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1 | /* -*-c-*- |
2 | * |
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3 | * $Id: fipstest.c,v 1.3 2000/08/11 21:34:34 mdw Exp $ |
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4 | * |
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5 | * FIPS140 randomness tests |
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6 | * |
7 | * (c) 2000 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: fipstest.c,v $ |
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33 | * Revision 1.3 2000/08/11 21:34:34 mdw |
34 | * Change to use the new thresholds given in the draft FIPS140-2. |
35 | * |
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36 | * Revision 1.2 2000/06/17 12:21:39 mdw |
37 | * Add braces to shut compiler up. Reformat code slightly. |
38 | * |
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39 | * Revision 1.1 2000/06/17 10:55:38 mdw |
40 | * FIPS 140-1 random generator test. |
41 | * |
42 | */ |
43 | |
44 | /*----- Header files ------------------------------------------------------*/ |
45 | |
46 | #include <mLib/bits.h> |
47 | |
48 | #include "fipstest.h" |
49 | |
50 | /*----- Main code ---------------------------------------------------------*/ |
51 | |
52 | /* --- @monobit@ --- * |
53 | * |
54 | * Arguments: @const octet *p@ = pointer to buffer |
55 | * |
56 | * Returns: Zero if OK, @FIPSTEST_MONOBIT@ on failure. |
57 | * |
58 | * Use: Performs the monobit test on a buffer of data. If %$n_1$% is |
59 | * the number of 1 bits in the buffer, then the monobit test is |
60 | * passed when %$9654 < n_1 < 10346$%. |
61 | */ |
62 | |
63 | static unsigned monobit(const octet *p) |
64 | { |
65 | unsigned n1 = 0; |
66 | unsigned i, j; |
67 | |
68 | for (i = 0; i < FIPSTEST_BUFSZ; i++) { |
69 | octet x = p[i]; |
70 | for (j = 0; j < 8; j++) { |
71 | if (x & 1) |
72 | n1++; |
73 | x >>= 1; |
74 | } |
75 | } |
76 | |
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77 | if (9725 >= n1 || n1 >= 10275) |
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78 | return (FIPSTEST_MONOBIT); |
79 | return (0); |
80 | } |
81 | |
82 | /* --- @poker@ --- * |
83 | * |
84 | * Arguments: @const octet *p@ = pointer to buffer |
85 | * |
86 | * Returns: Zero if OK, @FIPSTEST_POKER@ on failure. |
87 | * |
88 | * Use: Performs the poker test on a buffer of data. The buffer is |
89 | * divided into 4-bit nibbles %$x_i$%. If |
90 | * %$f(x) = \sum_{x_i = x} 1$% is the frequency of each nibble, |
91 | * then the test is passed if |
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92 | * %$2.16 < 16/5000 \sum_i f(i)^2 - 5000 < 46.17$%. |
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93 | */ |
94 | |
95 | static unsigned poker(const octet *p) |
96 | { |
97 | unsigned long f[16] = { 0 }; |
98 | unsigned i; |
99 | unsigned long q = 0; |
100 | |
101 | /* --- Compute the frequencies --- */ |
102 | |
103 | for (i = 0; i < FIPSTEST_BUFSZ; i++) { |
104 | octet x = p[i]; |
105 | f[x & 0xf]++; |
106 | f[(x >> 4) & 0xf]++; |
107 | } |
108 | |
109 | /* --- Now do the comparison --- * |
110 | * |
111 | * This can be simplified. Multiply through the inequality by 5000 and |
112 | * we get %$5150 < 16 \sum_i f(i)^2 - 5000^2 < 287000$%. |
113 | */ |
114 | |
115 | for (i = 0; i < 16; i++) |
116 | q += f[i] * f[i]; |
117 | q <<= 4; |
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118 | q -= 5000ul * 5000ul; |
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119 | |
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120 | if (10800 >= q || q >= 230850) |
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121 | return (FIPSTEST_POKER); |
122 | return (0); |
123 | } |
124 | |
125 | /* --- @runs@ --- * |
126 | * |
127 | * Arguments: @const octet *p@ = pointer to buffer |
128 | * |
129 | * Returns: Zero for success, @FIPSTEST_RUNS@ or @FIPSTEST_LONGRUNS@ on |
130 | * failure. |
131 | * |
132 | * Use: Performs the runs and long runs tests. The frequency of each |
133 | * `run', or sequence of equal bits, is counted and tested. |
134 | */ |
135 | |
136 | static unsigned runs(const octet *p) |
137 | { |
138 | unsigned rc = 0; |
139 | unsigned i, j; |
140 | unsigned r = 0; |
141 | unsigned bb = 0; |
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142 | unsigned f[2][6] = { { 0 } }; |
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143 | |
144 | /* --- Count the run lengths --- */ |
145 | |
146 | for (i = 0; i < FIPSTEST_BUFSZ; i++) { |
147 | octet x = p[i]; |
148 | for (j = 0; j < 8; j++) { |
149 | unsigned b = x & 1; |
150 | x >>= 1; |
151 | if (b == bb) |
152 | r++; |
153 | else { |
154 | if (r) { |
155 | if (r >= 34) |
156 | rc |= FIPSTEST_LONGRUNS; |
157 | if (r > 6) |
158 | r = 6; |
159 | f[bb][r - 1]++; |
160 | } |
161 | r = 1; |
162 | bb = b; |
163 | } |
164 | } |
165 | } |
166 | |
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167 | if (r >= 26) |
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168 | rc |= FIPSTEST_LONGRUNS; |
169 | if (r > 6) |
170 | r = 6; |
171 | f[bb][r - 1]++; |
172 | |
173 | /* --- Check the results --- */ |
174 | |
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175 | if (2343 > f[0][0] || f[0][0] > 2657 || 2343 > f[1][0] || f[1][0] > 2657 || |
176 | 1135 > f[0][1] || f[0][1] > 1365 || 1135 > f[1][1] || f[1][1] > 1365 || |
177 | 542 > f[0][2] || f[0][2] > 708 || 542 > f[1][2] || f[1][2] > 708 || |
178 | 251 > f[0][3] || f[0][3] > 373 || 251 > f[1][3] || f[1][3] > 373 || |
179 | 111 > f[0][4] || f[0][4] > 201 || 111 > f[1][4] || f[1][4] > 201 || |
180 | 111 > f[0][5] || f[0][5] > 201 || 111 > f[1][5] || f[1][5] > 201) |
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181 | rc |= FIPSTEST_RUNS; |
182 | |
183 | return (rc); |
184 | } |
185 | |
186 | /* --- @fipstest@ --- * |
187 | * |
188 | * Arguments: @const octet *p@ = pointer to a buffer of @FIPSTEST_BUFSZ@ |
189 | * bytes |
190 | * |
191 | * Returns: Zero if OK, or a bitmask of failed tests. |
192 | * |
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193 | * Use: Performs the FIPS140 randomness tests on a block of data. |
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194 | */ |
195 | |
196 | unsigned fipstest(const octet *p) |
197 | { |
198 | unsigned rc = 0; |
199 | rc |= monobit(p); |
200 | rc |= poker(p); |
201 | rc |= runs(p); |
202 | return (rc); |
203 | } |
204 | |
205 | /*----- That's all, folks -------------------------------------------------*/ |