README
¶
go-bip32
An implementation of the BIP32 spec for Hierarchical Deterministic Bitcoin addresses as a simple Go library. The semantics of derived keys are up to the user. BIP43 and BIP44 are good schemes to implement with this library. An additional library for either or both of those on top of this library should be developed.
Example
It's very unlikely, but possible, that a given index does not produce a valid private key. Error checking is skipped in this example for brevity but should be handled in real code. In such a case, a ErrInvalidPrivateKey is returned.
ErrInvalidPrivateKey should be handled by trying the next index for a child key.
Any valid private key will have a valid public key so that Key.PublicKey()
method never returns an error.
package main
import (
"github.com/tyler-smith/go-bip32"
"fmt"
"log"
)
// Example address creation for a fictitious company ComputerVoice Inc. where
// each department has their own wallet to manage
func main(){
// Generate a seed to determine all keys from.
// This should be persisted, backed up, and secured
seed, err := bip32.NewSeed()
if err != nil {
log.Fatalln("Error generating seed:", err)
}
// Create master private key from seed
computerVoiceMasterKey, _ := bip32.NewMasterKey(seed)
// Map departments to keys
// There is a very small chance a given child index is invalid
// If so your real program should handle this by skipping the index
departmentKeys := map[string]*bip32.Key{}
departmentKeys["Sales"], _ = computerVoiceMasterKey.NewChildKey(0)
departmentKeys["Marketing"], _ = computerVoiceMasterKey.NewChildKey(1)
departmentKeys["Engineering"], _ = computerVoiceMasterKey.NewChildKey(2)
departmentKeys["Customer Support"], _ = computerVoiceMasterKey.NewChildKey(3)
// Create public keys for record keeping, auditors, payroll, etc
departmentAuditKeys := map[string]*bip32.Key{}
departmentAuditKeys["Sales"] = departmentKeys["Sales"].PublicKey()
departmentAuditKeys["Marketing"] = departmentKeys["Marketing"].PublicKey()
departmentAuditKeys["Engineering"] = departmentKeys["Engineering"].PublicKey()
departmentAuditKeys["Customer Support"] = departmentKeys["Customer Support"].PublicKey()
// Print public keys
for department, pubKey := range departmentAuditKeys {
fmt.Println(department, pubKey)
}
}
Thanks
The developers at Factom have contributed a lot to this library and have made many great improvements to it. Please check out their project(s) and give them a thanks if you use this library.
Thanks to bartekn from Stellar for some important bug catches.
Documentation
¶
Index ¶
Constants ¶
const ( // FirstHardenedChild is the index of the firxt "harded" child key as per the // bip32 spec FirstHardenedChild = uint32(0x80000000) // PublicKeyCompressedLength is the byte count of a compressed public key PublicKeyCompressedLength = 33 // NetworkTestNet is the string for BTC TestNet network NetworkTestNet = "testnet" // NetworkMainNet is the string for BTC MainNet network NetworkMainNet = "mainnet" )
Variables ¶
var ( // BTCNetwork is the BTC network on which the wallet is valid (decides public/private version flags) BTCNetwork = NetworkMainNet // PrivateWalletVersion is the version flag for serialized private keys for set BTCNetwork PrivateWalletVersion []byte // PublicWalletVersion is the version flag for serialized public keys for set BTCNetwork PublicWalletVersion []byte // PrivateMainNetWalletVersion is the version flag for mainnet serialized private keys PrivateMainNetWalletVersion, _ = hex.DecodeString("0488ADE4") // PublicMainNetWalletVersion is the version flag for mainnet serialized public keys PublicMainNetWalletVersion, _ = hex.DecodeString("0488B21E") // PrivateTestNetWalletVersion is the version flag for testnet serialized private keys PrivateTestNetWalletVersion, _ = hex.DecodeString("04358394") // PublicTestNetWalletVersion is the version flag for testnet serialized public keys PublicTestNetWalletVersion, _ = hex.DecodeString("043587cf") // ErrInvalidBTCNetwork is returned when trying to set a BTC network // which is not currently supported ErrInvalidBTCNetwork = errors.New("Invalid BTC network") // ErrSerializedKeyWrongSize is returned when trying to deserialize a key that // has an incorrect length ErrSerializedKeyWrongSize = errors.New("Serialized keys should by exactly 82 bytes") // ErrHardnedChildPublicKey is returned when trying to create a harded child // of the public key ErrHardnedChildPublicKey = errors.New("Can't create hardened child for public key") // ErrInvalidChecksum is returned when deserializing a key with an incorrect // checksum ErrInvalidChecksum = errors.New("Checksum doesn't match") // ErrInvalidPrivateKey is returned when a derived private key is invalid ErrInvalidPrivateKey = errors.New("Invalid private key") // ErrInvalidPublicKey is returned when a derived public key is invalid ErrInvalidPublicKey = errors.New("Invalid public key") )
var ( // BitcoinBase58Encoding is the encoding used for bitcoin addresses BitcoinBase58Encoding = basen.NewEncoding("123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz") )
Functions ¶
func SetBTCNetwork ¶
SetBTCNetwork sets BTCNetwork to the given network string if supported
Types ¶
type Key ¶
type Key struct {
Key []byte // 33 bytes
Version []byte // 4 bytes
ChildNumber []byte // 4 bytes
FingerPrint []byte // 4 bytes
ChainCode []byte // 32 bytes
Depth byte // 1 bytes
IsPrivate bool // unserialized
}
Key represents a bip32 extended key
func B58Deserialize ¶
B58Deserialize deserializes a Key encoded in base58 encoding
func NewMasterKey ¶
NewMasterKey creates a new master extended key from a seed
func (*Key) B58Serialize ¶
B58Serialize encodes the Key in the standard Bitcoin base58 encoding
func (*Key) NewChildKey ¶
NewChildKey derives a child key from a given parent as outlined by bip32
func (*Key) PublicKey ¶
PublicKey returns the public version of key or return a copy The 'Neuter' function from the bip32 spec
Source Files