From: Eric Biggers <ebigg...@google.com>

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 <ebigg...@google.com>
---
 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

Reply via email to