package smart_contract import ( "github.com/nspcc-dev/neo-go/pkg/interop/crypto" "github.com/nspcc-dev/neo-go/pkg/interop/engine" "github.com/nspcc-dev/neo-go/pkg/interop/runtime" "github.com/nspcc-dev/neo-go/pkg/interop/storage" "github.com/nspcc-dev/neo-go/pkg/interop/util" ) type node struct { addr []byte pub []byte } type check struct { id []byte height []byte } // GAS NEP-5 HASH const tokenHash = "\x77\xea\x59\x6b\x7a\xdf\x7e\x4d\xd1\x40\x76\x97\x31\xb7\xd2\xf0\xe0\x6b\xcd\x9b" const innerRingCandidateFee = 100 * 1000 * 1000 // 10^8 const version = 1 func Main(op string, args []interface{}) interface{} { // The trigger determines whether this smart-contract is being // run in 'verification' or 'application' mode. if runtime.GetTrigger() != runtime.Application() { return false } /* Utility operations - they will be changed in production: - Deploy(params: address, pubKey, ... ) - setup initial inner ring state User operations: - InnerRingList() - get list of inner ring nodes addresses and public keys - InnerRingAddress(params: address, pubKey) - update address of the inner ring node with given public key - InnerRingCandidateRemove(params: pubKey) - remove node with given public key from the inner ring candidate queue - InnerRingCandidateAdd(params: address, pubKey) - add node to the inner ring candidate queue - Deposit(params: pubKey, amount) - deposit GAS to the NeoFS account - Withdraw(params: withdrawCheque) - withdraw GAS from the NeoFS account - InnerRingUpdate(params: irCheque) - change list of inner ring nodes - Version() - get version of the NeoFS smart-contract Params: - address - string of the valid multiaddress (github.com/multiformats/multiaddr) - pubKey - 33 byte public key - withdrawCheque - serialized structure, that confirms GAS transfer; contains inner ring signatures - irCheque - serialized structure, that confirms new inner ring node list; contains inner ring signatures */ ctx := storage.GetContext() switch op { case "Deploy": irList := getSerialized(ctx, "InnerRingList").([]node) if len(irList) >= 3 { panic("contract already deployed") } ln := len(args) if ln%2 != 0 { panic("provide pairs of inner ring address and public key") } irList = []node{} for i := 0; i < ln/2; i++ { addr := args[i*2].([]byte) pub := args[i*2+1].([]byte) irList = append(irList, node{addr: addr, pub: pub}) } data := runtime.Serialize(irList) storage.Put(ctx, "InnerRingList", data) data = runtime.Serialize([]interface{}{}) storage.Put(ctx, "UsedVerifCheckList", data) storage.Put(ctx, "InnerRingCandidates", data) return true case "InnerRingList": irList := getSerialized(ctx, "InnerRingList").([]node) return irList case "InnerRingAddress": addr := args[0].([]byte) pub := args[1].([]byte) irList := getSerialized(ctx, "InnerRingList").([]node) if !containsPub(irList, pub) { panic("inner ring node does not exist") } if runtime.CheckWitness(pub) { n := node{addr: addr, pub: pub} delSerializedIR(ctx, "InnerRingList", pub) putSerialized(ctx, "InnerRingList", n) } return true case "InnerRingCandidateRemove": data := args[0].([]byte) // public key if !runtime.CheckWitness(data) { panic("you should be the owner of the public key") } delSerializedIR(ctx, "InnerRingCandidates", data) return true case "InnerRingCandidateAdd": addr := args[0].([]byte) // valid multiaddr string data := args[1].([]byte) // public key if !runtime.CheckWitness(data) { panic("you should be the owner of the public key") } candidates := getSerialized(ctx, "InnerRingCandidates").([]node) if containsPub(candidates, data) { panic("is already in list") } from := pubToScriptHash(data) to := engine.GetExecutingScriptHash() params := []interface{}{from, to, innerRingCandidateFee} transferred := engine.AppCall([]byte(tokenHash), "transfer", params).(bool) if !transferred { panic("failed to transfer funds, aborting") } candidate := node{ addr: addr, pub: data, } if !putSerialized(ctx, "InnerRingCandidates", candidate) { panic("failed to put candidate into the queue") } return true case "Deposit": pk := args[0].([]byte) if !runtime.CheckWitness(pk) { panic("you should be the owner of the public key") } amount := args[1].(int) if amount > 0 { amount = amount * 100000000 } from := pubToScriptHash(pk) to := engine.GetExecutingScriptHash() params := []interface{}{from, to, amount} transferred := engine.AppCall([]byte(tokenHash), "transfer", params).(bool) if !transferred { panic("failed to transfer funds, aborting") } runtime.Log("funds have been transferred") return true case "Withdraw": from := engine.GetExecutingScriptHash() data := args[0].([]byte) message := data[0:66] uuid := data[0:25] owner := data[25:50] value := data[50:58] height := data[58:66] offset := 68 usedList := getSerialized(ctx, "UsedVerifCheckList").