# ![DNSViz](doc/images/logo-220x100.png)


## Table of Contents
* [Installation](#installation)
* [Usage](#usage)
* [Pre-Deployment DNS Testing](#pre-deployment-dns-testing)
* [Docker Container](#docker-container)


## Description

DNSViz is a tool suite for analysis and visualization of Domain Name System
(DNS) behavior, including its security extensions (DNSSEC).  This tool suite
powers the Web-based analysis available at https://dnsviz.net/


## Installation

DNSViz packages are available in repositories for popular operating systems,
such as Debian, Ubuntu, and FreeBSD.  DNSViz can also be installed on Mac OS X
via Homebrew or MacPorts.

The remainer of this section covers other methods of installation, including a
list of [dependencies](#dependencies), installation to a
[virtual environment](#installation-in-a-virtual-environment), and installation
on [Fedora, RHEL 8, CentOS 8,](#fedora--rhel-8--centos-8-rpm-build-and-install) and
[RHEL 7](#rhel-7-rpm-build-and-install).

Instructions for running in a Docker container are also available
[later in this document](#docker-container).


### Dependencies

* python (2.7, 3.5 - 3.9) - https://www.python.org/

* dnspython (1.13.0 or later) - https://www.dnspython.org/

* pygraphviz (1.3 or later) - https://pygraphviz.github.io/

* M2Crypto (0.37.0 or later) - https://gitlab.com/m2crypto/m2crypto

Note that earlier versions of the software listed above might also work with
DNSViz, but with some caveats.  For example, M2Crypto 0.28.0 and later will
work, but versions of M2Crypto earlier than 0.37.0 lack support for DNSSEC
algorithms 15 (Ed25519) and 16 (Ed448).  Also, while DNSViz itself still works
with python 2.7, some versions of its software dependencies have moved on:
pygraphviz 1.6 and dnspython 2.0.0 dropped support for python 2.7.


### Optional Software

* OpenSSL GOST Engine - https://github.com/gost-engine/engine

  With OpenSSL version 1.1.0 and later, the OpenSSL GOST Engine is necessary to
  validate DNSSEC signatures with algorithm 12 (GOST R 34.10-2001) and create
  digests of type 3 (GOST R 34.11-94).

* ISC BIND - https://www.isc.org/bind/

  When using DNSViz for [pre-deployment testing](#pre-deployment-dns-testing)
  by specifying zone files and/or alternate delegation information on the
  command line (i.e., with `-N`, `-x`, or `-D`), `named(8)` is invoked to serve
  one or more zones.  ISC BIND is only needed in this case, and `named(8)` does
  not need to be running (i.e., as a server).

  Note that default AppArmor policies for Debian are known to cause issues when
  invoking `named(8)` from DNSViz for pre-deployment testing.  Two solutions to
  this problem are to either: 1) create a local policy for AppArmor that allows
  `named(8)` to run with fewer restrictions; or 2) disable AppArmor completely.


### Installation in a Virtual Environment

To install DNSViz to a virtual environment, first create and activate a virtual
environment, and install the dependencies:
```
$ virtualenv ~/myenv
$ source ~/myenv/bin/activate
(myenv) $ pip install -r requirements.txt
```
(Note that this installs the dependencies that are python packages, but some of
these packages have non-python dependecies, such as Graphviz (required for
pygraphviz) that are not installed automatically.)

Next download and install DNSViz from the Python Package Index (PyPI):
```
(myenv) $ pip install dnsviz
```
or locally, from a downloaded or cloned copy of DNSViz:
```
(myenv) $ pip install .
```


### Fedora / RHEL 8 / CentOS 8 RPM Build and Install

*RHEL 8 only*: Enable CodeReady Linux Builder by following the instructions [here](https://access.redhat.com/articles/4348511).

*CentOS 8 only*: Enable PowerTools and EPEL with the following two commands:
```
$ sudo dnf config-manager --set-enabled powertools
$ sudo dnf install epel-release
```

The remaining instructions are for Fedora, RHEL 8, and CentOS 8.

