252 lines
9.1 KiB
Groff
252 lines
9.1 KiB
Groff
.\" $NetBSD: openssl_blowfish.3,v 1.2 2002/02/07 07:00:43 ross Exp $
|
|
.\"
|
|
.\" Automatically generated by Pod::Man version 1.02
|
|
.\" Thu Apr 12 19:27:08 2001
|
|
.\"
|
|
.\" Standard preamble:
|
|
.\" ======================================================================
|
|
.de Sh \" Subsection heading
|
|
.br
|
|
.if t .Sp
|
|
.ne 5
|
|
.PP
|
|
\fB\\$1\fR
|
|
.PP
|
|
..
|
|
.de Sp \" Vertical space (when we can't use .PP)
|
|
.if t .sp .5v
|
|
.if n .sp
|
|
..
|
|
.de Ip \" List item
|
|
.br
|
|
.ie \\n(.$>=3 .ne \\$3
|
|
.el .ne 3
|
|
.IP "\\$1" \\$2
|
|
..
|
|
.de Vb \" Begin verbatim text
|
|
.ft CW
|
|
.nf
|
|
.ne \\$1
|
|
..
|
|
.de Ve \" End verbatim text
|
|
.ft R
|
|
|
|
.fi
|
|
..
|
|
.\" Set up some character translations and predefined strings. \*(-- will
|
|
.\" give an unbreakable dash, \*(PI will give pi, \*(L" will give a left
|
|
.\" double quote, and \*(R" will give a right double quote. | will give a
|
|
.\" real vertical bar. \*(C+ will give a nicer C++. Capital omega is used
|
|
.\" to do unbreakable dashes and therefore won't be available. \*(C` and
|
|
.\" \*(C' expand to `' in nroff, nothing in troff, for use with C<>
|
|
.tr \(*W-|\(bv\*(Tr
|
|
.ds C+ C\v'-.1v'\h'-1p'\s-2+\h'-1p'+\s0\v'.1v'\h'-1p'
|
|
.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" ""
|
|
. ds C` `
|
|
. ds C' '
|
|
'br\}
|
|
.el\{\
|
|
. ds -- \|\(em\|
|
|
. ds PI \(*p
|
|
. ds L" ``
|
|
. ds R" ''
|
|
'br\}
|
|
.\"
|
|
.\" If the F register is turned on, we'll generate index entries on stderr
|
|
.\" for titles (.TH), headers (.SH), subsections (.Sh), items (.Ip), and
|
|
.\" index entries marked with X<> in POD. Of course, you'll have to process
|
|
.\" the output yourself in some meaningful fashion.
|
|
.if \nF \{\
|
|
. de IX
|
|
. tm Index:\\$1\t\\n%\t"\\$2"
|
|
. .
|
|
. nr % 0
|
|
. rr F
|
|
.\}
|
|
.\"
|
|
.\" For nroff, turn off justification. Always turn off hyphenation; it
|
|
.\" makes way too many mistakes in technical documents.
|
|
.hy 0
|
|
.if n .na
|
|
.\"
|
|
.\" Accent mark definitions (@(#)ms.acc 1.5 88/02/08 SMI; from UCB 4.2).
|
|
.\" Fear. Run. Save yourself. No user-serviceable parts.
|
|
.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 /
|
|
.\}
|
|
.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 / \\k:\h'-(\\n(.wu*8/10-\*(#H)'\z\(sl\h'|\\n:u'
|
|
.\}
|
|
. \" 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 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
|
|
. \" 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 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
|
|
.\}
|
|
.rm #[ #] #H #V #F C
|
|
.\" ======================================================================
|
|
.\"
|
|
.IX Title "blowfish 3"
|
|
.TH blowfish 3 "0.9.6a" "2001-04-12" "OpenSSL"
|
|
.UC
|
|
.SH "NAME"
|
|
blowfish, BF_set_key, BF_encrypt, BF_decrypt, BF_ecb_encrypt, BF_cbc_encrypt,
|
|
BF_cfb64_encrypt, BF_ofb64_encrypt, BF_options \- Blowfish encryption
|
|
.SH "LIBRARY"
|
|
libcrypto, -lcrypto
|
|
.SH "SYNOPSIS"
|
|
.IX Header "SYNOPSIS"
|
|
.Vb 1
|
|
\& #include \*[Lt]openssl/blowfish.h\*[Gt]
|
|
.Ve
|
|
.Vb 1
|
|
\& void BF_set_key(BF_KEY *key, int len, const unsigned char *data);
|
|
.Ve
|
|
.Vb 10
|
|
\& void BF_ecb_encrypt(const unsigned char *in, unsigned char *out,
|
|
\& BF_KEY *key, int enc);
|
|
\& void BF_cbc_encrypt(const unsigned char *in, unsigned char *out,
|
|
\& long length, BF_KEY *schedule, unsigned char *ivec, int enc);
|
|
\& void BF_cfb64_encrypt(const unsigned char *in, unsigned char *out,
|
|
\& long length, BF_KEY *schedule, unsigned char *ivec, int *num,
|
|
\& int enc);
|
|
\& void BF_ofb64_encrypt(const unsigned char *in, unsigned char *out,
|
|
\& long length, BF_KEY *schedule, unsigned char *ivec, int *num);
|
|
\& const char *BF_options(void);
|
|
.Ve
|
|
.Vb 2
|
|
\& void BF_encrypt(BF_LONG *data,const BF_KEY *key);
|
|
\& void BF_decrypt(BF_LONG *data,const BF_KEY *key);
|
|
.Ve
|
|
.SH "DESCRIPTION"
|
|
.IX Header "DESCRIPTION"
|
|
This library implements the Blowfish cipher, which is invented and described
|
|
by Counterpane (see http://www.counterpane.com/blowfish.html ).
