From 01963a8f413af3151955edc97de5be59d45f159a Mon Sep 17 00:00:00 2001
From: arnaucube <arnaucube@gmail.com>
Date: Sun, 7 Apr 2019 15:57:01 +0200
Subject: [PATCH] node block PoW, sign and verify

---
 core/block.go     | 12 ++++++++++++
 node/node.go      |  6 +++++-
 node/node_test.go | 39 ++++++++++++++++++++++-----------------
 3 files changed, 39 insertions(+), 18 deletions(-)

diff --git a/core/block.go b/core/block.go
index 068e373..2d8a655 100644
--- a/core/block.go
+++ b/core/block.go
@@ -1,6 +1,7 @@
 package core
 
 import (
+	"crypto/ecdsa"
 	"encoding/json"
 	"time"
 )
@@ -80,15 +81,26 @@ func (block *Block) CalculatePoW(difficulty uint64) error {
 		hash = HashBytes(blockCopy.Bytes())
 	}
 	block.Hash = hash
+	block.Nonce = blockCopy.Nonce
 	return nil
 }
 
 func CheckBlockPoW(block *Block, difficulty uint64) bool {
 	blockCopy := block.Copy()
 	blockCopy.Hash = Hash{}
+	blockCopy.Signature = []byte{}
 	return CheckPoW(HashBytes(blockCopy.Bytes()), difficulty)
 }
 
+func VerifyBlockSignature(pubK *ecdsa.PublicKey, block *Block) bool {
+	sig, err := SignatureFromBytes(block.Signature)
+	if err != nil {
+		return false
+	}
+
+	return VerifySignature(pubK, block.Hash[:], *sig)
+}
+
 func BlockFromBytes(b []byte) (*Block, error) {
 	var block *Block
 	err := json.Unmarshal(b, &block)
diff --git a/node/node.go b/node/node.go
index 8fbc9ca..2610348 100644
--- a/node/node.go
+++ b/node/node.go
@@ -35,6 +35,10 @@ func (node *Node) Sign(m []byte) (*core.Signature, error) {
 	return core.Sign(node.PrivK, m)
 }
 
+func (node *Node) SignBlock(block *core.Block) (*core.Signature, error) {
+	return core.Sign(node.PrivK, block.Hash[:])
+}
+
 func (node *Node) AddToPendingTxs(tx core.Tx) {
 	node.PendingTxs = append(node.PendingTxs, tx)
 }
@@ -45,7 +49,7 @@ func (node *Node) BlockFromPendingTxs() (*core.Block, error) {
 	if err != nil {
 		return nil, err
 	}
-	sig, err := node.Sign(block.Bytes())
+	sig, err := node.SignBlock(block)
 	if err != nil {
 		return nil, err
 	}
diff --git a/node/node_test.go b/node/node_test.go
index 7eec9ec..db4d53c 100644
--- a/node/node_test.go
+++ b/node/node_test.go
@@ -51,23 +51,28 @@ func TestBlockFromPendingTxs(t *testing.T) {
 	tx := core.NewTx(addr0, addr1, []core.Input{}, []core.Output{})
 	node.AddToPendingTxs(*tx)
 	block, err := node.BlockFromPendingTxs()
+	assert.Nil(t, err)
 	assert.True(t, core.CheckBlockPoW(block, node.Bc.Difficulty))
-	// TODO add VerifyBlockSignature
+	assert.True(t, core.VerifyBlockSignature(&node.PrivK.PublicKey, block))
 }
 
-// func TestBlockFromPendingTxsIteration(t *testing.T) {
-//         dir, err := ioutil.TempDir("", "db")
-//         assert.Nil(t, err)
-//         db, err := db.New(dir)
-//         assert.Nil(t, err)
-//
-//         node, err := NewNode(db, uint64(1))
-//         assert.Nil(t, err)
-//
-//         addr0 := core.Address(core.HashBytes([]byte("addr0")))
-//         addr1 := core.Address(core.HashBytes([]byte("addr1")))
-//         for i := 0; i < 10; i++ {
-//                 tx := core.NewTx(addr0, addr1, []core.Input{}, []core.Output{})
-//
-//         }
-// }
+func TestBlockFromPendingTxsIteration(t *testing.T) {
+	dir, err := ioutil.TempDir("", "db")
+	assert.Nil(t, err)
+	db, err := db.New(dir)
+	assert.Nil(t, err)
+
+	node, err := NewNode(db, uint64(1))
+	assert.Nil(t, err)
+
+	addr0 := core.Address(core.HashBytes([]byte("addr0")))
+	addr1 := core.Address(core.HashBytes([]byte("addr1")))
+	for i := 0; i < 10; i++ {
+		tx := core.NewTx(addr0, addr1, []core.Input{}, []core.Output{})
+		node.AddToPendingTxs(*tx)
+	}
+	block, err := node.BlockFromPendingTxs()
+	assert.Nil(t, err)
+	assert.True(t, core.CheckBlockPoW(block, node.Bc.Difficulty))
+	assert.True(t, core.VerifyBlockSignature(&node.PrivK.PublicKey, block))
+}