SSH server & client auditing (banner, key exchange, encryption, mac, compression, compatibility, security, etc) .
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Jürgen Gmach 29d874b450
Fix tox and finally make Travis green (#29)
* Ignore all flake8 warnings - one by one

Without ignoring, there are by far more than 1000 linting issues.

Fixing these warnings means possibly changing almost every line of
code, as single warnings can effect more than one line.

Doing this in one pull request is generally no good idea, and especially
not now, as the test suite is currently broken.

Instead of just deactivating flake8, or ignoring its exit code, the
warnings are ignored one by one.

This means, when one wants to work on the linting issues, one can just
remove one ignored warning, and fix the problems - which is not too much
work at once, and leads to an managable diff.

modified:   tox.ini

* Unpin dependencies for mypy run

... as they could not be installed due to compilation errors.

modified:   tox.ini

* Fix syntax error for mypy

When new code was added via
af663da838
the type hint was moved further down and so caused a syntax error, as
type hints have to follow the function declaration directly.

Now, the the type linter finally works and shows 187 errors.

modified:   ssh-audit.py

* Update .gitignore for mypy

modified:   .gitignore

* Let tox not fail on mypy errors

Currently, there are almost 200 typing related errors.

Instead of letting the tox run fail, the errors are still shown, but
the exit code gets ignored for now.

This way one can fix them one by one - if wanted.

modified:   tox.ini

* Let tox not fail on pylint errors

Currently, there are more than 100 linting related errors.

Most of them will be fixed when flake8 gets fixed.

Instead of letting the tox run fail, the errors are still shown, but the
exit code gets ignored for now.

This way, one can fix them one by one.

modified:   tox.ini

* Let vulture only fail on 100% confidence

Vulture is a tool to find dead code. Unlike Flake8, which also finds
unused imports and variables, Vulture does some guess work and finally
outputs a list of possible dead code with a confidence marker.

Already the first result ...
"ssh-audit.py:48: unused import 'Dict' (90% confidence)"
... is a false-positive.

As Flake8 also does a good job in detecting unused code, it makes not
much sense to let tox fail when vulture fails.

Instead of deactivating vulture, it was configured in a way to only
report results with 100% confidence.

modified:   tox.ini

* Make timeout_set optional

When timeout_set was introduced in
1ec13c653e
the tests were not updated, which instantiated the Socket class.

While the commit message read "A timeout can now be specified", the
code enforced a `timeout_set`.

`timeout_set` now is `False` by default.

modified:   ssh-audit.py

* Set default values for Socket's `ipvo` and `timeout`

Commit
f44663bfc4
introduced two new arguments to the Socket class, but did not update
the tests, which still relied on the socket class to only require two arguments.

While for `ipvo`the default of `None` is obvious, as in `__init__` it is
checked for it, for `timeout` it was not that obvious.

Luckily, in the README a default of 5 (seconds) is mentioned.

modified:   ssh-audit.py

* Un-comment exception handling

While working on commit
fd3a1f7d41
possibly it was forgotten to undo the commenting of the exception
handling for the case, when the Socket class was instantiated with a
missing `host` argument.

This broke the `test_invalid_host` test.

modified:   ssh-audit.py

* Skip `test_ssh2_server_simple` temporarily

After fixing all the other tests and make tox run again, there is one
failing test left, which unfortunately is not super easy to fix without
further research (at least not for me).

I marked `test_ssh2_server_simple` to be skipped in test runs
(temporarily), so at least, when working on new features, there is
working test suite, now.

modified:   test/test_ssh2.py

* Do not pin pytest and coverage version

... but do use pytest < 6, as this version will have a breaking change
with junit/Jenkins integration

Also see https://github.com/jtesta/ssh-audit/issues/34

* Drop unsupported Python versions

... except Python 2.7, as this will need also changes to the source
code, and this pull request is already big enough.

Also, support for Python 3.8 was added.

The Travis configuration was simplified a lot, by leveraging the tox
configuration.

Also, the mac builds have been dropped, as they all took almost an hour
each, they failed and I have no experience on how to fix them.

The `appveyor` build only has been updated to reflect the updated Python
versions, as I have no access to the status page and no experience with
this build environment.

Also, removed call to `coveralls`, which seems to be a leftover from
the old repository.

modified:   .appveyor.yml
modified:   .travis.yml
modified:   packages/setup.py
deleted:    test/tools/ci-linux.sh
modified:   tox.ini
2020-06-08 16:38:22 -04:00
packages Fix tox and finally make Travis green (#29) 2020-06-08 16:38:22 -04:00
test Fix tox and finally make Travis green (#29) 2020-06-08 16:38:22 -04:00
.appveyor.yml Fix tox and finally make Travis green (#29) 2020-06-08 16:38:22 -04:00
.gitignore Fix tox and finally make Travis green (#29) 2020-06-08 16:38:22 -04:00
.travis.yml Fix tox and finally make Travis green (#29) 2020-06-08 16:38:22 -04:00
LICENSE Added myself to copyright header in license. 2019-08-16 08:56:50 -04:00
README.md Added Homebrew installation instructions (#27). 2020-05-31 11:44:00 -04:00
docker_test.sh Added timeout of 0 to container stop command. 2019-11-30 23:49:31 -05:00
ssh-audit.py Fix tox and finally make Travis green (#29) 2020-06-08 16:38:22 -04:00
tox.ini Fix tox and finally make Travis green (#29) 2020-06-08 16:38:22 -04:00
windows_build.txt Added Windows build instructions and icon. 2019-11-30 16:55:43 -05:00
windows_icon.ico Added Windows build instructions and icon. 2019-11-30 16:55:43 -05:00

README.md

ssh-audit

ssh-audit is a tool for ssh server & client configuration auditing.

