How to Send & receive Websocket client Requests, responses in JSON format in PowerShell - powershell

Question

With the below PowerShell commands, I am able to open the connection using Websocket.
$mySock = New-Object System.Net.WebSockets.ClientWebSocket
$CT = New-Object System.Threading.CancellationToken($false)
$CTS = New-Object System.Threading.CancellationTokenSource
$mySock.Options.UseDefaultCredentials = $true
$connectTask = $mySock.ConnectAsync($URL, $CTS.Token)
The result as below:
PS C:\PS1> $mySock
Options : System.Net.WebSockets.ClientWebSocketOptions
CloseStatus :
CloseStatusDescription :
SubProtocol :
State : Open
PS C:\PS1>
My question is how do I send a request JSON format & also expect to receive the response in JSON format? Any help/guide would be much appreciated.
The document states as below:
LOGIN Request
When WebSocket connection is opened, the first command to the Streamer Server must be a LOGIN command with the following parameters.
Sample login request:
{
"service": "ADMIN",
"requestid": "1",
"command": "LOGIN",
"account": "your_account",
"source": "your_source_id",
"parameters": {
"token": "027363a5a5acd5",
"version": "1.0",
"credential": "userid%3DMYUSER20%26token%abcd"
}
}
Sample login successful response:
{
"response": [
{
"service": "ADMIN",
"requestid": "1",
"command": "LOGIN",
"timestamp": 1400607506478,
"content": {
"code": 0,
"msg": "02-1"
}
}
]
}

Answer 1

Not sure if you figured it out yet or not. How I did it was to convert the logon request to JSON and encode it in UTF8 and put it into an 1024 bit array segment using example code I found. Then I send it asynchronously back to the target.
$Array = [byte[]] #(,0) * 1024
$Command = [System.Text.Encoding]::UTF8.GetBytes($LoginJSON)
$Send = New-Object System.ArraySegment[byte] -ArgumentList #(,$Command)
$Conn = $WS.SendAsync($Send, [System.Net.WebSockets.WebSocketMessageType]::Text, $True, $CT)
When you receieve the response it must also be an array segement data type.
$Recv = New-Object System.ArraySegment[byte] -ArgumentList #(,$Array)
$Conn = $WS.ReceiveAsync($Recv, $CT)
This line will then get the return
[System.Text.Encoding]::utf8.GetString($Recv.array)
To keep getting all future messages I then created a Do until loop that continues to run until the web socket is no longer open.