frostfs-node/pkg/services/tree/signature.go

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package tree
import (
"bytes"
"crypto/ecdsa"
"crypto/elliptic"
"errors"
"fmt"
"git.frostfs.info/TrueCloudLab/frostfs-api-go/v2/refs"
"git.frostfs.info/TrueCloudLab/frostfs-node/internal/logs"
core "git.frostfs.info/TrueCloudLab/frostfs-node/pkg/core/container"
"git.frostfs.info/TrueCloudLab/frostfs-sdk-go/bearer"
"git.frostfs.info/TrueCloudLab/frostfs-sdk-go/client"
"git.frostfs.info/TrueCloudLab/frostfs-sdk-go/container/acl"
cidSDK "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/container/id"
frostfscrypto "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/crypto"
frostfsecdsa "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/crypto/ecdsa"
"git.frostfs.info/TrueCloudLab/frostfs-sdk-go/eacl"
"git.frostfs.info/TrueCloudLab/frostfs-sdk-go/user"
"github.com/nspcc-dev/neo-go/pkg/crypto/keys"
"go.uber.org/zap"
)
type message interface {
SignedDataSize() int
ReadSignedData([]byte) ([]byte, error)
GetSignature() *Signature
SetSignature(*Signature)
}
func basicACLErr(op acl.Op) error {
return fmt.Errorf("access to operation %s is denied by basic ACL check", op)
}
func eACLErr(op eacl.Operation, err error) error {
return fmt.Errorf("access to operation %s is denied by extended ACL check: %w", op, err)
}
var (
errBearerWrongOwner = errors.New("bearer token must be signed by the container owner")
errBearerWrongContainer = errors.New("bearer token is created for another container")
errBearerSignature = errors.New("invalid bearer token signature")
)
// verifyClient verifies if the request for a client operation
// was signed by a key allowed by (e)ACL rules.
// Operation must be one of:
// - 1. ObjectPut;
// - 2. ObjectGet.
func (s *Service) verifyClient(req message, cid cidSDK.ID, rawBearer []byte, op acl.Op) error {
err := verifyMessage(req)
if err != nil {
return err
}
isAuthorized, err := s.isAuthorized(req, op)
if isAuthorized || err != nil {
return err
}
cnr, err := s.cnrSource.Get(cid)
if err != nil {
return fmt.Errorf("can't get container %s: %w", cid, err)
}
eaclOp := eACLOp(op)
bt, err := parseBearer(rawBearer, cid, eaclOp)
if err != nil {
return err
}
role, err := roleFromReq(cnr, req, bt)
if err != nil {
return fmt.Errorf("can't get request role: %w", err)
}
basicACL := cnr.Value.BasicACL()
// Basic ACL mask can be unset, if a container operations are performed
// with strict APE checks only.
if basicACL == 0x0 {
return nil
}
if !basicACL.IsOpAllowed(op, role) {
return basicACLErr(op)
}
if !basicACL.Extendable() {
return nil
}
var useBearer bool
if len(rawBearer) != 0 {
if !basicACL.AllowedBearerRules(op) {
s.log.Debug(logs.TreeBearerPresentedButNotAllowedByACL,
zap.String("cid", cid.EncodeToString()),
zap.Stringer("op", op),
)
} else {
useBearer = true
}
}
var tb eacl.Table
signer := req.GetSignature().GetKey()
if useBearer && !bt.Impersonate() {
if !bearer.ResolveIssuer(*bt).Equals(cnr.Value.Owner()) {
return eACLErr(eaclOp, errBearerWrongOwner)
}
tb = bt.EACLTable()
} else {
tbCore, err := s.eaclSource.GetEACL(cid)
if err != nil {
return handleGetEACLError(err)
}
tb = *tbCore.Value
if useBearer && bt.Impersonate() {
signer = bt.SigningKeyBytes()
}
}
return checkEACL(tb, signer, eACLRole(role), eaclOp)
}
// Returns true iff the operation is read-only and request was signed
// with one of the authorized keys.
