1 .\" Automatically generated by Pod::Man 2.25 (Pod::Simple 3.19)
4 .\" ========================================================================
5 .de Sp \" Vertical space (when we can't use .PP)
9 .de Vb \" Begin verbatim text
14 .de Ve \" End verbatim text
18 .\" Set up some character translations and predefined strings. \*(-- will
19 .\" give an unbreakable dash, \*(PI will give pi, \*(L" will give a left
20 .\" double quote, and \*(R" will give a right double quote. \*(C+ will
21 .\" give a nicer C++. Capital omega is used to do unbreakable dashes and
22 .\" therefore won't be available. \*(C` and \*(C' expand to `' in nroff,
23 .\" nothing in troff, for use with C<>.
25 .ds C+ C\v'-.1v'\h'-1p'\s-2+\h'-1p'+\s0\v'.1v'\h'-1p'
29 . if (\n(.H=4u)&(1m=24u) .ds -- \(*W\h'-12u'\(*W\h'-12u'-\" diablo 10 pitch
30 . if (\n(.H=4u)&(1m=20u) .ds -- \(*W\h'-12u'\(*W\h'-8u'-\" diablo 12 pitch
43 .\" Escape single quotes in literal strings from groff's Unicode transform.
47 .\" If the F register is turned on, we'll generate index entries on stderr for
48 .\" titles (.TH), headers (.SH), subsections (.SS), items (.Ip), and index
49 .\" entries marked with X<> in POD. Of course, you'll have to process the
50 .\" output yourself in some meaningful fashion.
53 . tm Index:\\$1\t\\n%\t"\\$2"
63 .\" Accent mark definitions (@(#)ms.acc 1.5 88/02/08 SMI; from UCB 4.2).
64 .\" Fear. Run. Save yourself. No user-serviceable parts.
65 . \" fudge factors for nroff and troff
74 . ds #H ((1u-(\\\\n(.fu%2u))*.13m)
80 . \" simple accents for nroff and troff
90 . ds ' \\k:\h'-(\\n(.wu*8/10-\*(#H)'\'\h"|\\n:u"
91 . ds ` \\k:\h'-(\\n(.wu*8/10-\*(#H)'\`\h'|\\n:u'
92 . ds ^ \\k:\h'-(\\n(.wu*10/11-\*(#H)'^\h'|\\n:u'
93 . ds , \\k:\h'-(\\n(.wu*8/10)',\h'|\\n:u'
94 . ds ~ \\k:\h'-(\\n(.wu-\*(#H-.1m)'~\h'|\\n:u'
95 . ds / \\k:\h'-(\\n(.wu*8/10-\*(#H)'\z\(sl\h'|\\n:u'
97 . \" troff and (daisy-wheel) nroff accents
98 .ds : \\k:\h'-(\\n(.wu*8/10-\*(#H+.1m+\*(#F)'\v'-\*(#V'\z.\h'.2m+\*(#F'.\h'|\\n:u'\v'\*(#V'
99 .ds 8 \h'\*(#H'\(*b\h'-\*(#H'
100 .ds o \\k:\h'-(\\n(.wu+\w'\(de'u-\*(#H)/2u'\v'-.3n'\*(#[\z\(de\v'.3n'\h'|\\n:u'\*(#]
101 .ds d- \h'\*(#H'\(pd\h'-\w'~'u'\v'-.25m'\f2\(hy\fP\v'.25m'\h'-\*(#H'
102 .ds D- D\\k:\h'-\w'D'u'\v'-.11m'\z\(hy\v'.11m'\h'|\\n:u'
103 .ds th \*(#[\v'.3m'\s+1I\s-1\v'-.3m'\h'-(\w'I'u*2/3)'\s-1o\s+1\*(#]
104 .ds Th \*(#[\s+2I\s-2\h'-\w'I'u*3/5'\v'-.3m'o\v'.3m'\*(#]
105 .ds ae a\h'-(\w'a'u*4/10)'e
106 .ds Ae A\h'-(\w'A'u*4/10)'E
107 . \" corrections for vroff
108 .if v .ds ~ \\k:\h'-(\\n(.wu*9/10-\*(#H)'\s-2\u~\d\s+2\h'|\\n:u'
109 .if v .ds ^ \\k:\h'-(\\n(.wu*10/11-\*(#H)'\v'-.4m'^\v'.4m'\h'|\\n:u'
110 . \" for low resolution devices (crt and lpr)
111 .if \n(.H>23 .if \n(.V>19 \
124 .\" ========================================================================
127 .TH dh 3 "2012-04-19" "1.0.1a" "OpenSSL"
128 .\" For nroff, turn off justification. Always turn off hyphenation; it makes
129 .\" way too many mistakes in technical documents.
