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[u/mdw/catacomb] / dh.h
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44c240ee 1/* -*-c-*-
2 *
3688eb75 3 * $Id$
052b36d0 4 *
5 * Diffie-Hellman and related public-key systems
44c240ee 6 *
44c240ee 7 * (c) 1999 Straylight/Edgeware
8 */
9
45c0fd36 10/*----- Licensing notice --------------------------------------------------*
44c240ee 11 *
12 * This file is part of Catacomb.
13 *
14 * Catacomb is free software; you can redistribute it and/or modify
15 * it under the terms of the GNU Library General Public License as
16 * published by the Free Software Foundation; either version 2 of the
17 * License, or (at your option) any later version.
45c0fd36 18 *
44c240ee 19 * Catacomb is distributed in the hope that it will be useful,
20 * but WITHOUT ANY WARRANTY; without even the implied warranty of
21 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
22 * GNU Library General Public License for more details.
45c0fd36 23 *
44c240ee 24 * You should have received a copy of the GNU Library General Public
25 * License along with Catacomb; if not, write to the Free
26 * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
27 * MA 02111-1307, USA.
28 */
29
b3f05084 30#ifndef CATACOMB_DH_H
31#define CATACOMB_DH_H
44c240ee 32
33#ifdef __cplusplus
34 extern "C" {
35#endif
36
37/*----- Header files ------------------------------------------------------*/
38
34e4f738 39#ifndef CATACOMB_GROUP_H
40# include "group.h"
41#endif
42
052b36d0 43#ifndef CATACOMB_GRAND_H
44# include "grand.h"
44c240ee 45#endif
46
e23471a7 47#ifndef CATACOMB_KEY_H
48# include "key.h"
49#endif
50
600127f0 51#ifndef CATACOMB_KEYCHECK_H
52# include "keycheck.h"
53#endif
54
052b36d0 55#ifndef CATACOMB_PGEN_H
56# include "pgen.h"
57#endif
44c240ee 58
34e4f738 59#ifndef CATACOMB_QDPARSE_H
60# include "qdparse.h"
61#endif
62
052b36d0 63/*----- Data structures ---------------------------------------------------*/
44c240ee 64
34e4f738 65typedef gprime_param dh_param; /* Group parameters */
44c240ee 66
600127f0 67typedef struct dh_pub {
45c0fd36 68 dh_param dp; /* Shared parameters */
600127f0 69 mp *y; /* Public key */
e23471a7 70} dh_pub;
71
600127f0 72typedef struct dh_priv {
73 dh_param dp; /* Shared parameters */
74 mp *x; /* Private key */
75 mp *y; /* %$y \equiv g^x \pmod{p}$% */
e23471a7 76} dh_priv;
77
78/*----- Key fetching ------------------------------------------------------*/
79
80extern const key_fetchdef dh_paramfetch[];
81#define DH_PARAMFETCHSZ 5
82
83extern const key_fetchdef dh_pubfetch[];
84#define DH_PUBFETCHSZ 6
85
86extern const key_fetchdef dh_privfetch[];
87#define DH_PRIVFETCHSZ 9
88
b92da8eb 89/* --- @dh_paramfree@, @dh_pubfree@, @dh_privfree@ --- *
90 *
91 * Arguments: @dh_param *dp@, @dh_pub *dp@, @dh_priv *dp@ = pointer to
92 * key block to free
93 *
94 * Returns: ---
95 *
96 * Use: Frees a Diffie-Hellman key block.
97 */
98
99extern void dh_paramfree(dh_param */*dp*/);
100extern void dh_pubfree(dh_pub */*dp*/);
101extern void dh_privfree(dh_priv */*dp*/);
102
44c240ee 103/*----- Functions provided ------------------------------------------------*/
104
052b36d0 105/* --- @dh_gen@ --- *
44c240ee 106 *
052b36d0 107 * Arguments: @dh_param *dp@ = pointer to output parameter block
108 * @unsigned ql@ = length of %$q$% in bits, or zero
109 * @unsigned pl@ = length of %$p$% in bits
110 * @unsigned steps@ = number of steps to go
111 * @grand *r@ = random number source
112 * @pgen_proc *event@ = event handler function
113 * @void *ectx@ = argument for the event handler
44c240ee 114 *
052b36d0 115 * Returns: @PGEN_DONE@ if it worked, @PGEN_ABORT@ if it didn't.
44c240ee 116 *
052b36d0 117 * Use: Generates Diffie-Hellman parameters.
44c240ee 118 *
052b36d0 119 * The parameters are a prime %$q$%, relatively small, and a
120 * large prime %$p = kq + 1$% for some %$k$%, together with a
121 * generator %$g$% of the cyclic subgroup of order %$q$%. These
122 * are actually the same as the DSA parameter set, but the
123 * generation algorithm is different. Also, if @ql@ is zero,
124 * this algorithm forces %$k = 2$%, and chooses %$g = 4$%. Make
125 * sure you have something interesting to do if you choose this
126 * option.
