351bb7a4e8
RFC 8446 specifies cipher suites that use three symmetric encryption algorithms, all of which are Authenticated Encryption with Associated Data (AEAD) algorithms. In each of these algorithms when data is encryption an authentication tag is created, which allows the recipient to verify that the data has not been modified. The authentication may also cover some additional data that was not encrypted. The current implementations of these algorithms in testssl.sh decrypt the ciphertext, but do not check that the authentication tag is correct (which involves the recipient computing the correct tag for the received data and then comparing it to the provided tag). While testssl.sh can get away with not checking authentication tags when receiving data, the ability to compute authentication tags is needed in order to send encrypted data as TLS servers would reject any encrypted data that did not have a correct authentication tag. Being able to send encrypted data is necessary to be able to complete the TLS 1.3 handshake. This PR replaces the current implementations of the symmetric encryption algorithms with full implementations of each of the algorithms. These full implementations include the ability to encrypt data for sending, and can also verify the authentication tag when decrypting data. Since the Bash implementations of these algorithms is very slow, the decryption code is designed to only compute and check authentication tags in debug mode. While the implementation of the code to compute authentication tags for AES-CCM was based on NIST Special Publication 800-38C, I was not able to implement the code for AES-GCM or Poly1305 from their specifications (NIST Special Publication 800-38D and RFC 8439, respectively). So, I would very much like to thank the implementers of https://github.com/mko-x/SharedAES-GCM and https://github.com/floodyberry/poly1305-donna. The implementations of AES-GCM and Poly1305 in the PR were developed by translating the C code in https://github.com/mko-x/SharedAES-GCM and https://github.com/floodyberry/poly1305-donna into Bash. I don't understand what that code is doing, but it seems to work. :-) I have only tested this code on a computer with a 64-bit operating system. While I have not tested it, I believe that the decryption code will work with 32-bit integers if not in debug mode (i.e., if not trying to compute the authentication tags). I also believe that the AES-CCM code for computing authentication tags will work with 32-bit integers. However, AES-GCM and Poly1305 code for computing authentication tags will definitely only work on systems that have 64-bit integers. So, on systems that do not have 64-bit integers, encryption will not work for AES-GCM or ChaCha20-Poly1305, and decryption will not work for these algorithms if in debug mode. |
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| .github | ||
| bin | ||
| doc | ||
| etc | ||
| t | ||
| utils | ||
| .gitignore | ||
| .travis.yml | ||
| CHANGELOG.md | ||
| CONTRIBUTING.md | ||
| CREDITS.md | ||
| Dockerfile | ||
| Dockerfile.md | ||
| LICENSE | ||
| openssl-iana.mapping.html | ||
| Readme.md | ||
| testssl.sh | ||
Intro
testssl.sh is a free command line tool which checks a server's service on
any port for the support of TLS/SSL ciphers, protocols as well as some
cryptographic flaws.
Key features
- Clear output: you can tell easily whether anything is good or bad.
- Machine readable output.
- No installation needed: Linux, OSX/Darwin, FreeBSD, NetBSD, MSYS2/Cygwin, WSL work out of the box. Only OpenBSD needs bash. No need to install or to configure something. No gems, CPAN, pip or the like.
- A Dockerfile is provided, there's also an offical container @ dockerhub.
- Flexibility: You can test any SSL/TLS enabled and STARTTLS service, not only web servers at port 443.
- Toolbox: Several command line options help you to run your test and configure your output.
- Reliability: features are tested thoroughly.
- Privacy: It's only you who sees the result, not a third party.
- Freedom: It's 100% open source. You can look at the code, see what's going on.
- The development is open (github) and participation is welcome.
License
This software is free. You can use it under the terms of GPLv2, see LICENSE. In addition starting from version 3.0rc1 if you're offering a scanner based on testssl.sh as a public and / or paid service in the internet you need to mention to your audience that you're using this program and where to get this program from.
Compatibility
testssl.sh is working on every Linux/BSD distribution out of the box. Latest by 2.9dev
most of the limitations of disabled features from the openssl client are gone
due to bash-socket-based checks. As a result you can also use e.g. LibreSSL or OpenSSL
1.1.1 . testssl.sh also works on other unixoid system out of the box, supposed they have
/bin/bash >= version 3.2 and standard tools like sed and awk installed. An implicit
(silent) check for binaries is done when you start testssl.sh . System V needs probably
to have GNU grep installed. MacOS X and Windows (using MSYS2, Cygwin or WSL) work too.
Update notification here or @ twitter.
Installation
You can download testssl.sh by cloning this git repository:
git clone --depth 1 https://github.com/drwetter/testssl.sh.git
Or help yourself downloading the ZIP archive https://github.com/drwetter/testssl.sh/archive/3.0.zip. Just cd to the directory created (=INSTALLDIR) and run it off there.
Docker
Testssl.sh has minimal requirements. As stated you don't have to install or build anything. You can just run it from the pulled/cloned directory. Still if you don't want to pull the github repo to your directory of choice you can pull a container from dockerhub and run it:
docker run --rm -ti drwetter/testssl.sh <your_cmd_line>
Or if you have cloned this repo you also can just cd to the INSTALLDIR and run
docker build .
followed by docker exec -ti <ID> <your_cmd_line> where ID is the identifier in the last line from the build command like
---> 889fa2f99933
Successfully built 889fa2f99933
Status
We're currently in the late release candidate phase. That means you can and should use it for production and let us know if you encounter any additional bugs. Features implemented in 3.0 are listed in the Changelog.
Support for 2.9.5 has been dropped.
Documentation
- .. it is there for reading. Please do so :-) -- at least before asking questions. See man page in groff, html and markdown format in
~/doc/. - https://testssl.sh/ will help to get you started.
- Will Hunt provides a longer, good description for the (older) version 2.8, including useful background info.
Contributing
Contributions are welcome! See CONTRIBUTING.md for details.
Bug reports
Bug reports are important. It makes this project more robust.
Please file bugs in the issue tracker @ github. Do not forget to provide detailed information, see template for issue, and further details @ https://github.com/drwetter/testssl.sh/wiki/Bug-reporting. Nobody can read your thoughts -- yet. And only agencies your screen ;-)
You can also debug yourself, see here.
External/related projects
Please address questions not specifically to the code of testssl.sh to the respective projects below.