Switch from OpenSSL 0.9.7d to 0.9.7e.
[dragonfly.git] / secure / lib / libcrypto / man / dh.3
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1.rn '' }`
2''' $RCSfile$$Revision$$Date$
3'''
4''' $Log$
5'''
6.de Sh
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7.br
8.if t .Sp
9.ne 5
10.PP
11\fB\\$1\fR
12.PP
13..
74dab6c2 14.de Sp
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15.if t .sp .5v
16.if n .sp
17..
74dab6c2 18.de Ip
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19.br
20.ie \\n(.$>=3 .ne \\$3
21.el .ne 3
22.IP "\\$1" \\$2
23..
74dab6c2 24.de Vb
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25.ft CW
26.nf
27.ne \\$1
28..
74dab6c2 29.de Ve
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30.ft R
31
32.fi
33..
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34'''
35'''
36''' Set up \*(-- to give an unbreakable dash;
37''' string Tr holds user defined translation string.
38''' Bell System Logo is used as a dummy character.
39'''
984263bc 40.tr \(*W-|\(bv\*(Tr
984263bc 41.ie n \{\
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42.ds -- \(*W-
43.ds PI pi
44.if (\n(.H=4u)&(1m=24u) .ds -- \(*W\h'-12u'\(*W\h'-12u'-\" diablo 10 pitch
45.if (\n(.H=4u)&(1m=20u) .ds -- \(*W\h'-12u'\(*W\h'-8u'-\" diablo 12 pitch
46.ds L" ""
47.ds R" ""
48''' \*(M", \*(S", \*(N" and \*(T" are the equivalent of
49''' \*(L" and \*(R", except that they are used on ".xx" lines,
50''' such as .IP and .SH, which do another additional levels of
51''' double-quote interpretation
52.ds M" """
53.ds S" """
54.ds N" """""
55.ds T" """""
56.ds L' '
57.ds R' '
58.ds M' '
59.ds S' '
60.ds N' '
61.ds T' '
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62'br\}
63.el\{\
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64.ds -- \(em\|
65.tr \*(Tr
66.ds L" ``
67.ds R" ''
68.ds M" ``
69.ds S" ''
70.ds N" ``
71.ds T" ''
72.ds L' `
73.ds R' '
74.ds M' `
75.ds S' '
76.ds N' `
77.ds T' '
78.ds PI \(*p
984263bc 79'br\}
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80.\" If the F register is turned on, we'll generate
81.\" index entries out stderr for the following things:
82.\" TH Title
83.\" SH Header
84.\" Sh Subsection
85.\" Ip Item
86.\" X<> Xref (embedded
87.\" Of course, you have to process the output yourself
88.\" in some meaninful fashion.
89.if \nF \{
90.de IX
91.tm Index:\\$1\t\\n%\t"\\$2"
984263bc 92..
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93.nr % 0
94.rr F
984263bc 95.\}
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96.TH dh 3 "0.9.7d" "2/Sep/2004" "OpenSSL"
97.UC
98.if n .hy 0
984263bc 99.if n .na
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100.ds C+ C\v'-.1v'\h'-1p'\s-2+\h'-1p'+\s0\v'.1v'\h'-1p'
101.de CQ \" put $1 in typewriter font
102.ft CW
103'if n "\c
104'if t \\&\\$1\c
105'if n \\&\\$1\c
106'if n \&"
107\\&\\$2 \\$3 \\$4 \\$5 \\$6 \\$7
108'.ft R
109..
110.\" @(#)ms.acc 1.5 88/02/08 SMI; from UCB 4.2
111. \" AM - accent mark definitions
984263bc 112.bd B 3
74dab6c2 113. \" fudge factors for nroff and troff
984263bc 114.if n \{\
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115. ds #H 0
116. ds #V .8m
117. ds #F .3m
118. ds #[ \f1
119. ds #] \fP
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120.\}
121.if t \{\
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122. ds #H ((1u-(\\\\n(.fu%2u))*.13m)
123. ds #V .6m
124. ds #F 0
125. ds #[ \&
126. ds #] \&
984263bc 127.\}
74dab6c2 128. \" simple accents for nroff and troff
984263bc 129.if n \{\
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130. ds ' \&
131. ds ` \&
132. ds ^ \&
133. ds , \&
134. ds ~ ~
135. ds ? ?