133 dh \- Diffie\-Hellman key agreement
135 .IX Header "SYNOPSIS"
137 \& #include <openssl/dh.h>
138 \& #include <openssl/engine.h>
140 \& DH * DH_new(void);
141 \& void DH_free(DH *dh);
143 \& int DH_size(const DH *dh);
145 \& DH * DH_generate_parameters(int prime_len, int generator,
146 \& void (*callback)(int, int, void *), void *cb_arg);
147 \& int DH_check(const DH *dh, int *codes);
149 \& int DH_generate_key(DH *dh);
150 \& int DH_compute_key(unsigned char *key, BIGNUM *pub_key, DH *dh);
152 \& void DH_set_default_method(const DH_METHOD *meth);
153 \& const DH_METHOD *DH_get_default_method(void);
154 \& int DH_set_method(DH *dh, const DH_METHOD *meth);
155 \& DH *DH_new_method(ENGINE *engine);
156 \& const DH_METHOD *DH_OpenSSL(void);
158 \& int DH_get_ex_new_index(long argl, char *argp, int (*new_func)(),
159 \& int (*dup_func)(), void (*free_func)());
160 \& int DH_set_ex_data(DH *d, int idx, char *arg);
161 \& char *DH_get_ex_data(DH *d, int idx);
163 \& DH * d2i_DHparams(DH **a, unsigned char **pp, long length);
164 \& int i2d_DHparams(const DH *a, unsigned char **pp);
166 \& int DHparams_print_fp(FILE *fp, const DH *x);
167 \& int DHparams_print(BIO *bp, const DH *x);
170 .IX Header "DESCRIPTION"
171 These functions implement the Diffie-Hellman key agreement protocol.
172 The generation of shared \s-1DH\s0 parameters is described in
173 \&\fIDH_generate_parameters\fR\|(3); \fIDH_generate_key\fR\|(3) describes how
174 to perform a key agreement.
176 The \fB\s-1DH\s0\fR structure consists of several \s-1BIGNUM\s0 components.
181 \& BIGNUM *p; // prime number (shared)
182 \& BIGNUM *g; // generator of Z_p (shared)
183 \& BIGNUM *priv_key; // private DH value x
184 \& BIGNUM *pub_key; // public DH value g^x
190 Note that \s-1DH\s0 keys may use non-standard \fB\s-1DH_METHOD\s0\fR implementations,
191 either directly or by the use of \fB\s-1ENGINE\s0\fR modules. In some cases (eg. an
192 \&\s-1ENGINE\s0 providing support for hardware-embedded keys), these \s-1BIGNUM\s0 values
193 will not be used by the implementation or may be used for alternative data
194 storage. For this reason, applications should generally avoid using \s-1DH\s0
195 structure elements directly and instead use \s-1API\s0 functions to query or
198 .IX Header "SEE ALSO"
199 \&\fIdhparam\fR\|(1), \fIbn\fR\|(3), \fIdsa\fR\|(3), \fIerr\fR\|(3),
200 \&\fIrand\fR\|(3), \fIrsa\fR\|(3), \fIengine\fR\|(3),
201 \&\fIDH_set_method\fR\|(3), \fIDH_new\fR\|(3),
202 \&\fIDH_get_ex_new_index\fR\|(3),
203 \&\fIDH_generate_parameters\fR\|(3),
204 \&\fIDH_compute_key\fR\|(3), \fId2i_DHparams\fR\|(3),
205 \&\fIRSA_print\fR\|(3)