Install the tools for building an RPM, and set up the rpmbuild tree.
```
$ sudo dnf install rpm-build rpmdevtools python3-devel
$ rpmdev-setuptree
```

From within the DNSViz source directory, create a source distribution tarball
and copy it and the DNSViz spec file to the appropriate rpmbuild
subdirectories.
```
$ python3 setup.py sdist
$ cp dist/dnsviz-*.tar.gz ~/rpmbuild/SOURCES/
$ cp contrib/dnsviz.spec ~/rpmbuild/SPECS/
```

Install dnspython, pygraphviz, and M2Crypto.
```
$ sudo dnf install python3-dns python3-pygraphviz python3-m2crypto
```
(Note that as of Fedora 33 / RHEL 8 / CentOS 8, the latest version of M2Crypto is 0.35.2.  If you
would like support for DNSSEC algorithms 15 (Ed25519) and 16 (Ed448), you will
need to install M2Crypto using `pip3`.  For example, see [installation to a
virtual environment](#installation-in-a-virtual-environment).)

Build and install the DNSViz RPM.
```
$ rpmbuild -ba rpmbuild/SPECS/dnsviz.spec
$ sudo rpm -iv rpmbuild/RPMS/noarch/dnsviz-*-1.*.noarch.rpm
```


### RHEL 7 RPM Build and Install

Install pygraphviz, M2Crypto, and dnspython, after installing their build dependencies.
```
$ sudo yum install python3 gcc python3-devel graphviz-devel openssl-devel swig
$ pip3 install --user pbr m2crypto pygraphviz dnspython
```

Install rpm-build tools, then build and install the DNSViz RPM.
```
$ sudo yum install rpm-build
$ python3 setup.py bdist_rpm --install-script contrib/rpm-install.sh --distribution-name el7
$ sudo rpm -iv dist/dnsviz-*-1.noarch.rpm
```

Note that a custom install script is used to properly install the DNSViz man
pages.


## Usage

DNSViz is invoked using the `dnsviz` command-line utility.  `dnsviz` itself
uses several subcommands: `probe`, `grok`, `graph`, `print`, and `query`.  See
the man pages associated with each subcommand, in the form of
"dnsviz-<subcommand> (1)" (e.g., "man dnsviz-probe") for more detailed
documentation and usage.

### dnsviz probe

`dnsviz probe` takes one or more domain names as input and performs a series of
queries to either recursive (default) or authoritative DNS servers, the results
of which are serialized into JSON format.


#### Examples

Analyze the domain name example.com using your configured DNS resolvers (i.e.,
in `/etc/resolv.conf`) and store the queries and responses in the file named
"example.com.json":
```
$ dnsviz probe example.com > example.com.json
```

Same thing:
```
$ dnsviz probe -o example.com.json example.com
```

Analyze the domain name example.com by querying its authoritative servers
directly:
```
$ dnsviz probe -A -o example.com.json example.com
```

Analyze the domain name example.com by querying explicitly-defined
authoritative servers, rather than learning the servers through referrals from
the IANA root servers:
```
$ dnsviz probe -A \
  -x example.com:a.iana-servers.org=199.43.132.53,a.iana-servers.org=[2001:500:8c::53] \
  -x example.com:b.iana-servers.org=199.43.133.53,b.iana-servers.org=[2001:500:8d::53] \
  -o example.com.json example.com
```

Same, but have `dnsviz probe` resolve the names:
```
$ dnsviz probe -A \
  -x example.com:a.iana-servers.org,b.iana-servers.org \
  -o example.com.json example.com
```

Analyze the domain name example.com and its entire ancestry by querying
authoritative servers and following delegations, starting at the root:
```
$ dnsviz probe -A -a . -o example.com.json example.com
```

Analyze multiple names in parallel (four threads) using explicit recursive
resolvers (replace *192.0.1.2* and *2001:db8::1* with legitimate resolver
addresses):
```
$ dnsviz probe -s 192.0.2.1,[2001:db8::1] -t 4 -o multiple.json \
  example.com sandia.gov verisignlabs.com dnsviz.net
```


### dnsviz grok

`dnsviz grok` takes serialized query results in JSON format (i.e., output from
`dnsviz probe`) as input and assesses specified domain names based on their
corresponding content in the input.  The output is also serialized into JSON
format.


