free_shash(tfm);
		tfm = prev_tfm;
		}
		}

		{
		SHASH_DESC_ON_STACK(desc, tfm);
		desc->tfm = tfm;
		desc->flags = 0;

		return crypto_shash_digest(desc, key, keysize, salt);
		}
		}

		static int init_essiv_generator(struct fscrypt_info ci, const u8 raw_key,
		int keysize)
		{
		int err;
		struct crypto_cipher *essiv_tfm;
		u8 salt[SHA256_DIGEST_SIZE];

		essiv_tfm = crypto_alloc_cipher("aes", 0, 0);
		if (IS_ERR(essiv_tfm))
		return PTR_ERR(essiv_tfm);

		ci->ci_essiv_tfm = essiv_tfm;

		err = derive_essiv_salt(raw_key, keysize, salt);
		if (err)
		goto out;

		/*
		* Using SHA256 to derive the salt/key will result in AES-256 being
		* used for IV generation. File contents encryption will still use the
		* configured keysize (AES-128) nevertheless.
		*/
		err = crypto_cipher_setkey(essiv_tfm, salt, sizeof(salt));
		if (err)
		goto out;

		out:
		memzero_explicit(salt, sizeof(salt));
		return err;
		}

		void __exit fscrypt_essiv_cleanup(void)
		{
		crypto_free_shash(essiv_hash_tfm);
		}

		int fscrypt_get_encryption_info(struct inode *inode)
		{
		struct fscrypt_info *crypt_info;
		@@ -212,6 +294,7 @@ int fscrypt_get_encryption_info(struct inode *inode)
		crypt_info->ci_data_mode = ctx.contents_encryption_mode;
		crypt_info->ci_filename_mode = ctx.filenames_encryption_mode;
		crypt_info->ci_ctfm = NULL;
		crypt_info->ci_essiv_tfm = NULL;
		memcpy(crypt_info->ci_master_key, ctx.master_key_descriptor,
		sizeof(crypt_info->ci_master_key));

		@@ -228,10 +311,12 @@ int fscrypt_get_encryption_info(struct inode *inode)
		if (!raw_key)
		goto out;

		res = validate_user_key(crypt_info, &ctx, raw_key, FS_KEY_DESC_PREFIX);
		res = validate_user_key(crypt_info, &ctx, raw_key, FS_KEY_DESC_PREFIX,
		keysize);
		if (res && inode->i_sb->s_cop->key_prefix) {
		int res2 = validate_user_key(crypt_info, &ctx, raw_key,
		inode->i_sb->s_cop->key_prefix);
		inode->i_sb->s_cop->key_prefix,
		keysize);
		if (res2) {
		if (res2 == -ENOKEY)
		res = -ENOKEY;
		@@ -243,18 +328,30 @@ int fscrypt_get_encryption_info(struct inode *inode)
		ctfm = crypto_alloc_skcipher(cipher_str, 0, 0);
		if (!ctfm \|\| IS_ERR(ctfm)) {
		res = ctfm ? PTR_ERR(ctfm) : -ENOMEM;
		printk(KERN_DEBUG
		"%s: error %d (inode %u) allocating crypto tfm\n",
		__func__, res, (unsigned) inode->i_ino);
		pr_debug("%s: error %d (inode %lu) allocating crypto tfm\n",
		__func__, res, inode->i_ino);
		goto out;
		}
		crypt_info->ci_ctfm = ctfm;
		crypto_skcipher_clear_flags(ctfm, ~0);
		crypto_skcipher_set_flags(ctfm, CRYPTO_TFM_REQ_WEAK_KEY);
		/*
		* if the provided key is longer than keysize, we use the first
		* keysize bytes of the derived key only
		*/
		res = crypto_skcipher_setkey(ctfm, raw_key, keysize);
		if (res)
		goto out;

		if (S_ISREG(inode->i_mode) &&
		crypt_info->ci_data_mode == FS_ENCRYPTION_MODE_AES_128_CBC) {
		res = init_essiv_generator(crypt_info, raw_key, keysize);
		if (res) {
		pr_debug("%s: error %d (inode %lu) allocating essiv tfm\n",
		__func__, res, inode->i_ino);
		goto out;
		}
		}
		if (cmpxchg(&inode->i_crypt_info, NULL, crypt_info) == NULL)
		crypt_info = NULL;
		out:

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