-
Notifications
You must be signed in to change notification settings - Fork 3
/
MerkleTree.js
executable file
·175 lines (169 loc) · 5.04 KB
/
MerkleTree.js
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
var sha256 = require('js-sha256');
class MerkleHash{
ComputeHash(value){
var SHA256 = sha256(value);
var hashValue = sha256(SHA256);
return hashValue;
}
CompareHash(hash1, hash2){
return hash1 === hash2;
}
CombinedHash(hash1, hash2){
var finalPreHash = hash1 + hash2;
var finalHash = this.ComputeHash(finalPreHash);
return finalHash;
}
}
class MerkleNode{
constructor(data, left = null, right = null, parent = null, direction = null){
this.data = data;
this.left = left;
this.right = right;
this.parent = parent;
this.direction = direction;
}
CreateCombinedNode(leftNode, rightNode){
var hash1 = leftNode.data;
var hash2 = rightNode.data;
// console.log(sha256(hash1 + hash2));
var newNode = new MerkleNode(sha256(hash1 + hash2));
return newNode;
}
}
class MerkleTree{
constructor(){
this.nodes = [];
this.leaves = [];
this.rootNode = '';
}
AppendNode(merkleNode){
this.nodes.push(merkleNode);
this.leaves.push(merkleNode);
}
AppendHash(merkleHash){
var node = new MerkleNode(merkleHash);
this.nodes.push(node);
this.leaves.push(node);
}
ConstructTree(){
if(this.leaves.length != 0){
this.BuildTree(this.leaves);
}
}
BuildTree(nodes){
if(nodes.length == 1){
this.rootNode = nodes[0];
return;
}else{
var parents = [];
for(var i=0; i<nodes.length; i=i+2){
var right = null;
if(i + 1 < nodes.length){
right = nodes[i + 1];
}else{
right = nodes[i];
right.direction = 'left';
}
var parent = new MerkleNode(0);
var parentNode = parent.CreateCombinedNode(nodes[i], right);
parents.push(parentNode);
nodes[i].parent = parentNode;
nodes[i].direction = 'left';
parentNode.left = nodes[i];
if(right!=null){
right.parent = parentNode;
right.direction = 'right';
parentNode.right = right;
}
}
this.BuildTree(parents);
}
}
FindLeaf(leafHash){
for(var i=0; i<this.leaves.length; i++){
if(this.leaves[i].data == leafHash){
return this.leaves[i];
}
}
return null;
}
AuditProof(leafHash){
var auditTrail = [];
var leafNode = this.FindLeaf(leafHash);
if(leafNode != null){
var parent = leafNode.parent;
this.BuildAuditTrail(auditTrail, parent, leafNode);
}
return auditTrail;
}
BuildAuditTrail(auditTrail, parentNode, childNode){
if(parentNode != null){
var nextChild = parentNode.left == childNode ? parentNode.right : parentNode.left;
if(nextChild != null){
auditTrail.push(nextChild);
}
if(childNode.parent!=null)
this.BuildAuditTrail(auditTrail, childNode.parent.parent, childNode.parent);
else{
return;
}
}
}
TreeTraversal(){
for(var i=0; i<this.nodes.length; i++){
console.log(this.nodes[i].data);
}
}
}
var tree = new MerkleTree();
var txn1 = 't1';
var txn2 = 't2';
var txn3 = 't3';
var txn4 = 't4';
var txn5 = 't5';
var txn6 = 't6';
var txn7 = 't7';
var txn8 = 't8';
var merkleHash = new MerkleHash();
var hash1 = merkleHash.ComputeHash(txn1);
var hash2 = merkleHash.ComputeHash(txn2);
var hash3 = merkleHash.ComputeHash(txn3);
var hash4 = merkleHash.ComputeHash(txn4);
var hash5 = merkleHash.ComputeHash(txn5);
var hash6 = merkleHash.ComputeHash(txn6);
var hash7 = merkleHash.ComputeHash(txn7);
var hash8 = merkleHash.ComputeHash(txn8);
tree.AppendHash(hash1);
tree.AppendHash(hash2);
tree.AppendHash(hash3);
tree.AppendHash(hash4);
tree.AppendHash(hash5);
tree.AppendHash(hash6);
tree.AppendHash(hash7);
tree.AppendHash(hash8);
tree.ConstructTree();
// console.log(tree.rootNode);
tree.TreeTraversal();
console.log("====================================================================================");
console.log("Merkle Proof of Transaction: " + txn7);
var trail = tree.AuditProof(hash7);
var currentHash = hash7;
console.log(trail);
for(var i=0; i<trail.length; i++){
console.log(trail[i].data);
}
for(var i=0; i<trail.length; i++){
// console.log(trail[i].data + " " + trail[i].direction);
if(trail[i].direction == 'left'){
currentHash = sha256(trail[i].data + currentHash);
}else{
currentHash = sha256(currentHash + trail[i].data);
}
}
if(tree.rootNode.data == currentHash){
console.log("Transaction Valid...");
console.log("Generated Hash: " + currentHash);
console.log("Merkle Root: " + tree.rootNode.data);
}else{
console.log(currentHash);
}