---
name: "md5crypt"
section: "3tcl"
platform: "linux"
package: "tcllib"
version: "2.0+dfsg-4"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/md5crypt"
---

# md5crypt(3tcl)

MD5-based password encryption

```

```

## NAME

md5crypt - MD5-based password encryption

## SYNOPSIS

package require **Tcl 8.5 9**

package require **md5 2.0**

package require **md5crypt ?1.2.0?**

**::md5crypt::md5crypt** *password* *salt*

**::md5crypt::aprcrypt** *password* *salt*

**::md5crypt::salt** ?*length*?

```

```

## DESCRIPTION

This package provides an implementation of the MD5-crypt password encryption algorithm as pioneered by FreeBSD and currently in use as a replacement for the unix [crypt(3)](/crypt/3.md) function in many modern systems. An implementation of the closely related Apache MD5-crypt is also available. The output of these commands are compatible with the BSD and OpenSSL implementation of md5crypt and the Apache 2 htpasswd program.

## COMMANDS

- **::md5crypt::md5crypt** *password* *salt*

  Generate a BSD compatible md5-encoded password hash from the plaintext password and a random salt (see SALT).

- **::md5crypt::aprcrypt** *password* *salt*

  Generate an Apache compatible md5-encoded password hash from the plaintext password and a random salt (see SALT).

- **::md5crypt::salt** ?*length*?

  Generate a random salt string suitable for use with the **md5crypt** and **aprcrypt** commands.

## SALT

The salt passed to either of the encryption schemes implemented here is checked to see if it begins with the encryption scheme magic string (either "$1$" for MD5-crypt or "$apr1$" for Apache crypt). If so, this is removed. The remaining characters up to the next $ and up to a maximum of 8 characters are then used as the salt. The salt text should probably be restricted to the set of ASCII alphanumeric characters plus "./" (dot and forward-slash) - this is to preserve maximum compatibility with the unix password file format.

If a password is being generated rather than checked from a password file then the **salt** command may be used to generate a random salt.

## EXAMPLES

```
% md5crypt::md5crypt password 01234567
$1$01234567$b5lh2mHyD2PdJjFfALlEz1
```

```
% md5crypt::aprcrypt password 01234567
$apr1$01234567$IXBaQywhAhc0d75ZbaSDp/
```

```
% md5crypt::md5crypt password [md5crypt::salt]
$1$dFmvyRmO$T.V3OmzqeEf3hqJp2WFcb.
```

## BUGS, IDEAS, FEEDBACK

This document, and the package it describes, will undoubtedly contain bugs and other problems. Please report such in the category *md5crypt* of the *Tcllib Trackers* \[http://core.tcl.tk/tcllib/reportlist\]. Please also report any ideas for enhancements you may have for either package and/or documentation.

When proposing code changes, please provide *unified diffs*, i.e the output of **diff -u**.

Note further that *attachments* are strongly preferred over inlined patches. Attachments can be made by going to the **Edit** form of the ticket immediately after its creation, and then using the left-most button in the secondary navigation bar.

## SEE ALSO

md5

## KEYWORDS

hashing, md5, md5crypt, message-digest, security

## CATEGORY

Hashes, checksums, and encryption

## COPYRIGHT

```
Copyright (c) 2003, Pat Thoyts <patthoyts@users.sourceforge.net>
```