Bip39 package

Introduction

This package implements the BIP-0039 specification. This includes:

• Mnemonic generation from a specified number of words, using random entropy
• Mnemonic generation from a specified entropy
• Mnemonic validation
• Seed generation from a mnemonic with a specified passphrase

NOTE: only the English words list is currently supported.

Installation

The package can be installed by simply running:

go get -u github.com/ebellocchia/go-bip39

Usage

The package is pretty easy to use, so a code example is probably self-explanatory.

Example

package main

import (
  "github.com/ebellocchia/go-bip39"
  "fmt"
  "encoding/hex"
)

func main() {
    // Generate a random entropy with the specified number of bits
    // An error is returned if the entropy bit length is not valid
    entropy, err := bip39.GenerateEntropy(bip39.EntropyBits128)
    if err != nil {
        panic(err)
    }
    fmt.Println(hex.EncodeToString(entropy))

    // Generate a mnemonic from the entropy
    // An error is returned if the entropy bit length is not valid
    mnemonic, err := bip39.MnemonicFromEntropy(entropy)
    if err != nil {
        panic(err)
    }
    fmt.Println(mnemonic.Words)

    // Generate a mnemonic with a specified number of words (a random entropy will be generated internally)
    // An error is returned if the number of words is not valid
    mnemonic, err = bip39.MnemonicFromWordsNum(bip39.WordsNum12)
    if err != nil {
        panic(err)
    }
    fmt.Println(mnemonic.Words)

    // Create a mnemonic directly from an existent string
    mnemonic = bip39.MnemonicFromString("legal winner thank year wave sausage worth useful legal winner thank yellow")
    fmt.Println(mnemonic.Words)

    // Get entropy back from the mnemonic
    // An error is returned if the mnemonic is not valid
    entropy, err = mnemonic.ToEntropy()
    if err != nil {
        panic(err)
    }
    fmt.Println(hex.EncodeToString(entropy))

    // Validate a mnemonic, return an error if not valid
    err = mnemonic.Validate()
    if err != nil {
        panic(err)
    }

    // Get if the mnemonic is valid. Same of before but bool is returned instead of error.
    is_valid := mnemonic.IsValid()
    if !is_valid {
        // Do something...
    }

    // Generate a seed from the mnemonic using the specified passphrase (can be also empty)
    // An error is returned if the mnemonic is not valid
    seed, err := mnemonic.GenerateSeed("my_passphrase")
    if err != nil {
        panic(err)
    }
    fmt.Println(hex.EncodeToString(seed))
}

The valid bit lengths for entropy generation are:

• bip39.EntropyBits128
• bip39.EntropyBits160
• bip39.EntropyBits192
• bip39.EntropyBits224
• bip39.EntropyBits256

The valid words number for mnemonic generation are:

• bip39.WordsNum12
• bip39.WordsNum15
• bip39.WordsNum18
• bip39.WordsNum21
• bip39.WordsNum24

License

This software is available under the MIT license.