Fix CI: harden OpenSSL download and move it before MSBuild

.github/workflows/build-installer.yml

@@ -26,19 +26,37 @@ jobs:
       - name: Setup MSBuild in PATH (VS2022)
         uses: microsoft/setup-msbuild@v2
 
+      - name: Download OpenSSL Libraries
+        shell: pwsh
+        run: |
+          $ErrorActionPreference = 'Stop'
+
+          $opensslZip = Join-Path $env:RUNNER_TEMP "openssl.zip"
+          $uri = "https://github.com/IndySockets/OpenSSL-Binaries/raw/master/Archive/openssl-1.0.2u-x64_86-win64.zip"
+
+          $resp = Invoke-WebRequest -Uri $uri -OutFile $opensslZip -MaximumRedirection 10 -PassThru
+          Write-Host "HTTP status: $($resp.StatusCode)"
+          Write-Host "Content-Type: $($resp.Headers.'Content-Type')"
+          Write-Host "Downloaded bytes: $((Get-Item $opensslZip).Length)"
+
+          # Validate: ZIP files start with 'PK' (0x50 0x4B)
+          $bytes = Get-Content -Path $opensslZip -Encoding Byte -TotalCount 2
+          if ($bytes[0] -ne 0x50 -or $bytes[1] -ne 0x4B) {
+            Write-Host "First bytes: $('{0:X2} {1:X2}' -f $bytes[0], $bytes[1])"
+            Write-Host "File head (as text):"
+            Get-Content -Path $opensslZip -TotalCount 20 | ForEach-Object { $_ }
+            throw "OpenSSL download is not a ZIP (likely received HTML). URL may have changed or requires different source."
+          }
+
+          Expand-Archive -Path $opensslZip -DestinationPath "utils" -Force
+          Remove-Item $opensslZip
+
       - name: Build Solution (Release | x64)
         run: |
           New-Item -ItemType Directory -Force -Path $env:OPENSAL_BUILD_DIR
           # We do NOT pass /p:OutDir here, we let the project props use OPENSAL_BUILD_DIR
           msbuild $env:SOLUTION_PATH /m /t:Build /p:Configuration=$env:BUILD_CONFIGURATION /p:Platform=x64 /p:PreferredToolArchitecture=x64
 
-      - name: Download OpenSSL Libraries
-        run: |
-          $opensslZip = "openssl.zip"
-          Invoke-WebRequest -Uri "https://github.com/IndySockets/OpenSSL-Binaries/raw/master/Archive/openssl-1.0.2u-x64_86-win64.zip" -OutFile $opensslZip
-          Expand-Archive -Path $opensslZip -DestinationPath "utils" -Force
-          Remove-Item $opensslZip
-
       - name: Install Inno Setup
         run: |
           choco install innosetup -y --no-progress