#### Examples

Process the query/response output produced by `dnsviz probe`, and store the
serialized results in a file named "example.com-chk.json":
```
$ dnsviz grok < example.com.json > example.com-chk.json
```

Same thing:
```
$ dnsviz grok -r example.com.json -o example.com-chk.json example.com
```

Show only info-level information: descriptions, statuses, warnings, and errors:
```
$ dnsviz grok -l info -r example.com.json -o example.com-chk.json
```

Show descriptions only if there are related warnings or errors:
```
$ dnsviz grok -l warning -r example.com.json -o example.com-chk.json
```

Show descriptions only if there are related errors:
```
$ dnsviz grok -l error -r example.com.json -o example.com-chk.json
```

Use root key as DNSSEC trust anchor, to additionally indicate
authentication status of responses:
```
$ dig +noall +answer . dnskey | awk '$5 % 2 { print $0 }' > tk.txt
$ dnsviz grok -l info -t tk.txt -r example.com.json -o example.com-chk.json
```

Pipe `dnsviz probe` output directly to `dnsviz grok`:
```
$ dnsviz probe example.com | \
      dnsviz grok -l info -o example.com-chk.json
```

Same thing, but save the raw output (for re-use) along the way:
```
$ dnsviz probe example.com | tee example.com.json | \
      dnsviz grok -l info -o example.com-chk.json
```

Assess multiple names at once with error level:
```
$ dnsviz grok -l error -r multiple.json -o example.com-chk.json
```


### dnsviz graph

`dnsviz graph` takes serialized query results in JSON format (i.e., output from
`dnsviz probe`) as input and assesses specified domain names based on their
corresponding content in the input.  The output is an image file, a `dot`
(directed graph) file, or an HTML file, depending on the options passed.


#### Examples

Process the query/response output produced by `dnsviz probe`, and produce a
graph visually representing the results in a png file named "example.com.png".
```
$ dnsviz graph -Tpng < example.com.json > example.com.png
```

Same thing:
```
$ dnsviz graph -Tpng -o example.com.png example.com < example.com.json
```

Same thing, but produce interactive HTML format:
interactive HTML output in a file named "example.com.html":
```
$ dnsviz graph -Thtml < example.com.json > example.com.html
```

Same thing (filename is derived from domain name and output format):
```
$ dnsviz graph -Thtml -O -r example.com.json
```

Use alternate DNSSEC trust anchor:
```
$ dig +noall +answer example.com dnskey | awk '$5 % 2 { print $0 }' > tk.txt
$ dnsviz graph -Thtml -O -r example.com.json -t tk.txt
```

Pipe `dnsviz probe` output directly to `dnsviz graph`:
```
$ dnsviz probe example.com | \
      dnsviz graph -Thtml -O
```

Same thing, but save the raw output (for re-use) along the way:
```
$ dnsviz probe example.com | tee example.com.json | \
      dnsviz graph -Thtml -O
```

Process analysis of multiple domain names, creating an image for each name
processed:
```
$ dnsviz graph -Thtml -O -r multiple.json
```

Process analysis of multiple domain names, creating a single image for all
names.
```
$ dnsviz graph -Thtml -r multiple.json > multiple.html
```


### dnsviz print

`dnsviz print` takes serialized query results in JSON format (i.e., output from
`dnsviz probe`) as input and assesses specified domain names based on their
corresponding content in the input.  The output is textual output suitable for
file or terminal display.


#### Examples

Process the query/response output produced by `dnsviz probe`, and output the
results to the terminal:
```
$ dnsviz print < example.com.json
```

Use alternate DNSSEC trust anchor:
```
$ dig +noall +answer example.com dnskey | awk '$5 % 2 { print $0 }' > tk.txt
$ dnsviz print -r example.com.json -t tk.txt
```

Pipe `dnsviz probe` output directly to `dnsviz print`:
```
$ dnsviz probe example.com | \
      dnsviz print
```

Same thing, but save the raw output (for re-use) along the way:
```
$ dnsviz probe example.com | tee example.com.json | \
      dnsviz print
```


### dnsviz query

`dnsviz query` is a wrapper that couples the functionality of `dnsviz probe`
and `dnsviz print` into a tool with minimal dig-like usage, used to make
analysis queries and return the textual output to terminal or file output in
one go.


#### Examples

Analyze the domain name example.com using the first of your configured DNS
resolvers (i.e., in `/etc/resolv.conf`):
```
$ dnsviz query example.com
```

Same, but specify an alternate trust anchor:
```
$ dnsviz query +trusted-key=tk.txt example.com
```

Analyze example.com through the recursive resolver at 192.0.2.1:
```
$ dnsviz query @192.0.2.1 +trusted-key=tk.txt example.com
```


## Pre-Deployment DNS Testing

The examples in this section demonstrate usage of DNSViz for pre-deployment
testing.


