DNS plugin: currently reviews if there is SPF entry

Signed-off-by: Miguel Angel Garcia <miguelangel.garcia@gmail.com>

addOns/dns/CHANGELOG.md

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+# Changelog
+All notable changes to this add-on will be documented in this file.
+
+The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
+
+## Unreleased
+
+- First version.
+- Detection if SPF record is not present
+- Detection of more than one SPF record

addOns/dns/dns.gradle.kts

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+description = "Performs DNS checks"
+
+zapAddOn {
+    addOnName.set("DNS")
+
+    manifest {
+        author.set("ZAP Dev Team")
+    }
+}
+
+crowdin {
+    configuration {
+        val resourcesPath = "org/zaproxy/addon/${zapAddOn.addOnId.get()}/resources/"
+        tokens.put("%messagesPath%", resourcesPath)
+        tokens.put("%helpPath%", resourcesPath)
+    }
+}
+
+dependencies {
+    testImplementation(project(":testutils"))
+}

addOns/dns/gradle.properties

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+version=0.0.1
+release=false

addOns/dns/src/main/java/org/zaproxy/addon/dns/DnsClient.java

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+/*
+ * Zed Attack Proxy (ZAP) and its related class files.
+ *
+ * ZAP is an HTTP/HTTPS proxy for assessing web application security.
+ *
+ * Copyright 2023 The ZAP Development Team
+ *
+ * Licensed 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.zaproxy.addon.dns;
+
+import java.util.ArrayList;
+import java.util.Hashtable;
+import java.util.List;
+import javax.naming.NamingEnumeration;
+import javax.naming.directory.Attribute;
+import javax.naming.directory.Attributes;
+import javax.naming.directory.DirContext;
+import javax.naming.directory.InitialDirContext;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+
+public class DnsClient {
+    private static final Logger LOGGER = LogManager.getLogger(DnsClient.class);
+
+    public List<String> getTxtRecord(String host) {
+        Hashtable<String, String> env = new Hashtable<String, String>();
+        env.put("java.naming.factory.initial", "com.sun.jndi.dns.DnsContextFactory");
+
+        List<String> result = new ArrayList<String>();
+        try {
+            DirContext dirContext = new InitialDirContext(env);
+            Attributes attrs = dirContext.getAttributes(host, new String[] {"TXT"});
+            Attribute attr = attrs.get("TXT");
+
+            if (attr != null) {
+                NamingEnumeration<?> attrenum = attr.getAll();
+                while (attrenum.hasMore()) {
+                    result.add(attrenum.next().toString());
+                }
+            }
+        } catch (javax.naming.NamingException e) {
+            LOGGER.debug("There was a problem getting the TXT record: {}", e);
+        }
+        return result;
+    }
+}

addOns/dns/src/main/java/org/zaproxy/addon/dns/ExtensionDns.java

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+/*
+ * Zed Attack Proxy (ZAP) and its related class files.
+ *
+ * ZAP is an HTTP/HTTPS proxy for assessing web application security.
+ *
+ * Copyright 2023 The ZAP Development Team
+ *
+ * Licensed 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.zaproxy.addon.dns;
+
+import org.parosproxy.paros.Constant;
+import org.parosproxy.paros.extension.ExtensionAdaptor;
+
+/** An ZAP extension which performs DNS operations to get information or vulnerabilities. */
+public class ExtensionDns extends ExtensionAdaptor {
+
+    // The name is public so that other extensions can access it
+    public static final String NAME = "ExtensionSpfScanner";
+
+    protected static final String PREFIX = "dns";
+
+    public ExtensionDns() {
+        super(NAME);
+        setI18nPrefix(PREFIX);
+    }
+
+    @Override
+    public void init() {
+        super.init();
+    }
+
+    @Override
+    public String getDescription() {
+        return Constant.messages.getString(PREFIX + ".description");
+    }
+}

addOns/dns/src/main/java/org/zaproxy/addon/dns/SpfParser.java

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+/*
+ * Zed Attack Proxy (ZAP) and its related class files.
+ *
+ * ZAP is an HTTP/HTTPS proxy for assessing web application security.
+ *
+ * Copyright 2023 The ZAP Development Team
+ *
+ * Licensed 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.zaproxy.addon.dns;
+
+import java.util.List;
+import org.zaproxy.addon.dns.exceptions.TooManyRecordsException;
+
+public class SpfParser {
+
+    private String record = null;
+
+    public SpfParser(List<String> txtRecord) throws TooManyRecordsException {
+        for (String entry : txtRecord) {
+            if (!entry.startsWith("v=spf1 ")) {
+                continue;
+            }
+            if (record != null) {
+                throw new TooManyRecordsException();
+            }
+            record = entry;
+        }
+    }
+
+    public boolean hasSpfRecord() {
+        return record != null;
+    }
+}

