3p-circuit-oram-prac-repro/ObliVMGC/com/oblivm/backend/oram/TreeBasedOramParty.java

// Copyright (C) 2014 by Xiao Shaun Wang <wangxiao@cs.umd.edu>
package com.oblivm.backend.oram;

import com.oblivm.backend.flexsc.CompEnv;
import com.oblivm.backend.flexsc.Mode;
import com.oblivm.backend.flexsc.Party;

public abstract class TreeBasedOramParty<T> extends OramParty<T> {
	public PlainBlock[][] tree;
	protected int capacity;

	public TreeBasedOramParty(CompEnv<T> env, int N, int dataSize, int capacity) {
		super(env, N, dataSize);
		this.capacity = capacity;

		if (env.mode != Mode.COUNT) {
			tree = new PlainBlock[this.N][capacity];

			PlainBlock b = getDummyBlock(p == Party.Alice);

			for (int i = 0; i < this.N; ++i)
				for (int j = 0; j < capacity; ++j)
					tree[i][j] = b;
		}
	}

	protected PlainBlock[][] getPath(boolean[] path) {
		PlainBlock[][] result = new PlainBlock[logN][];
		if (env.mode == Mode.COUNT) {
			for (int i = 0; i < logN; ++i) {
				result[i] = new PlainBlock[capacity];
				for (int j = 0; j < capacity; ++j)
					result[i][j] = getDummyBlock(true);
			}
			return result;
		}
		int index = 1;
		result[0] = tree[index];
		for (int i = 1; i < logN; ++i) {
			index *= 2;
			if (path[lengthOfPos - i])
				++index;
			result[i] = tree[index];
		}
		return result;
	}

	protected void putPath(PlainBlock[][] blocks, boolean[] path) {
		if (env.mode == Mode.COUNT)
			return;
		int index = 1;
		tree[index] = blocks[0];
		for (int i = 1; i < logN; ++i) {
			index *= 2;
			if (path[lengthOfPos - i])
				++index;
			tree[index] = blocks[i];
		}
	}

	public Block<T>[][] preparePath(PlainBlock[][] clientBlock, PlainBlock[][] serverBlock) {
		Block<T>[][] s = inputPathOfServer(serverBlock);
		Block<T>[][] c = inputPathOfClient(clientBlock);
		return lib.xor(s, c);
	}

	public Block<T>[][] inputPathOfClient(PlainBlock[][] b) {
		int length = 0;
		for (int i = 0; i < b.length; ++i)
			length += b[i].length;

		PlainBlock[] tmp = new PlainBlock[length];
		int cnt = 0;
		for (int i = 0; i < b.length; ++i)
			for (int j = 0; j < b[i].length; ++j)
				tmp[cnt++] = b[i][j];

		Block<T>[] tmpResult = inputBucketOfClient(tmp);
		cnt = 0;
		Block<T>[][] result = lib.newBlockMatrix(b.length);
		for (int i = 0; i < b.length; ++i) {
			result[i] = lib.newBlockArray(b[i].length);
			for (int j = 0; j < b[i].length; ++j)
				result[i][j] = tmpResult[cnt++];
		}
		return result;
	}

	public Block<T>[][] inputPathOfServer(PlainBlock[][] b) {
		int length = 0;
		for (int i = 0; i < b.length; ++i)
			length += b[i].length;

		PlainBlock[] tmp = new PlainBlock[length];
		int cnt = 0;
		for (int i = 0; i < b.length; ++i)
			for (int j = 0; j < b[i].length; ++j)
				tmp[cnt++] = b[i][j];
		Block<T>[] tmpResult = inputBucketOfServer(tmp);

		cnt = 0;
		Block<T>[][] result = lib.newBlockMatrix(b.length);
		for (int i = 0; i < b.length; ++i) {
			result[i] = lib.newBlockArray(b[i].length);
			for (int j = 0; j < b[i].length; ++j)
				result[i][j] = tmpResult[cnt++];
		}
		return result;
	}

	public PlainBlock[][] preparePlainPath(Block<T>[][] blocks) {
		Block<T>[][] randomSCPath = lib.newBlockMatrix(blocks.length);

		PlainBlock[][] randomPath = new PlainBlock[blocks.length][];
		for (int i = 0; i < randomPath.length; ++i) {
			randomPath[i] = randomBucket(blocks[i].length);
		}
		env.flush();

		randomSCPath = inputPathOfServer(randomPath);

		PlainBlock[][] result = outputBuckets(lib.xor(blocks, randomSCPath));

		if (p == Party.Alice)
			return result;
		else
			return randomPath;
	}

	public PlainBlock[][] randomPath(PlainBlock[][] path) {
		PlainBlock[][] result = new PlainBlock[path.length][];
		for (int i = 0; i < path.length; ++i)
			result[i] = randomBucket(path[i].length);
		return result;
	}
}