Contents of /tags/mkinitrd-6_1_3/busybox/libbb/sha1.c
Parent Directory | Revision Log
Revision 846 -
(show annotations)
(download)
Mon May 4 18:51:23 2009 UTC (15 years, 4 months ago) by niro
File MIME type: text/plain
File size: 5199 byte(s)
Mon May 4 18:51:23 2009 UTC (15 years, 4 months ago) by niro
File MIME type: text/plain
File size: 5199 byte(s)
tagged 'mkinitrd-6_1_3'
1 | /* 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 | void FAST_FUNC sha1_begin(sha1_ctx_t *ctx) |
87 | { |
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 | void FAST_FUNC sha1_hash(const void *data, size_t length, sha1_ctx_t *ctx) |
99 | { |
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 | void* FAST_FUNC sha1_end(void *resbuf, sha1_ctx_t *ctx) |
120 | { |
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 | } |