any-sync/pkg/acl/list/aclstate.go
2022-08-21 15:23:47 +02:00

450 lines
12 KiB
Go

package list
import (
"bytes"
"errors"
"fmt"
"github.com/anytypeio/go-anytype-infrastructure-experiments/app/logger"
"github.com/anytypeio/go-anytype-infrastructure-experiments/pkg/acl/aclchanges/aclpb"
"github.com/anytypeio/go-anytype-infrastructure-experiments/util/keys"
"github.com/anytypeio/go-anytype-infrastructure-experiments/util/keys/asymmetric/encryptionkey"
"github.com/anytypeio/go-anytype-infrastructure-experiments/util/keys/asymmetric/signingkey"
"github.com/anytypeio/go-anytype-infrastructure-experiments/util/keys/symmetric"
"github.com/gogo/protobuf/proto"
"go.uber.org/zap"
"hash/fnv"
)
var log = logger.NewNamed("acllist")
var ErrNoSuchUser = errors.New("no such user")
var ErrFailedToDecrypt = errors.New("failed to decrypt key")
var ErrUserRemoved = errors.New("user was removed from the document")
var ErrDocumentForbidden = errors.New("your user was forbidden access to the document")
var ErrUserAlreadyExists = errors.New("user already exists")
var ErrNoSuchRecord = errors.New("no such record")
var ErrInsufficientPermissions = errors.New("insufficient permissions")
type UserPermissionPair struct {
Identity string
Permission aclpb.ACLChangeUserPermissions
}
type ACLState struct {
currentReadKeyHash uint64
userReadKeys map[uint64]*symmetric.Key
userStates map[string]*aclpb.ACLChangeUserState
userInvites map[string]*aclpb.ACLChangeUserInvite
signingPubKeyDecoder keys.Decoder
encryptionKey encryptionkey.PrivKey
identity string
permissionsAtRecord map[string][]UserPermissionPair
}
func newACLStateWithIdentity(
identity string,
encryptionKey encryptionkey.PrivKey,
decoder keys.Decoder) *ACLState {
return &ACLState{
identity: identity,
encryptionKey: encryptionKey,
userReadKeys: make(map[uint64]*symmetric.Key),
userStates: make(map[string]*aclpb.ACLChangeUserState),
userInvites: make(map[string]*aclpb.ACLChangeUserInvite),
signingPubKeyDecoder: decoder,
permissionsAtRecord: make(map[string][]UserPermissionPair),
}
}
func newACLState(decoder keys.Decoder) *ACLState {
return &ACLState{
signingPubKeyDecoder: decoder,
userReadKeys: make(map[uint64]*symmetric.Key),
userStates: make(map[string]*aclpb.ACLChangeUserState),
userInvites: make(map[string]*aclpb.ACLChangeUserInvite),
permissionsAtRecord: make(map[string][]UserPermissionPair),
}
}
func (st *ACLState) CurrentReadKeyHash() uint64 {
return st.currentReadKeyHash
}
func (st *ACLState) UserReadKeys() map[uint64]*symmetric.Key {
return st.userReadKeys
}
func (st *ACLState) PermissionsAtRecord(id string, identity string) (UserPermissionPair, error) {
permissions, ok := st.permissionsAtRecord[id]
if !ok {
return UserPermissionPair{}, ErrNoSuchRecord
}
for _, perm := range permissions {
if perm.Identity == identity {
return perm, nil
}
}
return UserPermissionPair{}, ErrNoSuchUser
}
func (st *ACLState) applyRecord(record *aclpb.Record) (err error) {
// TODO: this should be probably changed
aclData := &aclpb.ACLChangeACLData{}
err = proto.Unmarshal(record.Data, aclData)
if err != nil {
return
}
defer func() {
if err != nil {
return
}
st.currentReadKeyHash = record.CurrentReadKeyHash
}()
return st.applyChangeData(aclData, record.CurrentReadKeyHash, record.Identity)
}
func (st *ACLState) applyChangeAndUpdate(recordWrapper *Record) (err error) {
change := recordWrapper.Content
aclData := &aclpb.ACLChangeACLData{}
if recordWrapper.ParsedModel != nil {
aclData = recordWrapper.ParsedModel.(*aclpb.ACLChangeACLData)
} else {
err = proto.Unmarshal(change.Data, aclData)
if err != nil {
return
}
recordWrapper.ParsedModel = aclData
}
err = st.applyChangeData(aclData, recordWrapper.Content.CurrentReadKeyHash, recordWrapper.Content.Identity)
if err != nil {
return err
}
var permissions []UserPermissionPair
for _, state := range st.userStates {
permission := UserPermissionPair{
Identity: state.Identity,
Permission: state.Permissions,
}
permissions = append(permissions, permission)
}
