[src/netbsd-1-5]: src/lib/libcrypto/man Pull up revision 1.4 (requested by wiz):

[he <he%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/1dbfa0e26f1f
branches:  netbsd-1-5
changeset: 491083:1dbfa0e26f1f
user:      he <he%NetBSD.org@localhost>
date:      Wed Apr 04 17:05:14 2001 +0000

description:
Pull up revision 1.4 (requested by wiz):
  Spelling fix.

diffstat:

 lib/libcrypto/man/des_modes.7 |  418 ++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 418 insertions(+), 0 deletions(-)

diffs (truncated from 422 to 300 lines):

diff -r b4403d3ea237 -r 1dbfa0e26f1f lib/libcrypto/man/des_modes.7
--- /dev/null   Thu Jan 01 00:00:00 1970 +0000
+++ b/lib/libcrypto/man/des_modes.7     Wed Apr 04 17:05:14 2001 +0000
@@ -0,0 +1,418 @@
+.rn '' }`
+'''
+'''
+.de Sh
+.br
+.if t .Sp
+.ne 5
+.PP
+\fB\\$1\fR
+.PP
+..
+.de Sp
+.if t .sp .5v
+.if n .sp
+..
+.de Ip
+.br
+.ie \\n(.$>=3 .ne \\$3
+.el .ne 3
+.IP "\\$1" \\$2
+..
+.de Vb
+.ft CW
+.nf
+.ne \\$1
+..
+.de Ve
+.ft R
+
+.fi
+..
+'''
+'''
+'''     Set up \*(-- to give an unbreakable dash;
+'''     string Tr holds user defined translation string.
+'''     Bell System Logo is used as a dummy character.
+'''
+.tr \(*W-|\(bv\*(Tr
+.ie n \{\
+.ds -- \(*W-
+.ds PI pi
+.if (\n(.H=4u)&(1m=24u) .ds -- \(*W\h'-12u'\(*W\h'-12u'-\" diablo 10 pitch
+.if (\n(.H=4u)&(1m=20u) .ds -- \(*W\h'-12u'\(*W\h'-8u'-\" diablo 12 pitch
+.ds L" ""
+.ds R" ""
+'''   \*(M", \*(S", \*(N" and \*(T" are the equivalent of
+'''   \*(L" and \*(R", except that they are used on ".xx" lines,
+'''   such as .IP and .SH, which do another additional levels of
+'''   double-quote interpretation
+.ds M" """
+.ds S" """
+.ds N" """""
+.ds T" """""
+.ds L' '
+.ds R' '
+.ds M' '
+.ds S' '
+.ds N' '
+.ds T' '
+'br\}
+.el\{\
+.ds -- \(em\|
+.tr \*(Tr
+.ds L" ``
+.ds R" ''
+.ds M" ``
+.ds S" ''
+.ds N" ``
+.ds T" ''
+.ds L' `
+.ds R' '
+.ds M' `
+.ds S' '
+.ds N' `
+.ds T' '
+.ds PI \(*p
+'br\}
+.\"    If the F register is turned on, we'll generate
+.\"    index entries out stderr for the following things:
+.\"            TH      Title 
+.\"            SH      Header
+.\"            Sh      Subsection 
+.\"            Ip      Item
+.\"            X<>     Xref  (embedded
+.\"    Of course, you have to process the output yourself
+.\"    in some meaninful fashion.
+.if \nF \{
+.de IX
+.tm Index:\\$1\t\\n%\t"\\$2"
+..
+.nr % 0
+.rr F
+.\}
+.TH des_modes 7 "0.9.5a" "22/Jul/100" "OpenSSL"
+.UC
+.if n .hy 0
+.if n .na
+.ds C+ C\v'-.1v'\h'-1p'\s-2+\h'-1p'+\s0\v'.1v'\h'-1p'
+.de CQ          \" put $1 in typewriter font
+.ft CW
+'if n "\c
+'if t \\&\\$1\c
+'if n \\&\\$1\c
+'if n \&"
+\\&\\$2 \\$3 \\$4 \\$5 \\$6 \\$7
+'.ft R
+..
+.\" @(#)ms.acc 1.5 88/02/08 SMI; from UCB 4.2
+.      \" AM - accent mark definitions
+.bd B 3
+.      \" fudge factors for nroff and troff
+.if n \{\
+.      ds #H 0
+.      ds #V .8m
+.      ds #F .3m
+.      ds #[ \f1
+.      ds #] \fP
+.\}
+.if t \{\
+.      ds #H ((1u-(\\\\n(.fu%2u))*.13m)
+.      ds #V .6m
+.      ds #F 0
+.      ds #[ \&
+.      ds #] \&
+.\}
+.      \" simple accents for nroff and troff
+.if n \{\
+.      ds ' \&
+.      ds ` \&
+.      ds ^ \&
+.      ds , \&
+.      ds ~ ~
+.      ds ? ?
+.      ds ! !
+.      ds /
+.      ds q
+.\}
+.if t \{\
+.      ds ' \\k:\h'-(\\n(.wu*8/10-\*(#H)'\'\h"|\\n:u"
+.      ds ` \\k:\h'-(\\n(.wu*8/10-\*(#H)'\`\h'|\\n:u'
+.      ds ^ \\k:\h'-(\\n(.wu*10/11-\*(#H)'^\h'|\\n:u'
+.      ds , \\k:\h'-(\\n(.wu*8/10)',\h'|\\n:u'
