crypt(1) [sunos man page]
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)
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crypt(1) General Commands Manual crypt(1) NAME
crypt - encode and decode files SYNOPSIS
[password] DESCRIPTION
reads from the standard input and writes on the standard output. password is a key that selects a particular transformation. If no pass- word is given, demands a key from the terminal and turns off printing while the key is being typed in. encrypts and decrypts with the same key: The latter command decrypts the file and prints the clear version. Files encrypted by are compatible with those treated by the editor in encryption mode (see ed(1)). 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 clear text can become visible must be minimized. 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 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, for example, three lowercase 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 command, it is potentially visible to users executing the or a derivative (see ps(1)). The choice of keys and key security are the most vulnerable aspect of EXAMPLES
The following example demonstrates the use of to edit a file that the user wants to keep strictly confidential: ... ... ... Note that the option is the encryption mode of and prompts the user for the same key with which the file was encrypted. WARNINGS
If output is piped to and the encryption key is given on the command line, can leave terminal modes in a strange state (see nroff(1) and stty(1)). If two or more files encrypted with the same key are concatenated and an attempt is made to decrypt the result, only the the first of the original files is decrypted correctly. FILES
for typed key SEE ALSO
ed(1), makekey(1), stty(1). crypt(1)