From 74878ee3130cff56dcd096a69ed7a3b97e7d233f Mon Sep 17 00:00:00 2001
From: Ethan Frey <ethanfrey@users.noreply.github.com>
Date: Tue, 12 Sep 2017 09:50:07 +0200
Subject: [PATCH] Update code to work with current nano implementation

---
 nano/sign.go      |  9 ++++++++-
 nano/sign_test.go | 19 ++++++++++++-------
 2 files changed, 20 insertions(+), 8 deletions(-)

diff --git a/nano/sign.go b/nano/sign.go
index b98b7f469..50b874d15 100644
--- a/nano/sign.go
+++ b/nano/sign.go
@@ -2,9 +2,11 @@ package nano
 
 import (
 	"bytes"
+	"crypto/sha512"
 	"fmt"
 
 	"github.com/pkg/errors"
+
 	crypto "github.com/tendermint/go-crypto"
 )
 
@@ -14,7 +16,7 @@ const (
 	Update    = 0x01
 	Digest    = 0x02
 	MaxChunk  = 253
-	KeyLength = 65
+	KeyLength = 32
 	SigLength = 64
 )
 
@@ -76,3 +78,8 @@ func parseSig(data []byte) (key crypto.Signature, err error) {
 	copy(ed[:], data)
 	return ed.Wrap(), nil
 }
+
+func hashMsg(data []byte) []byte {
+	res := sha512.Sum512(data)
+	return res[:]
+}
diff --git a/nano/sign_test.go b/nano/sign_test.go
index be1e66c86..2f94c5e6f 100644
--- a/nano/sign_test.go
+++ b/nano/sign_test.go
@@ -18,9 +18,9 @@ func TestParseDigest(t *testing.T) {
 		valid  bool
 	}{
 		{
-			output: "800204338EB1DD3CCDEE1F6FB586F66E640F56FFDD14537A3F0ED9EEEDF10B528FE4195FD17AC9EDAE9718A50196A1459E2434C1E53F1238F4CFDF177FAFBA8B39249B00CAFE00FFDEA42A699205B217004E7E2FFB884E174A548D644116F4B20469CBC32F60A9CB0EEB5BB6A7F266BD0F6A0A99A45B4F18F0F477AED7C854C404EF43530DAB00",
-			key:    "04338EB1DD3CCDEE1F6FB586F66E640F56FFDD14537A3F0ED9EEEDF10B528FE4195FD17AC9EDAE9718A50196A1459E2434C1E53F1238F4CFDF177FAFBA8B39249B",
-			sig:    "FFDEA42A699205B217004E7E2FFB884E174A548D644116F4B20469CBC32F60A9CB0EEB5BB6A7F266BD0F6A0A99A45B4F18F0F477AED7C854C404EF43530DAB00",
+			output: "80028E8754F012C2FDB492183D41437FD837CB81D8BBE731924E2E0DAF43FD3F2C9300CAFE00787DC03E9E4EE05983E30BAE0DEFB8DB0671DBC2F5874AC93F8D8CA4018F7A42D6F9A9BCEADB422AC8E27CEE9CA205A0B88D22CD686F0A43EB806E8190A3C400",
+			key:    "8E8754F012C2FDB492183D41437FD837CB81D8BBE731924E2E0DAF43FD3F2C93",
+			sig:    "787DC03E9E4EE05983E30BAE0DEFB8DB0671DBC2F5874AC93F8D8CA4018F7A42D6F9A9BCEADB422AC8E27CEE9CA205A0B88D22CD686F0A43EB806E8190A3C400",
 			valid:  true,
 		},
 		{
@@ -75,9 +75,9 @@ func TestCryptoConvert(t *testing.T) {
 
 	cases := []cryptoCase{
 		{
-			msg:   "00",
-			key:   "04338EB1DD3CCDEE1F6FB586F66E640F56FFDD14537A3F0ED9EEEDF10B528FE4195FD17AC9EDAE9718A50196A1459E2434C1E53F1238F4CFDF177FAFBA8B39249B",
-			sig:   "FFDEA42A699205B217004E7E2FFB884E174A548D644116F4B20469CBC32F60A9CB0EEB5BB6A7F266BD0F6A0A99A45B4F18F0F477AED7C854C404EF43530DAB00",
+			msg:   "F00D",
+			key:   "8E8754F012C2FDB492183D41437FD837CB81D8BBE731924E2E0DAF43FD3F2C93",
+			sig:   "787DC03E9E4EE05983E30BAE0DEFB8DB0671DBC2F5874AC93F8D8CA4018F7A42D6F9A9BCEADB422AC8E27CEE9CA205A0B88D22CD686F0A43EB806E8190A3C400",
 			valid: true,
 		},
 	}
@@ -91,8 +91,13 @@ func TestCryptoConvert(t *testing.T) {
 		psig, err := parseSig(sig)
 		require.Nil(err, "%d: %+v", i, err)
 
-		// how do i make this valid?
+		// it is not the signature of the message itself
 		valid := pk.VerifyBytes(msg, psig)
+		assert.NotEqual(tc.valid, valid, "%d", i)
+
+		// but rather of the hash of the msg
+		hmsg := hashMsg(msg)
+		valid = pk.VerifyBytes(hmsg, psig)
 		assert.Equal(tc.valid, valid, "%d", i)
 	}
 }