MerkleTreeNodeSource (Bouncy Castle Library 1.86 API Specification)

All Known Implementing Classes:

ListMerkleTreeNodeSource
```
public interface MerkleTreeNodeSource
```
Source of Merkle tree node hashes for the proof generators in MerkleTreePrimitives, backed by whatever a log or CA keeps its tree in.
The generators walk the tree in the recursive form of RFC 9162 Section 2.1 and the draft's Section 4.4.1, and every hash they need is either a full subtree - a range [start, end) whose size is a power of two and whose start is a multiple of that size, MTH(D[start:end]) being one node of the tree - or a right-hand range that MerkleTreePrimitives.computeMerkleTreeHash(MerkleTreeNodeSource, long, long, MerkleTreeHash) combines from at most one full subtree per level. So a production log, which cannot hold its entries in memory, only has to answer for the nodes it would store or cache anyway; an in-memory tree of entry hashes can be adapted with ListMerkleTreeNodeSource.

A proof over a tree of size n makes O(log n) requests per proof element for a range that is not itself full, O(log^2 n) in all. Requests are never made outside the ranges the caller passed to the generator, so an implementation may treat any other request as an error.

See Also:

RFC 9162 Section 2.1

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method	Description
`byte[]`	`getFullSubtreeHash(long start, long end)`	Returns the hash `MTH(D[start:end])` of a full subtree.

- Method Detail
  - getFullSubtreeHash
```
byte[] getFullSubtreeHash(long start,
                          long end)
```
    Returns the hash MTH(D[start:end]) of a full subtree.
    
    Parameters:
    
    start - subtree start index (inclusive), a multiple of end - start
    
    end - subtree end index (exclusive); end - start is a power of two
    
    Returns:
    
    the node hash; for end == start + 1 this is the entry hash MTH({entry}), i.e. MerkleTreeHash.hashLeaf(byte[]) of the entry
    
    Throws:
    
    java.lang.IllegalArgumentException - if the node is not available, for instance because end is beyond the tree's current size