NEO utilities

This package contains useful functions that make your life easier when working with NEO blockchain.

List of functions available in this library

Wallet

import "github.com/o3labs/neo-utils/neoutils"

Wallet struct

type Wallet struct {
	PublicKey       []byte
	PrivateKey      []byte
	Address         string
	WIF             string
	HashedSignature []byte
}

Create a new wallet address for NEO blockchain

neoutils.NewWallet() (*Wallet, error)

Restore a wallet from WIF

neoutils.GenerateFromWIF(wif string) (*Wallet, error)

Restore a wallet from raw private key string

neoutils.GenerateFromPrivateKey(privateKey string) (*Wallet, error)

---

Encryption

import "github.com/o3labs/neo-utils/neoutils"

Sign data using ECDSA

neoutils.Sign(data []byte, key string) ([]byte, error) 

Encrypt data using AES

neoutils.Encrypt(key []byte, text string) string 

Decrypt AES encrypted data

neoutils.Decrypt(key []byte, encryptedText string) string

Public key encryption using ECDH

(w *Wallet) ComputeSharedSecret(publicKey []byte) []byte

Create N-parts shared secret using Shamir's Secret Sharing

neoutils.GenerateShamirSharedSecret(secret string) (*SharedSecret, error)

Restore data from shared secret using Shamir's Secret Sharing

neoutils.RecoverFromSharedSecret(first []byte, second []byte) (string, error)

NEO Nodes utilities

import "github.com/o3labs/neo-utils/neoutils"

Select best node

Select NEO best node by measuring the latency between caller and the nodes concurrently.

type SeedNodeResponse struct {
	URL          string
	BlockCount   int
	ResponseTime int64 //milliseconds
}

neoutils.SelectBestSeedNode(commaSeparatedURLs string) *SeedNodeResponse 

---

Utilities methods

import "github.com/o3labs/neo-utils/neoutils"

Reverse bytes

neoutils.ReverseBytes(b []byte) []byte 

Hex string to bytes

neoutils.HexTobytes(hexstring string) (b []byte)

Bytes to hex string

neoutils.BytesToHex(b []byte) string

Convert script hash to NEO address

neoutils.ScriptHashToNEOAddress(scriptHash string) string

Convert NEO Address to script hash

neoutils.NEOAddressToScriptHash(neoAddress string) string 

Validate NEO Address

neoutils.ValidateNEOAddress(address string) bool 

Convert Byte array to big int

neoutils.ConvertByteArrayToBigInt(hexString string) *big.Int

Parse NEP9 URI

type SimplifiedNEP9 struct {
	To      string  `json:"to"`
	AssetID string  `json:"assetID"`
	Amount  float64 `json:"amount"`
}
neoutils.ParseNEP9URI(uri string) (*SimplifiedNEP9, error) 

---

NEO JSON RPC

import "github.com/o3labs/neo-utils/neoutils/neorpc"

Get contract state with smart contract's script hash

client := neorpc.NewClient("http://localhost:30333")
if client == nil {
	return
}

result := client.GetContractState("ce575ae1bb6153330d20c560acb434dc5755241b")

Send raw transaction

client := neorpc.NewClient("http://localhost:30333")
if client == nil {
	return
}
raw := ""
result := client.SendRawTransaction(raw)

Get raw transaction with TXID

client := neorpc.NewClient("http://localhost:30333")
if client == nil {
	return
}
txID := "bde02f8c6482e23d5b465259e3e438f0acacaba2a7a938d5eecd90bba0e9d1ad"
result := client.GetRawTransaction(txID)

---

City of Zion APIs

import "github.com/o3labs/neo-utils/neoutils/coz"

Get unspent data by NEO Address

client := coz.NewClient("http://127.0.0.1:5000")
unspent, err := client.GetUnspentByAddress("AK2nJJpJr6o664CWJKi1QRXjqeic2zRp8y")
for _, v := range unspent.GAS.Unspent {
	log.Printf("%+v", v)
}	

---

NEO Smart contract

import "github.com/o3labs/neo-utils/neoutils/smartcontract"

Generate invocation script data

smartcontract.GenerateContractInvocationData(scriptHash ScriptHash, operation string, args []interface{}) []byte

Generate invocation inputs data

smartconract.GenerateTransactionInput(unspent Unspent, assetToSend NativeAsset, amountToSend float64) ([]byte, error)

Generate invocation output data

smartcontract.GenerateTransactionOutput(sender NEOAddress, receiver NEOAddress, unspent Unspent, assetToSend NativeAsset, amountToSend float64) ([]byte, error)

Generate transaction attributes data

smartcontract.GenerateTransactionAttributes(attributes map[TransactionAttribute][]byte) ([]byte, error)

Generate invocation and verification script with signatures

smartcontract.GenerateVerificationScripts(signatures []TransactionSignature) []byte

Parse raw transaction's script to operation name and args

p := smartcontract.NewParserWithScript("51143acefb110cba488ae0d809f5837b0ac9c895405e52c10c6d696e74546f6b656e73546f67b17f078543788c588ce9e75544e325a050f8c1b7")

//you can define the known method signature here
type methodSignature struct {
	Operation smartcontract.Operation  //operation
	To        smartcontract.NEOAddress //args[0]
	Amount    int                      //args[1]
}
m := methodSignature{}
list, err := p.Parse(&m)
if err != nil {
	return
}
for _, v := range list {
	log.Printf("%+v", v.(*methodSignature))
}

Parse raw transaction's script that contains multiple appcall

script := `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`
p := smartcontract.NewParserWithScript(script)
type methodSignature struct {
	Operation smartcontract.Operation  //operation
	From      smartcontract.NEOAddress //args[0]
	To        smartcontract.NEOAddress //args[1]
	Amount    int                      //args[2]
}
m := methodSignature{}
list, err := p.Parse(&m)
if err != nil {
	return
}

for _, v := range list {
	log.Printf("%+v", v.(*methodSignature))
}

Get invoked operations from raw transaction's script data

p := smartcontract.NewParserWithScript("51143acefb110cba488ae0d809f5837b0ac9c895405e52c10c6d696e74546f6b656e73546f67b17f078543788c588ce9e75544e325a050f8c1b7")
result, err := p.GetListOfOperations()
if err != nil {
	return
}

log.Printf("result = %v", result)

Get invoked smart contract script hashes from raw transaction's script data

p := smartcontract.NewParserWithScript("51143acefb110cba488ae0d809f5837b0ac9c895405e52c10c6d696e74546f6b656e73546f67b17f078543788c588ce9e75544e325a050f8c1b7")
result, err := p.GetListOfScriptHashes()
if err != nil {
	return
}

log.Printf("result = %v", result)

Generate ready-for-sendrawtransaction smart contract invocation data

var validSmartContract = neoutils.UseSmartContract("b7c1f850a025e34455e7e98c588c784385077fb1")
validSmartContract.GenerateInvokeFunctionRawTransaction(wallet Wallet, unspent smartcontract.Unspent, attributes map[smartcontract.TransactionAttribute][]byte, operation string, args []interface{}) ([]byte, error)