[JENKINS-41891] Resource domain support

core/src/main/java/hudson/model/DirectoryBrowserSupport.java

@@ -24,6 +24,7 @@
 package hudson.model;
 
 import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
+import hudson.ExtensionList;
 import hudson.FilePath;
 import hudson.Util;
 import java.io.IOException;
@@ -54,6 +55,8 @@
 import javax.servlet.http.HttpServletResponse;
 import jenkins.model.Jenkins;
 import jenkins.security.MasterToSlaveCallable;
+import jenkins.security.ResourceDomainConfiguration;
+import jenkins.security.ResourceDomainRootAction;
 import jenkins.util.SystemProperties;
 import jenkins.util.VirtualFile;
 import org.apache.commons.io.IOUtils;
@@ -88,6 +91,14 @@ public final class DirectoryBrowserSupport implements HttpResponse {
     private final boolean serveDirIndex;
     private String indexFileName = "index.html";
 
+    @Restricted(NoExternalUse.class)
+    public static final String CSP_PROPERTY_NAME = DirectoryBrowserSupport.class.getName() + ".CSP";
+
+    /**
+     * Keeps track of whether this has been registered from use via {@link ResourceDomainRootAction}.
+     */
+    private ResourceDomainRootAction.Token resourceToken;
+
     /**
      * @deprecated as of 1.297
      *      Use {@link #DirectoryBrowserSupport(ModelObject, FilePath, String, String, boolean)}
@@ -137,6 +148,10 @@ public DirectoryBrowserSupport(ModelObject owner, VirtualFile base, String title
     }
 
     public void generateResponse(StaplerRequest req, StaplerResponse rsp, Object node) throws IOException, ServletException {
+        if (!ResourceDomainConfiguration.isResourceRequest(req) && ResourceDomainConfiguration.isResourceDomainConfigured()) {
+            resourceToken = ResourceDomainRootAction.get().getToken(this, req);
+        }
+
         try {
             serveFile(req,rsp,base,icon,serveDirIndex);
         } catch (InterruptedException e) {
@@ -290,7 +305,11 @@ private void serveFile(StaplerRequest req, StaplerResponse rsp, VirtualFile root
                 req.setAttribute("path", path);
                 req.setAttribute("pattern",rest);
                 req.setAttribute("dir", baseFile);
-                req.getView(this,"dir.jelly").forward(req, rsp);
+                if (ResourceDomainConfiguration.isResourceRequest(req)) {
+                    req.getView(this, "plaindir.jelly").forward(req, rsp);
+                } else {
+                    req.getView(this, "dir.jelly").forward(req, rsp);
+                }
                 return;
             }
 
@@ -339,17 +358,25 @@ private void serveFile(StaplerRequest req, StaplerResponse rsp, VirtualFile root
             // pseudo file name to let the Stapler set text/plain
             rsp.serveFile(req, in, lastModified, -1, length, "plain.txt");
         } else {
-            String csp = SystemProperties.getString(DirectoryBrowserSupport.class.getName() + ".CSP", DEFAULT_CSP_VALUE);
-            if (!csp.trim().equals("")) {
-                // allow users to prevent sending this header by setting empty system property
-                for (String header : new String[]{"Content-Security-Policy", "X-WebKit-CSP", "X-Content-Security-Policy"}) {
-                    rsp.setHeader(header, csp);
+            if (resourceToken != null) {
+                // redirect to second domain
+                rsp.sendRedirect(302, ResourceDomainRootAction.get().getRedirectUrl(resourceToken, req.getRestOfPath()));
+            } else {
+                if (!ResourceDomainConfiguration.isResourceRequest(req)) {
+                    // if we're serving this from the main domain, set CSP headers
+                    String csp = SystemProperties.getString(CSP_PROPERTY_NAME, DEFAULT_CSP_VALUE);
+                    if (!csp.trim().equals("")) {
+                        // allow users to prevent sending this header by setting empty system property
+                        for (String header : new String[]{"Content-Security-Policy", "X-WebKit-CSP", "X-Content-Security-Policy"}) {
+                            rsp.setHeader(header, csp);
+                        }
+                    }
                 }
+                rsp.serveFile(req, in, lastModified, -1, length, baseFile.getName());
             }
-            rsp.serveFile(req, in, lastModified, -1, length, baseFile.getName() );
         }
     }
-    
+
     private List<List<Path>> keepReadabilityOnlyOnDescendants(VirtualFile root, boolean patternUsed, List<List<Path>> pathFragmentsList){
         Stream<List<Path>> pathFragmentsStream = pathFragmentsList.stream().map((List<Path> pathFragments) -> {
             List<Path> mappedFragments = new ArrayList<>(pathFragments.size());

