com.aresstack.winproxy

Class WindowsProxyResolver

java.lang.Object

com.aresstack.winproxy.WindowsProxyResolver

public final class WindowsProxyResolver
extends Object

Detects proxy settings on Windows by reading the Windows Registry and evaluating PAC/WPAD auto-configuration scripts via GraalJS.

No PowerShell required. Works on hardened systems where PowerShell Constrained Language Mode (CLM) blocks .NET method calls.

How it works

1. Searches all four registry hives (GPO first!) for AutoConfigURL
2. Checks the DefaultConnectionSettings binary blob for an embedded PAC URL
3. Tries WPAD auto-detect (http://wpad/wpad.dat) if the flag is set
4. Falls back to static proxy settings across all four registry hives
5. Respects the ProxyOverride bypass list

Usage

 // Full auto-detection:
 ProxyResult result = WindowsProxyResolver.resolve("https://example.com");

 // Choose PAC URL source explicitly:
 ProxyResult r1 = WindowsProxyResolver.resolve(target, PacUrlSource.DIRECT,
     "http://wpad.corp.local/wpad.dat");
 ProxyResult r2 = WindowsProxyResolver.resolve(target, PacUrlSource.REGISTRY, null);
 ProxyResult r3 = WindowsProxyResolver.resolve(target, PacUrlSource.POWERSHELL, null);

 if (result.isDirect()) {
     connection = url.openConnection();
 } else {
     connection = url.openConnection(result.toJavaProxy());
 }
 

See Also:

ProxyResult, PacUrlSource

Field Summary

Fields

Modifier and Type	Field and Description
static String	DEFAULT_PAC_DISCOVERY_SCRIPT Default PowerShell command to discover the PAC URL from the Windows Registry.
static String	INTERNET_SETTINGS_KEY The Windows Registry key containing user-level Internet/proxy settings.

Method Summary

Modifier and Type	Method and Description
static ProxyResult	evaluatePac(String pacUrl, String targetUrl) Evaluates a PAC auto-configuration script from the given URL via GraalJS.
static ProxyResult	evaluatePacScript(String pacScript, String targetUrl) Evaluates a PAC script string (not a URL) against the given target URL.
static boolean	isBypassed(String host, String proxyOverride) Checks if a host matches the Windows proxy bypass pattern list.
static boolean	isWpadAutoDetectEnabled() Returns true if WPAD auto-detect is enabled in connection settings.
static int	readConnectionFlags() Reads the raw connection flags byte.
static String	readRegistryValue(String key, String valueName) Reads a single value from the Windows Registry via reg.exe.
static String	readRegistryValueFromAllHives(String valueName) Searches all four registry hives for the given value name (GPO first).
static ProxyResult	resolve(String url) Resolves the proxy using the full Windows auto-detection chain (registry-based).
static ProxyResult	resolve(String targetUrl, PacUrlSource source, String pacUrlOrScript) Resolves the proxy using the specified PacUrlSource strategy.
static ProxyResult	resolveStatic(String url) Resolves using only static registry settings (ProxyEnable + ProxyServer).

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

INTERNET_SETTINGS_KEY

public static final String INTERNET_SETTINGS_KEY

The Windows Registry key containing user-level Internet/proxy settings.

See Also:

Constant Field Values

DEFAULT_PAC_DISCOVERY_SCRIPT

public static final String DEFAULT_PAC_DISCOVERY_SCRIPT

Default PowerShell command to discover the PAC URL from the Windows Registry. Works even under PowerShell Constrained Language Mode (CLM).

See Also:

Constant Field Values

Method Detail

resolve

public static ProxyResult resolve(String url)

Resolves the proxy using the full Windows auto-detection chain (registry-based). Equivalent to resolve(url, PacUrlSource.REGISTRY, null).

resolve

public static ProxyResult resolve(String targetUrl,
                                  PacUrlSource source,
                                  String pacUrlOrScript)

Resolves the proxy using the specified PacUrlSource strategy. This is the primary facade method.

Parameters:

targetUrl - the URL to resolve the proxy for

source - how to obtain the PAC URL

pacUrlOrScript - PAC URL, PowerShell command, or null (depending on source)

Returns:

a ProxyResult — never null

resolveStatic

public static ProxyResult resolveStatic(String url)

Resolves using only static registry settings (ProxyEnable + ProxyServer).

evaluatePac

public static ProxyResult evaluatePac(String pacUrl,
                                      String targetUrl)

Evaluates a PAC auto-configuration script from the given URL via GraalJS.

evaluatePacScript

public static ProxyResult evaluatePacScript(String pacScript,
                                            String targetUrl)

Evaluates a PAC script string (not a URL) against the given target URL.

readRegistryValue

public static String readRegistryValue(String key,
                                       String valueName)

Reads a single value from the Windows Registry via reg.exe.

readRegistryValueFromAllHives

public static String readRegistryValueFromAllHives(String valueName)

Searches all four registry hives for the given value name (GPO first).

isBypassed

public static boolean isBypassed(String host,
                                 String proxyOverride)

Checks if a host matches the Windows proxy bypass pattern list.

isWpadAutoDetectEnabled

public static boolean isWpadAutoDetectEnabled()

Returns true if WPAD auto-detect is enabled in connection settings.

readConnectionFlags

public static int readConnectionFlags()

Reads the raw connection flags byte. Returns -1 if unreadable.