Fix NoneType error when querying SOA records (#42)

* Fix `NoneType` error

* Remove deprecated versions of python

* Prepare the release candidate

* Update minimal required version of python

* Update CHANGELOG.md

* Update CHANGELOG.md

* Update setup.py

---------

Co-authored-by: mschwager <mschwager@users.noreply.github.com>

.github/workflows/ci.yml

@@ -10,8 +10,6 @@ jobs:
           - macos-latest
           - windows-latest
         python-version:
-          - '3.6'
-          - '3.7'
           - '3.8'
           - '3.9'
           - '3.10'

CHANGELOG.md

@@ -1,98 +1,143 @@
 # Change Log
+
 All notable changes to this project will be documented in this file.
 This project adheres to [Semantic Versioning](http://semver.org/).
 This project adheres to [CHANGELOG](http://keepachangelog.com/).
 
 ## [Unreleased]
 
+### Fixed
+
+- Add proper error handling for cases when SOA record is None
+
+### Removed
+
+- Official Python 3.6 support
+- Official Python 3.7 support
+
 ## [1.5.0] - 2021-12-05
+
 ### Added
+
 - Official Python 3.9 support
 - Official Python 3.10 support
 
 ### Changed
+
 - Improved various error handling
 
 ### Removed
+
 - Official Python 3.5 support
 
 ## [1.4.0] - 2019-11-07
+
 ### Added
+
 - Official Python 3.8 support
 - The --tcp flag to use TCP instead of UDP DNS queries
 
 ### Removed
+
 - Official Python 3.4 support, it's EOL
 
 ## [1.3.0] - 2019-05-15
+
 ### Changed
+
 - Print out all A records for wildcard, not just first one
 
 ### Added
+
 - Filter out subdomains with an A record matching a wildcard A record
 - Official Python 3.7 support
 
 ### Fixed
+
 - Prevent out of bounds error when expanding IPs near 0.0.0.0 or 255.255.255.255
 
 ## [1.2.2] - 2018-04-24
+
 ### Changed
+
 - Python 3 is now a requirement when installing via setup.py (including pip)
 - The README markdown is now included in the package's long description
 
 ## [1.2.1] - 2018-03-01
+
 ### Changed
+
 - Nearby IP reverse queries are now multithread, which improves performance significantly
 - Updated development dependencies
 - Subdomain lists use package_data instead of data_files
 
 ### Added
+
 - Gracefully handle users exiting the script with Ctrl+C
 - Gracefully handle incorrect file or IP range arguments
 
 ### Removed
+
 - Official Python 3.3 support, it's EOL
 
 ## [1.2.0] - 2017-05-07
+
 ### Added
+
 - Official Python 3.6 support
 
 ### Fixed
+
 - Handling of subdomains specified that are actually FQDNs
 - Gracefully handling timeouts when querying nameservers
 - Gracefully handling timeouts when querying zone transfers
 
 ## [1.1.5] - 2017-01-08
+
 ### Fixed
+
 - Fixed bug with CNAME records pointing to an A record without an associated IP
 - Fixed bug with connections being closed by remote peer
 
 ## [1.1.4] - 2016-08-30
+
 ### Fixed
+
 - Undo a PR that was breaking everything
 
 ## [1.1.3] - 2016-08-30
+
 ### Fixed
+
 - Fixed a subdomain concatenation bug
 
 ## [1.1.2] - 2016-08-15
+
 ### Changed
+
 - PyPI is absolutely ridiculous and needs a new version to upload the same package
 
 ## [1.1.1] - 2016-08-11
+
 ### Changed
+
 - Better error handling when making network connections
 - PEP8 formatting
 
 ## [1.1.0] - 2016-05-16
+
 ### Added
+
 - Intelligent subdomain file searching
 - PyPI classifiers
 
 ### Changed
+
 - Using more modern setuptools instead of distutils
 - Small README improvements
 
 ## [1.0.0] - 2016-05-08
+
 ### Added
+
 - Initial release of Fierce

fierce/fierce.py

@@ -319,8 +319,12 @@ def fierce(**kwargs):
     if soa:
         soa_mname = soa[0].mname
         master = query(resolver, soa_mname, record_type='A', tcp=kwargs["tcp"])
-        master_address = master[0].address
-        print("SOA: {} ({})".format(soa_mname, master_address))
+        if master:
+            master_address = master[0].address
+            print("SOA: {} ({})".format(soa_mname, master_address))
+        else:
+            print("SOA: failure")
+            fatal("Failed to lookup NS/SOA, Domain does not exist")
     else:
         print("SOA: failure")
         fatal("Failed to lookup NS/SOA, Domain does not exist")

setup.py

@@ -38,16 +38,14 @@
         'Operating System :: MacOS :: MacOS X',
         'Operating System :: Microsoft :: Windows',
         'Operating System :: POSIX',
-        'Programming Language :: Python :: 3.6',
-        'Programming Language :: Python :: 3.7',
         'Programming Language :: Python :: 3.8',
         'Programming Language :: Python :: 3.9',
         'Programming Language :: Python :: 3.10',
         'Topic :: Security',
     ],
     install_requires=install_requires,
     tests_require=tests_require,
-    python_requires='>=3.0',
+    python_requires='>=3.8',
     entry_points={
         'console_scripts': [
             'fierce = fierce.fierce:main',