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Интерактивная система просмотра системных руководств (man-ов)

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crypt (1)
  • >> crypt (1) ( Solaris man: Команды и прикладные программы пользовательского уровня )
  • crypt (1) ( FreeBSD man: Команды и прикладные программы пользовательского уровня )
  • crypt (3) ( Solaris man: Библиотечные вызовы )
  • crypt (3) ( FreeBSD man: Библиотечные вызовы )
  • crypt (3) ( Русские man: Библиотечные вызовы )
  • crypt (3) ( Linux man: Библиотечные вызовы )
  • crypt (3) ( POSIX man: Библиотечные вызовы )
  • Ключ crypt обнаружен в базе ключевых слов.
  •  

    NAME

    crypt - encode or decode a file
     
    

    SYNOPSIS

    crypt [password]
    

     

    DESCRIPTION

    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 substantial 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.  

    FILES

    /dev/tty

    for typed key

     

    ATTRIBUTES

    See attributes(5) for descriptions of the following attributes:

    ATTRIBUTE TYPEATTRIBUTE VALUE

    AvailabilitySUNWcsu

     

    SEE ALSO

    des(1), ed(1), ex(1), ps(1), vi(1), attributes(5)


     

    Index

    NAME
    SYNOPSIS
    DESCRIPTION
    FILES
    ATTRIBUTES
    SEE ALSO


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