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1 | /* -*-c-*- |
2 | * |
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3 | * $Id: fipstest.c,v 1.2 2000/06/17 12:21:39 mdw Exp $ |
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4 | * |
5 | * FIPS 140-1 randomness tests |
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 1.2 2000/06/17 12:21:39 mdw |
34 | * Add braces to shut compiler up. Reformat code slightly. |
35 | * |
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36 | * Revision 1.1 2000/06/17 10:55:38 mdw |
37 | * FIPS 140-1 random generator test. |
38 | * |
39 | */ |
40 | |
41 | /*----- Header files ------------------------------------------------------*/ |
42 | |
43 | #include <mLib/bits.h> |
44 | |
45 | #include "fipstest.h" |
46 | |
47 | /*----- Main code ---------------------------------------------------------*/ |
48 | |
49 | /* --- @monobit@ --- * |
50 | * |
51 | * Arguments: @const octet *p@ = pointer to buffer |
52 | * |
53 | * Returns: Zero if OK, @FIPSTEST_MONOBIT@ on failure. |
54 | * |
55 | * Use: Performs the monobit test on a buffer of data. If %$n_1$% is |
56 | * the number of 1 bits in the buffer, then the monobit test is |
57 | * passed when %$9654 < n_1 < 10346$%. |
58 | */ |
59 | |
60 | static unsigned monobit(const octet *p) |
61 | { |
62 | unsigned n1 = 0; |
63 | unsigned i, j; |
64 | |
65 | for (i = 0; i < FIPSTEST_BUFSZ; i++) { |
66 | octet x = p[i]; |
67 | for (j = 0; j < 8; j++) { |
68 | if (x & 1) |
69 | n1++; |
70 | x >>= 1; |
71 | } |
72 | } |
73 | |
74 | if (9654 >= n1 || n1 >= 10346) |
75 | return (FIPSTEST_MONOBIT); |
76 | return (0); |
77 | } |
78 | |
79 | /* --- @poker@ --- * |
80 | * |
81 | * Arguments: @const octet *p@ = pointer to buffer |
82 | * |
83 | * Returns: Zero if OK, @FIPSTEST_POKER@ on failure. |
84 | * |
85 | * Use: Performs the poker test on a buffer of data. The buffer is |
86 | * divided into 4-bit nibbles %$x_i$%. If |
87 | * %$f(x) = \sum_{x_i = x} 1$% is the frequency of each nibble, |
88 | * then the test is passed if |
89 | * %$1.03 < 16/5000 \sum_i f(i)^2 - 5000 < 57.4$%. |
90 | */ |
91 | |
92 | static unsigned poker(const octet *p) |
93 | { |
94 | unsigned long f[16] = { 0 }; |
95 | unsigned i; |
96 | unsigned long q = 0; |
97 | |
98 | /* --- Compute the frequencies --- */ |
99 | |
100 | for (i = 0; i < FIPSTEST_BUFSZ; i++) { |
101 | octet x = p[i]; |
102 | f[x & 0xf]++; |
103 | f[(x >> 4) & 0xf]++; |
104 | } |
105 | |
106 | /* --- Now do the comparison --- * |
107 | * |
108 | * This can be simplified. Multiply through the inequality by 5000 and |
109 | * we get %$5150 < 16 \sum_i f(i)^2 - 5000^2 < 287000$%. |
110 | */ |
111 | |
112 | for (i = 0; i < 16; i++) |
113 | q += f[i] * f[i]; |
114 | q <<= 4; |
115 | q -= 5000 * 5000; |
116 | |
117 | if (5150 >= q || q >= 287000) |
118 | return (FIPSTEST_POKER); |
119 | return (0); |
120 | } |
121 | |
122 | /* --- @runs@ --- * |
123 | * |
124 | * Arguments: @const octet *p@ = pointer to buffer |
125 | * |
126 | * Returns: Zero for success, @FIPSTEST_RUNS@ or @FIPSTEST_LONGRUNS@ on |
127 | * failure. |
128 | * |
129 | * Use: Performs the runs and long runs tests. The frequency of each |
130 | * `run', or sequence of equal bits, is counted and tested. |
131 | */ |
132 | |
133 | static unsigned runs(const octet *p) |
134 | { |
135 | unsigned rc = 0; |
136 | unsigned i, j; |
137 | unsigned r = 0; |
138 | unsigned bb = 0; |
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139 | unsigned f[2][6] = { { 0 } }; |
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140 | |
141 | /* --- Count the run lengths --- */ |
142 | |
143 | for (i = 0; i < FIPSTEST_BUFSZ; i++) { |
144 | octet x = p[i]; |
145 | for (j = 0; j < 8; j++) { |
146 | unsigned b = x & 1; |
147 | x >>= 1; |
148 | if (b == bb) |
149 | r++; |
150 | else { |
151 | if (r) { |
152 | if (r >= 34) |
153 | rc |= FIPSTEST_LONGRUNS; |
154 | if (r > 6) |
155 | r = 6; |
156 | f[bb][r - 1]++; |
157 | } |
158 | r = 1; |
159 | bb = b; |
160 | } |
161 | } |
162 | } |
163 | |
164 | if (r >= 34) |
165 | rc |= FIPSTEST_LONGRUNS; |
166 | if (r > 6) |
167 | r = 6; |
168 | f[bb][r - 1]++; |
169 | |
170 | /* --- Check the results --- */ |
171 | |
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172 | if (2267 > f[0][0] || f[0][0] > 2733 || 2267 > f[1][0] || f[1][0] > 2733 || |
173 | 1079 > f[0][1] || f[0][1] > 1421 || 1079 > f[1][1] || f[1][1] > 1421 || |
174 | 502 > f[0][2] || f[0][2] > 748 || 502 > f[1][2] || f[1][2] > 748 || |
175 | 223 > f[0][3] || f[0][3] > 402 || 223 > f[1][3] || f[1][3] > 402 || |
176 | 90 > f[0][4] || f[0][4] > 223 || 90 > f[1][4] || f[1][4] > 223 || |
177 | 90 > f[0][5] || f[0][5] > 223 || 90 > f[1][5] || f[1][5] > 223) |
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178 | rc |= FIPSTEST_RUNS; |
179 | |
180 | return (rc); |
181 | } |
182 | |
183 | /* --- @fipstest@ --- * |
184 | * |
185 | * Arguments: @const octet *p@ = pointer to a buffer of @FIPSTEST_BUFSZ@ |
186 | * bytes |
187 | * |
188 | * Returns: Zero if OK, or a bitmask of failed tests. |
189 | * |
190 | * Use: Performs the FIPS 140-1 randomness tests on a block of data. |
191 | */ |
192 | |
193 | unsigned fipstest(const octet *p) |
194 | { |
195 | unsigned rc = 0; |
196 | rc |= monobit(p); |
197 | rc |= poker(p); |
198 | rc |= runs(p); |
199 | return (rc); |
200 | } |
201 | |
202 | /*----- That's all, folks -------------------------------------------------*/ |