Add encrypt and decrypt helper cmd

pkg/cli/encrypt.go

@@ -0,0 +1,62 @@
+package cli
+
+import (
+	"fmt"
+
+	"github.com/convox/rack/pkg/crypt"
+	"github.com/convox/rack/sdk"
+	"github.com/convox/stdcli"
+)
+
+func init() {
+	register("encrypt", "encrypt data using key", Encrypt, stdcli.CommandOptions{
+		Flags: []stdcli.Flag{
+			stdcli.StringFlag("key", "", "key"),
+			stdcli.StringFlag("data", "", "data"),
+		},
+		Usage: "",
+	})
+
+	register("decrypt", "decrypt data using key", Decrypt, stdcli.CommandOptions{
+		Flags: []stdcli.Flag{
+			stdcli.StringFlag("key", "", "key"),
+			stdcli.StringFlag("data", "", "data"),
+		},
+		Usage: "",
+	})
+}
+
+func Encrypt(_ sdk.Interface, c *stdcli.Context) error {
+
+	key := c.String("key")
+	data := c.String("data")
+
+	if key == "" || data == "" {
+		return fmt.Errorf("key and data must be non empty")
+	}
+
+	val, err := crypt.Encrypt(key, []byte(data))
+	if err != nil {
+		return err
+	}
+
+	fmt.Println(val)
+	return nil
+}
+
+func Decrypt(_ sdk.Interface, c *stdcli.Context) error {
+	key := c.String("key")
+	data := c.String("data")
+
+	if key == "" || data == "" {
+		return fmt.Errorf("key and data must be non empty")
+	}
+
+	val, err := crypt.Decrypt(key, data)
+	if err != nil {
+		return err
+	}
+
+	fmt.Println(string(val))
+	return nil
+}

pkg/crypt/helpers.go

@@ -0,0 +1,105 @@
+package crypt
+
+import (
+	"crypto/rand"
+	"crypto/sha256"
+	"encoding/base64"
+	"encoding/json"
+	"fmt"
+	"io"
+
+	"github.com/pkg/errors"
+	"golang.org/x/crypto/nacl/secretbox"
+)
+
+const (
+	KeySize   = 32
+	NonceSize = 24
+)
+
+type RandEnvelope struct {
+	Nonce      *[NonceSize]byte
+	CipherText []byte
+}
+
+func OneWay(str string) string {
+	enc := sha256.Sum256([]byte(str))
+	return base64.StdEncoding.EncodeToString(enc[:])
+}
+
+func Encrypt(ekey string, data []byte) (string, error) {
+	key, err := decodeKey(ekey)
+	if err != nil {
+		return "", errors.WithStack(err)
+	}
+
+	nonce, err := generateNonce()
+	if err != nil {
+		return "", errors.WithStack(err)
+	}
+
+	var cipherText []byte
+	cipherText = secretbox.Seal(cipherText, data, nonce, key)
+
+	envelope := RandEnvelope{
+		Nonce:      nonce,
+		CipherText: cipherText,
+	}
+
+	envelopeJson, err := json.Marshal(envelope)
+	if err != nil {
+		return "", errors.WithStack(err)
+	}
+
+	return base64.StdEncoding.EncodeToString(envelopeJson), nil
+}
+
+func Decrypt(ekey string, sealed string) ([]byte, error) {
+	decoded, err := base64.StdEncoding.DecodeString(sealed)
+	if err != nil {
+		return nil, errors.WithStack(err)
+	}
+
+	var envelope RandEnvelope
+
+	if err := json.Unmarshal(decoded, &envelope); err != nil {
+		return nil, errors.WithStack(err)
+	}
+
+	key, err := decodeKey(ekey)
+	if err != nil {
+		return nil, errors.WithStack(err)
+	}
+
+	data := []byte{}
+
+	data, ok := secretbox.Open(nil, envelope.CipherText, envelope.Nonce, key)
+	if !ok {
+		return nil, errors.WithStack(fmt.Errorf("could not decrypt data"))
+	}
+
+	return data, nil
+}
+
+func decodeKey(ekey string) (*[KeySize]byte, error) {
+	var key [KeySize]byte
+
+	data, err := base64.StdEncoding.DecodeString(ekey)
+	if err != nil {
+		return nil, errors.WithStack(err)
+	}
+
+	copy(key[:], data[0:KeySize])
+
+	return &key, nil
+}
+
+func generateNonce() (*[NonceSize]byte, error) {
+	nonce := new([NonceSize]byte)
+	_, err := io.ReadFull(rand.Reader, nonce[:])
+	if err != nil {
+		return nil, errors.WithStack(err)
+	}
+
+	return nonce, nil
+}