// Override in derived class to extend the behavior.
// Alternatively, we could implement a factory pattern.
protected virtual MerkleNode CreateNode(MerkleHash hash)
{
return(new MerkleNode(hash));
}
public MerkleNode AppendLeaf(MerkleHash hash) => AppendLeaf(CreateNode(hash));
/*
* /// <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 VerifyConsistency(MerkleHash oldRootHash, List<MerkleProofHash> proof)
* {
* MerkleHash hash, lhash, rhash;
*
* if (proof.Count > 1)
* {
* lhash = proof[proof.Count - 2].Hash;
* int hidx = proof.Count - 1;
* hash = rhash = MerkleTree.ComputeHash(lhash, proof[hidx].Hash);
* hidx -= 2;
*
* // foreach (var nextHashNode in proof.Skip(1))
* while (hidx >= 0)
* {
* lhash = proof[hidx].Hash;
* hash = rhash = MerkleTree.ComputeHash(lhash, rhash);
*
* --hidx;
* }
* }
* else
* {
* hash = proof[0].Hash;
* }
*
* return hash == oldRootHash;
* }
*/
public static MerkleHash ComputeHash(MerkleHash left, MerkleHash right)
{
return(MerkleHash.Create(left.Value.Concat(right.Value).ToArray()));
}
protected MerkleNode FindLeaf(MerkleHash leafHash)
{
return(RootNode.Leaves().FirstOrDefault(l => l.Hash == leafHash));
}
protected override MerkleNode CreateNode(MerkleHash hash)
{
return(new EventMerkleNode(hash));
}
public static EventMerkleNode Create(string s)
{
return(new EventMerkleNode(MerkleHash.Create(s)));
}
public EventMerkleNode(MerkleHash hash)
{
Hash = hash;
}
/// <summary>
/// Constructor for a base node (leaf), representing the lowest level of the tree.
/// </summary>
public MerkleNode(MerkleHash hash)
{
Hash = hash;
}
public MerkleHash ComputeHash(byte[] buffer)
{
Hash = MerkleHash.Create(buffer);
return(Hash);
}