Annotation of /tags/mkinitrd-6_1_12/busybox/libbb/sha1.c
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Tue Nov 17 21:24:51 2009 UTC (14 years, 10 months ago) by niro
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Tue Nov 17 21:24:51 2009 UTC (14 years, 10 months ago) by niro
File MIME type: text/plain
File size: 5199 byte(s)
tagged 'mkinitrd-6_1_12'
1 | niro | 532 | /* vi: set sw=4 ts=4: */ |
2 | /* | ||
3 | * Based on shasum from http://www.netsw.org/crypto/hash/ | ||
4 | * Majorly hacked up to use Dr Brian Gladman's sha1 code | ||
5 | * | ||
6 | * Copyright (C) 2002 Dr Brian Gladman <brg@gladman.me.uk>, Worcester, UK. | ||
7 | * Copyright (C) 2003 Glenn L. McGrath | ||
8 | * Copyright (C) 2003 Erik Andersen | ||
9 | * | ||
10 | * Licensed under GPLv2 or later, see file LICENSE in this tarball for details. | ||
11 | * | ||
12 | * --------------------------------------------------------------------------- | ||
13 | * Issue Date: 10/11/2002 | ||
14 | * | ||
15 | * This is a byte oriented version of SHA1 that operates on arrays of bytes | ||
16 | * stored in memory. It runs at 22 cycles per byte on a Pentium P4 processor | ||
17 | */ | ||
18 | |||
19 | #include "libbb.h" | ||
20 | |||
21 | #define SHA1_BLOCK_SIZE 64 | ||
22 | #define SHA1_DIGEST_SIZE 20 | ||
23 | #define SHA1_HASH_SIZE SHA1_DIGEST_SIZE | ||
24 | #define SHA2_GOOD 0 | ||
25 | #define SHA2_BAD 1 | ||
26 | |||
27 | #define rotl32(x,n) (((x) << n) | ((x) >> (32 - n))) | ||
28 | |||
29 | #define SHA1_MASK (SHA1_BLOCK_SIZE - 1) | ||
30 | |||
31 | /* reverse byte order in 32-bit words */ | ||
32 | #define ch(x,y,z) ((z) ^ ((x) & ((y) ^ (z)))) | ||
33 | #define parity(x,y,z) ((x) ^ (y) ^ (z)) | ||
34 | #define maj(x,y,z) (((x) & (y)) | ((z) & ((x) | (y)))) | ||
35 | |||
36 | /* A normal version as set out in the FIPS. This version uses */ | ||
37 | /* partial loop unrolling and is optimised for the Pentium 4 */ | ||
38 | #define rnd(f,k) \ | ||
39 | do { \ | ||
40 | t = a; a = rotl32(a,5) + f(b,c,d) + e + k + w[i]; \ | ||
41 | e = d; d = c; c = rotl32(b, 30); b = t; \ | ||
42 | } while (0) | ||
43 | |||
44 | static void sha1_compile(sha1_ctx_t *ctx) | ||
45 | { | ||
46 | uint32_t w[80], i, a, b, c, d, e, t; | ||
47 | |||
48 | /* note that words are compiled from the buffer into 32-bit */ | ||
49 | /* words in big-endian order so an order reversal is needed */ | ||
50 | /* here on little endian machines */ | ||
51 | for (i = 0; i < SHA1_BLOCK_SIZE / 4; ++i) | ||
52 | w[i] = htonl(ctx->wbuf[i]); | ||
53 | |||
54 | for (i = SHA1_BLOCK_SIZE / 4; i < 80; ++i) | ||
55 | w[i] = rotl32(w[i - 3] ^ w[i - 8] ^ w[i - 14] ^ w[i - 16], 1); | ||
56 | |||
57 | a = ctx->hash[0]; | ||
58 | b = ctx->hash[1]; | ||
59 | c = ctx->hash[2]; | ||
60 | d = ctx->hash[3]; | ||
61 | e = ctx->hash[4]; | ||
62 | |||
63 | for (i = 0; i < 20; ++i) { | ||
64 | rnd(ch, 0x5a827999); | ||
65 | } | ||
66 | |||
67 | for (i = 20; i < 40; ++i) { | ||
68 | rnd(parity, 0x6ed9eba1); | ||
69 | } | ||
70 | |||
71 | for (i = 40; i < 60; ++i) { | ||
72 | rnd(maj, 0x8f1bbcdc); | ||
73 | } | ||
74 | |||
75 | for (i = 60; i < 80; ++i) { | ||
76 | rnd(parity, 0xca62c1d6); | ||
77 | } | ||
78 | |||
79 | ctx->hash[0] += a; | ||
80 | ctx->hash[1] += b; | ||
81 | ctx->hash[2] += c; | ||
82 | ctx->hash[3] += d; | ||
83 | ctx->hash[4] += e; | ||
84 | } | ||
85 | |||
86 | niro | 816 | void FAST_FUNC sha1_begin(sha1_ctx_t *ctx) |
87 | niro | 532 | { |
88 | ctx->count[0] = ctx->count[1] = 0; | ||
