crypt(1) on Solnix vs Linux and the BSDs
On Solnix, crypt is the illumos /usr/bin/crypt, a filter that encrypts or decrypts stdin to stdout with a one-rotor Enigma-style machine. It takes only an optional password argument. FreeBSD's crypt (also called enigma) adds -s and -k and is documented as a separate, incompatible-by-option implementation.
The manual pages
- Solnix: crypt(1) from
pkgs.solnix.illumos-world-man· illumos.org - FreeBSD: crypt(1) 15.1-RELEASE
What Solnix runs
A default Solnix system runs the illumos crypt at /usr/bin/crypt. No other variants are shipped. The Solnix page says the files are compatible with ed(1), ex(1) and vi(1) in encryption mode. The page lists des(1) under SEE ALSO.
Differences
| Compared with | Topic | What differs |
|---|---|---|
| FreeBSD | -k and CrYpTkEy | FreeBSD crypt -k reads the key from the environment variable CrYpTkEy. The Solnix synopsis has no options, and the page documents no environment variable for the key. The key comes from the argument or a terminal prompt.Source: FreeBSD crypt(1) -k, ENVIRONMENT; Solnix crypt(1) SYNOPSIS |
| FreeBSD | -s modified engine | FreeBSD crypt -s changes the encryption engine, making it incompatible with other implementations. Solnix has no -s. A FreeBSD script using -s fails on Solnix, and its output could not be read by the Solnix crypt.Source: FreeBSD crypt(1) -s; Solnix crypt(1) SYNOPSIS |
| FreeBSD | command names | FreeBSD installs the program as both enigma and crypt. The Solnix page documents only the name crypt. Source: FreeBSD crypt(1) NAME, SYNOPSIS; Solnix crypt(1) NAME |
| FreeBSD | key prompt | With no password argument, both prompt on the terminal. FreeBSD says it uses getpass(3) and calls the prompt the only safe way to give the key. Solnix says printing is turned off while the key is typed. Solnix does not name getpass. Source: FreeBSD crypt(1) DESCRIPTION; Solnix crypt(1) DESCRIPTION |
| FreeBSD | key exposure in ps | Both pages warn that a password argument can be seen with ps(1). Solnix says crypt destroys any record of the key immediately on entry to minimize this. FreeBSD does not say it does this. Source: Solnix crypt(1) DESCRIPTION (last paragraph); FreeBSD crypt(1) DESCRIPTION |
| FreeBSD | security guidance | FreeBSD says enigma's cryptographic value is small, exists only for compatibility, and points to openssl(1) or gpg(1) for real encryption. Solnix also says crypt provides minimal security, but names no replacement. It lists des(1) under SEE ALSO. Source: FreeBSD crypt(1) Warning; Solnix crypt(1) DESCRIPTION, SEE ALSO |
| Linux, OpenBSD, NetBSD | no counterpart in the bundle | The bundle has no crypt(1) page for Linux, OpenBSD or NetBSD, so the manual comparison cannot say whether those systems ship a crypt command or what options it takes. Source: Bundle header: only a freebsd counterpart is listed |
Standards
- POSIX: crypt is not a POSIX.1-2024 utility.
Writing portable scripts
- Do not rely on crypt for security. Both pages call it weak. Use a tool such as openssl(1) or gpg(1) (named on the FreeBSD page) for real encryption.
- Use only the bare form crypt [password] or the terminal prompt in scripts. Avoid
-sand-k, which exist only on FreeBSD, and avoid putting the key on the command line, where ps(1) can show it.
Every difference here is taken from the manual pages linked above: Solnix's published page, Linux (man-pages and the GNU and util-linux manuals), FreeBSD, OpenBSD and NetBSD. Each row names its source. Where a manual is silent, this page is too. Compiled 2026-10-26. Found a mistake? Mail hackers@lists.solnix.io.