crypto-test-task

gistfile1.txt

# cryptography-task

## Get Started

### Installation

```
npm install --save cryptography-task
```

### Example

https://runkit.com/miukki/cryptography-task

### Test

```bash
yarn test -- --watch -u
#-u update jest snapshots
```

### Task
```bash
requirements: 
entry point : ByteStream.cs line 121 public void Write(Transaction)
the idea is to convert an JSON to -> byte array -> base64 String

example

JSON input :
{"Hash":"DWQnIVCxKZ+/XA2Gd5XFrlGJ2JMTuknP6236rl77MsQ=","Expire":636587692108677703,"Inputs":[{"Address":"qyl68tygnjx6qqwrsmynmejmc9wxlw7almv3397j","Currency":"BTC","Amount":10.0},{"Address":"qyaj20aksyvxlfmznyjdqzxrvvf0w7ca7mamwzll","Currency":"LTC","Amount":30.0}],"Outputs":[{"Address":"qyaj20aksyvxlfmznyjdqzxrvvf0w7ca7mamwzll","Currency":"BTC","Amount":10.0},{"Address":"qyl68tygnjx6qqwrsmynmejmc9wxlw7almv3397j","Currency":"LTC","Amount":30.0}],"Message":"\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000","Fees":null}

Base64 byte output :
byte array -> base64  (represent binary data in an ASCII string format by translating it into a radix-64 representation)

RwKGGCKd1QgAAAIB/o6yInI2gAcOGyT3mW8Fcb7vd/uUBADKmjsAAAAAAeyU/toEYb6dimSTQCMNjEvd7Hfb/B4AXtCyAAAAAAIB7JT+2gRhvp2KZJNAIw2MS93sd9uUBADKmjsAAAAAAf6OsiJyNoAHDhsk95lvBXG+73f7/B4AXtCyAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA==

```

1. Entry point 
        public void Write(Transaction transaction) [line 121]
        
1. Prepare Buffer Array in nodejs
2. Write(transaction.Expire): Json ->  Expire (Write(transaction.Expire)) [lin 123]-> use Buffer Array -> user method protected void Write(long longData)  [line 46] > user stream.Write(BitConverter.GetBytes(longData), 0, 8) it is meaning 8 bytes  put to Buffer Array
3. WriteNullable(transaction.Fees, Write) -> got to [line 33] -> private void WriteNullable<T>(T data, Action<T> write) -> then stream.Write(BitConverter.GetBytes(value), 0, 1) [line 43] -> BitConverter.GetBytes(value), 0, 1) take  single byte value 00 OR 01 (true or false) -> write to Buffer Array . BTW in our case only {Fees: null} look to JSON

about bit converter source : https://msdn.microsoft.com/en-us/library/system.bitconverter(v=vs.110).aspx
4. I dont have Declarations in json, Write(transaction.Declarations.ToList(), Write); [line 125]  -> [line 92] public void Write(TxDeclaration declaration)  ? -> [line 379] private TxDeclaration ReadTxDeclaration() ? -> For declaration if the list is empty (null), just write 1 byte to 0. Idea is if something null or empt dont put it in the json.

5. Write(transaction.Inputs.ToList(), Write) -> [line 56] public void Write<T>(List<T> items, Action<T> write, int bytes = 1) -> put items.Count (same as array.length) put to Buffer Array N bite . You can specify N by default it is equal 1 

actually we also write Array to buffer Bite look to 
foreach (var item in items) [line 62] -> [line 85] public void Write(TxInputOutput input) : 

- Write(input.Address.ToRawBytes()) : prop item Address.ToRawBytes() [line 87] -> byte array  public byte[] ToRawBytes()  ->  Address32Format  (Address32 fromat can be  using the js sdk bech32.js)->  stream.Write(bytes, 0, bytes.Length); [line 194] write to buffer  stream.Write(bytes, 0, bytes.Length)
- prop item Currency [line 88] Write(input.Currency); -> stream.Write(BitConverter.GetBytes(currency), 0, 2); Currency is a wrapper for short 2bytes
- prop iten Amount [line 89] -> Amount is wrapper for long 8bytes - stream.Write(BitConverter.GetBytes(amount), 0, 8);

6. Write(transaction.Outputs.ToList(), Write); same as  Write(transaction.Inputs.ToList(), Write)
7. Message str 301 missing  
return new TransactionMessage(stream.ReadBytes(TransactionMessage.SIZE));  > str 51 > 192

8. convert array buffer to string base64 > done
  
9. please agreed output is real and input it is real for debugging i have to know it.


Some types are in the same file then other classes. Look at payment.cs