core/src/main/java/jenkins/model/JenkinsLocationConfiguration.java

@@ -36,7 +36,8 @@
  * @author Kohsuke Kawaguchi
  * @since 1.494
  */
-@Extension @Symbol("location")
+@Extension(ordinal = JenkinsLocationConfiguration.ORDINAL)
+@Symbol("location")
 public class JenkinsLocationConfiguration extends GlobalConfiguration implements PersistentDescriptor {
 
     /**
@@ -50,6 +51,9 @@ public class JenkinsLocationConfiguration extends GlobalConfiguration implements
     public static /* not final */ boolean DISABLE_URL_VALIDATION =
             SystemProperties.getBoolean(JenkinsLocationConfiguration.class.getName() + ".disableUrlValidation");
 
+    @Restricted(NoExternalUse.class)
+    public static final int ORDINAL = 200;
+
     /**
      * @deprecated replaced by {@link #jenkinsUrl}
      */

core/src/main/java/jenkins/security/ResourceDomainConfiguration.java

@@ -0,0 +1,258 @@
+/*
+ * The MIT License
+ *
+ * Copyright 2019 CloudBees, Inc.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+package jenkins.security;
+
+import hudson.Extension;
+import hudson.ExtensionList;
+import hudson.Util;
+import hudson.util.FormValidation;
+import jenkins.diagnostics.RootUrlNotSetMonitor;
+import jenkins.model.GlobalConfiguration;
+import jenkins.model.Jenkins;
+import jenkins.model.JenkinsLocationConfiguration;
+import jenkins.model.identity.InstanceIdentityProvider;
+import jenkins.util.UrlHelper;
+import net.sf.json.JSONObject;
+import org.apache.commons.codec.binary.Base64;
+import org.jenkinsci.Symbol;
+import org.kohsuke.accmod.Restricted;
+import org.kohsuke.accmod.restrictions.NoExternalUse;
+import org.kohsuke.stapler.QueryParameter;
+import org.kohsuke.stapler.Stapler;
+import org.kohsuke.stapler.StaplerRequest;
+import org.kohsuke.stapler.verb.POST;
+
+import javax.servlet.http.HttpServletRequest;
+import java.io.IOException;
+import java.net.HttpURLConnection;
+import java.net.MalformedURLException;
+import java.net.URL;
+import java.net.URLConnection;
+import java.security.interfaces.RSAPublicKey;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+import static jenkins.security.ResourceDomainFilter.ERROR_RESPONSE;
+
+/**
+ * Configure the resource root URL, an alternative root URL to serve resources from
+ * to not need Content-Security-Policy headers, which mess with desired complex output.
+ *
+ * @see ResourceDomainFilter
+ * @see ResourceDomainRootAction
+ *
+ * @since TODO
+ */
+@Extension(ordinal = JenkinsLocationConfiguration.ORDINAL-1) // sort just below the regular location config
+@Restricted(NoExternalUse.class)
+@Symbol("resourceRoot")
+public class ResourceDomainConfiguration extends GlobalConfiguration {
+
+    private static final Logger LOGGER = Logger.getLogger(ResourceDomainConfiguration.class.getName());
+
+    private String url;
+
+    public ResourceDomainConfiguration() {
+        load();
+    }
+
+    @POST
+    public FormValidation doCheckUrl(@QueryParameter("url") String resourceRootUrlString) {
+        Jenkins.get().checkPermission(Jenkins.ADMINISTER);
+
+        return checkUrl(resourceRootUrlString, true);
+    }
+
+    private FormValidation checkUrl(String resourceRootUrlString, boolean allowOnlineIdentityCheck) {
+        if (ExtensionList.lookupSingleton(RootUrlNotSetMonitor.class).isActivated()) {
+            // This is needed to round-trip expired resource URLs through regular URLs to refresh them,
+            // so while it's not required in the strictest sense, it is required.
+            return FormValidation.warning(Messages.ResourceDomainConfiguration_NeedsRootURL());
+        }
+
+        resourceRootUrlString = Util.fixEmptyAndTrim(resourceRootUrlString);
+        if (resourceRootUrlString == null) {