|
|
.PP
|
|
Blowfish is a block cipher that operates on 64 bit (8 byte) blocks of data.
|
|
It uses a variable size key, but typically, 128 bit (16 byte) keys are
|
|
a considered good for strong encryption. Blowfish can be used in the same
|
|
modes as \s-1DES\s0 (see des_modes(7)). Blowfish is currently one
|
|
of the faster block ciphers. It is quite a bit faster than \s-1DES\s0, and much
|
|
faster than \s-1IDEA\s0 or \s-1RC2\s0.
|
|
.PP
|
|
Blowfish consists of a key setup phase and the actual encryption or decryption
|
|
phase.
|
|
.PP
|
|
\&\fIBF_set_key()\fR sets up the \fB\s-1BF_KEY\s0\fR \fBkey\fR using the \fBlen\fR bytes long key
|
|
at \fBdata\fR.
|
|
.PP
|
|
\&\fIBF_ecb_encrypt()\fR is the basic Blowfish encryption and decryption function.
|
|
It encrypts or decrypts the first 64 bits of \fBin\fR using the key \fBkey\fR,
|
|
putting the result in \fBout\fR. \fBenc\fR decides if encryption (\fB\s-1BF_ENCRYPT\s0\fR)
|
|
or decryption (\fB\s-1BF_DECRYPT\s0\fR) shall be performed. The vector pointed at by
|
|
\&\fBin\fR and \fBout\fR must be 64 bits in length, no less. If they are larger,
|
|
everything after the first 64 bits is ignored.
|
|
.PP
|
|
The mode functions \fIBF_cbc_encrypt()\fR, \fIBF_cfb64_encrypt()\fR and \fIBF_ofb64_encrypt()\fR
|
|
all operate on variable length data. They all take an initialization vector
|
|
\&\fBivec\fR which needs to be passed along into the next call of the same function
|
|
for the same message. \fBivec\fR may be initialized with anything, but the
|
|
recipient needs to know what it was initialized with, or it won't be able
|
|
to decrypt. Some programs and protocols simplify this, like \s-1SSH\s0, where
|
|
\&\fBivec\fR is simply initialized to zero.
|
|
\&\fIBF_cbc_encrypt()\fR operates of data that is a multiple of 8 bytes long, while
|
|
\&\fIBF_cfb64_encrypt()\fR and \fIBF_ofb64_encrypt()\fR are used to encrypt an variable
|
|
number of bytes (the amount does not have to be an exact multiple of 8). The
|
|
purpose of the latter two is to simulate stream ciphers, and therefore, they
|
|
need the parameter \fBnum\fR, which is a pointer to an integer where the current
|
|
offset in \fBivec\fR is stored between calls. This integer must be initialized
|
|
to zero when \fBivec\fR is initialized.
|
|
.PP
|
|
\&\fIBF_cbc_encrypt()\fR is the Cipher Block Chaining function for Blowfish. It
|
|
encrypts or decrypts the 64 bits chunks of \fBin\fR using the key \fBschedule\fR,
|
|
putting the result in \fBout\fR. \fBenc\fR decides if encryption (\s-1BF_ENCRYPT\s0) or
|
|
decryption (\s-1BF_DECRYPT\s0) shall be performed. \fBivec\fR must point at an 8 byte
|
|
long initialization vector.
|
|
.PP
|
|
\&\fIBF_cfb64_encrypt()\fR is the \s-1CFB\s0 mode for Blowfish with 64 bit feedback.
|
|
It encrypts or decrypts the bytes in \fBin\fR using the key \fBschedule\fR,
|
|
putting the result in \fBout\fR. \fBenc\fR decides if encryption (\fB\s-1BF_ENCRYPT\s0\fR)
|
|
or decryption (\fB\s-1BF_DECRYPT\s0\fR) shall be performed. \fBivec\fR must point at an
|
|
8 byte long initialization vector. \fBnum\fR must point at an integer which must
|
|
be initially zero.
|
|
.PP
|
|
\&\fIBF_ofb64_encrypt()\fR is the \s-1OFB\s0 mode for Blowfish with 64 bit feedback.
|
|
It uses the same parameters as \fIBF_cfb64_encrypt()\fR, which must be initialized
|
|
the same way.
|
|
.PP
|
|
\&\fIBF_encrypt()\fR and \fIBF_decrypt()\fR are the lowest level functions for Blowfish
|
|
encryption. They encrypt/decrypt the first 64 bits of the vector pointed by
|
|
\&\fBdata\fR, using the key \fBkey\fR. These functions should not be used unless you
|
|
implement 'modes' of Blowfish. The alternative is to use \fIBF_ecb_encrypt()\fR.
|
|
If you still want to use these functions, you should be aware that they take
|
|
each 32\-bit chunk in host-byte order, which is little-endian on little-endian
|
|
platforms and big-endian on big-endian ones.
|
|
.SH "RETURN VALUES"
|
|
.IX Header "RETURN VALUES"
|
|
None of the functions presented here return any value.
|
|
.SH "NOTE"
|
|
.IX Header "NOTE"
|
|
Applications should use the higher level functions
|
|
EVP_EncryptInit(3) etc. instead of calling the
|
|
blowfish functions directly.
|
|
.SH "SEE ALSO"
|
|
.IX Header "SEE ALSO"
|
|
des_modes(7)
|
|
.SH "HISTORY"
|
|
.IX Header "HISTORY"
|
|
The Blowfish functions are available in all versions of SSLeay and OpenSSL.
|