author | zautrix <zautrix> | 2004-10-19 20:16:14 (UTC) |
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committer | zautrix <zautrix> | 2004-10-19 20:16:14 (UTC) |
commit | eca49bb06a71980ef61d078904573f25890fc7f2 (patch) (unidiff) | |
tree | c5338e3b12430248979a9ac2c1c7e6646ea9ecdf /pwmanager/libcrypt/zlib/crc32.c | |
parent | 53cc32b6e7b1f672bf91b2baf2df6c1e8baf3e0a (diff) | |
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Initial revision
Diffstat (limited to 'pwmanager/libcrypt/zlib/crc32.c') (more/less context) (ignore whitespace changes)
-rw-r--r-- | pwmanager/libcrypt/zlib/crc32.c | 163 |
1 files changed, 163 insertions, 0 deletions
diff --git a/pwmanager/libcrypt/zlib/crc32.c b/pwmanager/libcrypt/zlib/crc32.c new file mode 100644 index 0000000..81edc19 --- a/dev/null +++ b/pwmanager/libcrypt/zlib/crc32.c | |||
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1 | /* crc32.c -- compute the CRC-32 of a data stream | ||
2 | * Copyright (C) 1995-2002 Mark Adler | ||
3 | * For conditions of distribution and use, see copyright notice in zlib.h | ||
4 | */ | ||
5 | |||
6 | /* @(#) $Id$ */ | ||
7 | |||
8 | #include "zlib.h" | ||
9 | |||
10 | #define local static | ||
11 | |||
12 | #ifdef DYNAMIC_CRC_TABLE | ||
13 | |||
14 | local int crc_table_empty = 1; | ||
15 | local uLongf crc_table[256]; | ||
16 | local void make_crc_table OF((void)); | ||
17 | |||
18 | /* | ||
19 | Generate a table for a byte-wise 32-bit CRC calculation on the polynomial: | ||
20 | x^32+x^26+x^23+x^22+x^16+x^12+x^11+x^10+x^8+x^7+x^5+x^4+x^2+x+1. | ||
21 | |||
22 | Polynomials over GF(2) are represented in binary, one bit per coefficient, | ||
23 | with the lowest powers in the most significant bit. Then adding polynomials | ||
24 | is just exclusive-or, and multiplying a polynomial by x is a right shift by | ||
25 | one. If we call the above polynomial p, and represent a byte as the | ||
26 | polynomial q, also with the lowest power in the most significant bit (so the | ||
27 | byte 0xb1 is the polynomial x^7+x^3+x+1), then the CRC is (q*x^32) mod p, | ||
28 | where a mod b means the remainder after dividing a by b. | ||
29 | |||
30 | This calculation is done using the shift-register method of multiplying and | ||
31 | taking the remainder. The register is initialized to zero, and for each | ||
32 | incoming bit, x^32 is added mod p to the register if the bit is a one (where | ||
33 | x^32 mod p is p+x^32 = x^26+...+1), and the register is multiplied mod p by | ||
34 | x (which is shifting right by one and adding x^32 mod p if the bit shifted | ||
35 | out is a one). We start with the highest power (least significant bit) of | ||
36 | q and repeat for all eight bits of q. | ||
37 | |||
38 | The table is simply the CRC of all possible eight bit values. This is all | ||
39 | the information needed to generate CRC's on data a byte at a time for all | ||
40 | combinations of CRC register values and incoming bytes. | ||
41 | */ | ||
42 | local void make_crc_table() | ||
43 | { | ||
44 | uLong c; | ||
45 | int n, k; | ||
