3 * $Id: dh.h,v 1.7 2001/02/03 16:08:24 mdw Exp $
5 * Diffie-Hellman and related public-key systems
7 * (c) 1999 Straylight/Edgeware
10 /*----- Licensing notice --------------------------------------------------*
12 * This file is part of Catacomb.
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.
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.
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,
30 /*----- Revision history --------------------------------------------------*
33 * Revision 1.7 2001/02/03 16:08:24 mdw
34 * Add consistency checking for public keys.
36 * Revision 1.6 2000/07/29 10:01:16 mdw
37 * Supply commentry for the Diffie-Hellman parameters. Add Lim-Lee
38 * parameter generation.
40 * Revision 1.5 2000/07/01 11:20:51 mdw
41 * New functions for freeing public and private keys.
43 * Revision 1.4 2000/06/17 10:52:47 mdw
44 * Minor changes for key fetching.
46 * Revision 1.3 2000/02/12 18:21:02 mdw
47 * Overhaul of key management (again).
58 /*----- Header files ------------------------------------------------------*/
60 #ifndef CATACOMB_GRAND_H
64 #ifndef CATACOMB_KEY_H
68 #ifndef CATACOMB_KEYCHECK_H
69 # include "keycheck.h"
72 #ifndef CATACOMB_PGEN_H
76 /*----- Data structures ---------------------------------------------------*/
78 typedef struct dh_param
{
79 mp
*p
, *q
; /* Prime numbers %$p$% and %$q$% */
80 mp
*g
; /* Generates order-%$q$% subgroup */
83 typedef struct dh_pub
{
84 dh_param dp
; /* Shared parameters */
85 mp
*y
; /* Public key */
88 typedef struct dh_priv
{
89 dh_param dp
; /* Shared parameters */
90 mp
*x
; /* Private key */
91 mp
*y
; /* %$y \equiv g^x \pmod{p}$% */
94 /*----- Key fetching ------------------------------------------------------*/
96 extern const key_fetchdef dh_paramfetch
[];
97 #define DH_PARAMFETCHSZ 5
99 extern const key_fetchdef dh_pubfetch
[];
100 #define DH_PUBFETCHSZ 6
102 extern const key_fetchdef dh_privfetch
[];
103 #define DH_PRIVFETCHSZ 9
105 /* --- @dh_paramfree@, @dh_pubfree@, @dh_privfree@ --- *
107 * Arguments: @dh_param *dp@, @dh_pub *dp@, @dh_priv *dp@ = pointer to
112 * Use: Frees a Diffie-Hellman key block.
115 extern void dh_paramfree(dh_param */
*dp*/
);
116 extern void dh_pubfree(dh_pub */
*dp*/
);
117 extern void dh_privfree(dh_priv */
*dp*/
);
119 /*----- Functions provided ------------------------------------------------*/
121 /* --- @dh_gen@ --- *
123 * Arguments: @dh_param *dp@ = pointer to output parameter block
124 * @unsigned ql@ = length of %$q$% in bits, or zero
125 * @unsigned pl@ = length of %$p$% in bits
126 * @unsigned steps@ = number of steps to go
127 * @grand *r@ = random number source
128 * @pgen_proc *event@ = event handler function
129 * @void *ectx@ = argument for the event handler
131 * Returns: @PGEN_DONE@ if it worked, @PGEN_ABORT@ if it didn't.
133 * Use: Generates Diffie-Hellman parameters.
135 * The parameters are a prime %$q$%, relatively small, and a
136 * large prime %$p = kq + 1$% for some %$k$%, together with a
137 * generator %$g$% of the cyclic subgroup of order %$q$%. These
138 * are actually the same as the DSA parameter set, but the
139 * generation algorithm is different. Also, if @ql@ is zero,
140 * this algorithm forces %$k = 2$%, and chooses %$g = 4$%. Make
141 * sure you have something interesting to do if you choose this
145 extern int dh_gen(dh_param */
*dp*/
, unsigned /*ql*/, unsigned /*pl*/,
146 unsigned /*steps*/, grand */
*r*/
, pgen_proc */
*event*/
,
149 /* --- @dh_limlee@ --- *
151 * Arguments: @dh_param *dp@ = pointer to output parameter block
152 * @unsigned ql@ = length of smallest factor of %$(p - 1)/2$%
153 * @unsigned pl@ = length of %$p$% in bits
154 * @unsigned flags@ = other generation flags
155 * @unsigned steps@ = number of steps to go
156 * @grand *r@ = random number source
157 * @pgen_proc *oev@ = outer event handler function
158 * @void *oec@ = argument for the outer event handler
159 * @pgen_proc *iev@ = inner event handler function
160 * @void *iec@ = argument for the inner event handler
161 * @size_t *nf@, @mp ***f@ = output array for factors
163 * Returns: @PGEN_DONE@ if it worked, @PGEN_ABORT@ if it didn't.
165 * Use: Generates Diffie-Hellman parameters based on a Lim-Lee prime.
167 * The modulus is a large prime %$p = 2 \prod q_i + 1$%, @pl@
168 * bits long, where the %$q_i$% are smaller primes each at least
169 * @ql@ bits long. It is safe to set @nf@ and @f@ to zero if
170 * you're not interested in the factor values.
172 * The returned %$g$% generates a subgroup of order %$q_0$% (the
173 * first factor, returned as @f[0]@), if the flag @DH_SUBGROUP@
174 * is set on entry; otherwise %$g$% will have order
178 #define DH_SUBGROUP 1u
180 extern int dh_limlee(dh_param */
*dp*/
, unsigned /*ql*/, unsigned /*pl*/,
181 unsigned /*flags*/, unsigned /*steps*/, grand */
*r*/
,
182 pgen_proc */
*oev*/
, void */
*oec*/
, pgen_proc */
*iev*/
,
183 void */
*iec*/
, size_t */
*nf*/
, mp
***/
*f*/
);
185 /* --- @dh_checkparam@ --- *
187 * Arguments: @keycheck *kc@ = keycheck state
188 * @const dh_param *dp@ = pointer to the parameter set
189 * @mp **v@ = optional vector of factors
190 * @size_t n@ = size of vector
192 * Returns: Zero if all OK, or return status from function.
194 * Use: Checks a set of Diffie-Hellman parameters for consistency and
198 extern int dh_checkparam(keycheck */
*kc*/
, const dh_param */
*dp*/
,
199 mp
**/
*v*/
, size_t /*n*/);
201 /*----- That's all, folks -------------------------------------------------*/