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crypt(1) [freebsd man page]

ENIGMA(1)						    BSD General Commands Manual 						 ENIGMA(1)

NAME
enigma, crypt -- very simple file encryption SYNOPSIS
enigma [-s] [-k] [password] crypt [-s] [-k] [password] DESCRIPTION
The enigma utility, also known as crypt is a very simple encryption program, working on a ``secret-key'' basis. It operates as a filter, i.e., it encrypts or decrypts a stream of data from standard input, and writes the result to standard output. Since its operation is fully symmetrical, feeding the encrypted data stream again through the engine (using the same secret key) will decrypt it. There are several ways to provide the secret key to the program. By default, the program prompts the user on the controlling terminal for the key, using getpass(3). This is the only safe way of providing it. Alternatively, the key can be provided as the sole command-line argument password when starting the program. Obviously, this way the key can easily be spotted by other users running ps(1). As yet another alternative, enigma can be given the option -k, and it will take the key from the environment variable CrYpTkEy. While this at a first glance seems to be more secure than the previous option, it actually is not since environment variables can also be examined with ps(1). Thus this option is mainly provided for compatibility with other implementations of enigma. When specifying the option -s, enigma modifies the encryption engine in a way that is supposed to make it a little more secure, but incompat- ible with other implementations. Warning The cryptographic value of enigma is rather small. This program is only provided here for compatibility with other operating systems that also provide an implementation (usually called crypt(1) there). For real encryption, refer to bdes(1), openssl(1), pgp(1) (ports/security/pgp), or gpg(1) (ports/security/gnupg). However, restrictions for exporting, importing or using such tools might exist in some countries, so those stronger programs are not being shipped as part of the operating system by default. ENVIRONMENT
CrYpTkEy used to obtain the secret key when option -k has been given EXAMPLES
man enigma | enigma > encrypted Enter key: (XXX -- key not echoed) This will create an encrypted form of this man page, and store it in the file encrypted. enigma XXX < encrypted This displays the previously created file on the terminal. SEE ALSO
bdes(1), gpg(1), openssl(1), pgp(1), ps(1), getpass(3) HISTORY
Implementations of crypt are very common among UNIX operating systems. This implementation has been taken from the Cryptbreakers Workbench which is in the public domain. BSD
May 14, 2004 BSD

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crypt(1)                                                                                                                                  crypt(1)

NAME
crypt - encode or decode a file SYNOPSIS
crypt [password] The crypt utility encrypts and decrypts the contents of a file. crypt reads from the standard input and writes on the standard output. The password is a key that selects a particular transformation. If no password is given, crypt demands a key from the terminal and turns off printing while the key is being typed in. crypt encrypts and decrypts with the same key: example% crypt key < clear.file > encrypted.file example% crypt key < encrypted.file | pr prints the contents of clear.file. Files encrypted by crypt are compatible with those treated by the editors ed(1), ex(1), and vi(1) in encryption mode. The security of encrypted files depends on three factors: the fundamental method must be hard to solve; direct search of the key space must be infeasible; "sneak paths" by which keys or cleartext can become visible must be minimized. crypt implements a one-rotor machine designed along the lines of the German Enigma, but with a 256-element rotor. Methods of attack on such machines are widely known, thus crypt provides minimal security. The transformation of a key into the internal settings of the machine is deliberately designed to be expensive, that is, to take a substan- tial fraction of a second to compute. However, if keys are restricted to (say) three lower-case letters, then encrypted files can be read by expending only a substantial fraction of five minutes of machine time. Since the key is an argument to the crypt command, it is potentially visible to users executing ps(1) or a derivative command. To minimize this possibility, crypt takes care to destroy any record of the key immediately upon entry. No doubt the choice of keys and key security are the most vulnerable aspect of crypt. /dev/tty for typed key See attributes(5) for descriptions of the following attributes: +-----------------------------+-----------------------------+ | ATTRIBUTE TYPE | ATTRIBUTE VALUE | +-----------------------------+-----------------------------+ |Availability |SUNWcsu | +-----------------------------+-----------------------------+ des(1), ed(1), ex(1), ps(1), vi(1), attributes (5) 8 Mar 2005 crypt(1)