cmd/ethkey: new command line tool for keys (#15438)

ethkey is a new tool that serves as a command line interface to
the basic key management functionalities of geth. It currently
supports:
 
 - generating keyfiles
 - inspecting keyfiles (print public and private key)
 - signing messages
 - verifying signed messages

1 files changed, 117 insertions, 0 deletions

diff --git a/cmd/ethkey/generate.go b/cmd/ethkey/generate.go
new file mode 100644
index 000000000..dee0e9d70
--- /dev/null
+++ b/cmd/ethkey/generate.go
@@ -0,0 +1,117 @@
+package main
+
+import (
+	"crypto/ecdsa"
+	"crypto/rand"
+	"fmt"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+
+	"github.com/ethereum/go-ethereum/accounts/keystore"
+	"github.com/ethereum/go-ethereum/cmd/utils"
+	"github.com/ethereum/go-ethereum/crypto"
+	"github.com/pborman/uuid"
+	"gopkg.in/urfave/cli.v1"
+)
+
+type outputGenerate struct {
+	Address      string
+	AddressEIP55 string
+}
+
+var commandGenerate = cli.Command{
+	Name:      "generate",
+	Usage:     "generate new keyfile",
+	ArgsUsage: "[ <keyfile> ]",
+	Description: `
+Generate a new keyfile.
+If you want to use an existing private key to use in the keyfile, it can be 
+specified by setting --privatekey with the location of the file containing the 
+private key.`,
+	Flags: []cli.Flag{
+		passphraseFlag,
+		jsonFlag,
+		cli.StringFlag{
+			Name: "privatekey",
+			Usage: "the file from where to read the private key to " +
+				"generate a keyfile for",
+		},
+	},
+	Action: func(ctx *cli.Context) error {
+		// Check if keyfile path given and make sure it doesn't already exist.
+		keyfilepath := ctx.Args().First()
+		if keyfilepath == "" {
+			keyfilepath = defaultKeyfileName
+		}
+		if _, err := os.Stat(keyfilepath); err == nil {
+			utils.Fatalf("Keyfile already exists at %s.", keyfilepath)
+		} else if !os.IsNotExist(err) {
+			utils.Fatalf("Error checking if keyfile exists: %v", err)
+		}
+
+		var privateKey *ecdsa.PrivateKey
+
+		// First check if a private key file is provided.
+		privateKeyFile := ctx.String("privatekey")
+		if privateKeyFile != "" {
+			privateKeyBytes, err := ioutil.ReadFile(privateKeyFile)
+			if err != nil {
+				utils.Fatalf("Failed to read the private key file '%s': %v",
+					privateKeyFile, err)
+			}
+
+			pk, err := crypto.HexToECDSA(string(privateKeyBytes))
+			if err != nil {
+				utils.Fatalf(
+					"Could not construct ECDSA private key from file content: %v",
+					err)
+			}
+			privateKey = pk
+		}
+
+		// If not loaded, generate random.
+		if privateKey == nil {
+			pk, err := ecdsa.GenerateKey(crypto.S256(), rand.Reader)
+			if err != nil {
+				utils.Fatalf("Failed to generate random private key: %v", err)
+			}
+			privateKey = pk
+		}
+
+		// Create the keyfile object with a random UUID.
+		id := uuid.NewRandom()
+		key := &keystore.Key{
+			Id:         id,
+			Address:    crypto.PubkeyToAddress(privateKey.PublicKey),
+			PrivateKey: privateKey,
+		}
+
+		// Encrypt key with passphrase.
+		passphrase := getPassPhrase(ctx, true)
+		keyjson, err := keystore.EncryptKey(key, passphrase,
+			keystore.StandardScryptN, keystore.StandardScryptP)
+		if err != nil {
+			utils.Fatalf("Error encrypting key: %v", err)
+		}
+
+		// Store the file to disk.
+		if err := os.MkdirAll(filepath.Dir(keyfilepath), 0700); err != nil {
+			utils.Fatalf("Could not create directory %s", filepath.Dir(keyfilepath))
+		}
+		if err := ioutil.WriteFile(keyfilepath, keyjson, 0600); err != nil {
+			utils.Fatalf("Failed to write keyfile to %s: %v", keyfilepath, err)
+		}
+
+		// Output some information.
+		out := outputGenerate{
+			Address: key.Address.Hex(),
+		}
+		if ctx.Bool(jsonFlag.Name) {
+			mustPrintJSON(out)
+		} else {
+			fmt.Println("Address:       ", out.Address)
+		}
+		return nil
+	},
+}