st.permissionsAtRecord[recordWrapper.Id] = permissions
return nil
}
func (st *ACLState) applyChangeData(changeData *aclpb.ACLChangeACLData, hash uint64, identity string) (err error) {
defer func() {
if err != nil {
return
}
st.currentReadKeyHash = hash
}()
// we can't check this for the user which is joining, because it will not be in our list
// the same is for the first change to be added
skipIdentityCheck := st.isUserJoin(changeData) || (st.currentReadKeyHash == 0 && st.isUserAdd(changeData, identity))
if !skipIdentityCheck {
// we check signature when we add this to the Tree, so no need to do it here
if _, exists := st.userStates[identity]; !exists {
err = ErrNoSuchUser
return
}
if !st.hasPermission(identity, aclpb.ACLChange_Admin) {
err = fmt.Errorf("user %s must have admin permissions", identity)
return
}
}
for _, ch := range changeData.GetAclContent() {
if err = st.applyChangeContent(ch); err != nil {
log.Info("error while applying changes: %v; ignore", zap.Error(err))
return err
}
}
return nil
}
func (st *ACLState) applyChangeContent(ch *aclpb.ACLChangeACLContentValue) error {
switch {
case ch.GetUserPermissionChange() != nil:
return st.applyUserPermissionChange(ch.GetUserPermissionChange())
case ch.GetUserAdd() != nil:
return st.applyUserAdd(ch.GetUserAdd())
case ch.GetUserRemove() != nil:
return st.applyUserRemove(ch.GetUserRemove())
case ch.GetUserInvite() != nil:
return st.applyUserInvite(ch.GetUserInvite())
case ch.GetUserJoin() != nil:
return st.applyUserJoin(ch.GetUserJoin())
case ch.GetUserConfirm() != nil:
return st.applyUserConfirm(ch.GetUserConfirm())
default:
return fmt.Errorf("unexpected change type: %v", ch)
}
}
func (st *ACLState) applyUserPermissionChange(ch *aclpb.ACLChangeUserPermissionChange) error {
if _, exists := st.userStates[ch.Identity]; !exists {
return ErrNoSuchUser
}
st.userStates[ch.Identity].Permissions = ch.Permissions
return nil
}
func (st *ACLState) applyUserInvite(ch *aclpb.ACLChangeUserInvite) error {
st.userInvites[ch.InviteId] = ch
return nil
}
func (st *ACLState) applyUserJoin(ch *aclpb.ACLChangeUserJoin) error {
invite, exists := st.userInvites[ch.UserInviteId]
if !exists {
return fmt.Errorf("no such invite with id %s", ch.UserInviteId)
}
if _, exists = st.userStates[ch.Identity]; exists {
return ErrUserAlreadyExists
}
// validating signature
signature := ch.GetAcceptSignature()
verificationKey, err := st.signingPubKeyDecoder.DecodeFromBytes(invite.AcceptPublicKey)
if err != nil {
return fmt.Errorf("public key verifying invite accepts is given in incorrect format: %v", err)
}
rawSignedId, err := st.signingPubKeyDecoder.DecodeFromStringIntoBytes(ch.Identity)
if err != nil {
return fmt.Errorf("failed to decode signing identity as bytes")
}
res, err := verificationKey.(signingkey.PubKey).Verify(rawSignedId, signature)
if err != nil {
return fmt.Errorf("verification returned error: %w", err)
}
if !res {
return fmt.Errorf("signature is invalid")
}
// if ourselves -> we need to decrypt the read keys
if st.identity == ch.Identity {
for _, key := range ch.EncryptedReadKeys {
key, hash, err := st.decryptReadKeyAndHash(key)
if err != nil {
return ErrFailedToDecrypt
}
st.userReadKeys[hash] = key
}
}
// adding user to the list
userState := &aclpb.ACLChangeUserState{
Identity: ch.Identity,
EncryptionKey: ch.EncryptionKey,
EncryptedReadKeys: ch.EncryptedReadKeys,
Permissions: invite.Permissions,
IsConfirmed: true,
}
st.userStates[ch.Identity] = userState
return nil
}
func (st *ACLState) applyUserAdd(ch *aclpb.ACLChangeUserAdd) error {
if _, exists := st.userStates[ch.Identity]; exists {
return ErrUserAlreadyExists
}
st.userStates[ch.Identity] = &aclpb.ACLChangeUserState{
Identity: ch.Identity,
EncryptionKey: ch.EncryptionKey,
Permissions: ch.Permissions,
EncryptedReadKeys: ch.EncryptedReadKeys,
}
if ch.Identity == st.identity {
for _, key := range ch.EncryptedReadKeys {
key, hash, err := st.decryptReadKeyAndHash(key)
if err != nil {
return ErrFailedToDecrypt
}
st.userReadKeys[hash] = key
}
}
return nil