136. ds ! !
137. ds /
138. ds q
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139.\}
140.if t \{\
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141. ds ' \\k:\h'-(\\n(.wu*8/10-\*(#H)'\'\h"|\\n:u"
142. ds ` \\k:\h'-(\\n(.wu*8/10-\*(#H)'\`\h'|\\n:u'
143. ds ^ \\k:\h'-(\\n(.wu*10/11-\*(#H)'^\h'|\\n:u'
144. ds , \\k:\h'-(\\n(.wu*8/10)',\h'|\\n:u'
145. ds ~ \\k:\h'-(\\n(.wu-\*(#H-.1m)'~\h'|\\n:u'
146. ds ? \s-2c\h'-\w'c'u*7/10'\u\h'\*(#H'\zi\d\s+2\h'\w'c'u*8/10'
147. ds ! \s-2\(or\s+2\h'-\w'\(or'u'\v'-.8m'.\v'.8m'
148. ds / \\k:\h'-(\\n(.wu*8/10-\*(#H)'\z\(sl\h'|\\n:u'
149. 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'
984263bc 150.\}
74dab6c2 151. \" troff and (daisy-wheel) nroff accents
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152.ds : \\k:\h'-(\\n(.wu*8/10-\*(#H+.1m+\*(#F)'\v'-\*(#V'\z.\h'.2m+\*(#F'.\h'|\\n:u'\v'\*(#V'
153.ds 8 \h'\*(#H'\(*b\h'-\*(#H'
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154.ds v \\k:\h'-(\\n(.wu*9/10-\*(#H)'\v'-\*(#V'\*(#[\s-4v\s0\v'\*(#V'\h'|\\n:u'\*(#]
155.ds _ \\k:\h'-(\\n(.wu*9/10-\*(#H+(\*(#F*2/3))'\v'-.4m'\z\(hy\v'.4m'\h'|\\n:u'
156.ds . \\k:\h'-(\\n(.wu*8/10)'\v'\*(#V*4/10'\z.\v'-\*(#V*4/10'\h'|\\n:u'
157.ds 3 \*(#[\v'.2m'\s-2\&3\s0\v'-.2m'\*(#]
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158.ds o \\k:\h'-(\\n(.wu+\w'\(de'u-\*(#H)/2u'\v'-.3n'\*(#[\z\(de\v'.3n'\h'|\\n:u'\*(#]
159.ds d- \h'\*(#H'\(pd\h'-\w'~'u'\v'-.25m'\f2\(hy\fP\v'.25m'\h'-\*(#H'
160.ds D- D\\k:\h'-\w'D'u'\v'-.11m'\z\(hy\v'.11m'\h'|\\n:u'
161.ds th \*(#[\v'.3m'\s+1I\s-1\v'-.3m'\h'-(\w'I'u*2/3)'\s-1o\s+1\*(#]
162.ds Th \*(#[\s+2I\s-2\h'-\w'I'u*3/5'\v'-.3m'o\v'.3m'\*(#]
163.ds ae a\h'-(\w'a'u*4/10)'e
164.ds Ae A\h'-(\w'A'u*4/10)'E
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165.ds oe o\h'-(\w'o'u*4/10)'e
166.ds Oe O\h'-(\w'O'u*4/10)'E
167. \" corrections for vroff
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168.if v .ds ~ \\k:\h'-(\\n(.wu*9/10-\*(#H)'\s-2\u~\d\s+2\h'|\\n:u'
169.if v .ds ^ \\k:\h'-(\\n(.wu*10/11-\*(#H)'\v'-.4m'^\v'.4m'\h'|\\n:u'
74dab6c2 170. \" for low resolution devices (crt and lpr)
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171.if \n(.H>23 .if \n(.V>19 \
172\{\
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173. ds : e
174. ds 8 ss
175. ds v \h'-1'\o'\(aa\(ga'
176. ds _ \h'-1'^
177. ds . \h'-1'.
