Retry interrupted client package downloads

installer/update-ocsentinel.ps1

@@ -38,6 +38,39 @@ function Get-OCSentinelManifest {
     }
 }
 
+function Get-OCSentinelArtifact {
+    param(
+        [Parameter(Mandatory)][string]$Uri,
+        [Parameter(Mandatory)][string]$DestinationPath
+    )
+
+    $parameters = @{ Uri = $Uri; OutFile = $DestinationPath; TimeoutSec = 300 }
+    if ((Get-Command Invoke-WebRequest).Parameters.ContainsKey("UseBasicParsing")) {
+        $parameters.UseBasicParsing = $true
+    }
+
+    for ($attempt = 1; $attempt -le 3; $attempt++) {
+        try {
+            Remove-Item -LiteralPath $DestinationPath -Force -ErrorAction SilentlyContinue
+            Invoke-WebRequest @parameters
+
+            if (-not (Test-Path -LiteralPath $DestinationPath) -or (Get-Item -LiteralPath $DestinationPath).Length -eq 0) {
+                throw "The downloaded artifact is empty."
+            }
+
+            return
+        }
+        catch {
+            if ($attempt -eq 3) {
+                throw "Could not download the OCSentinel package after 3 attempts. Last error: $($_.Exception.Message)"
+            }
+
+            Write-Warning "Package download attempt $attempt failed. Retrying."
+            Start-Sleep -Seconds (5 * $attempt)
+        }
+    }
+}
+
 Initialize-OCSentinelTls
 
 $installRoot = Join-Path ${env:ProgramFiles} "OCSentinel"
@@ -122,7 +155,7 @@ $extractRoot = Join-Path $downloadRoot "payload"
 New-Item -ItemType Directory -Force -Path $downloadRoot, $extractRoot | Out-Null
 
 Write-Host "Downloading artifact: $($manifest.artifactUrl)"
-Invoke-WebRequest -Uri ([string]$manifest.artifactUrl) -OutFile $zipPath -TimeoutSec 300
+Get-OCSentinelArtifact -Uri ([string]$manifest.artifactUrl) -DestinationPath $zipPath
 
 $actualHash = Get-Sha256Hex -Path $zipPath
 $expectedHash = ([string]$manifest.sha256).ToLowerInvariant()