+            return FormValidation.ok(Messages.ResourceDomainConfiguration_Empty());
+        }
+
+        if (!UrlHelper.isValidRootUrl(resourceRootUrlString)) {
+            return FormValidation.error(Messages.ResourceDomainConfiguration_Invalid());
+        }
+
+        if (!resourceRootUrlString.endsWith("/")) {
+            resourceRootUrlString += '/';
+        }
+
+        URL resourceRootUrl;
+        try {
+            resourceRootUrl = new URL(resourceRootUrlString);
+        } catch (MalformedURLException ex) {
+            return FormValidation.error(Messages.ResourceDomainConfiguration_Invalid());
+        }
+
+        String resourceRootUrlHost = resourceRootUrl.getHost();
+        try {
+            String jenkinsRootUrlHost = new URL(JenkinsLocationConfiguration.get().getUrl()).getHost();
+            if (jenkinsRootUrlHost.equals(resourceRootUrlHost)) { // TODO this only checks the host, do we care about port differences?
+                return FormValidation.error(Messages.ResourceDomainConfiguration_SameAsJenkinsRoot());
+            }
+        } catch (Exception ex) {
+            LOGGER.log(Level.CONFIG, "Failed to create URL from the existing Jenkins root URL", ex);
+            return FormValidation.error(Messages.ResourceDomainConfiguration_InvalidRootURL(ex.getMessage()));
+        }
+
+        StaplerRequest currentRequest = Stapler.getCurrentRequest();
+        if (currentRequest != null) {
+            String currentRequestHost = currentRequest.getHeader("Host");
+
+            if (currentRequestHost.equals(resourceRootUrlHost)) {
+                return FormValidation.error(Messages.ResourceDomainConfiguration_SameAsCurrent());
+            }
+        }
+
+        // TODO We could perform more elaborate permission checks to prevent users from setting a subdomain (not great wrt cookies?)
+
+        if (!allowOnlineIdentityCheck) {
+            return FormValidation.ok();
+        }
+
+        // Send a request to /instance-identity/ at the resource root URL and check whether it is this Jenkins
+        try {
+            URLConnection urlConnection = new URL(resourceRootUrlString + "instance-identity/").openConnection();
+            if (urlConnection instanceof HttpURLConnection) {
+                HttpURLConnection httpURLConnection = (HttpURLConnection) urlConnection;
+                int responseCode = httpURLConnection.getResponseCode();
+
+                if (responseCode == 200) {
+                    String identityHeader = urlConnection.getHeaderField("X-Instance-Identity");
+                    if (identityHeader == null) {
+                        return FormValidation.warning(Messages.ResourceDomainConfiguration_NotJenkins());
+                    }
+                    // URL points to a Jenkins instance
+                    RSAPublicKey publicKey = InstanceIdentityProvider.RSA.getPublicKey();
+                    if (publicKey != null) {
+                        String identity = Base64.encodeBase64String(publicKey.getEncoded());
+                        if (identity.equals(identityHeader)) {
+                            return FormValidation.ok(Messages.ResourceDomainConfiguration_ThisJenkins());
+                        }
+                        return FormValidation.warning(Messages.ResourceDomainConfiguration_OtherJenkins());
+                    } // the current instance has no public key
+                    return FormValidation.warning(Messages.ResourceDomainConfiguration_SomeJenkins());
+                }
+                // response is error
+                String responseMessage = httpURLConnection.getResponseMessage();
+                if (responseCode == 404 && responseMessage.equals(ERROR_RESPONSE)) {