+.      ds ~ \\k:\h'-(\\n(.wu-\*(#H-.1m)'~\h'|\\n:u'
+.      ds ? \s-2c\h'-\w'c'u*7/10'\u\h'\*(#H'\zi\d\s+2\h'\w'c'u*8/10'
+.      ds ! \s-2\(or\s+2\h'-\w'\(or'u'\v'-.8m'.\v'.8m'
+.      ds / \\k:\h'-(\\n(.wu*8/10-\*(#H)'\z\(sl\h'|\\n:u'
+.      ds q o\h'-\w'o'u*8/10'\s-4\v'.4m'\z\(*i\v'-.4m'\s+4\h'\w'o'u*8/10'
+.\}
+.      \" troff and (daisy-wheel) nroff accents
+.ds : \\k:\h'-(\\n(.wu*8/10-\*(#H+.1m+\*(#F)'\v'-\*(#V'\z.\h'.2m+\*(#F'.\h'|\\n:u'\v'\*(#V'
+.ds 8 \h'\*(#H'\(*b\h'-\*(#H'
+.ds v \\k:\h'-(\\n(.wu*9/10-\*(#H)'\v'-\*(#V'\*(#[\s-4v\s0\v'\*(#V'\h'|\\n:u'\*(#]
+.ds _ \\k:\h'-(\\n(.wu*9/10-\*(#H+(\*(#F*2/3))'\v'-.4m'\z\(hy\v'.4m'\h'|\\n:u'
+.ds . \\k:\h'-(\\n(.wu*8/10)'\v'\*(#V*4/10'\z.\v'-\*(#V*4/10'\h'|\\n:u'
+.ds 3 \*(#[\v'.2m'\s-2\&3\s0\v'-.2m'\*(#]
+.ds o \\k:\h'-(\\n(.wu+\w'\(de'u-\*(#H)/2u'\v'-.3n'\*(#[\z\(de\v'.3n'\h'|\\n:u'\*(#]
+.ds d- \h'\*(#H'\(pd\h'-\w'~'u'\v'-.25m'\f2\(hy\fP\v'.25m'\h'-\*(#H'
+.ds D- D\\k:\h'-\w'D'u'\v'-.11m'\z\(hy\v'.11m'\h'|\\n:u'
+.ds th \*(#[\v'.3m'\s+1I\s-1\v'-.3m'\h'-(\w'I'u*2/3)'\s-1o\s+1\*(#]
+.ds Th \*(#[\s+2I\s-2\h'-\w'I'u*3/5'\v'-.3m'o\v'.3m'\*(#]
+.ds ae a\h'-(\w'a'u*4/10)'e
+.ds Ae A\h'-(\w'A'u*4/10)'E
+.ds oe o\h'-(\w'o'u*4/10)'e
+.ds Oe O\h'-(\w'O'u*4/10)'E
+.      \" corrections for vroff
+.if v .ds ~ \\k:\h'-(\\n(.wu*9/10-\*(#H)'\s-2\u~\d\s+2\h'|\\n:u'
+.if v .ds ^ \\k:\h'-(\\n(.wu*10/11-\*(#H)'\v'-.4m'^\v'.4m'\h'|\\n:u'
+.      \" for low resolution devices (crt and lpr)
+.if \n(.H>23 .if \n(.V>19 \
+\{\
+.      ds : e
+.      ds 8 ss
+.      ds v \h'-1'\o'\(aa\(ga'
+.      ds _ \h'-1'^
+.      ds . \h'-1'.
+.      ds 3 3
+.      ds o a
+.      ds d- d\h'-1'\(ga
+.      ds D- D\h'-1'\(hy
+.      ds th \o'bp'
+.      ds Th \o'LP'
+.      ds ae ae
+.      ds Ae AE
+.      ds oe oe
+.      ds Oe OE
+.\}
+.rm #[ #] #H #V #F C
+.SH "NAME"
+Modes of DES \- the variants of DES and other crypto algorithms of OpenSSL
+.SH "DESCRIPTION"
+Several crypto algorithms for OpenSSL can be used in a number of modes.  Those
+are used for using block ciphers in a way similar to stream ciphers, among
+other things.
+.SH "OVERVIEW"
+.Sh "Electronic Codebook Mode (\s-1ECB\s0)"
+Normally, this is found as the function \fIalgorithm\fR\fI_ecb_encrypt()\fR.
+.Ip "\(bu" 2
+64 bits are enciphered at a time.
+.Ip "\(bu" 2
+The order of the blocks can be rearranged without detection.
+.Ip "\(bu" 2
+The same plaintext block always produces the same ciphertext block
+(for the same key) making it vulnerable to a \*(L'dictionary attack\*(R'.
+.Ip "\(bu" 2
+An error will only affect one ciphertext block.
+.Sh "Cipher Block Chaining Mode (\s-1CBC\s0)"
+Normally, this is found as the function \fIalgorithm\fR\fI_cbc_encrypt()\fR.
+Be aware that \fIdes_cbc_encrypt()\fR is not really \s-1DES\s0 \s-1CBC\s0 (it does
+not update the \s-1IV\s0); use \fIdes_ncbc_encrypt()\fR instead.
+.Ip "\(bu" 2
+a multiple of 64 bits are enciphered at a time.
+.Ip "\(bu" 2
+The \s-1CBC\s0 mode produces the same ciphertext whenever the same
+plaintext is encrypted using the same key and starting variable.
+.Ip "\(bu" 2
+The chaining operation makes the ciphertext blocks dependent on the
+current and all preceding plaintext blocks and therefore blocks can not
+be rearranged.
+.Ip "\(bu" 2
+The use of different starting variables prevents the same plaintext
+enciphering to the same ciphertext.
+.Ip "\(bu" 2
+An error will affect the current and the following ciphertext blocks.
