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1 | /* -*-c-*- |
2 | * |
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3 | * $Id: maurer.h,v 1.2 2000/08/11 21:34:59 mdw Exp $ |
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4 | * |
5 | * Maurer's universal statistical test |
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: maurer.h,v $ |
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33 | * Revision 1.2 2000/08/11 21:34:59 mdw |
34 | * New restartable interface to Maurer testing. |
35 | * |
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36 | * Revision 1.1 2000/06/17 11:29:49 mdw |
37 | * Maurer's universal statistical test. |
38 | * |
39 | */ |
40 | |
41 | #ifndef CATACOMB_MAURER_H |
42 | #define CATACOMB_MAURER_H |
43 | |
44 | #ifdef __cplusplus |
45 | extern "C" { |
46 | #endif |
47 | |
48 | /*----- Header files ------------------------------------------------------*/ |
49 | |
50 | #include <mLib/bits.h> |
51 | |
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52 | /*----- Data structures ---------------------------------------------------*/ |
53 | |
54 | typedef struct maurer_ctx { |
55 | unsigned l; /* Chunk size, in bits */ |
56 | uint32 a; /* Bitscanner accumulator */ |
57 | unsigned b; /* Number of bits in accumulator */ |
58 | unsigned long n; /* Number of chunks read so far */ |
59 | double x; /* Statistic value */ |
60 | unsigned long *t; /* Offset table */ |
61 | } maurer_ctx; |
62 | |
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63 | /*----- Functions provided ------------------------------------------------*/ |
64 | |
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65 | /* --- @maurer_init@ --- * |
66 | * |
67 | * Arguments: @maurer_ctx *m@ = pointer to a context to initialize |
68 | * @unsigned l@ = number of bits to take at a time |
69 | * |
70 | * Returns: Minimum recommended amount of data to test. |
71 | * |
72 | * Use: Initializes a Maurer testing context. Note that @l@ values |
73 | * larger than 16 are not supported, and values less than 6 can |
74 | * give bizarre results. |
75 | */ |
76 | |
77 | extern unsigned long maurer_init(maurer_ctx */*m*/, unsigned /*l*/); |
78 | |
79 | /* --- @maurer_test@ --- * |
80 | * |
81 | * Arguments: @maurer_ctx *m@ = pointer to a Maurer testing context |
82 | * @const void *buf@ = pointer to a buffer of data |
83 | * @size_t sz@ = size of the buffer |
84 | * |
85 | * Returns: --- |
86 | * |
87 | * Use: Scans a buffer of data and updates the testing context. |
88 | */ |
89 | |
90 | extern void maurer_test(maurer_ctx */*m*/, |
91 | const void */*buf*/, size_t /*sz*/); |
92 | |
93 | /* --- @maurer_done@ --- * |
94 | * |
95 | * Arguments: @maurer_ctx *m@ = pointer to a Maurer testing context |
96 | * |
97 | * Returns: The statistic %$Z_u = (X_u - \mu)/\sigma$%, which should be |
98 | * normally distributed with a mean of 0 and variance of 1. |
99 | * |
100 | * Use: Returns the result of Maurer's universal statistical test. |
101 | * Also frees the memory allocated during initialization. |
102 | * |
103 | * If insufficient data was received, the value @HUGE_VAL@ is |
104 | * returned. |
105 | */ |
106 | |
107 | extern double maurer_done(maurer_ctx */*m*/); |
108 | |
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109 | /* --- @maurer@ --- * |
110 | * |
111 | * Arguments: @const octet *p@ = pointer to a buffer of data |
112 | * @size_t sz@ = size of the buffer |
113 | * @unsigned l@ = number of bits to take at a time |
114 | * |
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115 | * Returns: The statistic %$Z_u$%. |
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116 | * |
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117 | * Use: Simple interface to Maurer's universal statistical test. For |
118 | * large %$l$% you should use the more complicated restartable |
119 | * interface. |
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120 | */ |
121 | |
122 | extern double maurer(const octet */*p*/, size_t /*sz*/, unsigned /*l*/); |
123 | |
124 | /*----- That's all, folks -------------------------------------------------*/ |
125 | |
126 | #ifdef __cplusplus |
127 | } |
128 | #endif |
129 | |
130 | #endif |