46 | uLong poly; /* polynomial exclusive-or pattern */ | ||
47 | /* terms of polynomial defining this crc (except x^32): */ | ||
48 | static const Byte p[] = {0,1,2,4,5,7,8,10,11,12,16,22,23,26}; | ||
49 | |||
50 | /* make exclusive-or pattern from polynomial (0xedb88320L) */ | ||
51 | poly = 0L; | ||
52 | for (n = 0; n < sizeof(p)/sizeof(Byte); n++) | ||
53 | poly |= 1L << (31 - p[n]); | ||
54 | |||
55 | for (n = 0; n < 256; n++) | ||
56 | { | ||
57 | c = (uLong)n; | ||
58 | for (k = 0; k < 8; k++) | ||
59 | c = c & 1 ? poly ^ (c >> 1) : c >> 1; | ||
60 | crc_table[n] = c; | ||
61 | } | ||
62 | crc_table_empty = 0; | ||
63 | } | ||
64 | #else | ||
65 | /* ======================================================================== | ||
66 | * Table of CRC-32's of all single-byte values (made by make_crc_table) | ||
67 | */ | ||
68 | local const uLongf crc_table[256] = { | ||
69 | 0x00000000L, 0x77073096L, 0xee0e612cL, 0x990951baL, 0x076dc419L, | ||
70 | 0x706af48fL, 0xe963a535L, 0x9e6495a3L, 0x0edb8832L, 0x79dcb8a4L, | ||
71 | 0xe0d5e91eL, 0x97d2d988L, 0x09b64c2bL, 0x7eb17cbdL, 0xe7b82d07L, | ||
72 | 0x90bf1d91L, 0x1db71064L, 0x6ab020f2L, 0xf3b97148L, 0x84be41deL, | ||
73 | 0x1adad47dL, 0x6ddde4ebL, 0xf4d4b551L, 0x83d385c7L, 0x136c9856L, | ||
74 | 0x646ba8c0L, 0xfd62f97aL, 0x8a65c9ecL, 0x14015c4fL, 0x63066cd9L, | ||
75 | 0xfa0f3d63L, 0x8d080df5L, 0x3b6e20c8L, 0x4c69105eL, 0xd56041e4L, | ||
76 | 0xa2677172L, 0x3c03e4d1L, 0x4b04d447L, 0xd20d85fdL, 0xa50ab56bL, | ||
77 | 0x35b5a8faL, 0x42b2986cL, 0xdbbbc9d6L, 0xacbcf940L, 0x32d86ce3L, | ||
78 | 0x45df5c75L, 0xdcd60dcfL, 0xabd13d59L, 0x26d930acL, 0x51de003aL, | ||
79 | 0xc8d75180L, 0xbfd06116L, 0x21b4f4b5L, 0x56b3c423L, 0xcfba9599L, | ||
80 | 0xb8bda50fL, 0x2802b89eL, 0x5f058808L, 0xc60cd9b2L, 0xb10be924L, | ||
81 | 0x2f6f7c87L, 0x58684c11L, 0xc1611dabL, 0xb6662d3dL, 0x76dc4190L, | ||
82 | 0x01db7106L, 0x98d220bcL, 0xefd5102aL, 0x71b18589L, 0x06b6b51fL, | ||
83 | 0x9fbfe4a5L, 0xe8b8d433L, 0x7807c9a2L, 0x0f00f934L, 0x9609a88eL, | ||
84 | 0xe10e9818L, 0x7f6a0dbbL, 0x086d3d2dL, 0x91646c97L, 0xe6635c01L, | ||
85 | 0x6b6b51f4L, 0x1c6c6162L, 0x856530d8L, 0xf262004eL, 0x6c0695edL, | ||
86 | 0x1b01a57bL, 0x8208f4c1L, 0xf50fc457L, 0x65b0d9c6L, 0x12b7e950L, | ||
87 | 0x8bbeb8eaL, 0xfcb9887cL, 0x62dd1ddfL, 0x15da2d49L, 0x8cd37cf3L, | ||
88 | 0xfbd44c65L, 0x4db26158L, 0x3ab551ceL, 0xa3bc0074L, 0xd4bb30e2L, | ||
89 | 0x4adfa541L, 0x3dd895d7L, 0xa4d1c46dL, 0xd3d6f4fbL, 0x4369e96aL, | ||
90 | 0x346ed9fcL, 0xad678846L, 0xda60b8d0L, 0x44042d73L, 0x33031de5L, | ||
91 | 0xaa0a4c5fL, 0xdd0d7cc9L, 0x5005713cL, 0x270241aaL, 0xbe0b1010L, | ||
92 | 0xc90c2086L, 0x5768b525L, 0x206f85b3L, 0xb966d409L, 0xce61e49fL, | ||
93 | 0x5edef90eL, 0x29d9c998L, 0xb0d09822L, 0xc7d7a8b4L, 0x59b33d17L, | ||
94 | 0x2eb40d81L, 0xb7bd5c3bL, 0xc0ba6cadL, 0xedb88320L, 0x9abfb3b6L, | ||
95 | 0x03b6e20cL, 0x74b1d29aL, 0xead54739L, 0x9dd277afL, 0x04db2615L, | ||
96 | 0x73dc1683L, 0xe3630b12L, 0x94643b84L, 0x0d6d6a3eL, 0x7a6a5aa8L, | ||
97 | 0xe40ecf0bL, 0x9309ff9dL, 0x0a00ae27L, 0x7d079eb1L, 0xf00f9344L, | ||
