From bd4662fc7f62283736207296ea487b9d55674d4a Mon Sep 17 00:00:00 2001
From: LDE <lorianedehu@gmail.com>
Date: Sun, 3 Nov 2019 20:33:47 +0100
Subject: [PATCH 1/4] Class MerkleTree

---
 merkle_tree.py | 60 ++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 60 insertions(+)
 create mode 100644 merkle_tree.py

diff --git a/merkle_tree.py b/merkle_tree.py
new file mode 100644
index 0000000..1565433
--- /dev/null
+++ b/merkle_tree.py
@@ -0,0 +1,60 @@
+import hashlib
+
+class MerkleTree:
+    # Hash pairs of items recursively until a single value is obtained
+    @staticmethod
+    def merkle(hashList):
+        if len(hashList) == 1:
+            return hashList[0]
+        newHashList = []
+        # Process pairs. For odd length, the last is skipped
+        for i in range(0, len(hashList)-1, 2):
+            newHashList.append(MerkleTree.hashRoot(hashList[i], hashList[i+1]))
+        if len(hashList) % 2 == 1: # odd, hash last item twice
+            newHashList.append(MerkleTree.hashRoot(hashList[-1], hashList[-1]))
+        return MerkleTree.merkle(newHashList)
+
+    @staticmethod
+    def hashRoot(a, b):
+        strTmp=(a+b)
+        h = hashlib.sha256(strTmp.encode()).hexdigest()
+        return h
+
+    @staticmethod
+    def merkleProof(txs, tx, proof = None):
+        if proof is None:
+            proof = []
+
+        if len(txs) == 1:
+            return proof
+        tree = []
+
+        for i in range(0, len(txs)-1, 2):
+            tmpHash = MerkleTree.hashRoot(txs[i], txs[i+1])
+            if txs[i] == tx:
+                proof.append([1, txs[i+1]])
+                tx = tmpHash
+            elif txs[i+1] == tx:
+                tx = tmpHash
+                proof.append([0, txs[i]])
+            tree.append(tmpHash)
+
+        if len(txs) % 2 == 1: # odd, hash last item twice
+            tmpHash = MerkleTree.hashRoot(txs[-1], txs[-1])
+            if txs[i] == tx:
+                proof.append([1, txs[-1]])
+                tx = tmpHash
+            tree.append(tmpHash)
+
+        return MerkleTree.merkleProof(tree, tx, proof)
+
+    @staticmethod
+    def merkleProofRoot(root, proof, tx):
+        tmpHash = tx
+        for i in range(0, len(proof), 1):
+            if proof[i][0] == 0:
+                tmpHash = MerkleTree.hashRoot(proof[i][1], tmpHash)
+            else:
+                tmpHash = MerkleTree.hashRoot(tmpHash, proof[i][1])
+        return root == tmpHash
+                

From 11758b45f3f8d4213298f9167855787b21ac88bb Mon Sep 17 00:00:00 2001
From: LDE <lorianedehu@gmail.com>
Date: Tue, 5 Nov 2019 00:40:40 +0100
Subject: [PATCH 2/4] Ajout du merkleRoot dans chaque block

---
 block.py | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/block.py b/block.py
index 95bb2a9..a0a4031 100644
--- a/block.py
+++ b/block.py
@@ -2,8 +2,10 @@
 from time import time
 import hashlib
 
+from merkle_tree import MerkleTree
+
 MINING_DIFFICULTY = 2
-HASH_GENESIS_BLOCK = "a37c5dfb2a28763c7e4468f4d817f109d9ae4ccbbb7fdefe9ee2f27b0ab3974f"
+HASH_GENESIS_BLOCK = "b4358083b2c93824360c5779e1cbe00998d7f09553fd7d18ef8f012b59e82a0f"
 
 
 class Block(object):
@@ -14,6 +16,15 @@ def __init__(self, nonce, transactions, index, previous_hash):
         self.timestamp = time()
         self.previous_hash = previous_hash
 
+        self.merkle_root
+
+    @property
+    def merkle_root(self):
+        txs_hashes = []
+        for tx in self.transactions:
+            txs_hashes.append(hashlib.sha256(tx.toJSON().encode()).hexdigest())
+        return MerkleTree.merkle(txs_hashes)
+
     @staticmethod
     def hash(block):
         """

From f5765eb62bc60b3b235172ba87e1a3d95b17ddc1 Mon Sep 17 00:00:00 2001
From: LDE <lorianedehu@gmail.com>
Date: Tue, 5 Nov 2019 01:02:59 +0100
Subject: [PATCH 3/4] Test : fonction get MerkleRoot

---
 merkle_tree.py      |  2 ++
 test_merkle_tree.py | 15 +++++++++++++++
 2 files changed, 17 insertions(+)
 create mode 100644 test_merkle_tree.py

diff --git a/merkle_tree.py b/merkle_tree.py
index 1565433..1161805 100644
--- a/merkle_tree.py
+++ b/merkle_tree.py
@@ -4,6 +4,8 @@ class MerkleTree:
     # Hash pairs of items recursively until a single value is obtained
     @staticmethod
     def merkle(hashList):
+        if len(hashList) == 0:
+            return False
         if len(hashList) == 1:
             return hashList[0]
         newHashList = []
diff --git a/test_merkle_tree.py b/test_merkle_tree.py
new file mode 100644
index 0000000..f8a8b42
--- /dev/null
+++ b/test_merkle_tree.py
@@ -0,0 +1,15 @@
+from merkle_tree import MerkleTree
+
+txHashes = [
+  'ca978112ca1bbdcafac231b39a23dc4da786eff8147c4e72b9807785afee48bb', # a
+  '3e23e8160039594a33894f6564e1b1348bbd7a0088d42c4acb73eeaed59c009d', # b
+  '2e7d2c03a9507ae265ecf5b5356885a53393a2029d241394997265a1a25aefc6', # c
+  '18ac3e7343f016890c510e93f935261169d9e3f565436429830faf0934f4f8e4', # d
+  '3f79bb7b435b05321651daefd374cdc681dc06faa65e374e38337b88ca046dea' # e
+]
+
+def test_merkle():
+    assert MerkleTree.merkle([]) == False
+    assert MerkleTree.merkle(['aa']) == 'aa'
+    assert MerkleTree.merkle(txHashes[:2]) == '62af5c3cb8da3e4f25061e829ebeea5c7513c54949115b1acc225930a90154da'
+    assert MerkleTree.merkle(txHashes[:3]) == '0bdf27bf7ec894ca7cadfe491ec1a3ece840f117989e8c5e9bd7086467bf6c38'

From afce7c45141b6631badf5c5ad93d374280ac2ada Mon Sep 17 00:00:00 2001
From: LDE <lorianedehu@gmail.com>
Date: Wed, 6 Nov 2019 00:27:12 +0100
Subject: [PATCH 4/4] Correction merkle root

---
 block.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/block.py b/block.py
index 1ea0b35..75d1918 100644
--- a/block.py
+++ b/block.py
@@ -22,7 +22,7 @@ def __init__(self, nonce, transactions, index, previous_hash):
     def merkle_root(self):
         txs_hashes = []
         for tx in self.transactions:
-            txs_hashes.append(hashlib.sha256(tx.toJSON().encode()).hexdigest())
+            txs_hashes.append(hashlib.sha256(tx.signature).hexdigest())
         return MerkleTree.merkle(txs_hashes)
 
     @staticmethod