NIFI-13594 Added web-servlet-shared abstracted from web-utils (apache…

…#9123)

- Moved RequestUriBuilder from web-utils to web-servlet-shared
- Refactored proxy header parsing from WebUtils to StandardRequestUriProvider
- Renamed WebUtils to WebClientUtils

This closes apache#9123

nifi-commons/nifi-web-servlet-shared/pom.xml

@@ -0,0 +1,32 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+  Licensed to the Apache Software Foundation (ASF) under one or more
+  contributor license agreements.  See the NOTICE file distributed with
+  this work for additional information regarding copyright ownership.
+  The ASF licenses this file to You under the Apache License, Version 2.0
+  (the "License"); you may not use this file except in compliance with
+  the License.  You may obtain a copy of the License at
+      http://www.apache.org/licenses/LICENSE-2.0
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+-->
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+    <parent>
+        <groupId>org.apache.nifi</groupId>
+        <artifactId>nifi-commons</artifactId>
+        <version>2.0.0-SNAPSHOT</version>
+    </parent>
+    <artifactId>nifi-web-servlet-shared</artifactId>
+    <description>Shared classes for handling HTTP Servlet requests and responses</description>
+    <dependencies>
+        <dependency>
+            <groupId>jakarta.servlet</groupId>
+            <artifactId>jakarta.servlet-api</artifactId>
+            <version>${servlet-api.version}</version>
+        </dependency>
+    </dependencies>
+</project>

nifi-commons/nifi-web-servlet-shared/src/main/java/org/apache/nifi/web/servlet/shared/ProxyHeader.java

@@ -0,0 +1,52 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.nifi.web.servlet.shared;
+
+/**
+ * Enumeration of supported Proxy Headers that provide information about the original request properties
+ */
+public enum ProxyHeader {
+    HOST("Host"),
+
+    PROXY_CONTEXT_PATH("X-ProxyContextPath"),
+
+    PROXY_SCHEME("X-ProxyScheme"),
+
+    PROXY_HOST("X-ProxyHost"),
+
+    PROXY_PORT("X-ProxyPort"),
+
+    FORWARDED_CONTEXT("X-Forwarded-Context"),
+
+    FORWARDED_PREFIX("X-Forwarded-Prefix"),
+
+    FORWARDED_PROTO("X-Forwarded-Proto"),
+
+    FORWARDED_HOST("X-Forwarded-Host"),
+
+    FORWARDED_PORT("X-Forwarded-Port");
+
+    private final String header;
+
+    ProxyHeader(final String header) {
+        this.header = header;
+    }
+
+    public String getHeader() {
+        return header;
+    }
+}

nifi-commons/nifi-web-utils/src/main/java/org/apache/nifi/web/util/RequestUriBuilder.java → nifi-commons/nifi-web-servlet-shared/src/main/java/org/apache/nifi/web/servlet/shared/RequestUriBuilder.java

@@ -14,9 +14,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package org.apache.nifi.web.util;
-
-import org.apache.commons.lang3.StringUtils;
+package org.apache.nifi.web.servlet.shared;
 
 import jakarta.servlet.ServletContext;
 import jakarta.servlet.http.HttpServletRequest;
@@ -72,12 +70,9 @@ public static RequestUriBuilder fromHttpServletRequest(final HttpServletRequest
      * @return Request URI Builder
      */
     public static RequestUriBuilder fromHttpServletRequest(final HttpServletRequest httpServletRequest, final List<String> allowedContextPaths) {
-        final String scheme = StringUtils.defaultIfEmpty(WebUtils.determineProxiedScheme(httpServletRequest), httpServletRequest.getScheme());
-        final String host = WebUtils.determineProxiedHost(httpServletRequest);
-        final int port = WebUtils.getServerPort(httpServletRequest);
-        final String contextPath = WebUtils.determineContextPath(httpServletRequest);
-        WebUtils.verifyContextPath(allowedContextPaths, contextPath);
-        return new RequestUriBuilder(scheme, host, port, contextPath);
+        final RequestUriProvider requestUriProvider = new StandardRequestUriProvider(allowedContextPaths);
+        final URI requestUri = requestUriProvider.getRequestUri(httpServletRequest);
+        return new RequestUriBuilder(requestUri.getScheme(), requestUri.getHost(), requestUri.getPort(), requestUri.getPath());
     }
 
