From 10e42591ac72285736d5cc4ee5e7c2f68dbf1e4b Mon Sep 17 00:00:00 2001 From: Xavier Del Campo Romero Date: Wed, 8 Oct 2025 13:50:52 +0200 Subject: Replace OpenSSL with libsodium and argon2id The SHA256-based password hashing algorithm used by slcl(1) and usergen(1) is considered insecure against several kinds of attacks, including brute force attacks. [1] Therefore, a stronger password hashing algorithm based on the Argon2id key derivation function is now used by default. While OpenSSL does support Argon2id, it is only supported by very recent versions [2], which are still not packaged by most distributions as of the time of this writing. [3] As an alternative to OpenSSL, libsodium [4] had several benefits: - It provides easy-to-use functions for password hashing, base64 encoding/decoding and other cryptographic primitives used by slcl(1) and usergen(1). - It is packaged by most distributions [5], and most often only the patch version differs, which ensures good compatibility across distributions. Unfortunately, and as opposed to OpenSSL, libsodium does not come with command-line tools. Therefore, usergen(1) had to be rewritten in C. In order to maintain backwards compatiblity with existing databases, slcl(1) and usergen(1) shall support the insecure, SHA256-based password hashing algorithm. However, Argon2id shall now be the default choice for usergen(1). [1]: https://security.stackexchange.com/questions/195563/why-is-sha-256-not-good-for-passwords [2]: https://docs.openssl.org/3.3/man7/EVP_KDF-ARGON2/ [3]: https://repology.org/project/openssl/versions [4]: https://www.libsodium.org/ [5]: https://repology.org/project/libsodium/versions --- README.md | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) (limited to 'README.md') diff --git a/README.md b/README.md index 80e850f..685d58c 100644 --- a/README.md +++ b/README.md @@ -58,7 +58,6 @@ to `slcl`. If required, encryption should be done before uploading e.g.: using (provided as a `git` submodule). - [`fdzipstream`](https://github.com/CTrabant/fdzipstream.git) (provided as a `git` submodule). -- `jq` (for [`usergen`](usergen) only). - CMake (optional). ### Ubuntu / Debian @@ -66,7 +65,7 @@ to `slcl`. If required, encryption should be done before uploading e.g.: using #### Mandatory packages ```sh -sudo apt install build-essential libcjson-dev libssl-dev m4 jq zlib1g +sudo apt install build-essential libcjson-dev libssl-dev m4 zlib1g ``` #### Optional packages @@ -176,7 +175,7 @@ schema: } ``` -[`usergen`](usergen) is an interactive script that consumes a directory, +[`usergen`](usergen) is an interactive program that consumes a directory, a username, a password and, optionally, a user quota in MiB. A salt is randomly generated using `openssl` and passwords are hashed multiple times beforehand - see [`usergen`](usergen) and [`auth.c`](auth.c) for further -- cgit v1.2.3