waku-org/go-waku

package keygen

import (
    "encoding/json"
    "fmt"
    "os"

    "github.com/ethereum/go-ethereum/accounts/keystore"
    "github.com/ethereum/go-ethereum/crypto"
    "github.com/urfave/cli/v2"
    "github.com/waku-org/go-waku/waku/v2/utils"
    "go.uber.org/zap"
)

// Command generates a key file used to generate the node's peerID, encrypted with an optional password
var Command = cli.Command{
    Name:  "generate-key",
    Usage: "Generate private key file at path specified in --key-file with the password defined by --key-password",
    Action: func(cCtx *cli.Context) error {
        if err := generateKeyFile(Options.KeyFile, []byte(Options.KeyPasswd), Options.Overwrite); err != nil {
            utils.Logger().Fatal("could not write keyfile", zap.Error(err))
        }
        return nil
    },
    Flags: []cli.Flag{
        KeyFile,
        KeyPassword,
        Overwrite,
    },
}

func checkForFileExistence(path string, overwrite bool) error {
    _, err := os.Stat(path)

    if err == nil && !overwrite {
        return fmt.Errorf("%s already exists. Use --overwrite to overwrite the file", path)
    }

    if err := os.Remove(path); err != nil && !os.IsNotExist(err) {
        return err
    }

    return nil
}

func generatePrivateKey() ([]byte, error) {
    key, err := crypto.GenerateKey()
    if err != nil {
        return nil, err
    }

    return key.D.Bytes(), nil
}

func writeKeyFile(path string, key []byte, passwd []byte) error {
    encryptedK, err := keystore.EncryptDataV3(key, passwd, keystore.StandardScryptN, keystore.StandardScryptP)
    if err != nil {
        return err
    }

    output, err := json.Marshal(encryptedK)
    if err != nil {
        return err
    }

    return os.WriteFile(path, output, 0600)
}

func generateKeyFile(path string, passwd []byte, overwrite bool) error {
    if err := checkForFileExistence(path, overwrite); err != nil {
        return err
    }

    key, err := generatePrivateKey()
    if err != nil {
        return err
    }

    return writeKeyFile(path, key, passwd)
}