     /**
@@ -109,7 +104,7 @@ public RequestUriBuilder fragment(final String fragment) {
      * @throws IllegalArgumentException Thrown on URI syntax exceptions
      */
     public URI build() {
-        final String resourcePath = StringUtils.join(contextPath, path);
+        final String resourcePath = getResourcePath();
         try {
             return new URI(scheme, null, host, port, resourcePath, null, fragment);
         } catch (final URISyntaxException e) {
@@ -118,9 +113,29 @@ public URI build() {
     }
 
     private static List<String> getAllowedContextPathsConfigured(final HttpServletRequest httpServletRequest) {
+        final List<String> allowedContextPathsConfigured;
+
         final ServletContext servletContext = httpServletRequest.getServletContext();
         final String allowedContextPathsParameter = servletContext.getInitParameter(ALLOWED_CONTEXT_PATHS_PARAMETER);
-        final String[] allowedContextPathsParsed = StringUtils.split(allowedContextPathsParameter, COMMA_SEPARATOR);
-        return allowedContextPathsParsed == null ? Collections.emptyList() : Arrays.asList(allowedContextPathsParsed);
+        if (allowedContextPathsParameter == null) {
+            allowedContextPathsConfigured = Collections.emptyList();
+        } else {
+            final String[] allowedContextPathsParsed = allowedContextPathsParameter.split(COMMA_SEPARATOR);
+            allowedContextPathsConfigured = Arrays.asList(allowedContextPathsParsed);
+        }
+
+        return allowedContextPathsConfigured;
+    }
+
+    private String getResourcePath() {
+        final String resourcePath;
+
+        if (path == null) {
+            resourcePath = contextPath;
+        } else {
+            resourcePath = contextPath + path;
+        }
+
+        return resourcePath;
     }
 }

nifi-commons/nifi-web-servlet-shared/src/main/java/org/apache/nifi/web/servlet/shared/RequestUriProvider.java

@@ -0,0 +1,34 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.nifi.web.servlet.shared;
+
+import jakarta.servlet.http.HttpServletRequest;
+
+import java.net.URI;
+
+/**
+ * Abstraction for resolving and returning an HTTP Request URI based on presented headers and configured properties
+ */
+public interface RequestUriProvider {
+    /**
+     * Get Request URI from HTTP Servlet Request containing optional headers
+     *
+     * @param request HTTP Servlet Request
+     * @return Request URI
+     */
+    URI getRequestUri(HttpServletRequest request);
+}

nifi-commons/nifi-web-servlet-shared/src/main/java/org/apache/nifi/web/servlet/shared/StandardRequestUriProvider.java

