using System;

using System.Linq;

using Org.BouncyCastle.Crypto.Digests;

​

namespace myNamespace

{

    public static class TransactionTool

    {

        public static string GetTransactionHash(string rawTransaction)

        {

            var offset = rawTransaction.StartsWith("0x") ? 2 : 0;

​

            var txByte = Enumerable.Range(offset, rawTransaction.Length - offset)

                             .Where(x => x % 2 == 0)

                             .Select(x => Convert.ToByte(rawTransaction.Substring(x, 2), 16))

                             .ToArray();

​

            //Note: Not intended for intensive use so we create a new Digest.

            //if digest reuse, prevent concurrent access + call Reset before BlockUpdate

            var digest = new KeccakDigest(256);

​

            digest.BlockUpdate(txByte, 0, txByte.Length);

            var calculatedHash = new byte[digest.GetByteLength()];

            digest.DoFinal(calculatedHash, 0);

​

            var transactionHash = BitConverter.ToString(calculatedHash, 0, 32).Replace("-", "").ToLower();

​

            return transactionHash;

        }

    }

}