protected void ComputeHash()
{
Hash = RightNode == null ?
LeftNode.Hash : //MerkleHash.Create(LeftNode.Hash.Value.Concat(LeftNode.Hash.Value).ToArray()) :
MerkleHash.Create(LeftNode.Hash.Value.Concat(RightNode.Hash.Value).ToArray());
Parent?.ComputeHash(); // 부모가 있다면 부모노드로 가서 또 ComputeHash를 수행.
}
/// <summary>
/// For demo / debugging purposes, we return the pairs of hashes used to verify the audit proof.
/// </summary>
public static List <Tuple <MerkleHash, MerkleHash> > AuditHashPairs(MerkleHash leafHash, List <MerkleProofHash> auditTrail)
{
Contract(() => auditTrail.Count > 0, "Audit trail cannot be empty.");
var auditPairs = new List <Tuple <MerkleHash, MerkleHash> >();
MerkleHash testHash = leafHash;
// TODO: Inefficient - compute hashes directly.
foreach (MerkleProofHash auditHash in auditTrail)
{
switch (auditHash.Direction)
{
case MerkleProofHash.Branch.Left:
auditPairs.Add(new Tuple <MerkleHash, MerkleHash>(testHash, auditHash.Hash));
testHash = MerkleHash.Create(testHash.Value.Concat(auditHash.Hash.Value).ToArray());
break;
case MerkleProofHash.Branch.Right:
auditPairs.Add(new Tuple <MerkleHash, MerkleHash>(auditHash.Hash, testHash));
testHash = MerkleHash.Create(auditHash.Hash.Value.Concat(testHash.Value).ToArray());
break;
}
}
return(auditPairs);
}
public static bool VerifyAudit(MerkleHash rootHash, MerkleHash leafHash, List <MerkleProofHash> auditTrail)
{
Contract(() => auditTrail.Count > 0, "Audit trail cannot be empty.");
MerkleHash testHash = leafHash;
// TODO: Inefficient - compute hashes directly.
foreach (MerkleProofHash auditHash in auditTrail)
{
testHash = auditHash.Direction == MerkleProofHash.Branch.Left ?
MerkleHash.Create(testHash.Value.Concat(auditHash.Hash.Value).ToArray()) :
MerkleHash.Create(auditHash.Hash.Value.Concat(testHash.Value).ToArray());
}
return(rootHash == testHash);
}
/// <summary>
/// 검증
/// </summary>
/// <returns></returns>
public bool VerifyHash()
{
//왼쪽, 오른쪽 노드 둘다 Null이면 true
if (LeftNode == null && RightNode == null)
{
return(true);
}
//오른쪽 노드가 널이라면
if (RightNode == null)
{
//부모의 해쉬와 왼쪽노드의 해쉬가 같다면 true
return(Hash.Equals(LeftNode.Hash));
}
MerkleTree.Contract(() => LeftNode != null, "Left branch must be a node if right branch is a node.");
MerkleHash leftRightHash = MerkleHash.Create(LeftNode.Hash, RightNode.Hash);
//왼쪽, 오른쪽 노드의 해쉬 Sum 시킨값이 이 노드의 Hash와 같다면 true.
return(Hash.Equals(leftRightHash));
}
public MerkleHash ComputeHash(byte[] buffer)
{
Hash = MerkleHash.Create(buffer);
return(Hash);
}
public static MerkleHash ComputeHash(MerkleHash left, MerkleHash right)
{
return(MerkleHash.Create(left.Value.Concat(right.Value).ToArray()));
}