89 | ctx->hash[0] = 0x67452301; | ||
90 | ctx->hash[1] = 0xefcdab89; | ||
91 | ctx->hash[2] = 0x98badcfe; | ||
92 | ctx->hash[3] = 0x10325476; | ||
93 | ctx->hash[4] = 0xc3d2e1f0; | ||
94 | } | ||
95 | |||
96 | /* SHA1 hash data in an array of bytes into hash buffer and call the */ | ||
97 | /* hash_compile function as required. */ | ||
98 | niro | 816 | void FAST_FUNC sha1_hash(const void *data, size_t length, sha1_ctx_t *ctx) |
99 | niro | 532 | { |
100 | uint32_t pos = (uint32_t) (ctx->count[0] & SHA1_MASK); | ||
101 | uint32_t freeb = SHA1_BLOCK_SIZE - pos; | ||
102 | const unsigned char *sp = data; | ||
103 | |||
104 | if ((ctx->count[0] += length) < length) | ||
105 | ++(ctx->count[1]); | ||
106 | |||
107 | while (length >= freeb) { /* tranfer whole blocks while possible */ | ||
108 | memcpy(((unsigned char *) ctx->wbuf) + pos, sp, freeb); | ||
109 | sp += freeb; | ||
110 | length -= freeb; | ||
111 | freeb = SHA1_BLOCK_SIZE; | ||
112 | pos = 0; | ||
113 | sha1_compile(ctx); | ||
114 | } | ||
115 | |||
116 | memcpy(((unsigned char *) ctx->wbuf) + pos, sp, length); | ||
117 | } | ||
118 | |||
119 | niro | 816 | void* FAST_FUNC sha1_end(void *resbuf, sha1_ctx_t *ctx) |
120 | niro | 532 | { |
121 | /* SHA1 Final padding and digest calculation */ | ||
122 | #if BB_BIG_ENDIAN | ||
123 | static uint32_t mask[4] = { 0x00000000, 0xff000000, 0xffff0000, 0xffffff00 }; | ||
124 | static uint32_t bits[4] = { 0x80000000, 0x00800000, 0x00008000, 0x00000080 }; | ||
125 | #else | ||
126 | static uint32_t mask[4] = { 0x00000000, 0x000000ff, 0x0000ffff, 0x00ffffff }; | ||
127 | static uint32_t bits[4] = { 0x00000080, 0x00008000, 0x00800000, 0x80000000 }; | ||
128 | #endif | ||
129 | |||
130 | uint8_t *hval = resbuf; | ||
131 | uint32_t i, cnt = (uint32_t) (ctx->count[0] & SHA1_MASK); | ||
132 | |||
133 | /* mask out the rest of any partial 32-bit word and then set */ | ||
134 | /* the next byte to 0x80. On big-endian machines any bytes in */ | ||
135 | /* the buffer will be at the top end of 32 bit words, on little */ | ||
136 | /* endian machines they will be at the bottom. Hence the AND */ | ||
137 | /* and OR masks above are reversed for little endian systems */ | ||
138 | ctx->wbuf[cnt >> 2] = | ||
139 | (ctx->wbuf[cnt >> 2] & mask[cnt & 3]) | bits[cnt & 3]; | ||
140 | |||
141 | /* we need 9 or more empty positions, one for the padding byte */ | ||
142 | /* (above) and eight for the length count. If there is not */ | ||
143 | /* enough space pad and empty the buffer */ | ||
144 | if (cnt > SHA1_BLOCK_SIZE - 9) { | ||
145 | if (cnt < 60) | ||
146 | ctx->wbuf[15] = 0; | ||
147 | sha1_compile(ctx); | ||
148 | cnt = 0; | ||
149 | } else /* compute a word index for the empty buffer positions */ | ||
150 | cnt = (cnt >> 2) + 1; | ||
151 | |||
152 | while (cnt < 14) /* and zero pad all but last two positions */ | ||
153 | ctx->wbuf[cnt++] = 0; | ||
154 | |||
155 | /* assemble the eight byte counter in the buffer in big-endian */ | ||
156 | /* format */ | ||
157 | |||
158 | ctx->wbuf[14] = htonl((ctx->count[1] << 3) | (ctx->count[0] >> 29)); | ||
159 | ctx->wbuf[15] = htonl(ctx->count[0] << 3); | ||
160 | |||
161 | sha1_compile(ctx); | ||
162 | |||
163 | /* extract the hash value as bytes in case the hash buffer is */ | ||
164 | /* misaligned for 32-bit words */ | ||
165 | |||
166 | for (i = 0; i < SHA1_DIGEST_SIZE; ++i) | ||
167 | hval[i] = (unsigned char) (ctx->hash[i >> 2] >> 8 * (~i & 3)); | ||
168 | |||
169 | return resbuf; | ||
170 | } |