save confirmations sigs into app state

contracts/.travis.yml

@@ -6,8 +6,8 @@ before_script:
   - npm install -g [email protected] [email protected]
   - npm install
 
-script: 
-  - ganache-cli -m=plasma_mvp > /dev/null &
+script:
+  - ganache-cli -m "they only media any modify banner suffer pole tag rule creek harvest" > /dev/null &
   - sleep 5
   - truffle migrate
   - truffle test

contracts/CONTRIBUTING.md

@@ -2,7 +2,7 @@
 
 Thank you for considering making contributions to Fourth State's Plasma MVP implementation! We welcome contributions from anyone! See the [open issues](https://github.com/FourthState/plasma-mvp-rootchain/issues) for things we need help with!
 
-Contribute to design discussions and conversation by joining the #plasma-dev channel on Blockchain @ Berkeley's [public slack](https://www.berkeleyblockchain.slack.com/).
+Contribute to design discussions and conversation by joining our [Discord Server](https://discord.gg/YTB5A4P).
 
 ## How to get started:
 
@@ -17,7 +17,7 @@ Otherwise:
 Install dependencies with:
 ``npm install``
 
-**Note**: requires Solidity 0.4.24 and Truffle 4.1.13
+**Note**: requires Solidity 0.4.24 and Truffle 4.1.14
 
 Make sure the tests pass:
 1. Start ganache-cli: ``ganache-cli -m=plasma_mvp``

contracts/README.md

@@ -15,12 +15,12 @@ The root contract of a Plasma child chain represents an intermediary who can res
 A transaction is encoded in the following form:
 
 ```
-[ 
-  [Blknum1, TxIndex1, Oindex1, DepositNonce1, Amount1, ConfirmSig1,
+[
+  [Blknum1, TxIndex1, Oindex1, DepositNonce1, Owner1, Input1ConfirmSig,
 
-  Blknum2, TxIndex2, Oindex2, DepositNonce2, Amount2, ConfirmSig2,
+   Blknum2, TxIndex2, Oindex2, DepositNonce2, Owner2, Input2ConfirmSig,
 
-  NewOwner, Denom1, NewOwner, Denom2, Fee],
+   NewOwner, Denom1, NewOwner, Denom2, Fee],
 
   [Signature1, Signature2]
 ]

contracts/contracts/libraries/Validator.sol

@@ -8,30 +8,64 @@ library Validator {
     // @param leaf     a leaf of the tree
     // @param index    position of this leaf in the tree that is zero indexed
     // @param rootHash block header of the merkle tree
-    // @param proof    sequence of hashes from the leaf to check against the root
-    function checkMembership(bytes32 leaf, uint256 index, bytes32 rootHash, bytes proof)
+    // @param proof    sequence of 32-byte hashes from the leaf up to, but excluding, the root
+    function checkMembership(bytes32 leaf, uint256 index, bytes32 rootHash, bytes proof, uint256 total)
         internal
         pure
         returns (bool)
     {
-        // depth 16 merkle tree
-        require(proof.length == 512, "Incorrect proof length");
+        // variable size Merkle tree, but proof must consist of 32-byte hashes
+        require(proof.length % 32 == 0, "Incorrect proof length");
 
+        bytes32 computedHash = computeHashFromAunts(index, total, leaf, proof);
+        return computedHash == rootHash;
+    }
+
+    // from https://tendermint.com/docs/spec/blockchain/encoding.html#merkle-trees
+    function computeHashFromAunts(uint256 index, uint256 total, bytes32 leaf, bytes innerHashes)
+        internal
+        pure
+        returns (bytes32)
+    {
+        require(index < total, "Index must be less than total number of leaf nodes");
+        require(total > 0, "Must have at least one leaf node");
+
+        if (total == 1) {
+            require(innerHashes.length == 0, "Simple Tree with 1 txn should have no innerHashes");
+            return leaf;
+        }
+        require(innerHashes.length != 0, "Simple Tree with > 1 txn should have innerHashes");
+
+        uint256 numLeft = (total + 1) / 2;
         bytes32 proofElement;
-        bytes32 computedHash = leaf;
 
-        for (uint256 i = 32; i <= 512; i += 32) {
+        // prepend 0x20 byte literal to hashes
+        // tendermint prefixes intermediate hashes with 0x20 bytes literals
+        // before hashing them.
+        bytes memory b = new bytes(1);
+        assembly {
+            let memPtr := add(b, 0x20)
+            mstore8(memPtr, 0x20)
+        }
+
+        if (index < numLeft) {
+            bytes32 leftHash = computeHashFromAunts(index, numLeft, leaf, slice(innerHashes, 0, innerHashes.length - 32));
+            uint innerHashesMemOffset = innerHashes.length - 32;
             assembly {
-                proofElement := mload(add(proof, i))
+                // get the last 32-byte hash from innerHashes array
+                proofElement := mload(add(add(innerHashes, 0x20), innerHashesMemOffset))
             }
-            if (index % 2 == 0) {
-                computedHash = keccak256(abi.encodePacked(computedHash, proofElement));
-            } else {
-                computedHash = keccak256(abi.encodePacked(proofElement, computedHash));
+
+            return sha256(abi.encodePacked(b, leftHash, b, proofElement));
+        } else {
+            bytes32 rightHash = computeHashFromAunts(index-numLeft, total-numLeft, leaf, slice(innerHashes, 0, innerHashes.length - 32));
+            innerHashesMemOffset = innerHashes.length - 32;
+            assembly {
+                    // get the last 32-byte hash from innerHashes array
+                    proofElement := mload(add(add(innerHashes, 0x20), innerHashesMemOffset))
             }
-            index = index / 2;
+            return sha256(abi.encodePacked(b, proofElement, b, rightHash));
         }
-        return computedHash == rootHash;
     }
 
     // @param txHash      transaction hash

contracts/contracts/libraries/Validator_Test.sol

@@ -10,12 +10,12 @@ contract Validator_Test {
 
   using Validator for bytes32;
 
-  function checkMembership(bytes32 leaf, uint256 index, bytes32 rootHash, bytes proof)
+  function checkMembership(bytes32 leaf, uint256 index, bytes32 rootHash, bytes proof, uint256 total)
       public
       pure
       returns (bool)
   {
-      return leaf.checkMembership(index, rootHash, proof);
+      return leaf.checkMembership(index, rootHash, proof, total);
   }
 
   function checkSigs(bytes32 txHash, bytes32 confirmationHash, bool input1, bytes sig0, bytes sig1, bytes confirmSignatures)