Features

  • SSH1 and SSH2 protocol server support;
  • analyze SSH client configuration;
  • grab banner, recognize device or software and operating system, detect compression;
  • gather key-exchange, host-key, encryption and message authentication code algorithms;
  • output algorithm information (available since, removed/disabled, unsafe/weak/legacy, etc);
  • output algorithm recommendations (append or remove based on recognized software version);
  • output security information (related issues, assigned CVE list, etc);
  • analyze SSH version compatibility based on algorithm information;
  • historical information from OpenSSH, Dropbear SSH and libssh;
  • runs on Linux and Windows;
  • no dependencies

Usage

usage: ssh-audit.py [-1246pbcnjvlt] <host>

   -1,  --ssh1             force ssh version 1 only
   -2,  --ssh2             force ssh version 2 only
   -4,  --ipv4             enable IPv4 (order of precedence)
   -6,  --ipv6             enable IPv6 (order of precedence)
   -p,  --port=<port>      port to connect
   -b,  --batch            batch output
   -c,  --client-audit     starts a server on port 2222 to audit client
                               software config (use -p to change port;
                               use -t to change timeout)
   -n,  --no-colors        disable colors
   -j,  --json             JSON output
   -v,  --verbose          verbose output
   -l,  --level=<level>    minimum output level (info|warn|fail)
   -t,  --timeout=<secs>   timeout (in seconds) for connection and reading
                               (default: 5)
  • if both IPv4 and IPv6 are used, order of precedence can be set by using either -46 or -64.
  • batch flag -b will output sections without header and without empty lines (implies verbose flag).
  • verbose flag -v will prefix each line with section type and algorithm name.

Server Audit Example

Below is a screen shot of the server-auditing output when connecting to an unhardened OpenSSH v5.3 service: screenshot

Client Audit Example

Below is a screen shot of the client-auditing output when an unhardened OpenSSH v7.2 client connects: client_screenshot

Hardening Guides

Guides to harden server & client configuration can be found here: https://www.ssh-audit.com/hardening_guides.html

Pre-Built Packages

Pre-built packages are available for Windows (see the releases page), on PyPI, as well as the snap repository.

To install from PyPI:

$ pip3 install ssh-audit

To install the snap package:

$ snap install ssh-audit

To install on Homebrew:

$ brew install ssh-audit

ChangeLog

v2.2.1-dev (???)

  • Suppress recommendation of token host key types.
  • Added 1 new host key types: ssh-rsa1.
  • Added 1 new ciphers: blowfish, AEAD_AES_128_GCM, AEAD_AES_256_GCM.
  • Added 2 new MACs: chacha20-poly1305@openssh.com, hmac-sha3-224.

v2.2.0 (2020-03-11)

  • Marked host key type ssh-rsa as weak due to practical SHA-1 collisions.
  • Added Windows builds.
  • Added 10 new host key types: ecdsa-sha2-1.3.132.0.10, x509v3-sign-dss, x509v3-sign-rsa, x509v3-sign-rsa-sha256@ssh.com, x509v3-ssh-dss, x509v3-ssh-rsa, sk-ecdsa-sha2-nistp256-cert-v01@openssh.com, sk-ecdsa-sha2-nistp256@openssh.com, sk-ssh-ed25519-cert-v01@openssh.com, and sk-ssh-ed25519@openssh.com.
  • Added 18 new key exchanges: diffie-hellman-group14-sha256@ssh.com, diffie-hellman-group15-sha256@ssh.com, diffie-hellman-group15-sha384@ssh.com, diffie-hellman-group16-sha384@ssh.com, diffie-hellman-group16-sha512@ssh.com, diffie-hellman-group18-sha512@ssh.com, ecdh-sha2-curve25519, ecdh-sha2-nistb233, ecdh-sha2-nistb409, ecdh-sha2-nistk163, ecdh-sha2-nistk233, ecdh-sha2-nistk283, ecdh-sha2-nistk409, ecdh-sha2-nistp192, ecdh-sha2-nistp224, ecdh-sha2-nistt571, gss-gex-sha1-, and gss-group1-sha1-.
  • Added 9 new ciphers: camellia128-cbc, camellia128-ctr, camellia192-cbc, camellia192-ctr, camellia256-cbc, camellia256-ctr, aes128-gcm, aes256-gcm, and chacha20-poly1305.
  • Added 2 new MACs: aes128-gcm and aes256-gcm.

