File: sha.c

package info (click to toggle)
xdelta 1.1.3-9.1
  • links: PTS, VCS
  • area: main
  • in suites: jessie, jessie-kfreebsd, stretch
  • size: 2,256 kB
  • ctags: 1,552
  • sloc: sh: 11,470; ansic: 10,490; lisp: 1,525; makefile: 123
file content (239 lines) | stat: -rw-r--r-- 7,273 bytes parent folder | download | duplicates (10)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
/* NIST Secure Hash Algorithm */
/* heavily modified by Uwe Hollerbach <uh@alumni.caltech edu> */
/* from Peter C. Gutmann's implementation as found in */
/* Applied Cryptography by Bruce Schneier */
/* Further modifications to include the "UNRAVEL" stuff, below */

/* This code is in the public domain */

#include "edsio.h"
#include <string.h>

#define SHA_BLOCKSIZE           64
#define SHA_DIGESTSIZE          20

/* UNRAVEL should be fastest & biggest */
/* UNROLL_LOOPS should be just as big, but slightly slower */
/* both undefined should be smallest and slowest */

#define UNRAVEL
/* #define UNROLL_LOOPS */

/* by default, compile for little-endian machines (Intel, Vax) */
/* change for big-endian machines; for machines which are neither, */
/* you will need to change the definition of maybe_byte_reverse */

#ifndef WORDS_BIGENDIAN /* from config.h */
#define SHA_LITTLE_ENDIAN
#endif

/* NIST's proposed modification to SHA of 7/11/94 may be */
/* activated by defining USE_MODIFIED_SHA; leave it off for now */
#undef USE_MODIFIED_SHA

/* SHA f()-functions */

#define f1(x,y,z)       ((x & y) | (~x & z))
#define f2(x,y,z)       (x ^ y ^ z)
#define f3(x,y,z)       ((x & y) | (x & z) | (y & z))
#define f4(x,y,z)       (x ^ y ^ z)

/* SHA constants */

#define CONST1          0x5a827999L
#define CONST2          0x6ed9eba1L
#define CONST3          0x8f1bbcdcL
#define CONST4          0xca62c1d6L

/* 32-bit rotate */

#define ROT32(x,n)      ((x << n) | (x >> (32 - n)))

/* the generic case, for when the overall rotation is not unraveled */

#define FG(n)   \
    T = ROT32(A,5) + f##n(B,C,D) + E + *WP++ + CONST##n;        \
    E = D; D = C; C = ROT32(B,30); B = A; A = T

/* specific cases, for when the overall rotation is unraveled */

#define FA(n)   \
    T = ROT32(A,5) + f##n(B,C,D) + E + *WP++ + CONST##n; B = ROT32(B,30)

#define FB(n)   \
    E = ROT32(T,5) + f##n(A,B,C) + D + *WP++ + CONST##n; A = ROT32(A,30)

#define FC(n)   \
    D = ROT32(E,5) + f##n(T,A,B) + C + *WP++ + CONST##n; T = ROT32(T,30)

#define FD(n)   \
    C = ROT32(D,5) + f##n(E,T,A) + B + *WP++ + CONST##n; E = ROT32(E,30)

#define FE(n)   \
    B = ROT32(C,5) + f##n(D,E,T) + A + *WP++ + CONST##n; D = ROT32(D,30)

#define FT(n)   \
    A = ROT32(B,5) + f##n(C,D,E) + T + *WP++ + CONST##n; C = ROT32(C,30)

/* do SHA transformation */

static void sha_transform(EdsioSHACtx *ctx)
{
    int i;
    guint32 T, A, B, C, D, E, W[80], *WP;

    for (i = 0; i < 16; ++i) {
        W[i] = ctx->data[i];
    }
    for (i = 16; i < 80; ++i) {
        W[i] = W[i-3] ^ W[i-8] ^ W[i-14] ^ W[i-16];
#ifdef USE_MODIFIED_SHA
        W[i] = ROT32(W[i], 1);
#endif /* USE_MODIFIED_SHA */
    }
    A = ctx->digest[0];
    B = ctx->digest[1];
    C = ctx->digest[2];
    D = ctx->digest[3];
    E = ctx->digest[4];
    WP = W;
#ifdef UNRAVEL
    FA(1); FB(1); FC(1); FD(1); FE(1); FT(1); FA(1); FB(1); FC(1); FD(1);
    FE(1); FT(1); FA(1); FB(1); FC(1); FD(1); FE(1); FT(1); FA(1); FB(1);
    FC(2); FD(2); FE(2); FT(2); FA(2); FB(2); FC(2); FD(2); FE(2); FT(2);
    FA(2); FB(2); FC(2); FD(2); FE(2); FT(2); FA(2); FB(2); FC(2); FD(2);
    FE(3); FT(3); FA(3); FB(3); FC(3); FD(3); FE(3); FT(3); FA(3); FB(3);
    FC(3); FD(3); FE(3); FT(3); FA(3); FB(3); FC(3); FD(3); FE(3); FT(3);
    FA(4); FB(4); FC(4); FD(4); FE(4); FT(4); FA(4); FB(4); FC(4); FD(4);
    FE(4); FT(4); FA(4); FB(4); FC(4); FD(4); FE(4); FT(4); FA(4); FB(4);
    ctx->digest[0] += E;
    ctx->digest[1] += T;
    ctx->digest[2] += A;
    ctx->digest[3] += B;
    ctx->digest[4] += C;
#else /* !UNRAVEL */
#ifdef UNROLL_LOOPS
    FG(1); FG(1); FG(1); FG(1); FG(1); FG(1); FG(1); FG(1); FG(1); FG(1);
    FG(1); FG(1); FG(1); FG(1); FG(1); FG(1); FG(1); FG(1); FG(1); FG(1);
    FG(2); FG(2); FG(2); FG(2); FG(2); FG(2); FG(2); FG(2); FG(2); FG(2);
    FG(2); FG(2); FG(2); FG(2); FG(2); FG(2); FG(2); FG(2); FG(2); FG(2);
    FG(3); FG(3); FG(3); FG(3); FG(3); FG(3); FG(3); FG(3); FG(3); FG(3);
    FG(3); FG(3); FG(3); FG(3); FG(3); FG(3); FG(3); FG(3); FG(3); FG(3);
    FG(4); FG(4); FG(4); FG(4); FG(4); FG(4); FG(4); FG(4); FG(4); FG(4);
    FG(4); FG(4); FG(4); FG(4); FG(4); FG(4); FG(4); FG(4); FG(4); FG(4);
#else /* !UNROLL_LOOPS */
    for (i =  0; i < 20; ++i) { FG(1); }
    for (i = 20; i < 40; ++i) { FG(2); }
    for (i = 40; i < 60; ++i) { FG(3); }
    for (i = 60; i < 80; ++i) { FG(4); }
#endif /* !UNROLL_LOOPS */
    ctx->digest[0] += A;
    ctx->digest[1] += B;
    ctx->digest[2] += C;
    ctx->digest[3] += D;
    ctx->digest[4] += E;
#endif /* !UNRAVEL */
}

