diff options
Diffstat (limited to 'usr.bin/bdes/bdes.1')
| -rw-r--r-- | usr.bin/bdes/bdes.1 | 304 |
1 files changed, 0 insertions, 304 deletions
diff --git a/usr.bin/bdes/bdes.1 b/usr.bin/bdes/bdes.1 deleted file mode 100644 index eecd81b..0000000 --- a/usr.bin/bdes/bdes.1 +++ /dev/null @@ -1,304 +0,0 @@ -.\" Copyright (c) 1991, 1993 -.\" The Regents of the University of California. All rights reserved. -.\" -.\" This code is derived from software contributed to Berkeley by -.\" Matt Bishop of Dartmouth College. -.\" -.\" Redistribution and use in source and binary forms, with or without -.\" modification, are permitted provided that the following conditions -.\" are met: -.\" 1. Redistributions of source code must retain the above copyright -.\" notice, this list of conditions and the following disclaimer. -.\" 2. Redistributions in binary form must reproduce the above copyright -.\" notice, this list of conditions and the following disclaimer in the -.\" documentation and/or other materials provided with the distribution. -.\" 3. All advertising materials mentioning features or use of this software -.\" must display the following acknowledgement: -.\" This product includes software developed by the University of -.\" California, Berkeley and its contributors. -.\" 4. Neither the name of the University nor the names of its contributors -.\" may be used to endorse or promote products derived from this software -.\" without specific prior written permission. -.\" -.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND -.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE -.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE -.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE -.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL -.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS -.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) -.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT -.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY -.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF -.\" SUCH DAMAGE. -.\" -.\" @(#)bdes.1 8.1 (Berkeley) 6/29/93 -.\" -.TH BDES 1 "June 29, 1993" -.UC 6 -.SH NAME -bdes \- encrypt/decrypt using the Data Encryption Standard -.SH SYNOPSIS -.nf -.ft B -bdes [ \-abdp ] [ \-F N ] [ \-f N ] [ \-k key ] -.ti +5 -[ \-m N ] [ \-o N ] [ \-v vector ] -.ft R -.fi -.SH DESCRIPTION -.I Bdes -implements all DES modes of operation described in FIPS PUB 81, -including alternative cipher feedback mode and both authentication -modes. -.I Bdes -reads from the standard input and writes to the standard output. -By default, the input is encrypted using cipher block chaining mode. -Using the same key for encryption and decryption preserves plain text. -.PP -All modes but the electronic code book mode require an initialization -vector; if none is supplied, the zero vector is used. -If no -.I key -is specified on the command line, the user is prompted for one (see -.IR getpass (3) -for more details). -.PP -The options are as follows: -.TP -\-a -The key and initialization vector strings are to be taken as ASCII, -suppressing the special interpretation given to leading ``0X'', ``0x'', -``0B'', and ``0b'' characters. -This flag applies to -.I both -the key and initialization vector. -.TP -\-b -Use electronic code book mode. -.TP -\-d -Decrypt the input. -.TP -\-F -Use -.IR N -bit -alternative cipher feedback mode. -Currently -.I N -must be a multiple of 7 between 7 and 56 inclusive (this does not conform -to the alternative CFB mode specification). -.TP -\-f -Use -.IR N -bit -cipher feedback mode. -Currently -.I N -must be a multiple of 8 between 8 and 64 inclusive (this does not conform -to the standard CFB mode specification). -.TP -\-k -Use -.I key -as the cryptographic key. -.TP -\-m -Compute a message authentication code (MAC) of -.I N -bits on the input. -The value of -.I N -must be between 1 and 64 inclusive; if -.I N -is not a multiple of 8, enough 0 bits will be added to pad the MAC length -to the nearest multiple of 8. -Only the MAC is output. -MACs are only available in cipher block chaining mode or in cipher feedback -mode. -.TP -\-o -Use -.IR N -bit -output feedback mode. -Currently -.I N -must be a multiple of 8 between 8 and 64 inclusive (this does not conform -to the OFB mode specification). -.TP -\-p -Disable the resetting of the parity bit. -This flag forces the parity bit of the key to be used as typed, rather than -making each character be of odd parity. -It is used only if the key is given in ASCII. -.TP -\-v -Set the initialization vector to -.IR vector ; -the vector is interpreted in the same way as the key. -The vector is ignored in electronic codebook mode. -.PP -The key and initialization vector are taken as sequences of ASCII -characters which are then mapped into their bit representations. -If either begins with ``0X'' or ``0x'', -that one is taken as a sequence of hexadecimal digits indicating the -bit pattern; -if either begins with ``0B'' or ``0b'', -that one is taken as a sequence of binary digits indicating the bit pattern. -In either case, -only the leading 64 bits of the key or initialization vector -are used, -and if fewer than 64 bits are provided, enough 0 bits are appended -to pad the key to 64 bits. -.PP -According to the DES standard, the low-order bit of each character in the -key string is deleted. -Since most ASCII representations set the high-order bit to 0, simply -deleting the low-order bit effectively reduces the size of the key space -from 2\u\s-356\s0\d to 2\u\s-348\s0\d keys. -To prevent this, the