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1 | /* -*-c-*- |
2 | * |
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3 | * $Id: dh.h,v 1.8 2004/04/01 12:50:09 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 1.8 2004/04/01 12:50:09 mdw |
34 | * Add cyclic group abstraction, with test code. Separate off exponentation |
35 | * functions for better static linking. Fix a buttload of bugs on the way. |
36 | * Generally ensure that negative exponents do inversion correctly. Add |
37 | * table of standard prime-field subgroups. (Binary field subgroups are |
38 | * currently unimplemented but easy to add if anyone ever finds a good one.) |
39 | * |
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40 | * Revision 1.7 2001/02/03 16:08:24 mdw |
41 | * Add consistency checking for public keys. |
42 | * |
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43 | * Revision 1.6 2000/07/29 10:01:16 mdw |
44 | * Supply commentry for the Diffie-Hellman parameters. Add Lim-Lee |
45 | * parameter generation. |
46 | * |
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47 | * Revision 1.5 2000/07/01 11:20:51 mdw |
48 | * New functions for freeing public and private keys. |
49 | * |
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50 | * Revision 1.4 2000/06/17 10:52:47 mdw |
51 | * Minor changes for key fetching. |
52 | * |
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53 | * Revision 1.3 2000/02/12 18:21:02 mdw |
54 | * Overhaul of key management (again). |
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55 | * |
56 | */ |
57 | |
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58 | #ifndef CATACOMB_DH_H |
59 | #define CATACOMB_DH_H |
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60 | |
61 | #ifdef __cplusplus |
62 | extern "C" { |
63 | #endif |
64 | |
65 | /*----- Header files ------------------------------------------------------*/ |
66 | |
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67 | #ifndef CATACOMB_GROUP_H |
68 | # include "group.h" |
69 | #endif |
70 | |
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71 | #ifndef CATACOMB_GRAND_H |
72 | # include "grand.h" |
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73 | #endif |
74 | |
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75 | #ifndef CATACOMB_KEY_H |
76 | # include "key.h" |
77 | #endif |
78 | |
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79 | #ifndef CATACOMB_KEYCHECK_H |
80 | # include "keycheck.h" |
81 | #endif |
82 | |
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83 | #ifndef CATACOMB_PGEN_H |
84 | # include "pgen.h" |
85 | #endif |
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86 | |
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87 | #ifndef CATACOMB_QDPARSE_H |
88 | # include "qdparse.h" |
89 | #endif |
90 | |
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91 | /*----- Data structures ---------------------------------------------------*/ |
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92 | |
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93 | typedef gprime_param dh_param; /* Group parameters */ |
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94 | |
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95 | typedef struct dh_pub { |
96 | dh_param dp; /* Shared parameters */ |
97 | mp *y; /* Public key */ |
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98 | } dh_pub; |
99 | |
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100 | typedef struct dh_priv { |
101 | dh_param dp; /* Shared parameters */ |
102 | mp *x; /* Private key */ |
103 | mp *y; /* %$y \equiv g^x \pmod{p}$% */ |
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104 | } dh_priv; |
105 | |
106 | /*----- Key fetching ------------------------------------------------------*/ |
107 | |
108 | extern const key_fetchdef dh_paramfetch[]; |
109 | #define DH_PARAMFETCHSZ 5 |
110 | |
111 | extern const key_fetchdef dh_pubfetch[]; |
112 | #define DH_PUBFETCHSZ 6 |
113 | |
114 | extern const key_fetchdef dh_privfetch[]; |
115 | #define DH_PRIVFETCHSZ 9 |
116 | |
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117 | /* --- @dh_paramfree@, @dh_pubfree@, @dh_privfree@ --- * |
118 | * |
119 | * Arguments: @dh_param *dp@, @dh_pub *dp@, @dh_priv *dp@ = pointer to |
120 | * key block to free |
121 | * |
122 | * Returns: --- |
123 | * |
124 | * Use: Frees a Diffie-Hellman key block. |
125 | */ |
126 | |
127 | extern void dh_paramfree(dh_param */*dp*/); |
128 | extern void dh_pubfree(dh_pub */*dp*/); |
129 | extern void dh_privfree(dh_priv */*dp*/); |
130 | |
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131 | /*----- Functions provided ------------------------------------------------*/ |
132 | |
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133 | /* --- @dh_gen@ --- * |
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134 | * |
