From 8220d591784cfa064e003c4344dc7d1aa138882a Mon Sep 17 00:00:00 2001
From: Ethan Frey <ethanfrey@users.noreply.github.com>
Date: Sat, 29 Jul 2017 13:35:52 -0400
Subject: [PATCH] Work on using returned bytes as crypto keys

---
 nano/sign.go      | 19 +++++++++++++++++++
 nano/sign_test.go | 47 +++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 66 insertions(+)

diff --git a/nano/sign.go b/nano/sign.go
index fbe550548..b98b7f469 100644
--- a/nano/sign.go
+++ b/nano/sign.go
@@ -5,6 +5,7 @@ import (
 	"fmt"
 
 	"github.com/pkg/errors"
+	crypto "github.com/tendermint/go-crypto"
 )
 
 const (
@@ -57,3 +58,21 @@ func parseDigest(resp []byte) (key, sig []byte, err error) {
 	sig = resp[len(separator):]
 	return key, sig, nil
 }
+
+func parseKey(data []byte) (key crypto.PubKey, err error) {
+	ed := crypto.PubKeyEd25519{}
+	if len(data) < len(ed) {
+		return key, errors.Errorf("Key length too short: %d", len(data))
+	}
+	copy(ed[:], data)
+	return ed.Wrap(), nil
+}
+
+func parseSig(data []byte) (key crypto.Signature, err error) {
+	ed := crypto.SignatureEd25519{}
+	if len(data) < len(ed) {
+		return key, errors.Errorf("Sig length too short: %d", len(data))
+	}
+	copy(ed[:], data)
+	return ed.Wrap(), nil
+}
diff --git a/nano/sign_test.go b/nano/sign_test.go
index 8029ef828..be1e66c86 100644
--- a/nano/sign_test.go
+++ b/nano/sign_test.go
@@ -49,3 +49,50 @@ func TestParseDigest(t *testing.T) {
 		}
 	}
 }
+
+type cryptoCase struct {
+	msg   string
+	key   string
+	sig   string
+	valid bool
+}
+
+func toBytes(c cryptoCase) (msg, key, sig []byte, err error) {
+	msg, err = hex.DecodeString(c.msg)
+	if err != nil {
+		return
+	}
+	key, err = hex.DecodeString(c.key)
+	if err != nil {
+		return
+	}
+	sig, err = hex.DecodeString(c.sig)
+	return
+}
+
+func TestCryptoConvert(t *testing.T) {
+	assert, require := assert.New(t), require.New(t)
+
+	cases := []cryptoCase{
+		{
+			msg:   "00",
+			key:   "04338EB1DD3CCDEE1F6FB586F66E640F56FFDD14537A3F0ED9EEEDF10B528FE4195FD17AC9EDAE9718A50196A1459E2434C1E53F1238F4CFDF177FAFBA8B39249B",
+			sig:   "FFDEA42A699205B217004E7E2FFB884E174A548D644116F4B20469CBC32F60A9CB0EEB5BB6A7F266BD0F6A0A99A45B4F18F0F477AED7C854C404EF43530DAB00",
+			valid: true,
+		},
+	}
+
+	for i, tc := range cases {
+		msg, key, sig, err := toBytes(tc)
+		require.Nil(err, "%d: %+v", i, err)
+
+		pk, err := parseKey(key)
+		require.Nil(err, "%d: %+v", i, err)
+		psig, err := parseSig(sig)
+		require.Nil(err, "%d: %+v", i, err)
+
+		// how do i make this valid?
+		valid := pk.VerifyBytes(msg, psig)
+		assert.Equal(tc.valid, valid, "%d", i)
+	}
+}