diff options
| -rw-r--r-- | cmd/fscrypt/errors.go | 4 | ||||
| -rw-r--r-- | keyring/keyring.go | 48 |
2 files changed, 36 insertions, 16 deletions
diff --git a/cmd/fscrypt/errors.go b/cmd/fscrypt/errors.go index bef6c2a..c242552 100644 --- a/cmd/fscrypt/errors.go +++ b/cmd/fscrypt/errors.go @@ -113,6 +113,10 @@ func getErrorSuggestions(err error) string { return fmt.Sprintf(`You can only use %s to access the user keyring of another user if you are running as root.`, shortDisplay(userFlag)) + case keyring.ErrV2PoliciesUnsupported: + return fmt.Sprintf(`v2 encryption policies are only supported by kernel + version 5.4 and later. Either use a newer kernel, or change + policy_version to 1 in %s.`, actions.ConfigFileLocation) case actions.ErrBadConfigFile: return `Run "sudo fscrypt setup" to recreate the file.` case actions.ErrNoConfigFile: diff --git a/keyring/keyring.go b/keyring/keyring.go index f873bac..e232de3 100644 --- a/keyring/keyring.go +++ b/keyring/keyring.go @@ -43,15 +43,16 @@ import ( // Keyring error values var ( - ErrKeyAdd = util.SystemError("could not add key to the keyring") - ErrKeyRemove = util.SystemError("could not remove key from the keyring") - ErrKeyNotPresent = errors.New("key not present or already removed") - ErrKeyFilesOpen = errors.New("some files using the key are still open") - ErrKeyAddedByOtherUsers = errors.New("other users have added the key too") - ErrKeySearch = errors.New("could not find key with descriptor") - ErrSessionUserKeying = errors.New("user keyring not linked into session keyring") - ErrAccessUserKeyring = errors.New("could not access user keyring") - ErrLinkUserKeyring = util.SystemError("could not link user keyring into root keyring") + ErrKeyAdd = util.SystemError("could not add key to the keyring") + ErrKeyRemove = util.SystemError("could not remove key from the keyring") + ErrKeyNotPresent = errors.New("key not present or already removed") + ErrKeyFilesOpen = errors.New("some files using the key are still open") + ErrKeyAddedByOtherUsers = errors.New("other users have added the key too") + ErrKeySearch = errors.New("could not find key with descriptor") + ErrSessionUserKeying = errors.New("user keyring not linked into session keyring") + ErrAccessUserKeyring = errors.New("could not access user keyring") + ErrLinkUserKeyring = util.SystemError("could not link user keyring into root keyring") + ErrV2PoliciesUnsupported = errors.New("kernel is too old to support v2 encryption policies") ) // Options are the options which specify *which* keyring the key should be @@ -69,16 +70,19 @@ type Options struct { UseFsKeyringForV1Policies bool } -func shouldUseFsKeyring(descriptor string, options *Options) bool { +func shouldUseFsKeyring(descriptor string, options *Options) (bool, error) { // For v1 encryption policy keys, use the filesystem keyring if // use_fs_keyring_for_v1_policies is set in /etc/fscrypt.conf and the // kernel supports it. if len(descriptor) == hex.EncodedLen(unix.FSCRYPT_KEY_DESCRIPTOR_SIZE) { - return options.UseFsKeyringForV1Policies && isFsKeyringSupported(options.Mount) + return options.UseFsKeyringForV1Policies && isFsKeyringSupported(options.Mount), nil } // For v2 encryption policy keys, always use the filesystem keyring; the // kernel doesn't support any other way. - return true + if !isFsKeyringSupported(options.Mount) { + return true, ErrV2PoliciesUnsupported + } + return true, nil } // buildKeyDescription builds the description for an fscrypt key of type @@ -101,7 +105,11 @@ func AddEncryptionKey(key *crypto.Key, descriptor string, options *Options) erro if err := util.CheckValidLength(metadata.PolicyKeyLen, key.Len()); err != nil { return errors.Wrap(err, "policy key") } - if shouldUseFsKeyring(descriptor, options) { + useFsKeyring, err := shouldUseFsKeyring(descriptor, options) + if err != nil { + return err + } + if useFsKeyring { return fsAddEncryptionKey(key, descriptor, options.Mount, options.User) } return userAddKey(key, buildKeyDescription(options, descriptor), options.User) @@ -111,7 +119,11 @@ func AddEncryptionKey(key *crypto.Key, descriptor string, options *Options) erro // It uses either the filesystem keyring for the target Mount or the user // keyring for the target User. func RemoveEncryptionKey(descriptor string, options *Options, allUsers bool) error { - if shouldUseFsKeyring(descriptor, options) { + useFsKeyring, err := shouldUseFsKeyring(descriptor, options) + if err != nil { + return err + } + if useFsKeyring { user := options.User if allUsers { user = nil @@ -154,10 +166,14 @@ func (status KeyStatus) String() string { // kernel keyring. It uses either the filesystem keyring for the target Mount // or the user keyring for the target User. func GetEncryptionKeyStatus(descriptor string, options *Options) (KeyStatus, error) { - if shouldUseFsKeyring(descriptor, options) { + useFsKeyring, err := shouldUseFsKeyring(descriptor, options) + if err != nil { + return KeyStatusUnknown, err + } + if useFsKeyring { return fsGetEncryptionKeyStatus(descriptor, options.Mount, options.User) } - _, err := userFindKey(buildKeyDescription(options, descriptor), options.User) + _, err = userFindKey(buildKeyDescription(options, descriptor), options.User) if err != nil { return KeyAbsent, nil } |