truebitfoundation/webasm-solidity

[DEPRECATED] On-chain interpreter for WebAssembly written in Solidity

webasm-solidity's Issues

Several kinds of judges

Perhaps the tasks should have a reference to the judge they use.

Better directory hierarchy

Put stuff to different directories.

Handle wrong number of steps properly

If the verifier tries to get the state of a program after n steps, and there were not really n steps, currently there would be no result at all.

Implement off-chain interpreter in Solidity

To be sure that on-chain and off-chain interpreter always match, the off-chain interpreter should also be implemented in Solidity. For this, some refactoring is first needed.
Some ideas:
https://github.com/TrueBitFoundation/webasm-solidity/wiki/Memory-abstraction

[test node] Option to change error location and whether verifier or solver makes the error

Add this to the user interface (app.html) and make corresponding changes in app.js

deleteChallenge is public

Noticed that the deleteChallenge method in interactive is public and doesn't include any requires. need to change this.

Undefined hint values should fail

Check that the interpreter always fails if the hint is incorrect.

Setting VM parameters

The task giver needs to be able to set the VM parameters like how much memory is available, stack size etc.
Then there has to be a way to build the initial state from these parameters.

Dispute Resolution support preprocessing pipeline task

Before a normal wasm task is submitted there can also be a preprocessing step. This preprocessing can involve a pipeline

Pipeline

-Preprocess code (initialize wasm task)
-Floating point
-Metering
-Linking (Optional)

Each of these steps could use their own verification games, or they can be combined into one game (aka the pipeline task). This single pipeline task can simply return the root hash of the preprocessed files.

In the case where a verifier challenges a task, and that task uses the preprocessing step, a verifier will dispute the preprocessing task first. Then once that passes, the game will carry on to the normal wasm task dispute.

tasks contract should include timeout for taskGiver

Need to be able to timeout if a task doesnt get solved for a period of time

Need to be able to timeout if the solver doesnt post solution in time

Uploading data to blockchain

Find out if there already is a good mechanism for loading data to blockchain without using too much gas.

Offchain interpreter that can generate proofs

At the moment, the solidity offchain interpreter isn't able to generate the proofs that are needed for running the onchain version.

Use abi.encodePacked for inputs to keccak256

Solidity compiler gives this type of warning quite a bit.
fs.sol:52:20: Warning: This function only accepts a single "bytes" argument. Please use "abi.encodePacked(...)" or a similar function to encode the data.

I believe this is a breaking change in 0.5.0, so it would be good to change this sooner than later.

Merkle computer should take interpreter path as input

Right now the wasmInterpreterPath is expected to be ../ from the cwd. It would be best to be able to input the path as a parameter somewhere.

Perhaps splitting up the merkle-computer file into compute, and utils might make this easier.

When accessing input from blockchain, do not require merkle roots

Needs some changes to proof generation.

Handle final state

Making sure that the state posted by the solver is really final, or execution ended with error.

Handling runtime errors

Test and implement the handling run time errors properly.

Add CI

Add automated testing.

Implement new input and output instructions

Going to implement these after they are working in the offchain intrepreter.

More tests

Need to test the following cases:

• solver and verifier have different number of steps
• solver and verifier disagree whether the state is final
• solver and verifier disagree whether an runtime error has happened in the execution

Solvers should check if the task has already been solved

Native execution of wasm files

What is blocking this at the moment:

• verified initialization: TrueBitFoundation/ocaml-offchain#39
• the result will have to be just the hash of output, when the challenge is posted, the solver will have to submit the initial and final state with proofs that they are compatible with the posted initial code, input and output
• also have to post the number of steps at that time

Add tests to CI

Currently travis only runs this test https://github.com/TrueBitFoundation/webasm-solidity/blob/master/test/judge.js

We need to add continuous integration support for the newly added tests such as:
test/task-lifecycle.js
test/task-lifecycle-ipfs.js
test/task-alphabet.js
test/task-alphabet-challenge.js

This will also involve adding ipfs to travis because all the tests above (beside task-lifecycle) depend on it.

FPU Emulation

Each floating point opcode should be changed into a function call. These functions implement the floating point ops with integer ops and use a fixed amount of steps, so they can be skipped by the interpreter.

Perhaps first it will be easiest to just pre-process it and always run the functions without skipping.

how to get result for giver?

for example, when i run

./wasm -m  -memory-size 16 -stack-size 14 -table-size 8 -globals-size 8 -call-stack-size 10 -case 0 ./factorial.wast -output

off-chain, it may show that

{"vm": { "code": "0x4ce57322d69eb9f405acdc0d13174b14595414a75df8c458a5e7c68739bb5f78", "stack": "0xd37da133d3b660a1aa6bdfe5f7f7a805c1ce5ce693da5138065878648e015319", "memory": "0x2733e50f526ec2fa19a22b31e8ed50f23cd1fdf94c9154ed3a7609a2f1ff981f", "input_size": "0xf9dc3e7fe016e050eff260334f18a5d4fe391d82092319f5964f2e2eb7c1c3a5", "input_name": "0xf9dc3e7fe016e050eff260334f18a5d4fe391d82092319f5964f2e2eb7c1c3a5", "input_data": "0xe026cc5a4aed3c22a58cbd3d2ac754c9352c5436f638042dca99034e83636516", "call_stack": "0x6b2a56fef280042cd8f791b2b1d47198ee5a21cfb40cc8c13e7adb5dab2db3b7", "globals": "0x9867cc5f7f196b93bae1e27e6320742445d290f2263827498b54fec539f756af", "calltable": "0x9dc25e3b944260e342d33236a1c3aba8c451c07733651c561e0a53b843757217", "calltypes": "0x9867cc5f7f196b93bae1e27e6320742445d290f2263827498b54fec539f756af", "pc": 1099511627775, "stack_ptr": 1, "call_ptr": 0, "memsize": 0 }, "hash": "0xb54475a73855987df7992919637f0bcbc8a434a03d77f903960f269f8b254ee7", "steps": 499, "files": []}

how can i get the task output result? thanks a log

Split instruction.sol to multiple files

Use inheritance to split it up to more manageable pieces.