func (s *Service) isAuthorized(req message, op acl.Op) (bool, error) {
if op != acl.OpObjectGet {
return false, nil
}
sign := req.GetSignature()
if sign == nil {
return false, errors.New("missing signature")
}
key := sign.GetKey()
for i := range s.authorizedKeys {
if bytes.Equal(s.authorizedKeys[i], key) {
return true, nil
}
}
return false, nil
}
func parseBearer(rawBearer []byte, cid cidSDK.ID, eaclOp eacl.Operation) (*bearer.Token, error) {
if len(rawBearer) == 0 {
return nil, nil
}
bt := new(bearer.Token)
if err := bt.Unmarshal(rawBearer); err != nil {
return nil, eACLErr(eaclOp, fmt.Errorf("invalid bearer token: %w", err))
}
if !bt.AssertContainer(cid) {
return nil, eACLErr(eaclOp, errBearerWrongContainer)
}
if !bt.VerifySignature() {
return nil, eACLErr(eaclOp, errBearerSignature)
}
return bt, nil
}
func handleGetEACLError(err error) error {
if client.IsErrEACLNotFound(err) {
return nil
}
return fmt.Errorf("get eACL table: %w", err)
}
func verifyMessage(m message) error {
binBody, err := m.ReadSignedData(nil)
if err != nil {
return fmt.Errorf("marshal request body: %w", err)
}
sig := m.GetSignature()
// TODO(@cthulhu-rider): #468 use Signature message from FrostFS API to avoid conversion
var sigV2 refs.Signature
sigV2.SetKey(sig.GetKey())
sigV2.SetSign(sig.GetSign())
sigV2.SetScheme(refs.ECDSA_SHA512)
var sigSDK frostfscrypto.Signature
if err := sigSDK.ReadFromV2(sigV2); err != nil {
return fmt.Errorf("can't read signature: %w", err)
}
if !sigSDK.Verify(binBody) {
return errors.New("invalid signature")
}
return nil
}
// SignMessage uses the provided key and signs any protobuf
// message that was generated for the TreeService by the
// protoc-gen-go-frostfs generator. Returns any errors directly.
func SignMessage(m message, key *ecdsa.PrivateKey) error {
binBody, err := m.ReadSignedData(nil)
if err != nil {
return err
}
keySDK := frostfsecdsa.Signer(*key)
data, err := keySDK.Sign(binBody)
if err != nil {
return err
}
rawPub := make([]byte, keySDK.Public().MaxEncodedSize())
rawPub = rawPub[:keySDK.Public().Encode(rawPub)]
m.SetSignature(&Signature{
Key: rawPub,
Sign: data,
})
return nil
}
func roleFromReq(cnr *core.Container, req message, bt *bearer.Token) (acl.Role, error) {
role := acl.RoleOthers
owner := cnr.Value.Owner()
rawKey := req.GetSignature().GetKey()
if bt != nil && bt.Impersonate() {
rawKey = bt.SigningKeyBytes()
}
pub, err := keys.NewPublicKeyFromBytes(rawKey, elliptic.P256())
if err != nil {
return role, fmt.Errorf("invalid public key: %w", err)
}
var reqSigner user.ID
user.IDFromKey(&reqSigner, (ecdsa.PublicKey)(*pub))
if reqSigner.Equals(owner) {
role = acl.RoleOwner
}
return role, nil
}
func eACLOp(op acl.Op) eacl.Operation {
switch op {
case acl.OpObjectGet:
return eacl.OperationGet
case acl.OpObjectPut:
return eacl.OperationPut
default:
panic(fmt.Sprintf("unexpected tree service ACL operation: %s", op))
}
}
func eACLRole(role acl.Role) eacl.Role {
switch role {
case acl.RoleOwner:
return eacl.RoleUser
case acl.RoleOthers:
return eacl.RoleOthers
default:
panic(fmt.Sprintf("unexpected tree service ACL role: %s", role))
}
}
var (
errDENY = errors.New("DENY eACL rule")
errNoAllowRules = errors.New("not found allowing rules for the request")
)
// checkEACL searches for the eACL rules that could be applied to the request
// (a tuple of a signer key, his FrostFS role and a request operation).
// It does not filter the request by the filters of the eACL table since tree
// requests do not contain any "object" information that could be filtered and,
// therefore, filtering leads to unexpected results.
// The code was copied with the minor updates from the SDK repo:
// https://github.com/nspcc-dev/frostfs-sdk-go/blob/43a57d42dd50dc60465bfd3482f7f12bcfcf3411/eacl/validator.go#L28.
func checkEACL(tb eacl.Table, signer []byte, role eacl.Role, op eacl.Operation) error {
for _, record := range tb.Records() {
// check type of operation
if record.Operation() != op {
continue
}
// check target
if !targetMatches(record, role, signer) {
continue
}
switch a := record.Action(); a {
case eacl.ActionAllow:
return nil
case eacl.ActionDeny:
return eACLErr(op, errDENY)
default:
return eACLErr(op, fmt.Errorf("unexpected action: %s", a))
}
}
return eACLErr(op, errNoAllowRules)
}
func targetMatches(rec eacl.Record, role eacl.Role, signer []byte) bool {
for _, target := range rec.Targets() {
// check public key match
if pubs := target.BinaryKeys(); len(pubs) != 0 {
for _, key := range pubs {
if bytes.Equal(key, signer) {
return true
}
}
continue
}
// check target group match
if role == target.Role() {
return true
}
}
return false
}