cosmos-sdk/crypto/keys/bip39/wordcodec.go

67 lines
1.9 KiB
Go

package bip39
import (
"strings"
"github.com/bartekn/go-bip39"
)
// ValidSentenceLen defines the mnemonic sentence lengths supported by this BIP 39 library.
type ValidSentenceLen uint8
const (
// FundRaiser is the sentence length used during the cosmos fundraiser (12 words).
FundRaiser ValidSentenceLen = 12
// Size of the checksum employed for the fundraiser
FundRaiserChecksumSize = 4
// FreshKey is the sentence length used for newly created keys (24 words).
FreshKey ValidSentenceLen = 24
// Size of the checksum employed for new keys
FreshKeyChecksumSize = 8
)
// NewMnemonic will return a string consisting of the mnemonic words for
// the given sentence length.
func NewMnemonic(len ValidSentenceLen) (words []string, err error) {
// len = (entropySize + checksum) / 11
var entropySize int
switch len {
case FundRaiser:
// entropySize = 128
entropySize = int(len)*11 - FundRaiserChecksumSize
case FreshKey:
// entropySize = 256
entropySize = int(len)*11 - FreshKeyChecksumSize
}
var entropy []byte
entropy, err = bip39.NewEntropy(entropySize)
if err != nil {
return
}
var mnemonic string
mnemonic, err = bip39.NewMnemonic(entropy)
if err != nil {
return
}
words = strings.Split(mnemonic, " ")
return
}
// MnemonicToSeed creates a BIP 39 seed from the passed mnemonic (with an empty BIP 39 password).
// This method does not validate the mnemonics checksum.
func MnemonicToSeed(mne string) (seed []byte) {
// we do not checksum here...
seed = bip39.NewSeed(mne, "")
return
}
// MnemonicToSeedWithErrChecking returns the same seed as MnemonicToSeed.
// It creates a BIP 39 seed from the passed mnemonic (with an empty BIP 39 password).
//
// Different from MnemonicToSeed it validates the checksum.
// For details on the checksum see the BIP 39 spec.
func MnemonicToSeedWithErrChecking(mne string) (seed []byte, err error) {
seed, err = bip39.NewSeedWithErrorChecking(mne, "")
return
}