+                    return FormValidation.ok(Messages.ResourceDomainConfiguration_ResourceResponse());
+                }
+                return FormValidation.error(Messages.ResourceDomainConfiguration_FailedIdentityCheck(responseCode, responseMessage));
+            }
+            return FormValidation.error(Messages.ResourceDomainConfiguration_Invalid()); // unlikely to ever be hit
+        } catch (MalformedURLException ex) {
+            // Not expected to be hit
+            LOGGER.log(Level.FINE, "MalformedURLException occurred during instance identity check for " + resourceRootUrlString, ex);
+            return FormValidation.error(Messages.ResourceDomainConfiguration_Exception(ex.getMessage()));
+        } catch (IOException ex) {
+            LOGGER.log(Level.FINE, "IOException occurred during instance identity check for " + resourceRootUrlString, ex);
+            return FormValidation.warning(Messages.ResourceDomainConfiguration_IOException(ex.getMessage()));
+        }
+    }
+
+    public String getUrl() {
+        return url;
+    }
+
+    public void setUrl(String url) {
+        if (checkUrl(url, false).kind == FormValidation.Kind.OK) {
+            // only accept valid configurations, both with and without URL, but allow for networking issues
+            url = Util.fixEmpty(url);
+            if (url != null && !url.endsWith("/")) {
+                url += "/";
+            }
+            this.url = url;
+            save();
+        }
+    }
+
+    /**
+     * Returns true if and only if this is a request to URLs under the resource root URL.
+     *
+     * For this to be the case, the requested host and port (from the Host HTTP request header) must match what is
+     * configured for the resource root URL.
+     *
+     * @param req the request to check
+     * @return whether the request is a resource URL request
+     */
+    public static boolean isResourceRequest(HttpServletRequest req) {
+        if (!isResourceDomainConfigured()) {
+            return false;
+        }
+        String resourceRootUrl = get().getUrl();
+        try {
+            URL url = new URL(resourceRootUrl);
+
+            String resourceRootHost = url.getHost();
+            if (!resourceRootHost.equalsIgnoreCase(req.getServerName())) {
+                return false;
+            }
+
+            int resourceRootPort = url.getPort();
+            if (resourceRootPort == -1) {
+                resourceRootPort = url.getDefaultPort();
+            }
+
+            // let's hope this gives the default port if the Host header exists but doesn't specify a port
+            int requestedPort = req.getServerPort();
+
+            if (requestedPort != resourceRootPort) {
+                return false;
+            }
+        } catch (MalformedURLException ex) {
+            // the URL here cannot be so broken that we cannot call `new URL(String)` on it...
+            return false;
+        }
+        return true;
+    }
+
+    /**
+     * Returns true if and only if a domain has been configured to serve resource URLs from
+     *
+     * @return whether a domain has been configured
+     */
+    public static boolean isResourceDomainConfigured() {
+        String resourceRootUrl = get().getUrl();
+        if (resourceRootUrl == null || resourceRootUrl.isEmpty()) {
+            return false;
+        }
+
+        // effectively not configured when the location configuration is empty
+        if (Util.nullify(JenkinsLocationConfiguration.get().getUrl()) == null) {
+            return false;
+        }
+        return true;
+    }
+
+    public static ResourceDomainConfiguration get() {
+        return ExtensionList.lookupSingleton(ResourceDomainConfiguration.class);
+    }
+}