Add Zone walking NSEC module

modules/check/nsec.py

@@ -0,0 +1,56 @@
+# https://www.icann.org/resources/pages/dnssec-what-is-it-why-important-2019-03-20-zh
+# https://appsecco.com/books/subdomain-enumeration/active_techniques/zone_walking.html
+
+from common.module import Module
+from common import utils
+
+
+class CheckNSEC(Module):
+    def __init__(self, domain):
+        Module.__init__(self)
+        self.domain = self.register(domain)
+        self.module = 'check'
+        self.source = "CheckNSEC"
+
+    def walk(self):
+        domain = self.domain
+        while True:
+            answer = utils.dns_query(domain, 'NSEC')
+            if answer is None:
+                break
+            subdomain = str()
+            for item in answer:
+                record = item.to_text()
+                subdomains = self.match_subdomains(self.domain, record)
+                subdomain = ''.join(subdomains)  # 其实这里的subdomains的长度为1 也就是说只会有一个子域
+                self.subdomains = self.subdomains.union(subdomains)
+                self.gen_record(subdomains, record)
+            if subdomain == self.domain:  # 当查出子域为主域 说明完成了一个循环 不再继续查询
+                break
+            domain = subdomain
+        return self.subdomains
+
+    def run(self):
+        """
+        类执行入口
+        """
+        self.begin()
+        self.walk()
+        self.finish()
+        self.save_json()
+        self.gen_result()
+        self.save_db()
+
+
+def do(domain):  # 统一入口名字 方便多线程调用
+    """
+    类统一调用入口
+
+    :param str domain: 域名
+    """
+    brute = CheckNSEC(domain)
+    brute.run()
+
+
+if __name__ == '__main__':
+    do('iana.org')