[Boost-users] Writing a stratum client using boost:asio

Subject: [Boost-users] Writing a stratum client using boost:asio
From: Jan Willem Penterman (jw_at_[hidden])
Date: 2016-02-11 06:41:21

Hi,

I'm trying to write a stratum client for a cryptocurrency mining
application. The mining application connects to a stratum server to receive
new work to mine on and submit solutions.

The stratum protocol is a simple TCP based line protocol with JSON payload.
Documentation here:
https://mining.bitcoin.cz/help/#!/manual/stratum-protocol

I've chosen to use boost::asio, as boost is already heavily used in the
fork of the project I'm building the miner for. But I'm having difficulties
to understand why my current implementation doesn't work.

The basic flow is as follows:
1. connect to the server. this works
2. send subscribe method. this also works
3. authorize worker(s). doesn't work.
4. stratum server should start pushing new work periodically. doesn't work.
5. submit solution when found. not implemented yet.

Without authorization, the server should still start pushing work. So I've
skipped step 3 for now.

The source code as I have it now is available here:
https://github.com/Genoil/cpp-ethereum/blob/stratum/libstratum/

The output I get from this is as follows:

  i  12:19:14|<unknown>  Connected to stratum server coinotron.com : 3344
  i  12:19:15|<unknown>  {"error": null, "id": 1, "result":
[["mining.notify", "91d0025c5ea54509977e3475d065169e"], "080016D0", 4]}
  i  12:19:15|<unknown>  Subscribed
  i  12:19:15|<unknown>  { "id": null, "method": "mining.set_difficulty",
"params": [32768]}
  i  12:19:15|<unknown>  mining.set_difficulty
  i  12:19:15|<unknown>  {"params": ["31065",
"0xc09361c52e9dddd141040cc79c52eaed382e92c1dd350324c040482a4c4ac0fa","0x5a46dd85298b0beff65ccf3006c4b5d2f7fa6ca8a5885a7f2132714fe7a48602","0x0000000200000000000000000000000000000000000000000000000000000000",
true], "id": null, "method": "mining.notify"}
  i  12:19:15|<unknown>  mining.notify

>From this I can conclude that the subscription call works. Then at the end
of handleResponse, I simply queue up a new async_read_until to wait for the
next line of JSON to come in from the server. This also kind of works, but
the idea is that after a few seconds, new work should come in as a
"mining.notify". This never happens. Can anybody explain what I'm doing
wrong?

Regarding the mining.authorize call on line 113. I've understood from the
documentation that I can send that whenever I want, so I tried to do this
immediately after the subscribe method returned. But if I do this, it a)
doesn't return and b) all lines after "Subscribed" don't come in any
longer. This is the second problem I'm trying to figure out.

I'm using this as reference, but my Python is even worse than my C++
https://github.com/slush0/stratum-mining-proxy

But when I run the binaries connecting to the same host (coinotron.com:3344),
I do get new work coming in...

Thanks for having a look at this.