ethereum offline signer c#

Question

is there any C# version of the offline signer for transaction. like ethereumjs-tx

var Tx = require('ethereumjs-tx') var privateKey = new Buffer('e331b6d69882b4cb4ea581d88e0b604039a3de5967688d3dcffdd2270c0fd109', 'hex')

var rawTx = { nonce: '0x00', gasPrice: '0x09184e72a000', gasLimit: '0x2710', to: '0x0000000000000000000000000000000000000000', value: '0x00', data: '0x7f7465737432000000000000000000000000000000000000000000000000000000600057' }

var tx = new Tx(rawTx) tx.sign(privateKey)

var serializedTx = tx.serialize() console.log(serializedTx.toString('hex'))

need similar in c# i am trying nethereum this implementation not working

How can I sign a transaction using c#?

var privateKey = "0xb5b1870957d373ef0eeffecc6e4812c0fd08f554b37b233526acc331bf1544f7"; var senderAddress = "0x12890d2cce102216644c59daE5baed380d84830c";

Now using web3 first you will need to retrieve the total number of transactions of your sender address.

var web3 = new Web3(); var txCount = await web3.Eth.Transactions.GetTransactionCount.SendRequestAsync(senderAddress);

The txCount will be used as the nonce to sign the transaction.

Now using web3 again, you can build an encoded transaction as following:

var encoded = web3.OfflineTransactionSigning.SignTransaction(privateKey, receiveAddress, 10, txCount.Value);

If you need to include the data and gas there are overloads for it.

You can verify an encoded transaction: Assert.True(web3.OfflineTransactionSigning.VerifyTransaction(encoded));

Or get the sender address from an encoded transaction:

web3.OfflineTransactionSigning.GetSenderAddress(encoded);

To send the encoded transaction you will "SendRawTransaction"

var txId = await web3.Eth.Transactions.SendRawTransaction.SendRequestAsync("0x" + encoded);

Answer 1

You basically answered your own question.

https://nethereum.readthedocs.io/en/latest/introduction/web3/

You have offline transaction signing function but the docs have not been updated. The method call looks different now because it was moved to static context or something like that:

Web3.OfflineTransactionSigner.SignTransaction.....

For more info check this out: https://github.com/Nethereum/Nethereum/issues/151

Answer 2

If you would like a signer based on secp256k1lib instead of Bouncy Castle then you probably would like to use the signer from Nethermind project:

Proxy for secp256k1lib: https://github.com/tkstanczak/nethermind/tree/master/src/Nethermind/Nethermind.Secp256k1

Actual usage with Ethereum protocol specifics that you may want to look at to base your solution on: https://github.com/tkstanczak/nethermind/blob/master/src/Nethermind/Nethermind.Core/Crypto/EthereumSigner.cs