([]check) c := check{ id: uuid, height: height, } if containsCheck(usedList, c) { panic("verification check has already been used") } irList := getSerialized(ctx, "InnerRingList").([]node) if !verifySignatures(irList, data, message, offset) { panic("can't verify signatures") } h := owner[1:21] params := []interface{}{from, h, value} transferred := engine.AppCall([]byte(tokenHash), "transfer", params).(bool) if !transferred { panic("failed to transfer funds, aborting") } putSerialized(ctx, "UsedVerifCheckList", c) return true case "InnerRingUpdate": data := args[0].([]byte) id := data[:8] var ln interface{} = data[8:10] listItemCount := ln.(int) listSize := listItemCount * 33 offset := 8 + 2 + listSize msg := data[:offset] message := crypto.SHA256(msg) irList := getSerialized(ctx, "InnerRingList").([]node) if !verifySignatures(irList, data, message, offset) { panic("can't verify signatures") } usedList := getSerialized(ctx, "UsedVerifCheckList").([]check) c := check{ id: id, height: []byte{1}, // ir update cheques use height as id } if containsCheck(usedList, c) { panic("check has already been used") } candidates := getSerialized(ctx, "InnerRingCandidates").([]node) offset = 10 newIR := []node{} for i := 0; i < listItemCount; i++ { pub := data[offset : offset+33] finished := false for j := 0; j < len(irList); j++ { n := irList[j] if util.Equals(n.pub, pub) { newIR = append(newIR, n) finished = true break } } if !finished { for j := 0; j < len(candidates); j++ { n := candidates[j] if util.Equals(n.pub, pub) { newIR = append(newIR, n) finished = true break } } if !finished { panic("unknown inner ring candidate present in the list") } } offset += 33 } if len(newIR) != listItemCount { panic("new inner ring wasn't processed correctly") } for i := 0; i < len(newIR); i++ { n := newIR[i] delSerializedIR(ctx, "InnerRingCandidates", n.pub) } newIRData := runtime.Serialize(newIR) storage.Put(ctx, "InnerRingList", newIRData) putSerialized(ctx, "UsedVerifCheckList", c) return true case "Version": return version } panic("unknown operation") } func getSerialized(ctx storage.Context, key string) interface{} { data := storage.Get(ctx, key).([]byte) if len(data) != 0 { return runtime.Deserialize(data) } return nil } func delSerialized(ctx storage.Context, key string, value []byte) bool { data := storage.Get(ctx, key).([]byte) deleted := false var newList [][]byte if len(data) != 0 { lst := runtime.Deserialize(data).([][]byte) for i := 0; i < len(lst); i++ { if util.Equals(value, lst[i]) { deleted = true } else { newList = append(newList, lst[i]) } } if deleted { if len(newList) != 0 { data := runtime.Serialize(newList) storage.Put(ctx, key, data) } else { storage.Delete(ctx, key) } runtime.Log("target element has been removed") return true } } runtime.Log("target element has not been removed") return false } func putSerialized(ctx storage.Context, key string, value interface{}) bool { data := storage.Get(ctx, key).([]byte) var lst []interface{} if len(data) != 0 { lst = runtime.Deserialize(data).([]interface{}) } lst = append(lst, value) data = runtime.Serialize(lst) storage.Put(ctx, key, data) return true } func pubToScriptHash(pkey []byte) []byte { pre := []byte{0x21} buf := append(pre, pkey...) buf = append(buf, 0xac) h := crypto.Hash160(buf) return h } func containsCheck(lst []check, c check) bool { for i := 0; i < len(lst); i++ { if util.Equals(c, lst[i]) { return true } } return false } func containsPub(lst []node, elem []byte) bool { for i := 0; i < len(lst); i++ { e := lst[i] if util.Equals(elem, e.pub) { return true } } return false } func delSerializedIR(ctx storage.Context, key string, value []byte) bool { data := storage.Get(ctx, key).([]byte) deleted := false newList := []node{} if len(data) != 0 { lst := runtime.Deserialize(data).([]node) for i := 0; i < len(lst); i++ { n := lst[i] if util.Equals(value, n.pub) { deleted = true } else { newList = append(newList, n) } } if deleted { data := runtime.Serialize(newList) storage.Put(ctx, key, data) runtime.Log("target element has been removed") return true } } runtime.Log("target element has not been removed") return false } func verifySignatures(irList []node, data []byte, message []byte, offset int) bool { n := len(irList) f := (n - 1) / 3 s := n - f if s < 3 { runtime.Log("not enough inner ring nodes for consensus") return false } used := [][]byte{} count := 0 for count < s && offset < len(data) { pubkey := data[offset : offset+33] signature := data[offset+33 : offset+97] if containsPub(irList, pubkey) { if crypto.VerifySignature(message, signature, pubkey) { count++ for i := 0; i < len(used); i++ { if util.Equals(used[i], pubkey) { panic("duplicate public keys") } } used = append(used, pubkey) } } offset += 97 } if count >= s { return true } runtime.Log("not enough verified signatures") return false }