}
func (st *ACLState) applyUserRemove(ch *aclpb.ACLChangeUserRemove) error {
if ch.Identity == st.identity {
return ErrDocumentForbidden
}
if _, exists := st.userStates[ch.Identity]; !exists {
return ErrNoSuchUser
}
delete(st.userStates, ch.Identity)
for _, replace := range ch.ReadKeyReplaces {
userState, exists := st.userStates[replace.Identity]
if !exists {
continue
}
userState.EncryptedReadKeys = append(userState.EncryptedReadKeys, replace.EncryptedReadKey)
// if this is our identity then we have to decrypt the key
if replace.Identity == st.identity {
key, hash, err := st.decryptReadKeyAndHash(replace.EncryptedReadKey)
if err != nil {
return ErrFailedToDecrypt
}
st.currentReadKeyHash = hash
st.userReadKeys[st.currentReadKeyHash] = key
}
}
return nil
}
func (st *ACLState) applyUserConfirm(ch *aclpb.ACLChangeUserConfirm) error {
if _, exists := st.userStates[ch.Identity]; !exists {
return ErrNoSuchUser
}
userState := st.userStates[ch.Identity]
userState.IsConfirmed = true
return nil
}
func (st *ACLState) decryptReadKeyAndHash(msg []byte) (*symmetric.Key, uint64, error) {
decrypted, err := st.encryptionKey.Decrypt(msg)
if err != nil {
return nil, 0, ErrFailedToDecrypt
}
key, err := symmetric.FromBytes(decrypted)
if err != nil {
return nil, 0, ErrFailedToDecrypt
}
hasher := fnv.New64()
hasher.Write(decrypted)
return key, hasher.Sum64(), nil
}
func (st *ACLState) hasPermission(identity string, permission aclpb.ACLChangeUserPermissions) bool {
state, exists := st.userStates[identity]
if !exists {
return false
}
return state.Permissions == permission
}
func (st *ACLState) isUserJoin(data *aclpb.ACLChangeACLData) bool {
// if we have a UserJoin, then it should always be the first one applied
return data.GetAclContent() != nil && data.GetAclContent()[0].GetUserJoin() != nil
}
func (st *ACLState) isUserAdd(data *aclpb.ACLChangeACLData, identity string) bool {
// if we have a UserAdd, then it should always be the first one applied
userAdd := data.GetAclContent()[0].GetUserAdd()
return data.GetAclContent() != nil && userAdd != nil && userAdd.GetIdentity() == identity
}
func (st *ACLState) getPermissionDecreasedUsers(ch *aclpb.ACLChange) (identities []*aclpb.ACLChangeUserPermissionChange) {
// this should be called after general checks are completed
if ch.GetAclData().GetAclContent() == nil {
return nil
}
contents := ch.GetAclData().GetAclContent()
for _, c := range contents {
if c.GetUserPermissionChange() != nil {
content := c.GetUserPermissionChange()
currentState := st.userStates[content.Identity]
// the comparison works in different direction :-)
if content.Permissions > currentState.Permissions {
identities = append(identities, &aclpb.ACLChangeUserPermissionChange{
Identity: content.Identity,
Permissions: content.Permissions,
})
}
}
if c.GetUserRemove() != nil {
content := c.GetUserRemove()
identities = append(identities, &aclpb.ACLChangeUserPermissionChange{
Identity: content.Identity,
Permissions: aclpb.ACLChange_Removed,
})
}
}
return identities
}
func (st *ACLState) equal(other *ACLState) bool {
if st == nil && other == nil {
return true
}
if st == nil || other == nil {
return false
}
if st.currentReadKeyHash != other.currentReadKeyHash {
return false
}
if st.identity != other.identity {
return false
}
if len(st.userStates) != len(other.userStates) {
return false
}
for _, st := range st.userStates {
otherSt, exists := other.userStates[st.Identity]
if !exists {
return false
}
if st.Permissions != otherSt.Permissions {
return false
}
if bytes.Compare(st.EncryptionKey, otherSt.EncryptionKey) != 0 {
return false
}
}
if len(st.userInvites) != len(other.userInvites) {
return false
}
// TODO: add detailed user invites comparison + compare other stuff
return true
}
func (st *ACLState) GetUserStates() map[string]*aclpb.ACLChangeUserState {
// TODO: we should provide better API that would not allow to change this map from the outside
return st.userStates
}
func (st *ACLState) isNodeIdentity() bool {
return st.identity == ""
}