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135 | * Arguments: @dh_param *dp@ = pointer to output parameter block |
136 | * @unsigned ql@ = length of %$q$% in bits, or zero |
137 | * @unsigned pl@ = length of %$p$% in bits |
138 | * @unsigned steps@ = number of steps to go |
139 | * @grand *r@ = random number source |
140 | * @pgen_proc *event@ = event handler function |
141 | * @void *ectx@ = argument for the event handler |
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142 | * |
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143 | * Returns: @PGEN_DONE@ if it worked, @PGEN_ABORT@ if it didn't. |
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144 | * |
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145 | * Use: Generates Diffie-Hellman parameters. |
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146 | * |
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147 | * The parameters are a prime %$q$%, relatively small, and a |
148 | * large prime %$p = kq + 1$% for some %$k$%, together with a |
149 | * generator %$g$% of the cyclic subgroup of order %$q$%. These |
150 | * are actually the same as the DSA parameter set, but the |
151 | * generation algorithm is different. Also, if @ql@ is zero, |
152 | * this algorithm forces %$k = 2$%, and chooses %$g = 4$%. Make |
153 | * sure you have something interesting to do if you choose this |
154 | * option. |
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155 | */ |
156 | |
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157 | extern int dh_gen(dh_param */*dp*/, unsigned /*ql*/, unsigned /*pl*/, |
158 | unsigned /*steps*/, grand */*r*/, pgen_proc */*event*/, |
159 | void */*ectx*/); |
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160 | |
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161 | /* --- @dh_limlee@ --- * |
162 | * |
163 | * Arguments: @dh_param *dp@ = pointer to output parameter block |
164 | * @unsigned ql@ = length of smallest factor of %$(p - 1)/2$% |
165 | * @unsigned pl@ = length of %$p$% in bits |
166 | * @unsigned flags@ = other generation flags |
167 | * @unsigned steps@ = number of steps to go |
168 | * @grand *r@ = random number source |
169 | * @pgen_proc *oev@ = outer event handler function |
170 | * @void *oec@ = argument for the outer event handler |
171 | * @pgen_proc *iev@ = inner event handler function |
172 | * @void *iec@ = argument for the inner event handler |
173 | * @size_t *nf@, @mp ***f@ = output array for factors |
174 | * |
175 | * Returns: @PGEN_DONE@ if it worked, @PGEN_ABORT@ if it didn't. |
176 | * |
177 | * Use: Generates Diffie-Hellman parameters based on a Lim-Lee prime. |
178 | * |
179 | * The modulus is a large prime %$p = 2 \prod q_i + 1$%, @pl@ |
180 | * bits long, where the %$q_i$% are smaller primes each at least |
181 | * @ql@ bits long. It is safe to set @nf@ and @f@ to zero if |
182 | * you're not interested in the factor values. |
183 | * |
184 | * The returned %$g$% generates a subgroup of order %$q_0$% (the |
185 | * first factor, returned as @f[0]@), if the flag @DH_SUBGROUP@ |
186 | * is set on entry; otherwise %$g$% will have order |
187 | * %$(p - 1)/2$%. |
188 | */ |
189 | |
190 | #define DH_SUBGROUP 1u |
191 | |
192 | extern int dh_limlee(dh_param */*dp*/, unsigned /*ql*/, unsigned /*pl*/, |
193 | unsigned /*flags*/, unsigned /*steps*/, grand */*r*/, |
194 | pgen_proc */*oev*/, void */*oec*/, pgen_proc */*iev*/, |
195 | void */*iec*/, size_t */*nf*/, mp ***/*f*/); |
196 | |
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197 | /* --- @dh_checkparam@ --- * |
198 | * |
199 | * Arguments: @keycheck *kc@ = keycheck state |
200 | * @const dh_param *dp@ = pointer to the parameter set |
201 | * @mp **v@ = optional vector of factors |
202 | * @size_t n@ = size of vector |
203 | * |
204 | * Returns: Zero if all OK, or return status from function. |
205 | * |
206 | * Use: Checks a set of Diffie-Hellman parameters for consistency and |
207 | * security. |
208 | */ |
209 | |
210 | extern int dh_checkparam(keycheck */*kc*/, const dh_param */*dp*/, |
211 | mp **/*v*/, size_t /*n*/); |
212 | |
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213 | /* --- @dh_parse@ --- * |
214 | * |
215 | * Arguments: @qd_parse *qd@ = parser context |
216 | * @dh_param *dp@ = parameters to fill in |
217 | * |
218 | * Returns: Zero if OK, nonzero on error. |
219 | * |
220 | * Use: Parses a prime group string. This is either one of the |
221 | * standard group strings, or a %$p$%, %$q$%, %$g$% triple |
222 | * separated by commas. |
223 | */ |
224 | |
225 | extern int dh_parse(qd_parse */*qd*/, dh_param */*dp*/); |
226 | |
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227 | /*----- That's all, folks -------------------------------------------------*/ |
228 | |
229 | #ifdef __cplusplus |
230 | } |
231 | #endif |
232 | |
233 | #endif |