@@ -0,0 +1,195 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.nifi.web.servlet.shared;
+
+import jakarta.servlet.http.HttpServletRequest;
+
+import java.net.URI;
+import java.net.URISyntaxException;
+import java.util.Arrays;
+import java.util.List;
+import java.util.Objects;
+import java.util.function.Predicate;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
+/**
+ * Standard implementation of Request URI Provider with allowed hosts and context paths
+ */
+public class StandardRequestUriProvider implements RequestUriProvider {
+    private static final Pattern HOST_PATTERN = Pattern.compile("^([^:]+):?([1-9][0-9]{2,4})?$");
+
+    private static final Pattern HOST_PORT_REQUIRED_PATTERN = Pattern.compile("^[^:]+:([1-9][0-9]{2,4})$");
+
+    private static final Pattern SCHEME_PATTERN = Pattern.compile("^https?$");
+
+    private static final int FIRST_GROUP = 1;
+
+    private static final int MINIMUM_PORT_NUMBER = 100;
+
+    private static final int MAXIMUM_PORT_NUMBER = 65535;
+
+    private static final String EMPTY_PATH = "";
+
+    private static final String ROOT_PATH = "/";
+
+    private final List<String> allowedContextPaths;
+
+    public StandardRequestUriProvider(final List<String> allowedContextPaths) {
+        this.allowedContextPaths = Objects.requireNonNull(allowedContextPaths);
+    }
+
+    /**
+     * Get Request URI from HTTP Servlet Request containing optional headers and validated against allowed context paths
+     *
+     * @param request HTTP Servlet Request
+     * @return Request URI
+     */
+    @Override
+    public URI getRequestUri(final HttpServletRequest request) {
+        Objects.requireNonNull(request, "HTTP Servlet Request required");
+
+        final String scheme = getScheme(request);
+        final String host = getHost(request);
+        final int port = getPort(request);
+        final String path = getPath(request);
+
+        try {
+            return new URI(scheme, null, host, port, path, null, null);
+        } catch (final URISyntaxException e) {
+            throw new IllegalArgumentException("Request URI construction failed", e);
+        }
+    }
+
+    private String getScheme(final HttpServletRequest request) {
+        final String scheme;
+
+        final String requestScheme = request.getScheme();
+        final String headerScheme = getFirstHeader(request, ProxyHeader.PROXY_SCHEME, ProxyHeader.FORWARDED_PROTO);
+        if (headerScheme == null) {
+            scheme = requestScheme;
+        } else {
+            final Matcher matcher = SCHEME_PATTERN.matcher(headerScheme);
+            if (matcher.matches()) {
+                scheme = headerScheme;
+            } else {
+                scheme = requestScheme;
+            }
+        }
+
+        return scheme;
+    }
+
+    private String getHost(final HttpServletRequest request) {
+        final String host;
+
+        final String serverName = request.getServerName();
+        final String headerHost = getFirstHeader(request, ProxyHeader.PROXY_HOST, ProxyHeader.FORWARDED_HOST, ProxyHeader.HOST);
+        if (headerHost == null) {
+            host = serverName;
+        } else {
+            final Matcher matcher = HOST_PATTERN.matcher(headerHost);
+            if (matcher.matches()) {
+                host = matcher.group(FIRST_GROUP);
+            } else {
+                host = serverName;
+            }
+        }
+
+        return host;
+    }
+
+    private int getPort(final HttpServletRequest request) {
+        final int port;
+
+        final int serverPort = request.getServerPort();
+        final String headerHost = getFirstHeader(request, ProxyHeader.PROXY_HOST, ProxyHeader.FORWARDED_HOST);
+        if (headerHost == null) {
+            port = getProxyPort(request);
+        } else {
+            final Matcher matcher = HOST_PORT_REQUIRED_PATTERN.matcher(headerHost);
+            if (matcher.matches()) {
+                final String headerPort = matcher.group(FIRST_GROUP);
+                port = getParsedPort(headerPort, serverPort);
+            } else {
+                port = getProxyPort(request);
+            }
+        }
+
+        return port;
+    }
+
+    private int getProxyPort(final HttpServletRequest request) {
+        final int port;
+
+        final int serverPort = request.getServerPort();
+        final String headerPort = getFirstHeader(request, ProxyHeader.PROXY_PORT, ProxyHeader.FORWARDED_PORT);
+        if (headerPort == null) {
+            port = serverPort;
+        } else {
+            port = getParsedPort(headerPort, serverPort);
+        }
+
+        return port;
+    }
+
+    private int getParsedPort(final String headerPort, final int serverPort) {
+        int port;
+
+        try {
+            final int parsedPort = Integer.parseInt(headerPort);
+            if (parsedPort < MINIMUM_PORT_NUMBER || parsedPort > MAXIMUM_PORT_NUMBER) {
+                port = serverPort;
+            } else {
+                port = parsedPort;
+            }
+        } catch (final Exception e) {
+            port = serverPort;
+        }
+
+        return port;
+    }
+
+    private String getPath(final HttpServletRequest request) {
+        final String path;
+
+        final String headerPath = getFirstHeader(request, ProxyHeader.PROXY_CONTEXT_PATH, ProxyHeader.FORWARDED_CONTEXT, ProxyHeader.FORWARDED_PREFIX);
+        if (headerPath == null) {
+            path = EMPTY_PATH;
+        } else if (ROOT_PATH.equals(headerPath)) {
+            path = ROOT_PATH;
+        } else {
+            if (allowedContextPaths.contains(headerPath)) {
+                path = headerPath;
+            } else {
+                throw new IllegalArgumentException("Request Header Context Path not allowed based on properties [nifi.web.proxy.context.path]");
+            }
+        }
+
+        return path;
+    }
+
+    private String getFirstHeader(final HttpServletRequest request, final ProxyHeader... proxyHeaders) {
+        return Arrays.stream(proxyHeaders)
+                .map(ProxyHeader::getHeader)
+                .map(request::getHeader)
+                .filter(Objects::nonNull)
+                .filter(Predicate.not(String::isBlank))
+                .findFirst()
+                .orElse(null);
+    }
+}