1 .\" Automatically generated by Pod::Man 2.27 (Pod::Simple 3.28)
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
45 .\" Escape single quotes in literal strings from groff's Unicode transform.
49 .\" If the F register is turned on, we'll generate index entries on stderr for
50 .\" titles (.TH), headers (.SH), subsections (.SS), items (.Ip), and index
51 .\" entries marked with X<> in POD. Of course, you'll have to process the
52 .\" output yourself in some meaningful fashion.
54 .\" Avoid warning from groff about undefined register 'F'.
58 .if \n(.g .if rF .nr rF 1
59 .if (\n(rF:(\n(.g==0)) \{
62 . tm Index:\\$1\t\\n%\t"\\$2"
72 .\" Accent mark definitions (@(#)ms.acc 1.5 88/02/08 SMI; from UCB 4.2).
73 .\" Fear. Run. Save yourself. No user-serviceable parts.
74 . \" fudge factors for nroff and troff
83 . ds #H ((1u-(\\\\n(.fu%2u))*.13m)
89 . \" simple accents for nroff and troff
99 . ds ' \\k:\h'-(\\n(.wu*8/10-\*(#H)'\'\h"|\\n:u"
100 . ds ` \\k:\h'-(\\n(.wu*8/10-\*(#H)'\`\h'|\\n:u'
101 . ds ^ \\k:\h'-(\\n(.wu*10/11-\*(#H)'^\h'|\\n:u'
102 . ds , \\k:\h'-(\\n(.wu*8/10)',\h'|\\n:u'
103 . ds ~ \\k:\h'-(\\n(.wu-\*(#H-.1m)'~\h'|\\n:u'
104 . ds / \\k:\h'-(\\n(.wu*8/10-\*(#H)'\z\(sl\h'|\\n:u'
106 . \" troff and (daisy-wheel) nroff accents
107 .ds : \\k:\h'-(\\n(.wu*8/10-\*(#H+.1m+\*(#F)'\v'-\*(#V'\z.\h'.2m+\*(#F'.\h'|\\n:u'\v'\*(#V'
108 .ds 8 \h'\*(#H'\(*b\h'-\*(#H'
109 .ds o \\k:\h'-(\\n(.wu+\w'\(de'u-\*(#H)/2u'\v'-.3n'\*(#[\z\(de\v'.3n'\h'|\\n:u'\*(#]
110 .ds d- \h'\*(#H'\(pd\h'-\w'~'u'\v'-.25m'\f2\(hy\fP\v'.25m'\h'-\*(#H'
111 .ds D- D\\k:\h'-\w'D'u'\v'-.11m'\z\(hy\v'.11m'\h'|\\n:u'
112 .ds th \*(#[\v'.3m'\s+1I\s-1\v'-.3m'\h'-(\w'I'u*2/3)'\s-1o\s+1\*(#]
113 .ds Th \*(#[\s+2I\s-2\h'-\w'I'u*3/5'\v'-.3m'o\v'.3m'\*(#]
114 .ds ae a\h'-(\w'a'u*4/10)'e
115 .ds Ae A\h'-(\w'A'u*4/10)'E
116 . \" corrections for vroff
117 .if v .ds ~ \\k:\h'-(\\n(.wu*9/10-\*(#H)'\s-2\u~\d\s+2\h'|\\n:u'
118 .if v .ds ^ \\k:\h'-(\\n(.wu*10/11-\*(#H)'\v'-.4m'^\v'.4m'\h'|\\n:u'
119 . \" for low resolution devices (crt and lpr)
120 .if \n(.H>23 .if \n(.V>19 \
133 .\" ========================================================================
135 .IX Title "DSA_generate_parameters 3"
136 .TH DSA_generate_parameters 3 "2015-03-19" "1.0.1m" "OpenSSL"
137 .\" For nroff, turn off justification. Always turn off hyphenation; it makes
138 .\" way too many mistakes in technical documents.
