sharedsecret.go

/*
 * Copyright 2018 The CovenantSQL Authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package rpc

import (
	"sync"

	"github.com/pkg/errors"

	"github.com/CovenantSQL/CovenantSQL/conf"
	"github.com/CovenantSQL/CovenantSQL/crypto/asymmetric"
	"github.com/CovenantSQL/CovenantSQL/crypto/kms"
	"github.com/CovenantSQL/CovenantSQL/proto"
	"github.com/CovenantSQL/CovenantSQL/route"
)

var symmetricKeyCache sync.Map

// GetSharedSecretWith gets shared symmetric key with ECDH.
func GetSharedSecretWith(nodeID *proto.RawNodeID, isAnonymous bool) (symmetricKey []byte, err error) {
	if isAnonymous {
		symmetricKey = []byte(`!&\\!qEyey*\cbLc,aKl`)
		//log.Debug("using anonymous ETLS")
	} else {
		symmetricKeyI, ok := symmetricKeyCache.Load(nodeID.String())
		if ok {
			symmetricKey, _ = symmetricKeyI.([]byte)
		} else {
			var remotePublicKey *asymmetric.PublicKey
			if route.IsBPNodeID(nodeID) {
				remotePublicKey = kms.BP.PublicKey
			} else if conf.RoleTag[0] == conf.BlockProducerBuildTag[0] {
				remotePublicKey, err = kms.GetPublicKey(proto.NodeID(nodeID.String()))
				if err != nil {
					err = errors.Wrapf(err, "get public key locally failed, node: %s", nodeID)
					return
				}
			} else {
				// if non BP running and key not found, ask BlockProducer
				var nodeInfo *proto.Node
				nodeInfo, err = GetNodeInfo(nodeID)
				if err != nil {
					err = errors.Wrapf(err, "get public key failed, node: %s", nodeID)
					return
				}
				remotePublicKey = nodeInfo.PublicKey
			}

			var localPrivateKey *asymmetric.PrivateKey
			localPrivateKey, err = kms.GetLocalPrivateKey()
			if err != nil {
				err = errors.Wrap(err, "get local private key failed")
				return
			}

			symmetricKey = asymmetric.GenECDHSharedSecret(localPrivateKey, remotePublicKey)
			symmetricKeyCache.Store(nodeID.String(), symmetricKey)
			//log.WithFields(log.Fields{
			//	"node":       nodeID.String(),
			//	"remotePub":  fmt.Sprintf("%#x", remotePublicKey.Serialize()),
			//	"sessionKey": fmt.Sprintf("%#x", symmetricKey),
			//}).Debug("generated shared secret")
		}
		//log.Debugf("ECDH for %s Public Key: %x, Private Key: %x Session Key: %x",
		//	nodeID.ToNodeID(), remotePublicKey.Serialize(), localPrivateKey.Serialize(), symmetricKey)
	}
	return
}