### Pre-Delegation Testing

The following examples involve issuing diagnostic queries for a zone before it
is ever delegated.

Issue queries against a zone file on the local system (`example.com.zone`).
`named(8)` is invoked to serve the file locally:
```
$ dnsviz probe -A -x example.com+:example.com.zone example.com
```
(Note the use of "+", which designates that the parent servers should not be
queried for DS records.)

Issue queries to a server that is serving the zone:
```
$ dnsviz probe -A -x example.com+:192.0.2.1 example.com
```
(Note that this server doesn't need to be a server in the NS RRset for
example.com.)

Issue queries to the servers in the authoritative NS RRset, specified by name
and/or address:
```
$ dnsviz probe -A \
      -x example.com+:ns1.example.com=192.0.2.1 \
      -x example.com+:ns2.example.com=192.0.2.1,ns2.example.com=[2001:db8::1] \
      example.com
```

Specify the names and addresses corresponding to the future delegation NS
records and (as appropriate) A/AAAA glue records in the parent zone (com):
```
$ dnsviz probe -A \
      -N example.com:ns1.example.com=192.0.2.1 \
      -N example.com:ns2.example.com=192.0.2.1,ns2.example.com=[2001:db8::1] \
      example.com
```

Also supply future DS records:
```
$ dnsviz probe -A \
      -N example.com:ns1.example.com=192.0.2.1 \
      -N example.com:ns2.example.com=192.0.2.1,ns2.example.com=[2001:db8::1] \
      -D example.com:dsset-example.com. \
      example.com
```


### Pre-Deployment Testing of Authoritative Zone Changes

The following examples involve issuing diagnostic queries for a delegated zone
before changes are deployed.

Issue diagnostic queries for a new zone file that has been created but not yet
been deployed (i.e., with changes to DNSKEY or other records):
```
$ dnsviz probe -A -x example.com:example.com.zone example.com
```
(Note the absence of "+", which designates that the parent servers will be
queried for DS records.)

Issue queries to a server that is serving the new version of the zone:
```
$ dnsviz probe -A -x example.com:192.0.2.1 example.com
```
(Note that this server doesn't need to be a server in the NS RRset for
example.com.)


### Pre-Deployment Testing of Delegation Changes

The following examples involve issuing diagnostic queries for a delegated zone
before changes are deployed to the delegation, glue, or DS records for that
zone.

Specify the names and addresses corresponding to the new delegation NS records
and (as appropriate) A/AAAA glue records in the parent zone (com):
```
$ dnsviz probe -A \
      -N example.com:ns1.example.com=192.0.2.1 \
      -N example.com:ns2.example.com=192.0.2.1,ns2.example.com=[2001:db8::1] \
      example.com
```

Also supply the replacement DS records:
```
$ dnsviz probe -A \
      -N example.com:ns1.example.com=192.0.2.1 \
      -N example.com:ns2.example.com=192.0.2.1,ns2.example.com=[2001:db8::1] \
      -D example.com:dsset-example.com. \
      example.com
```


## Docker Container

A ready-to-use docker container is available for use.

```
docker pull dnsviz/dnsviz
```

This section only covers Docker-related examples, for more information see the
[Usage](#usage) section.


### Simple Usage

```
$ docker run dnsviz/dnsviz help
$ docker run dnsviz/dnsviz query example.com
```


### Working with Files

It might be useful to mount a local working directory into the container,
especially when combining multiple commands or working with zone files.

```
$ docker run -v "$PWD:/data:rw" dnsviz/dnsviz probe dnsviz.net > probe.json
$ docker run -v "$PWD:/data:rw" dnsviz/dnsviz graph -r probe.json -T png -O
```


### Using a Host Network

When running authoritative queries, a host network is recommended.

```
$ docker run --network host dnsviz/dnsviz probe -4 -A example.com > example.json
```

Otherwise, you're likely to encounter the following error:
`dnsviz.query.SourceAddressBindError: Unable to bind to local address (EADDRNOTAVAIL)`


### Interactive Mode

When performing complex analyses, where you need to combine multiple DNSViz
commands, use bash redirection, etc., it might be useful to run the container
interactively:

```
$ docker run --network host -v "$PWD:/data:rw" --entrypoint /bin/sh -ti dnsviz/dnsviz
/data # dnsviz --help
```