github.com/kivutar/go-ethereum@v1.7.4-0.20180117074026-6fdb126e9630/cmd/ethkey/generate.go (about)

     1  package main
     2  
     3  import (
     4  	"crypto/ecdsa"
     5  	"crypto/rand"
     6  	"fmt"
     7  	"io/ioutil"
     8  	"os"
     9  	"path/filepath"
    10  
    11  	"github.com/ethereum/go-ethereum/accounts/keystore"
    12  	"github.com/ethereum/go-ethereum/cmd/utils"
    13  	"github.com/ethereum/go-ethereum/crypto"
    14  	"github.com/pborman/uuid"
    15  	"gopkg.in/urfave/cli.v1"
    16  )
    17  
    18  type outputGenerate struct {
    19  	Address      string
    20  	AddressEIP55 string
    21  }
    22  
    23  var commandGenerate = cli.Command{
    24  	Name:      "generate",
    25  	Usage:     "generate new keyfile",
    26  	ArgsUsage: "[ <keyfile> ]",
    27  	Description: `
    28  Generate a new keyfile.
    29  If you want to use an existing private key to use in the keyfile, it can be 
    30  specified by setting --privatekey with the location of the file containing the 
    31  private key.`,
    32  	Flags: []cli.Flag{
    33  		passphraseFlag,
    34  		jsonFlag,
    35  		cli.StringFlag{
    36  			Name: "privatekey",
    37  			Usage: "the file from where to read the private key to " +
    38  				"generate a keyfile for",
    39  		},
    40  	},
    41  	Action: func(ctx *cli.Context) error {
    42  		// Check if keyfile path given and make sure it doesn't already exist.
    43  		keyfilepath := ctx.Args().First()
    44  		if keyfilepath == "" {
    45  			keyfilepath = defaultKeyfileName
    46  		}
    47  		if _, err := os.Stat(keyfilepath); err == nil {
    48  			utils.Fatalf("Keyfile already exists at %s.", keyfilepath)
    49  		} else if !os.IsNotExist(err) {
    50  			utils.Fatalf("Error checking if keyfile exists: %v", err)
    51  		}
    52  
    53  		var privateKey *ecdsa.PrivateKey
    54  
    55  		// First check if a private key file is provided.
    56  		privateKeyFile := ctx.String("privatekey")
    57  		if privateKeyFile != "" {
    58  			privateKeyBytes, err := ioutil.ReadFile(privateKeyFile)
    59  			if err != nil {
    60  				utils.Fatalf("Failed to read the private key file '%s': %v",
    61  					privateKeyFile, err)
    62  			}
    63  
    64  			pk, err := crypto.HexToECDSA(string(privateKeyBytes))
    65  			if err != nil {
    66  				utils.Fatalf(
    67  					"Could not construct ECDSA private key from file content: %v",
    68  					err)
    69  			}
    70  			privateKey = pk
    71  		}
    72  
    73  		// If not loaded, generate random.
    74  		if privateKey == nil {
    75  			pk, err := ecdsa.GenerateKey(crypto.S256(), rand.Reader)
    76  			if err != nil {
    77  				utils.Fatalf("Failed to generate random private key: %v", err)
    78  			}
    79  			privateKey = pk
    80  		}
    81  
    82  		// Create the keyfile object with a random UUID.
    83  		id := uuid.NewRandom()
    84  		key := &keystore.Key{
    85  			Id:         id,
    86  			Address:    crypto.PubkeyToAddress(privateKey.PublicKey),
    87  			PrivateKey: privateKey,
    88  		}
    89  
    90  		// Encrypt key with passphrase.
    91  		passphrase := getPassPhrase(ctx, true)
    92  		keyjson, err := keystore.EncryptKey(key, passphrase,
    93  			keystore.StandardScryptN, keystore.StandardScryptP)
    94  		if err != nil {
    95  			utils.Fatalf("Error encrypting key: %v", err)
    96  		}
    97  
    98  		// Store the file to disk.
    99  		if err := os.MkdirAll(filepath.Dir(keyfilepath), 0700); err != nil {
   100  			utils.Fatalf("Could not create directory %s", filepath.Dir(keyfilepath))
   101  		}
   102  		if err := ioutil.WriteFile(keyfilepath, keyjson, 0600); err != nil {
   103  			utils.Fatalf("Failed to write keyfile to %s: %v", keyfilepath, err)
   104  		}
   105  
   106  		// Output some information.
   107  		out := outputGenerate{
   108  			Address: key.Address.Hex(),
   109  		}
   110  		if ctx.Bool(jsonFlag.Name) {
   111  			mustPrintJSON(out)
   112  		} else {
   113  			fmt.Println("Address:       ", out.Address)
   114  		}
   115  		return nil
   116  	},
   117  }