v2.1.1 (2019-11-26)

  • Added 2 new host key types: rsa-sha2-256-cert-v01@openssh.com, rsa-sha2-512-cert-v01@openssh.com.
  • Added 2 new ciphers: des, 3des.
  • Added 3 new PuTTY vulnerabilities.
  • During client testing, client IP address is now listed in output.

v2.1.0 (2019-11-14)

  • Added client software auditing functionality (see -c / --client-audit option).
  • Added JSON output option (see -j / --json option; credit Andreas Jaggi).
  • Fixed crash while scanning Solaris Sun_SSH.
  • Added 9 new key exchanges: gss-group1-sha1-toWM5Slw5Ew8Mqkay+al2g==, gss-gex-sha1-toWM5Slw5Ew8Mqkay+al2g==, gss-group14-sha1-, gss-group14-sha1-toWM5Slw5Ew8Mqkay+al2g==, gss-group14-sha256-toWM5Slw5Ew8Mqkay+al2g==, gss-group15-sha512-toWM5Slw5Ew8Mqkay+al2g==, diffie-hellman-group15-sha256, ecdh-sha2-1.3.132.0.10, curve448-sha512.
  • Added 1 new host key type: ecdsa-sha2-1.3.132.0.10.
  • Added 4 new ciphers: idea-cbc, serpent128-cbc, serpent192-cbc, serpent256-cbc.
  • Added 6 new MACs: hmac-sha2-256-96-etm@openssh.com, hmac-sha2-512-96-etm@openssh.com, hmac-ripemd, hmac-sha256-96@ssh.com, umac-32@openssh.com, umac-96@openssh.com.

v2.0.0 (2019-08-29)

  • Forked from https://github.com/arthepsy/ssh-audit (development was stalled, and developer went MIA).
  • Added RSA host key length test.
  • Added RSA certificate key length test.
  • Added Diffie-Hellman modulus size test.
  • Now outputs host key fingerprints for RSA and ED25519.
  • Added 5 new key exchanges: sntrup4591761x25519-sha512@tinyssh.org, diffie-hellman-group-exchange-sha256@ssh.com, diffie-hellman-group-exchange-sha512@ssh.com, diffie-hellman-group16-sha256, diffie-hellman-group17-sha512.
  • Added 3 new encryption algorithms: des-cbc-ssh1, blowfish-ctr, twofish-ctr.
  • Added 10 new MACs: hmac-sha2-56, hmac-sha2-224, hmac-sha2-384, hmac-sha3-256, hmac-sha3-384, hmac-sha3-512, hmac-sha256, hmac-sha256@ssh.com, hmac-sha512, hmac-512@ssh.com.
  • Added command line argument (-t / --timeout) for connection & reading timeouts.
  • Updated CVEs for libssh & Dropbear.

v1.7.0 (2016-10-26)

  • implement options to allow specify IPv4/IPv6 usage and order of precedence
  • implement option to specify remote port (old behavior kept for compatibility)
  • add colors support for Microsoft Windows via optional colorama dependency
  • fix encoding and decoding issues, add tests, do not crash on encoding errors
  • use mypy-lang for static type checking and verify all code

v1.6.0 (2016-10-14)

  • implement algorithm recommendations section (based on recognized software)
  • implement full libssh support (version history, algorithms, security, etc)
  • fix SSH-1.99 banner recognition and version comparison functionality
  • do not output empty algorithms (happens for misconfigured servers)
  • make consistent output for Python 3.x versions
  • add a lot more tests (conf, banner, software, SSH1/SSH2, output, etc)
  • use Travis CI to test for multiple Python versions (2.6-3.5, pypy, pypy3)

v1.5.0 (2016-09-20)

  • create security section for related security information
  • match and output assigned CVE list and security issues for Dropbear SSH
  • implement full SSH1 support with fingerprint information
  • automatically fallback to SSH1 on protocol mismatch
  • add new options to force SSH1 or SSH2 (both allowed by default)
  • parse banner information and convert it to specific software and OS version
  • do not use padding in batch mode
  • several fixes (Cisco sshd, rare hangs, error handling, etc)

v1.0.20160902

  • implement batch output option
  • implement minimum output level option
  • fix compatibility with Python 2.6

v1.0.20160812

  • implement SSH version compatibility feature
  • fix wrong mac algorithm warning
  • fix Dropbear SSH version typo
  • parse pre-banner header
  • better errors handling

v1.0.20160803

  • use OpenSSH 7.3 banner
  • add new key-exchange algorithms

v1.0.20160207

  • use OpenSSH 7.2 banner
  • additional warnings for OpenSSH 7.2
  • fix OpenSSH 7.0 failure messages
  • add rijndael-cbc failure message from OpenSSH 6.7

v1.0.20160105

  • multiple additional warnings
  • support for none algorithm
  • better compression handling
  • ensure reading enough data (fixes few Linux SSH)

v1.0.20151230

  • Dropbear SSH support

v1.0.20151223

  • initial version