98 | 0x8708a3d2L, 0x1e01f268L, 0x6906c2feL, 0xf762575dL, 0x806567cbL, | ||
99 | 0x196c3671L, 0x6e6b06e7L, 0xfed41b76L, 0x89d32be0L, 0x10da7a5aL, | ||
100 | 0x67dd4accL, 0xf9b9df6fL, 0x8ebeeff9L, 0x17b7be43L, 0x60b08ed5L, | ||
101 | 0xd6d6a3e8L, 0xa1d1937eL, 0x38d8c2c4L, 0x4fdff252L, 0xd1bb67f1L, | ||
102 | 0xa6bc5767L, 0x3fb506ddL, 0x48b2364bL, 0xd80d2bdaL, 0xaf0a1b4cL, | ||
103 | 0x36034af6L, 0x41047a60L, 0xdf60efc3L, 0xa867df55L, 0x316e8eefL, | ||
104 | 0x4669be79L, 0xcb61b38cL, 0xbc66831aL, 0x256fd2a0L, 0x5268e236L, | ||
105 | 0xcc0c7795L, 0xbb0b4703L, 0x220216b9L, 0x5505262fL, 0xc5ba3bbeL, | ||
106 | 0xb2bd0b28L, 0x2bb45a92L, 0x5cb36a04L, 0xc2d7ffa7L, 0xb5d0cf31L, | ||
107 | 0x2cd99e8bL, 0x5bdeae1dL, 0x9b64c2b0L, 0xec63f226L, 0x756aa39cL, | ||
108 | 0x026d930aL, 0x9c0906a9L, 0xeb0e363fL, 0x72076785L, 0x05005713L, | ||
109 | 0x95bf4a82L, 0xe2b87a14L, 0x7bb12baeL, 0x0cb61b38L, 0x92d28e9bL, | ||
110 | 0xe5d5be0dL, 0x7cdcefb7L, 0x0bdbdf21L, 0x86d3d2d4L, 0xf1d4e242L, | ||
111 | 0x68ddb3f8L, 0x1fda836eL, 0x81be16cdL, 0xf6b9265bL, 0x6fb077e1L, | ||
112 | 0x18b74777L, 0x88085ae6L, 0xff0f6a70L, 0x66063bcaL, 0x11010b5cL, | ||
113 | 0x8f659effL, 0xf862ae69L, 0x616bffd3L, 0x166ccf45L, 0xa00ae278L, | ||
114 | 0xd70dd2eeL, 0x4e048354L, 0x3903b3c2L, 0xa7672661L, 0xd06016f7L, | ||
115 | 0x4969474dL, 0x3e6e77dbL, 0xaed16a4aL, 0xd9d65adcL, 0x40df0b66L, | ||
116 | 0x37d83bf0L, 0xa9bcae53L, 0xdebb9ec5L, 0x47b2cf7fL, 0x30b5ffe9L, | ||
117 | 0xbdbdf21cL, 0xcabac28aL, 0x53b39330L, 0x24b4a3a6L, 0xbad03605L, | ||
118 | 0xcdd70693L, 0x54de5729L, 0x23d967bfL, 0xb3667a2eL, 0xc4614ab8L, | ||
119 | 0x5d681b02L, 0x2a6f2b94L, 0xb40bbe37L, 0xc30c8ea1L, 0x5a05df1bL, | ||
120 | 0x2d02ef8dL | ||
121 | }; | ||
122 | #endif | ||
123 | |||
124 | /* ========================================================================= | ||
125 | * This function can be used by asm versions of crc32() | ||
126 | */ | ||
127 | const uLongf * ZEXPORT get_crc_table() | ||
128 | { | ||
129 | #ifdef DYNAMIC_CRC_TABLE | ||
130 | if (crc_table_empty) make_crc_table(); | ||
131 | #endif | ||
132 | return (const uLongf *)crc_table; | ||
133 | } | ||
134 | |||
135 | /* ========================================================================= */ | ||
136 | #define DO1(buf) crc = crc_table[((int)crc ^ (*buf++)) & 0xff] ^ (crc >> 8); | ||
137 | #define DO2(buf) DO1(buf); DO1(buf); | ||
138 | #define DO4(buf) DO2(buf); DO2(buf); | ||
139 | #define DO8(buf) DO4(buf); DO4(buf); | ||
140 | |||
141 | /* ========================================================================= */ | ||
142 | uLong ZEXPORT crc32(crc, buf, len) | ||
143 | uLong crc; | ||
144 | const Bytef *buf; | ||
145 | uInt len; | ||
146 | { | ||
147 | if (buf == Z_NULL) return 0L; | ||
148 | #ifdef DYNAMIC_CRC_TABLE | ||
149 | if (crc_table_empty) | ||
150 | make_crc_table(); | ||
151 | #endif | ||
152 | crc = crc ^ 0xffffffffL; | ||
153 | while (len >= 8) | ||
154 | { | ||
155 | DO8(buf); | ||
156 | len -= 8; | ||
157 | } | ||
158 | if (len) do { | ||
159 | DO1(buf); | ||
160 | } while (--len); | ||
161 | return crc ^ 0xffffffffL; | ||
162 | } | ||
163 | |||