+.Sh "Cipher Feedback Mode (\s-1CFB\s0)"
+Normally, this is found as the function \fIalgorithm\fR\fI_cfb_encrypt()\fR.
+.Ip "\(bu" 2
+a number of bits (j) <= 64 are enciphered at a time.
+.Ip "\(bu" 2
+The \s-1CFB\s0 mode produces the same ciphertext whenever the same
+plaintext is encrypted using the same key and starting variable.
+.Ip "\(bu" 2
+The chaining operation makes the ciphertext variables dependent on the
+current and all preceding variables and therefore j-bit variables are
+chained together and can not be rearranged.
+.Ip "\(bu" 2
+The use of different starting variables prevents the same plaintext
+enciphering to the same ciphertext.
+.Ip "\(bu" 2
+The strength of the \s-1CFB\s0 mode depends on the size of k (maximal if
+j == k).  In my implementation this is always the case.
+.Ip "\(bu" 2
+Selection of a small value for j will require more cycles through
+the encipherment algorithm per unit of plaintext and thus cause
+greater processing overheads.
+.Ip "\(bu" 2
+Only multiples of j bits can be enciphered.
+.Ip "\(bu" 2
+An error will affect the current and the following ciphertext variables.
+.Sh "Output Feedback Mode (\s-1OFB\s0)"
+Normally, this is found as the function \fIalgorithm\fR\fI_ofb_encrypt()\fR.
+.Ip "\(bu" 2
+a number of bits (j) <= 64 are enciphered at a time.
+.Ip "\(bu" 2
+The \s-1OFB\s0 mode produces the same ciphertext whenever the same
+plaintext enciphered using the same key and starting variable.  More
+over, in the \s-1OFB\s0 mode the same key stream is produced when the same
+key and start variable are used.  Consequently, for security reasons
+a specific start variable should be used only once for a given key.
+.Ip "\(bu" 2
+The absence of chaining makes the \s-1OFB\s0 more vulnerable to specific attacks.
+.Ip "\(bu" 2
+The use of different start variables values prevents the same
+plaintext enciphering to the same ciphertext, by producing different
+key streams.
+.Ip "\(bu" 2
+Selection of a small value for j will require more cycles through
+the encipherment algorithm per unit of plaintext and thus cause
+greater processing overheads.
+.Ip "\(bu" 2
+Only multiples of j bits can be enciphered.
+.Ip "\(bu" 2
+\s-1OFB\s0 mode of operation does not extend ciphertext errors in the
+resultant plaintext output.  Every bit error in the ciphertext causes
+only one bit to be in error in the deciphered plaintext.
+.Ip "\(bu" 2
+\s-1OFB\s0 mode is not self-synchronising.  If the two operation of
+encipherment and decipherment get out of synchronism, the system needs
+to be re-initialised.
+.Ip "\(bu" 2
+Each re-initialisation should use a value of the start variable
+different from the start variable values used before with the same
+key.  The reason for this is that an identical bit stream would be
+produced each time from the same parameters.  This would be
+susceptible to a \*(L'known plaintext\*(R' attack.
+.Sh "Triple \s-1ECB\s0 Mode"
+Normally, this is found as the function \fIalgorithm\fR\fI_ecb3_encrypt()\fR.
+.Ip "\(bu" 2
+Encrypt with key1, decrypt with key2 and encrypt with key3 again.
+.Ip "\(bu" 2
+As for \s-1ECB\s0 encryption but increases the key length to 168 bits.
+There are theoretic attacks that can be used that make the effective
+key length 112 bits, but this attack also requires 2^56 blocks of
+memory, not very likely, even for the \s-1NSA\s0.
+.Ip "\(bu" 2
+If both keys are the same it is equivalent to encrypting once with
+just one key.