142 DSA_generate_parameters \- generate DSA parameters
144 .IX Header "SYNOPSIS"
146 \& #include <openssl/dsa.h>
148 \& DSA *DSA_generate_parameters(int bits, unsigned char *seed,
149 \& int seed_len, int *counter_ret, unsigned long *h_ret,
150 \& void (*callback)(int, int, void *), void *cb_arg);
153 .IX Header "DESCRIPTION"
154 \&\fIDSA_generate_parameters()\fR generates primes p and q and a generator g
155 for use in the \s-1DSA.\s0
157 \&\fBbits\fR is the length of the prime to be generated; the \s-1DSS\s0 allows a
158 maximum of 1024 bits.
160 If \fBseed\fR is \fB\s-1NULL\s0\fR or \fBseed_len\fR < 20, the primes will be
161 generated at random. Otherwise, the seed is used to generate
162 them. If the given seed does not yield a prime q, a new random
163 seed is chosen and placed at \fBseed\fR.
165 \&\fIDSA_generate_parameters()\fR places the iteration count in
166 *\fBcounter_ret\fR and a counter used for finding a generator in
167 *\fBh_ret\fR, unless these are \fB\s-1NULL\s0\fR.
169 A callback function may be used to provide feedback about the progress
170 of the key generation. If \fBcallback\fR is not \fB\s-1NULL\s0\fR, it will be
173 When a candidate for q is generated, \fBcallback(0, m++, cb_arg)\fR is called
174 (m is 0 for the first candidate).
176 When a candidate for q has passed a test by trial division,
177 \&\fBcallback(1, \-1, cb_arg)\fR is called.
178 While a candidate for q is tested by Miller-Rabin primality tests,
179 \&\fBcallback(1, i, cb_arg)\fR is called in the outer loop
180 (once for each witness that confirms that the candidate may be prime);
181 i is the loop counter (starting at 0).
183 When a prime q has been found, \fBcallback(2, 0, cb_arg)\fR and
184 \&\fBcallback(3, 0, cb_arg)\fR are called.
186 Before a candidate for p (other than the first) is generated and tested,
187 \&\fBcallback(0, counter, cb_arg)\fR is called.
189 When a candidate for p has passed the test by trial division,
190 \&\fBcallback(1, \-1, cb_arg)\fR is called.
191 While it is tested by the Miller-Rabin primality test,
192 \&\fBcallback(1, i, cb_arg)\fR is called in the outer loop
193 (once for each witness that confirms that the candidate may be prime).
194 i is the loop counter (starting at 0).
196 When p has been found, \fBcallback(2, 1, cb_arg)\fR is called.
198 When the generator has been found, \fBcallback(3, 1, cb_arg)\fR is called.
200 .IX Header "RETURN VALUE"
201 \&\fIDSA_generate_parameters()\fR returns a pointer to the \s-1DSA\s0 structure, or
202 \&\fB\s-1NULL\s0\fR if the parameter generation fails. The error codes can be
203 obtained by \fIERR_get_error\fR\|(3).
206 Seed lengths > 20 are not supported.
208 .IX Header "SEE ALSO"
209 \&\fIdsa\fR\|(3), \fIERR_get_error\fR\|(3), \fIrand\fR\|(3),
210 \&\fIDSA_free\fR\|(3)
213 \&\fIDSA_generate_parameters()\fR appeared in SSLeay 0.8. The \fBcb_arg\fR
214 argument was added in SSLeay 0.9.0.
215 In versions up to OpenSSL 0.9.4, \fBcallback(1, ...)\fR was called
216 in the inner loop of the Miller-Rabin test whenever it reached the
217 squaring step (the parameters to \fBcallback\fR did not reveal how many
218 witnesses had been tested); since OpenSSL 0.9.5, \fBcallback(1, ...)\fR
219 is called as in \fIBN_is_prime\fR\|(3), i.e. once for each witness.