From: Eric Biggers Subject: [PATCH 6/6] fscrypt: for v2 policies, support "fscrypt:" key prefix only Date: Wed, 12 Jul 2017 14:00:35 -0700 Message-ID: <20170712210035.51534-7-ebiggers3@gmail.com> References: <20170712210035.51534-1-ebiggers3@gmail.com> Cc: linux-fsdevel@vger.kernel.org, linux-ext4@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, linux-mtd@lists.infradead.org, linux-crypto@vger.kernel.org, "Theodore Y . Ts'o" , Jaegeuk Kim , Alex Cope , Eric Biggers To: linux-fscrypt@vger.kernel.org Return-path: In-Reply-To: <20170712210035.51534-1-ebiggers3@gmail.com> Sender: linux-ext4-owner@vger.kernel.org List-Id: linux-crypto.vger.kernel.org From: Eric Biggers Since v2 encryption policies are opt-in, take the opportunity to also drop support for the legacy filesystem-specific key description prefixes "ext4:", "f2fs:", and "ubifs:", instead requiring the generic prefix "fscrypt:". The generic prefix is preferred since it works for all filesystems. Also there is a performance benefit from not having to search the keyrings twice. The old prefixes remain supported for v1 encryption policies. Signed-off-by: Eric Biggers --- fs/crypto/fscrypt_private.h | 3 +-- fs/crypto/keyinfo.c | 16 ++++------------ fs/crypto/policy.c | 2 +- 3 files changed, 6 insertions(+), 15 deletions(-) diff --git a/fs/crypto/fscrypt_private.h b/fs/crypto/fscrypt_private.h index 4b158717a8c3..201906ff7033 100644 --- a/fs/crypto/fscrypt_private.h +++ b/fs/crypto/fscrypt_private.h @@ -167,8 +167,7 @@ extern struct page *fscrypt_alloc_bounce_page(struct fscrypt_ctx *ctx, gfp_t gfp_flags); /* keyinfo.c */ -extern int fscrypt_compute_key_hash(const struct inode *inode, - const struct fscrypt_policy *policy, +extern int fscrypt_compute_key_hash(const struct fscrypt_policy *policy, u8 hash[FSCRYPT_KEY_HASH_SIZE]); extern void __exit fscrypt_essiv_cleanup(void); diff --git a/fs/crypto/keyinfo.c b/fs/crypto/keyinfo.c index bf60e76f9599..e20b5e85c1b3 100644 --- a/fs/crypto/keyinfo.c +++ b/fs/crypto/keyinfo.c @@ -385,8 +385,7 @@ find_and_lock_keyring_key(const char *prefix, } static struct fscrypt_master_key * -load_master_key_from_keyring(const struct inode *inode, - const u8 descriptor[FS_KEY_DESCRIPTOR_SIZE], +load_master_key_from_keyring(const u8 descriptor[FS_KEY_DESCRIPTOR_SIZE], unsigned int min_keysize) { struct key *keyring_key; @@ -395,11 +394,6 @@ load_master_key_from_keyring(const struct inode *inode, keyring_key = find_and_lock_keyring_key(FS_KEY_DESC_PREFIX, descriptor, min_keysize, &payload); - if (keyring_key == ERR_PTR(-ENOKEY) && inode->i_sb->s_cop->key_prefix) { - keyring_key = find_and_lock_keyring_key( - inode->i_sb->s_cop->key_prefix, - descriptor, min_keysize, &payload); - } if (IS_ERR(keyring_key)) return ERR_CAST(keyring_key); @@ -441,8 +435,7 @@ find_or_create_master_key(const struct inode *inode, /* * The needed master key isn't in memory yet. Load it from the keyring. */ - master_key = load_master_key_from_keyring(inode, - ctx->master_key_descriptor, + master_key = load_master_key_from_keyring(ctx->master_key_descriptor, min_keysize); if (IS_ERR(master_key)) return master_key; @@ -676,8 +669,7 @@ void __exit fscrypt_essiv_cleanup(void) crypto_free_shash(essiv_hash_tfm); } -int fscrypt_compute_key_hash(const struct inode *inode, - const struct fscrypt_policy *policy, +int fscrypt_compute_key_hash(const struct fscrypt_policy *policy, u8 hash[FSCRYPT_KEY_HASH_SIZE]) { struct fscrypt_master_key *k; @@ -691,7 +683,7 @@ int fscrypt_compute_key_hash(const struct inode *inode, max(available_modes[policy->contents_encryption_mode].keysize, available_modes[policy->filenames_encryption_mode].keysize); - k = load_master_key_from_keyring(inode, policy->master_key_descriptor, + k = load_master_key_from_keyring(policy->master_key_descriptor, min_keysize); if (IS_ERR(k)) return PTR_ERR(k); diff --git a/fs/crypto/policy.c b/fs/crypto/policy.c index 7661c66a3533..cd8c9c7cc9a9 100644 --- a/fs/crypto/policy.c +++ b/fs/crypto/policy.c @@ -117,7 +117,7 @@ int fscrypt_ioctl_set_policy(struct file *filp, const void __user *arg) pr_warn_once("%s (pid %d) is setting less secure v0 encryption policy; recommend upgrading to v2.\n", current->comm, current->pid); } else { - ret = fscrypt_compute_key_hash(inode, &policy, key_hash); + ret = fscrypt_compute_key_hash(&policy, key_hash); if (ret) return ret; } -- 2.13.2.932.g7449e964c-goog