Help me craft a raw transaction

[bytemaster]

Good work!   

[ElMato]

It would be great if we can have our own blockcypher.com (or chain.com) or ask them to integrate bitshares.

I managed to create and broadcast a raw transaction using the code below.

Please give me some directions:

1) Who do i track records ids of accounts that are not in the wallet db? (read only accounts)
    Should i export the wallet to json and add a new account_record_type?

Code: [Select]

#include <iostream>
#include <vector>
#include <bts/blockchain/transaction.hpp>
#include <fc/crypto/elliptic.hpp>
#include <fc/io/json.hpp>
#include <fc/crypto/hex.hpp>
#include <bts/utilities/key_conversion.hpp>

using namespace bts::blockchain;
using namespace bts::utilities;

int main(int argc, char** argv)
{
  const std::string tx_json = R"(
  {
      "expiration": "20141028T085151",
      "delegate_slate_id": null,
      "operations": [{
          "type": "register_account_op_type",
          "data": {
            "name": "justtesting",
            "public_data": null,
            "owner_key": "BTSX6yNA6Kc1qYSUt1ppFe8oPKcnWGHCg11VLKTY36V9jfyQvswjdh",
            "active_key": "BTSX6yNA6Kc1qYSUt1ppFe8oPKcnWGHCg11VLKTY36V9jfyQvswjdh",
            "delegate_pay_rate": 255,
            "meta_data": {
              "type": "public_account",
              "data": ""
            }
          }
        },{
          "type": "withdraw_op_type",
          "data": {
            "balance_id": "BTSX6nhkTeg1qnBbCHtJ4q8GUrBU9Sq2fTS23",
            "amount": 50,
            "claim_input_data": ""
          }
        }
      ]
  }
  )";

  auto tx = fc::json::from_string(tx_json).as<signed_transaction>();

  auto priv = wif_to_key("[edited]");

  fc::sha256 chain_id;
  fc::from_variant("75c11a81b7670bbaa721cc603eadb2313756f94a3bcbb9928e9101432701ac5f", chain_id);

  auto signature = priv->sign_compact( tx.digest(chain_id) );

  tx.signatures.push_back(signature);

  std::cout << fc::json::to_pretty_string(tx) << std::endl;

  vector<char> data;
  data = fc::raw::pack(tx);

  std::cout << fc::to_hex(data) << std::endl;
 


  return 0;
}


[bytemaster]

We will need to add an RPC call that will create a raw transaction... and return the hash of the raw transaction and list of required signatures for the purposes of signing.

The signature must be on the full transaction.

[ElMato]

BM, thanks for your response.

Just let me know if I am on the right track.

wallet_account_balance_ids account
returns the complete "UTXO" set for the account?

Then i can use the balance ids to make this ...

{
  "trx": {
    "expiration": "20141027T205151",
    "delegate_slate_id": null,
    "operations": [{
        "type": "register_account_op_type",
        "data": {
          "name": "[put a name here]",
          "public_data": null,
          "owner_key": "[Public Key BTSX format]",
          "active_key": "[Public Key BTSX format]",
          "delegate_pay_rate": 255,
          "meta_data": {
            "type": "public_account",
            "data": ""
          }
        }
      },{
        "type": "withdraw_op_type",
        "data": {
          "balance_id": "[Balance Record ID]",
          "amount": 50000,
          "claim_input_data": ""
        }
      }
    ],
    "signatures": [
"[Signature for the withdraw]"
    ]
  }
}

Questions:

0) Is the above Json enough?

1) How is the signature generated ?
    (required_signatures adds balance_record.owner() but i can't figure what is signing)

2) How do i go from Json -> Hex? Is there any "createrawtransaction"?

[bytemaster]

Balance records are modified in place, but if you want a change address you can withdraw the whole balance and send to two new balances.

It would probably be easier to construct custom transactions in JSON format and then ask the C++ to serialize them. 

[ElMato]

I know that devs are involved in more important things, but it would be really helpful to have a simple example of how to create two types of raw transactions.

1) Account register.
2) Asset transfer.

Number one is useful when i want to register an account on behalf of other person. (ie: Mobile Client signup process)
We will create the private keys like wallet_account_create does.

So far, this is what i have diving into the source code.

uint32_t utc_seconds;
uint64_t delegate_slate_id;
VARINT  n_ops; (number of ops)
-- register account operation
uint8_t                 operation_type
VARINT                  name_length
char[name_length]       name
VARIANT                   public_data  (json string serialized as VARIANT?)
uint8_t[33]             owner_key
uint8_t[33]             active_key
uint8_t                 delegate_pay_rate
uint32_t                account_type
VARINT                  data_length
char[data_length]       data

--- withdraw operations
....
-- signatures
....

is this ok?


Then i have to provide the signatures of the spent record ids (from the pay account) that pays for the transaction fee.
For this i need to know the blockchain format.

I remember that drltc was working on this, is there any documentation to look?

Other questions:
Do we have an equivalent of change addresses in bitshares?
Or balance records are modified "in place"?

Do we have any tool in python/ruby to read the blockchain and extract information?