5d4a6be9 |
1 | /* -*-c-*- |
2 | * |
e8c3c91f |
3 | * $Id: dsarand.h,v 1.2 2000/06/17 10:54:14 mdw Exp $ |
5d4a6be9 |
4 | * |
5 | * Random number generator for DSA |
6 | * |
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: dsarand.h,v $ |
e8c3c91f |
33 | * Revision 1.2 2000/06/17 10:54:14 mdw |
34 | * Typesetting fixes. |
35 | * |
5d4a6be9 |
36 | * Revision 1.1 1999/12/22 15:53:12 mdw |
37 | * Random number generator for finding DSA parameters. |
38 | * |
39 | */ |
40 | |
41 | #ifndef CATACOMB_DSARAND_H |
42 | #define CATACOMB_DSARAND_H |
43 | |
44 | #ifdef __cplusplus |
45 | extern "C" { |
46 | #endif |
47 | |
48 | /*----- Header files ------------------------------------------------------*/ |
49 | |
50 | #include <mLib/bits.h> |
51 | |
52 | #ifndef CATACOMB_GRAND_H |
53 | # include "grand.h" |
54 | #endif |
55 | |
56 | #ifndef CATACOMB_SHA_H |
57 | # include "sha.h" |
58 | #endif |
59 | |
60 | /*----- Data structures ---------------------------------------------------*/ |
61 | |
62 | typedef struct dsarand { |
63 | octet *p; /* Pointer to seed (modified) */ |
64 | size_t sz; /* Size of the seed buffer */ |
65 | unsigned passes; /* Number of passes to make */ |
66 | } dsarand; |
67 | |
68 | /*----- Functions provided ------------------------------------------------*/ |
69 | |
70 | /* --- @dsarand_init@ --- * |
71 | * |
72 | * Arguments: @dsarand *d@ = pointer to context |
73 | * @const void *p@ = pointer to seed buffer |
74 | * @size_t sz@ = size of the buffer |
75 | * |
76 | * Returns: --- |
77 | * |
78 | * Use: Initializes a DSA random number generator. |
79 | */ |
80 | |
81 | extern void dsarand_init(dsarand */*d*/, const void */*p*/, size_t /*sz*/); |
82 | |
83 | /* --- @dsarand_reseed@ --- * |
84 | * |
85 | * Arguments: @dsarand *d@ = pointer to context |
86 | * @const void *p@ = pointer to seed buffer |
87 | * @size_t sz@ = size of the buffer |
88 | * |
89 | * Returns: --- |
90 | * |
91 | * Use: Initializes a DSA random number generator. |
92 | */ |
93 | |
94 | extern void dsarand_reseed(dsarand */*d*/, const void */*p*/, size_t /*sz*/); |
95 | |
96 | /* --- @dsarand_destroy@ --- * |
97 | * |
98 | * Arguments: @dsarand *d@ = pointer to context |
99 | * |
100 | * Returns: --- |
101 | * |
102 | * Use: Disposes of a DSA random number generation context. |
103 | */ |
104 | |
105 | extern void dsarand_destroy(dsarand */*d*/); |
106 | |
107 | /* --- @dsarand_fill@ --- * |
108 | * |
109 | * Arguments: @dsarand *d@ = pointer to context |
110 | * @void *p@ = pointer to output buffer |
111 | * @size_t sz@ = size of output buffer |
112 | * |
113 | * Returns: --- |
114 | * |
115 | * Use: Fills an output buffer with pseudorandom data. |
116 | * |
117 | * Let %$p$% be the numerical value of the input buffer, and let |
118 | * %$b$% be the number of bytes required. Let |
e8c3c91f |
119 | * %$z = \lceil b / 20 \rceil$% be the number of SHA outputs |
5d4a6be9 |
120 | * required. Then the output of pass %$n$% is |
121 | * |
122 | * %$P_n = \sum_{0 \le i < z} 2^{160i} SHA(p + nz + i)$% |
123 | * %${} \bmod 2^{8b}$% |
124 | * |
125 | * and the actual result in the output buffer is the XOR of all |
126 | * of the output passes. |
127 | * |
128 | * The DSA procedure for choosing @q@ involves two passes with |
129 | * %$z = 1$%; the procedure for choosing @p@ involves one pass |
130 | * with larger %$z$%. This generalization of the DSA generation |
131 | * procedure is my own invention but it seems relatively sound. |
132 | */ |
133 | |
134 | extern void dsarand_fill(dsarand */*d*/, void */*p*/, size_t /*sz*/); |
135 | |
136 | /*----- Generic pseudorandom-number generator interface -------------------*/ |
137 | |
138 | /* --- Miscellaneous operations --- */ |
139 | |
140 | enum { |
141 | DSARAND_PASSES = GRAND_SPECIFIC |
142 | }; |
143 | |
144 | /* --- @dsarand_create@ --- * |
145 | * |
146 | * Arguments: @const void *p@ = pointer to seed buffer |
147 | * @size_t sz@ = size of seed buffer |
148 | * |
149 | * Returns: Pointer to a generic generator. |
150 | * |
151 | * Use: Constructs a generic generator interface over a Catacomb |
152 | * entropy pool generator. |
153 | */ |
154 | |
155 | extern grand *dsarand_create(const void */*p*/, size_t /*sz*/); |
156 | |
157 | /*----- That's all, folks -------------------------------------------------*/ |
158 | |
159 | #ifdef __cplusplus |
160 | } |
161 | #endif |
162 | |
163 | #endif |