Init commit

send-command.ps1

@@ -0,0 +1,67 @@
+param(
+    [Parameter(Mandatory = $true)]
+    [string]$Worker,
+
+    [Parameter(Mandatory = $true)]
+    [string]$Agent,
+
+    [Parameter(Mandatory = $true)]
+    [string]$Secret,
+
+    [Parameter(Mandatory = $true)]
+    [string]$Command
+)
+
+# Signs requests exactly like the agent does:
+#   hex(HMAC-SHA256(secret, agent \n ts \n METHOD \n path+query \n sha256hex(body)))
+# No secret is ever placed in a URL.
+
+$ErrorActionPreference = "Stop"
+
+$base = $Worker.TrimEnd('/')
+$bodyBytes = [System.Text.Encoding]::UTF8.GetBytes($Command)
+
+function Get-Sha256Hex([byte[]]$Bytes)
+{
+    $sha = [System.Security.Cryptography.SHA256]::Create()
+
+    try
+    {
+        $stream = New-Object System.IO.MemoryStream(, $Bytes)
+        return ([BitConverter]::ToString($sha.ComputeHash($stream)) -replace "-", "").ToLower()
+    }
+    finally { $sha.Dispose() }
+}
+
+function Get-HmacHex([string]$Key, [string]$Message)
+{
+    $hmac = New-Object System.Security.Cryptography.HMACSHA256
+
+    try
+    {
+        $hmac.Key = [System.Text.Encoding]::UTF8.GetBytes($Key)
+        $hash = $hmac.ComputeHash([System.Text.Encoding]::UTF8.GetBytes($Message))
+        return ([BitConverter]::ToString($hash) -replace "-", "").ToLower()
+    }
+    finally { $hmac.Dispose() }
+}
+
+$ts = [string][DateTimeOffset]::UtcNow.ToUnixTimeSeconds()
+$canonical = "$Agent`n$ts`nPOST`nenqueue`n$(Get-Sha256Hex $bodyBytes)"
+$sign = Get-HmacHex $Secret $canonical
+
+$headers = @{
+    "X-Agent-Id"   = $Agent
+    "X-Agent-Ts"   = $ts
+    "X-Agent-Sign" = $sign
+}
+
+$response = Invoke-WebRequest `
+    -Method Post `
+    -Uri "$base/enqueue" `
+    -Body $bodyBytes `
+    -ContentType "application/octet-stream" `
+    -Headers $headers `
+    -UseBasicParsing
+
+$response.Content