ERR_OUT_OF_RANGE when executing '$node deploy-tasks.js > config.json

RangeError [ERR_OUT_OF_RANGE]: The value of "value" is out of range. It must be >= 0 and <= 4294967295. Received -1362828628
at checkInt (internal/buffer.js:35:11)
at writeU_Int32BE (internal/buffer.js:625:3)
at Buffer.writeUInt32BE (internal/buffer.js:638:10)
at WebSocketFrame.toBuffer (D:\HJ\Projects\WAGON\webasm-solidity-master\node_modules\websocket\lib\WebSocketFrame.js:257:24)
at WebSocketConnection.sendFrame (D:\HJ\Projects\WAGON\webasm-solidity-master\node_modules\websocket\lib\WebSocketConnection.js:852:43)
at WebSocketConnection.fragmentAndSend (D:\HJ\Projects\WAGON\webasm-solidity-master\node_modules\websocket\lib\WebSocketConnection.js:788:14)
at WebSocketConnection.sendUTF (D:\HJ\Projects\WAGON\webasm-solidity-master\node_modules\websocket\lib\WebSocketConnection.js:728:10)
at W3CWebSocket.send (D:\HJ\Projects\WAGON\webasm-solidity-master\node_modules\websocket\lib\W3CWebSocket.js:116:26)
at WebsocketProvider.send (D:\HJ\Projects\WAGON\webasm-solidity-master\node_modules\web3-providers-ws\src\index.js:223:21)
at Timeout._onTimeout (D:\HJ\Projects\WAGON\webasm-solidity-master\node_modules\web3-providers-ws\src\index.js:203:19)
at ontimeout (timers.js:427:11)
at tryOnTimeout (timers.js:289:5)
at listOnTimeout (timers.js:252:5)
at Timer.processTimers (timers.js:212:10)

this error occured with createContract("Judge")
Judge.bin file is to heavy
how can I finish this work?

Handle missing events

Try to find out the state of the verification game, and act accordingly.

Judges as external functions

There could be some kind of instruction that would trigger another verification game. For example there could be a function to execute another wasm program inside the wasm programs.

Error and warnings when compiling contracts

when running sh compile.sh with solc 0.4.19 i get the following error and warnings:

fs.sol:126:43: Warning: Unused function parameter. Remove or comment out the variable name to silence this warning.
   function debug_forwardData(bytes32 id, address a) public returns (uint) {
                                          ^-------^
fs.sol:126:4: Warning: Function state mutability can be restricted to view
   function debug_forwardData(bytes32 id, address a) public returns (uint) {
   ^
Spanning multiple lines.
Error: Documented parameter "limit
@param" not found in the parameter list of the function.

Running the node without needing ethereum node

Need to find out how to handle signing messages.

popcnt, ctz, clz

Implement popcnt, ctz and clz operations in Solidity.
Also other operations have to be checked properly.

Actually download the data from blockchain

Implement downloading data from blockchain in the test node

JSON error with app.js

Was running through the README and was able to run deploy-tasks.js with parity chain dev to create the config.json. But when I try to run app.js it gives a JSON error.

This is because deploy-tasks.js is outputting two json objects, instead of one, like app.js expects.

{ "interactive": "0x4d06047ed426e2a2f0bbe86cee268200d20b8d62", "tasks" : "0xcfa55b9b5c1c05e81a7f306a841ae6f3b489d057" }
{ "interactive": "0x7a0d30234e146a88cd65f0714ab7603b0568b16a", "tasks" : "0x6ec4905ff2bfbb1ee8f4c11006ef528df4d30b80" }

I can go in the file and delete the second object and then the app works.

Testing the interpreter

There should be a way to run the WASM tests using the Solidity offchain interpreter.

Checking the length of merkle proofs

Probably these lengths have to be a part of the global state ...

Too large or otherwise inaccessible IPFS files

Make sure we do not get stuck when trying to load IPFS files.

initialize shouldn't return false

https://github.com/TrueBitFoundation/webasm-solidity/blob/master/contracts/interactive.sol#L124
https://github.com/TrueBitFoundation/webasm-solidity/blob/master/contracts/interactive.sol#L127

Should just revert when not successful because it makes it seem like the tx went through

Should be deleted because if you don't have the proper data then there is a more underlying fault that probably wont be able to mended.

finalizeBundleIPFS not used/expensive

finalizeBundleIPFS returns a merkle root of the input files for a task. It is meant to be used by another smart contract, however there seem to be 2 issues with it:

1. It is not clear how an offchain solver is supposed to recreate the merkle root when initializing the challenge, as the data being used is different. This problem manifests itself at https://github.com/TrueBitFoundation/webasm-solidity/blob/master/contracts/interactive.sol#L125

2. The call is unoptimized. At only two files the call costs 1.5 mil gas

interactive vs interactive2 naming

interactive.sol should be replaced by interactive2.sol, with interactive.sol being the final name

JS Runtime

To run our wasm files with nodejs, we need to have a JS version of the runtime. Hardest part is figuring out generic system calls, and then we just need the input/output commands and getTotalMemory.

Task data input

Reading data from the blockchain.
A new merkle root will have to be added.

More uniform states for phases

The first and last state should be VM state hashes, and other states should be register machine hashes.