addOns/dns/src/main/java/org/zaproxy/addon/dns/SpfScanner.java

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+/*
+ * Zed Attack Proxy (ZAP) and its related class files.
+ *
+ * ZAP is an HTTP/HTTPS proxy for assessing web application security.
+ *
+ * Copyright 2023 The ZAP Development Team
+ *
+ * Licensed 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.zaproxy.addon.dns;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+import org.apache.commons.httpclient.URIException;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+import org.parosproxy.paros.Constant;
+import org.parosproxy.paros.core.scanner.AbstractHostPlugin;
+import org.parosproxy.paros.core.scanner.Alert;
+import org.parosproxy.paros.core.scanner.Category;
+import org.parosproxy.paros.network.HttpMessage;
+import org.zaproxy.addon.dns.exceptions.TooManyRecordsException;
+
+public class SpfScanner extends AbstractHostPlugin {
+    private static final int id = 90040;
+    private static final Logger LOGGER = LogManager.getLogger(SpfScanner.class);
+    private static final String MESSAGE_PREFIX = "dns.";
+    private volatile boolean enabled = true;
+    private static List<String> reviewedDomains = new ArrayList<String>();
+
+    private String getConstantString(String key) {
+        return Constant.messages.getString(MESSAGE_PREFIX + key);
+    }
+
+    private String getHigherSubdomain(String host) {
+        String[] hostarray = host.split("\\.");
+        if (hostarray.length < 2) {
+            return null;
+        }
+        return String.join(".", Arrays.copyOfRange(hostarray, 1, hostarray.length));
+    }
+
+    @Override
+    public void scan() {
+        final HttpMessage originalMsg = getBaseMsg();
+        try {
+            String host = originalMsg.getRequestHeader().getURI().getHost();
+            DnsClient dns = new DnsClient();
+            SpfParser spf = findValidSpfRecord(host, dns);
+            if (spf == null) {
+                newAlert()
+                        .setMessage(getBaseMsg())
+                        .setRisk(Alert.RISK_INFO)
+                        .setConfidence(Alert.CONFIDENCE_MEDIUM)
+                        .setDescription(getConstantString("nospfrecord.description"))
+                        .raise();
+            }
+        } catch (URIException e) {
+            LOGGER.debug("There was a problem getting the TXT records: {}", e);
+        } catch (TooManyRecordsException e) {
+            newAlert()
+                    .setMessage(getBaseMsg())
+                    .setRisk(Alert.RISK_INFO)
+                    .setConfidence(Alert.CONFIDENCE_MEDIUM)
+                    .setDescription(getConstantString("toomanyspfrecords.description"))
+                    .raise();
+        }
+    }
+
+    private SpfParser findValidSpfRecord(String host, DnsClient dns)
+            throws TooManyRecordsException {
+        SpfParser spf = null;
+        while (host != null) {
+            if (hasBeenAlreadyAnalyzed(host)) {
+                return null;
+            }
+            markAsAnalyzed(host);
+            spf = new SpfParser(dns.getTxtRecord(host));
+            if (spf.hasSpfRecord()) {
+                break;
+            }
+            host = getHigherSubdomain(host);
+        }
+        return spf;
+    }
+
+    private void markAsAnalyzed(String host) {
+        reviewedDomains.add(host);
+    }
+
+    private boolean hasBeenAlreadyAnalyzed(String host) {
+        return reviewedDomains.contains(host);
+    }
+
+    @Override
+    public void setEnabled(boolean enabled) {
+        this.enabled = enabled;
+        if (enabled == false) {
+            // Reset the scanner
+            reviewedDomains.clear();
+        }
+    }
+
+    @Override
+    public boolean isEnabled() {
+        return enabled;
+    }
+
+    @Override
+    public int getId() {
+        return id;
+    }
+
+    @Override
+    public int getCategory() {
+        return Category.MISC;
+    }
+
+    @Override
+    public String getName() {
+        return getConstantString("scanner");
+    }
+
+    @Override
+    public String getDescription() {
+        return getConstantString("description");
+    }
+
+    @Override
+    public String getSolution() {
+        return getConstantString("solution");
+    }
+
+    @Override
+    public String getReference() {
+        return getConstantString("reference");
+    }
+}

addOns/dns/src/main/java/org/zaproxy/addon/dns/exceptions/TooManyRecordsException.java

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+/*
+ * Zed Attack Proxy (ZAP) and its related class files.
+ *
+ * ZAP is an HTTP/HTTPS proxy for assessing web application security.
+ *
+ * Copyright 2023 The ZAP Development Team
+ *
+ * Licensed 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.zaproxy.addon.dns.exceptions;
+
+public class TooManyRecordsException extends Exception {
+
+    private static final long serialVersionUID = 1L;
+}

addOns/dns/src/main/javahelp/org/zaproxy/addon/dns/resources/help/contents/about.html

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+<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 3.2 Final//EN">
+<html>
+<head>
+<title>
+DNS - About
+</title>
+</head>
+<body>
+<h1>DNS - About</h1>
+
+<h2>Source Code</h2>
+<a href="https://github.com/zaproxy/zap-extensions/tree/main/addOns/dns">https://github.com/zaproxy/zap-extensions/tree/main/addOns/dns</a>
+
+<h2>Authors</h2>
+ZAP Dev Team
+
+<h2>History</h2>
+
+<h3>Version 0.0.1</h3>
+First Version
+<ul>
+    <li>Detection of no-SPF record</li>
+    <li>Detection of more than one SPF record</li>
+</ul>
+
+</body>
+</html>