completed work on run command, moved util files in cmd/utils

cmd/utils/crypto.go

@@ -0,0 +1,56 @@
+package utils
+
+import (
+	"crypto"
+	"crypto/ecdsa"
+	"crypto/elliptic"
+	"crypto/rand"
+	"crypto/x509"
+	"encoding/pem"
+	"errors"
+	"io/ioutil"
+	"os"
+)
+
+func generatePrivateKey(file string) (crypto.PrivateKey, error) {
+
+	privateKey, err := ecdsa.GenerateKey(elliptic.P384(), rand.Reader)
+	if err != nil {
+		return nil, err
+	}
+
+	keyBytes, err := x509.MarshalECPrivateKey(privateKey)
+	if err != nil {
+		return nil, err
+	}
+
+	pemKey := pem.Block{Type: "EC PRIVATE KEY", Bytes: keyBytes}
+
+	certOut, err := os.Create(file)
+	if err != nil {
+		return nil, err
+	}
+
+	pem.Encode(certOut, &pemKey)
+	certOut.Close()
+
+	return privateKey, nil
+}
+
+func loadPrivateKey(file string) (crypto.PrivateKey, error) {
+	keyBytes, err := ioutil.ReadFile(file)
+	if err != nil {
+		return nil, err
+	}
+
+	keyBlock, _ := pem.Decode(keyBytes)
+
+	switch keyBlock.Type {
+	case "RSA PRIVATE KEY":
+		return x509.ParsePKCS1PrivateKey(keyBlock.Bytes)
+	case "EC PRIVATE KEY":
+		return x509.ParseECPrivateKey(keyBlock.Bytes)
+	}
+
+	return nil, errors.New("Unknown private key type.")
+}