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1 | /* -*-c-*- |
2 | * |
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3 | * $Id: dh.h,v 1.7 2001/02/03 16:08:24 mdw Exp $ |
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4 | * |
5 | * Diffie-Hellman and related public-key systems |
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6 | * |
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7 | * (c) 1999 Straylight/Edgeware |
8 | */ |
9 | |
10 | /*----- Licensing notice --------------------------------------------------* |
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. |
18 | * |
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. |
23 | * |
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 | |
30 | /*----- Revision history --------------------------------------------------* |
31 | * |
32 | * $Log: dh.h,v $ |
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33 | * Revision 1.7 2001/02/03 16:08:24 mdw |
34 | * Add consistency checking for public keys. |
35 | * |
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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. |
39 | * |
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40 | * Revision 1.5 2000/07/01 11:20:51 mdw |
41 | * New functions for freeing public and private keys. |
42 | * |
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43 | * Revision 1.4 2000/06/17 10:52:47 mdw |
44 | * Minor changes for key fetching. |
45 | * |
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46 | * Revision 1.3 2000/02/12 18:21:02 mdw |
47 | * Overhaul of key management (again). |
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48 | * |
49 | */ |
50 | |
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51 | #ifndef CATACOMB_DH_H |
52 | #define CATACOMB_DH_H |
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53 | |
54 | #ifdef __cplusplus |
55 | extern "C" { |
56 | #endif |
57 | |
58 | /*----- Header files ------------------------------------------------------*/ |
59 | |
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60 | #ifndef CATACOMB_GRAND_H |
61 | # include "grand.h" |
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62 | #endif |
63 | |
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64 | #ifndef CATACOMB_KEY_H |
65 | # include "key.h" |
66 | #endif |
67 | |
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68 | #ifndef CATACOMB_KEYCHECK_H |
69 | # include "keycheck.h" |
70 | #endif |
71 | |
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72 | #ifndef CATACOMB_PGEN_H |
73 | # include "pgen.h" |
74 | #endif |
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75 | |
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76 | /*----- Data structures ---------------------------------------------------*/ |
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77 | |
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78 | typedef struct dh_param { |
79 | mp *p, *q; /* Prime numbers %$p$% and %$q$% */ |
80 | mp *g; /* Generates order-%$q$% subgroup */ |
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81 | } dh_param; |
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82 | |
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83 | typedef struct dh_pub { |
84 | dh_param dp; /* Shared parameters */ |
85 | mp *y; /* Public key */ |
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86 | } dh_pub; |
87 | |
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88 | typedef struct dh_priv { |
89 | dh_param dp; /* Shared parameters */ |
90 | mp *x; /* Private key */ |
91 | mp *y; /* %$y \equiv g^x \pmod{p}$% */ |
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92 | } dh_priv; |
93 | |
94 | /*----- Key fetching ------------------------------------------------------*/ |
95 | |
96 | extern const key_fetchdef dh_paramfetch[]; |
97 | #define DH_PARAMFETCHSZ 5 |
98 | |
99 | extern const key_fetchdef dh_pubfetch[]; |
100 | #define DH_PUBFETCHSZ 6 |
101 | |
102 | extern const key_fetchdef dh_privfetch[]; |
103 | #define DH_PRIVFETCHSZ 9 |
104 | |
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105 | /* --- @dh_paramfree@, @dh_pubfree@, @dh_privfree@ --- * |
106 | * |
107 | * Arguments: @dh_param *dp@, @dh_pub *dp@, @dh_priv *dp@ = pointer to |
108 | * key block to free |
109 | * |
110 | * Returns: --- |
111 | * |
112 | * Use: Frees a Diffie-Hellman key block. |
113 | */ |
114 | |
115 | extern void dh_paramfree(dh_param */*dp*/); |
116 | extern void dh_pubfree(dh_pub */*dp*/); |
117 | extern void dh_privfree(dh_priv */*dp*/); |
118 | |
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119 | /*----- Functions provided ------------------------------------------------*/ |
120 | |
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121 | /* --- @dh_gen@ --- * |
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122 | * |
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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 |
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130 | * |
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131 | * Returns: @PGEN_DONE@ if it worked, @PGEN_ABORT@ if it didn't. |
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132 | * |
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133 | * Use: Generates Diffie-Hellman parameters. |
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134 | * |
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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 |
142 | * option. |
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143 | */ |
144 | |
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145 | extern int dh_gen(dh_param */*dp*/, unsigned /*ql*/, unsigned /*pl*/, |
146 | unsigned /*steps*/, grand */*r*/, pgen_proc */*event*/, |
147 | void */*ectx*/); |
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148 | |
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149 | /* --- @dh_limlee@ --- * |
150 | * |
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 |
162 | * |
163 | * Returns: @PGEN_DONE@ if it worked, @PGEN_ABORT@ if it didn't. |
164 | * |
165 | * Use: Generates Diffie-Hellman parameters based on a Lim-Lee prime. |
166 | * |
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. |
171 | * |
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 |
175 | * %$(p - 1)/2$%. |
176 | */ |
177 | |
178 | #define DH_SUBGROUP 1u |
179 | |
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*/); |
184 | |
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185 | /* --- @dh_checkparam@ --- * |
186 | * |
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 |
191 | * |
192 | * Returns: Zero if all OK, or return status from function. |
193 | * |
194 | * Use: Checks a set of Diffie-Hellman parameters for consistency and |
195 | * security. |
196 | */ |
197 | |
198 | extern int dh_checkparam(keycheck */*kc*/, const dh_param */*dp*/, |
199 | mp **/*v*/, size_t /*n*/); |
200 | |
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201 | /*----- That's all, folks -------------------------------------------------*/ |
202 | |
203 | #ifdef __cplusplus |
204 | } |
205 | #endif |
206 | |
207 | #endif |