178. ds 3 3
179. ds o a
180. ds d- d\h'-1'\(ga
181. ds D- D\h'-1'\(hy
182. ds th \o'bp'
183. ds Th \o'LP'
184. ds ae ae
185. ds Ae AE
186. ds oe oe
187. ds Oe OE
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188.\}
189.rm #[ #] #H #V #F C
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190.SH "NAME"
191dh \- Diffie-Hellman key agreement
192.SH "SYNOPSIS"
74dab6c2 193.PP
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194.Vb 2
195\& #include <openssl/dh.h>
196\& #include <openssl/engine.h>
197.Ve
198.Vb 2
199\& DH * DH_new(void);
200\& void DH_free(DH *dh);
201.Ve
202.Vb 1
203\& int DH_size(const DH *dh);
204.Ve
205.Vb 3
206\& DH * DH_generate_parameters(int prime_len, int generator,
207\& void (*callback)(int, int, void *), void *cb_arg);
208\& int DH_check(const DH *dh, int *codes);
209.Ve
210.Vb 2
211\& int DH_generate_key(DH *dh);
212\& int DH_compute_key(unsigned char *key, BIGNUM *pub_key, DH *dh);
213.Ve
214.Vb 5
215\& void DH_set_default_method(const DH_METHOD *meth);
216\& const DH_METHOD *DH_get_default_method(void);
217\& int DH_set_method(DH *dh, const DH_METHOD *meth);
218\& DH *DH_new_method(ENGINE *engine);
219\& const DH_METHOD *DH_OpenSSL(void);
220.Ve
221.Vb 4
222\& int DH_get_ex_new_index(long argl, char *argp, int (*new_func)(),
223\& int (*dup_func)(), void (*free_func)());
224\& int DH_set_ex_data(DH *d, int idx, char *arg);
225\& char *DH_get_ex_data(DH *d, int idx);
226.Ve
227.Vb 2
228\& DH * d2i_DHparams(DH **a, unsigned char **pp, long length);
229\& int i2d_DHparams(const DH *a, unsigned char **pp);
230.Ve
231.Vb 2
232\& int DHparams_print_fp(FILE *fp, const DH *x);
233\& int DHparams_print(BIO *bp, const DH *x);
234.Ve
235.SH "DESCRIPTION"
984263bc 236These functions implement the Diffie-Hellman key agreement protocol.
74dab6c2 237The generation of shared DH parameters is described in
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238DH_generate_parameters(3); DH_generate_key(3) describes how
239to perform a key agreement.
240.PP
74dab6c2 241The \fBDH\fR structure consists of several BIGNUM components.
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242.PP
243.Vb 9
244\& struct
245\& {
246\& BIGNUM *p; // prime number (shared)
247\& BIGNUM *g; // generator of Z_p (shared)
248\& BIGNUM *priv_key; // private DH value x
249\& BIGNUM *pub_key; // public DH value g^x
250\& // ...
251\& };
252\& DH
253.Ve
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254Note that DH keys may use non-standard \fBDH_METHOD\fR implementations,
255either directly or by the use of \fBENGINE\fR modules. In some cases (eg. an
256ENGINE providing support for hardware-embedded keys), these BIGNUM values
984263bc 257will not be used by the implementation or may be used for alternative data
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258storage. For this reason, applications should generally avoid using DH
259structure elements directly and instead use API functions to query or
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260modify keys.
261.SH "SEE ALSO"
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262dhparam(1), bn(3), dsa(3), err(3),
263rand(3), rsa(3), engine(3),
264DH_set_method(3), DH_new(3),
265DH_get_ex_new_index(3),
266DH_generate_parameters(3),
267DH_compute_key(3), d2i_DHparams(3),
268RSA_print(3)
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269
270.rn }` ''
271.IX Title "dh 3"
272.IX Name "dh - Diffie-Hellman key agreement"
273
274.IX Header "NAME"
275
276.IX Header "SYNOPSIS"
277
278.IX Header "DESCRIPTION"
279
280.IX Header "SEE ALSO"
281