44c240ee 127 */
128
052b36d0 129extern int dh_gen(dh_param */*dp*/, unsigned /*ql*/, unsigned /*pl*/,
130 unsigned /*steps*/, grand */*r*/, pgen_proc */*event*/,
131 void */*ectx*/);
44c240ee 132
1269467c 133/* --- @dh_limlee@ --- *
134 *
135 * Arguments: @dh_param *dp@ = pointer to output parameter block
136 * @unsigned ql@ = length of smallest factor of %$(p - 1)/2$%
137 * @unsigned pl@ = length of %$p$% in bits
138 * @unsigned flags@ = other generation flags
139 * @unsigned steps@ = number of steps to go
140 * @grand *r@ = random number source
45c0fd36
MW
141 * @pgen_proc *oev@ = outer event handler function
142 * @void *oec@ = argument for the outer event handler
143 * @pgen_proc *iev@ = inner event handler function
144 * @void *iec@ = argument for the inner event handler
145 * @size_t *nf@, @mp ***f@ = output array for factors
1269467c 146 *
147 * Returns: @PGEN_DONE@ if it worked, @PGEN_ABORT@ if it didn't.
148 *
149 * Use: Generates Diffie-Hellman parameters based on a Lim-Lee prime.
150 *
151 * The modulus is a large prime %$p = 2 \prod q_i + 1$%, @pl@
152 * bits long, where the %$q_i$% are smaller primes each at least
153 * @ql@ bits long. It is safe to set @nf@ and @f@ to zero if
154 * you're not interested in the factor values.
155 *
156 * The returned %$g$% generates a subgroup of order %$q_0$% (the
157 * first factor, returned as @f[0]@), if the flag @DH_SUBGROUP@
158 * is set on entry; otherwise %$g$% will have order
159 * %$(p - 1)/2$%.
160 */
161
162#define DH_SUBGROUP 1u
163
164extern int dh_limlee(dh_param */*dp*/, unsigned /*ql*/, unsigned /*pl*/,
165 unsigned /*flags*/, unsigned /*steps*/, grand */*r*/,
166 pgen_proc */*oev*/, void */*oec*/, pgen_proc */*iev*/,
167 void */*iec*/, size_t */*nf*/, mp ***/*f*/);
168
4e67e30b
MW
169/* --- @dh_kcdsagen@ --- *
170 *
171 * Arguments: @dh_param *dp@ = pointer to output parameter block
172 * @unsigned ql@ = size of small factor of %$(p - 1)/2$%
173 * @unsigned pl@ = size of %$p$% in bits
174 * @unsigned flags@ = other generation flags (none defined)
175 * @unsigned steps@ = number of steps to go
176 * @grand *r@ = random number source
177 * @pgen_proc *ev@ = event handler function
178 * @void *ec@ = context for the event handler
179 *
180 * Returns: @PGEN_DONE@ if it worked, @PGEN_ABORT@ if it failed.
181 *
182 * Use: Generates a KCDSA prime group. That is, it chooses a prime
183 * %$p$%, such that $%p = 2 q v + 1$%, for primes %$q$% and
184 * %$v$%. The actual group of interest is the subgroup of order
185 * %$q$%.
186 */
187
188extern int dh_kcdsagen(dh_param */*dp*/, unsigned /*ql*/, unsigned /*pl*/,
189 unsigned /*flags*/, unsigned /*steps*/, grand */*r*/,
190 pgen_proc */*ev*/, void */*ec*/);
191
600127f0 192/* --- @dh_checkparam@ --- *
193 *
194 * Arguments: @keycheck *kc@ = keycheck state
195 * @const dh_param *dp@ = pointer to the parameter set
196 * @mp **v@ = optional vector of factors
197 * @size_t n@ = size of vector
198 *
199 * Returns: Zero if all OK, or return status from function.
200 *
201 * Use: Checks a set of Diffie-Hellman parameters for consistency and
202 * security.
203 */
204
205extern int dh_checkparam(keycheck */*kc*/, const dh_param */*dp*/,
206 mp **/*v*/, size_t /*n*/);
207
7b6d64f1 208/* ---- @dh_infofromdata@ --- *
209 *
210 * Arguments: @dh_param *dp@ = parameters to fill in
211 * @pdata *pd@ = packed data structure
212 *
213 * Returns: ---
214 *
215 * Use: Fills in a parameters structure from a packed data block.
216 */
217
218struct pdata;
219extern void dh_infofromdata(dh_param */*dp*/, struct pdata */*pd*/);
220
3688eb75 221/* --- @dh_parse@, @dhbin_parse@ --- *
34e4f738 222 *
223 * Arguments: @qd_parse *qd@ = parser context
224 * @dh_param *dp@ = parameters to fill in
225 *
226 * Returns: Zero if OK, nonzero on error.
227 *
3688eb75 228 * Use: Parses a prime/binary group string. This is either one of
229 * the standard group strings, or a %$p$%, %$q$%, %$g$% triple
34e4f738 230 * separated by commas.
231 */
232
233extern int dh_parse(qd_parse */*qd*/, dh_param */*dp*/);
3688eb75 234extern int dhbin_parse(qd_parse */*qd*/, gbin_param */*gb*/);
34e4f738 235
44c240ee 236/*----- That's all, folks -------------------------------------------------*/
237
238#ifdef __cplusplus
239 }
240#endif
241
242#endif