diff options
Diffstat (limited to 'fs/crypto/keysetup.c')
| -rw-r--r-- | fs/crypto/keysetup.c | 70 |
1 files changed, 48 insertions, 22 deletions
diff --git a/fs/crypto/keysetup.c b/fs/crypto/keysetup.c index 1129adfa097d..99d3e0d07fc6 100644 --- a/fs/crypto/keysetup.c +++ b/fs/crypto/keysetup.c @@ -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, }, }; @@ -64,9 +67,9 @@ 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; @@ -109,30 +112,54 @@ err_free_tfm: 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_enc_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) { 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; + 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; @@ -141,16 +168,15 @@ static int setup_per_mode_enc_key(struct fscrypt_info *ci, if (WARN_ON(mode_num > __FSCRYPT_MODE_MAX)) return -EINVAL; - /* pairs with smp_store_release() below */ - tfm = READ_ONCE(tfms[mode_num]); - if (likely(tfm != NULL)) { - ci->ci_ctfm = tfm; + prep_key = &keys[mode_num]; + if (fscrypt_is_key_prepared(prep_key, ci)) { + ci->ci_enc_key = *prep_key; return 0; } mutex_lock(&fscrypt_mode_key_setup_mutex); - if (tfms[mode_num]) + if (fscrypt_is_key_prepared(prep_key, ci)) goto done_unlock; BUILD_BUG_ON(sizeof(mode_num) != 1); @@ -167,16 +193,12 @@ static int setup_per_mode_enc_key(struct fscrypt_info *ci, mode_key, mode->keysize); if (err) goto out_unlock; - tfm = fscrypt_allocate_skcipher(mode, mode_key, inode); + err = fscrypt_prepare_key(prep_key, mode_key, ci); memzero_explicit(mode_key, mode->keysize); - if (IS_ERR(tfm)) { - err = PTR_ERR(tfm); + if (err) goto out_unlock; - } - /* pairs with READ_ONCE() above */ - smp_store_release(&tfms[mode_num], tfm); done_unlock: - ci->ci_ctfm = tfm; + ci->ci_enc_key = *prep_key; err = 0; out_unlock: mutex_unlock(&fscrypt_mode_key_setup_mutex); @@ -310,6 +332,10 @@ static int setup_file_encryption_key(struct fscrypt_info *ci, struct fscrypt_key_specifier mk_spec; int err; + err = fscrypt_select_encryption_impl(ci); + if (err) + return err; + switch (ci->ci_policy.version) { case FSCRYPT_POLICY_V1: mk_spec.type = FSCRYPT_KEY_SPEC_TYPE_DESCRIPTOR; @@ -402,7 +428,7 @@ 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_enc_key); key = ci->ci_master_key; if (key) { |