high-order bit must be a function depending in part -upon the low-order bit; so, the high-order bit is set to whatever value -gives odd parity. -This preserves the key space size. -Note this resetting of the parity bit is -.I not -done if the key is given in binary or hex, and can be disabled for ASCII -keys as well. -.PP -The DES is considered a very strong cryptosystem, and other than table lookup -attacks, key search attacks, and Hellman's time-memory tradeoff (all of which -are very expensive and time-consuming), no cryptanalytic methods for breaking -the DES are known in the open literature. -No doubt the choice of keys and key security are the most vulnerable aspect -of -.IR bdes . -.SH IMPLEMENTATION NOTES -For implementors wishing to write software compatible with this program, -the following notes are provided. -This software is believed to be compatible with the implementation of the -data encryption standard distributed by Sun Microsystems, Inc. -.PP -In the ECB and CBC modes, plaintext is encrypted in units of 64 bits (8 bytes, -also called a block). -To ensure that the plaintext file is encrypted correctly, -.I bdes -will (internally) append from 1 to 8 bytes, the last byte containing an -integer stating how many bytes of that final block are from the plaintext -file, and encrypt the resulting block. -Hence, when decrypting, the last block may contain from 0 to 7 characters -present in the plaintext file, and the last byte tells how many. -Note that if during decryption the last byte of the file does not contain an -integer between 0 and 7, either the file has been corrupted or an incorrect -key has been given. -A similar mechanism is used for the OFB and CFB modes, except that those -simply require the length of the input to be a multiple of the mode size, -and the final byte contains an integer between 0 and one less than the number -of bytes being used as the mode. -(This was another reason that the mode size must be a multiple of 8 for those -modes.) -.PP -Unlike Sun's implementation, unused bytes of that last block are not filled -with random data, but instead contain what was in those byte positions in -the preceding block. -This is quicker and more portable, and does not weaken the encryption -significantly. -.PP -If the key is entered in ASCII, the parity bits of the key characters are set -so that each key character is of odd parity. -Unlike Sun's implementation, it is possible to enter binary or hexadecimal -keys on the command line, and if this is done, the parity bits are -.I not -reset. -This allows testing using arbitrary bit patterns as keys. -.PP -The Sun implementation always uses an initialization vector of 0 -(that is, all zeroes). -By default, -.I bdes -does too, but this may be changed from the command line. -.SH SEE ALSO -crypt(1), crypt(3), getpass(3) -.sp -.IR "Data Encryption Standard" , -Federal Information Processing Standard #46, -National Bureau of Standards, -U.S. Department of Commerce, -Washington DC -(Jan. 1977) -.sp -.IR "DES Modes of Operation" , -Federal Information Processing Standard #81, -National Bureau of Standards, -U.S. Department of Commerce -Washington DC -(Dec. 1980) -.sp -Dorothy Denning, -.IR "Cryptography and Data Security" , -Addison-Wesley Publishing Co., -Reading, MA -\(co1982. -.sp -Matt Bishop, -.IR "Implementation Notes on bdes(1)" , -Technical Report PCS-TR-91-158, -Department of Mathematics and Computer Science, -Dartmouth College, -Hanover, NH 03755 -(Apr. 1991). -.SH DISCLAIMER -.nf -THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND -ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE -IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE -ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE -FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL -DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS -OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) -HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT -LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY -OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF -SUCH DAMAGE. -.fi -.SH BUGS -There is a controversy raging over whether the DES will still be secure -in a few years. -The advent of special-purpose hardware could reduce the cost of any of the -methods of attack named above so that they are no longer computationally -infeasible. -.PP -As the key or key schedule is stored in memory, the encryption can be -compromised if memory is readable. -Additionally, programs which display programs' arguments may compromise the -key and initialization vector, if they are specified on the command line. -To avoid this -.I bdes -overwrites its arguments, however, the obvious race cannot currently be -avoided. -.PP -Certain specific keys should be avoided because they introduce potential -weaknesses; these keys, called the -.I weak -and -.I semiweak -keys, are (in hex notation, where p is either 0 or 1, and P is either -e or f): -.sp -.nf -.in +10n -.ta \w'0x0p0p0p0p0p0p0p0p\0\0\0'u+5n -0x0p0p0p0p0p0p0p0p 0x0p1P0p1P0p0P0p0P -0x0pep0pep0pfp0pfp 0x0pfP0pfP0pfP0pfP -0x1P0p1P0p0P0p0P0p 0x1P1P1P1P0P0P0P0P -0x1Pep1Pep0Pfp0Pfp 0x1PfP1PfP0PfP0PfP -0xep0pep0pfp0pfp0p 0xep1Pep1pfp0Pfp0P -0xepepepepepepepep 0xepfPepfPfpfPfpfP -0xfP0pfP0pfP0pfP0p 0xfP1PfP1PfP0PfP0P -0xfPepfPepfPepfPep 0xfPfPfPfPfPfPfPfP -.fi -.in -10n -.sp -This is inherent in the DES algorithm (see Moore and Simmons, -\*(LqCycle structure of the DES with weak and semi-weak keys,\*(Rq -.I "Advances in Cryptology \- Crypto '86 Proceedings" , -Springer-Verlag New York, \(co1987, pp. 9-32.) |