#ifdef SHA_LITTLE_ENDIAN

/* change endianness of data */

static void maybe_byte_reverse(guint32 *buffer, int count)
{
    int i;
    guint32 in;

    count /= sizeof(guint32);
    for (i = 0; i < count; ++i) {
        in = *buffer;
        *buffer++ = ((in << 24) & 0xff000000) | ((in <<  8) & 0x00ff0000) |
                    ((in >>  8) & 0x0000ff00) | ((in >> 24) & 0x000000ff);
    }
}

#else /* !SHA_LITTLE_ENDIAN */

#define maybe_byte_reverse(a,b) /* do nothing */

#endif /* SHA_LITTLE_ENDIAN */

/* initialize the SHA digest */

void edsio_sha_init(EdsioSHACtx *ctx)
{
    ctx->digest[0] = 0x67452301L;
    ctx->digest[1] = 0xefcdab89L;
    ctx->digest[2] = 0x98badcfeL;
    ctx->digest[3] = 0x10325476L;
    ctx->digest[4] = 0xc3d2e1f0L;
    ctx->count_lo = 0L;
    ctx->count_hi = 0L;
    ctx->local = 0;
}

/* update the SHA digest */

void edsio_sha_update(EdsioSHACtx *ctx, const guint8 *buffer, guint count)
{
    int i;

    if ((ctx->count_lo + ((guint32) count << 3)) < ctx->count_lo) {
        ++ctx->count_hi;
    }
    ctx->count_lo += (guint32) count << 3;
    ctx->count_hi += (guint32) count >> 29;
    if (ctx->local) {
        i = SHA_BLOCKSIZE - ctx->local;
        if (i > count) {
            i = count;
        }
        memcpy(((guint8 *) ctx->data) + ctx->local, buffer, i);
        count -= i;
        buffer += i;
        ctx->local += i;
        if (ctx->local == SHA_BLOCKSIZE) {
            maybe_byte_reverse(ctx->data, SHA_BLOCKSIZE);
            sha_transform(ctx);
        } else {
            return;
        }
    }
    while (count >= SHA_BLOCKSIZE) {
        memcpy(ctx->data, buffer, SHA_BLOCKSIZE);
        buffer += SHA_BLOCKSIZE;
        count -= SHA_BLOCKSIZE;
        maybe_byte_reverse(ctx->data, SHA_BLOCKSIZE);
        sha_transform(ctx);
    }
    memcpy(ctx->data, buffer, count);
    ctx->local = count;
}

/* finish computing the SHA digest */

void edsio_sha_final(guint8* digest, EdsioSHACtx *ctx)
{
    int count;
    guint32 lo_bit_count, hi_bit_count;

    lo_bit_count = ctx->count_lo;
    hi_bit_count = ctx->count_hi;
    count = (int) ((lo_bit_count >> 3) & 0x3f);
    ((guint8 *) ctx->data)[count++] = 0x80;
    if (count > SHA_BLOCKSIZE - 8) {
        memset(((guint8 *) ctx->data) + count, 0, SHA_BLOCKSIZE - count);
        maybe_byte_reverse(ctx->data, SHA_BLOCKSIZE);
        sha_transform(ctx);
        memset((guint8 *) ctx->data, 0, SHA_BLOCKSIZE - 8);
    } else {
        memset(((guint8 *) ctx->data) + count, 0,
            SHA_BLOCKSIZE - 8 - count);
    }
    maybe_byte_reverse(ctx->data, SHA_BLOCKSIZE);
    ctx->data[14] = hi_bit_count;
    ctx->data[15] = lo_bit_count;
    sha_transform(ctx);

    memcpy (digest, ctx->digest, 20);
}