Annotation of sys/crypto/sha1.c, Revision 1.1.1.1
1.1 nbrk 1: /* $OpenBSD: sha1.c,v 1.7 2007/07/20 19:54:01 otto Exp $ */
2:
3: /*
4: * SHA-1 in C
5: * By Steve Reid <steve@edmweb.com>
6: * 100% Public Domain
7: *
8: * Test Vectors (from FIPS PUB 180-1)
9: * "abc"
10: * A9993E36 4706816A BA3E2571 7850C26C 9CD0D89D
11: * "abcdbcdecdefdefgefghfghighijhijkijkljklmklmnlmnomnopnopq"
12: * 84983E44 1C3BD26E BAAE4AA1 F95129E5 E54670F1
13: * A million repetitions of "a"
14: * 34AA973C D4C4DAA4 F61EEB2B DBAD2731 6534016F
15: */
16:
17: /* #define LITTLE_ENDIAN * This should be #define'd already, if true. */
18: /* #define SHA1HANDSOFF * Copies data before messing with it. */
19:
20: #define SHA1HANDSOFF
21:
22: #include <sys/param.h>
23: #include <sys/systm.h>
24:
25: #include <crypto/sha1.h>
26:
27: #define rol(value, bits) (((value) << (bits)) | ((value) >> (32 - (bits))))
28:
29: /* blk0() and blk() perform the initial expand. */
30: /* I got the idea of expanding during the round function from SSLeay */
31: #if BYTE_ORDER == LITTLE_ENDIAN
32: #define blk0(i) (block->l[i] = (rol(block->l[i],24)&0xFF00FF00) \
33: |(rol(block->l[i],8)&0x00FF00FF))
34: #else
35: #define blk0(i) block->l[i]
36: #endif
37: #define blk(i) (block->l[i&15] = rol(block->l[(i+13)&15]^block->l[(i+8)&15] \
38: ^block->l[(i+2)&15]^block->l[i&15],1))
39:
40: /* (R0+R1), R2, R3, R4 are the different operations used in SHA1 */
41: #define R0(v,w,x,y,z,i) z+=((w&(x^y))^y)+blk0(i)+0x5A827999+rol(v,5);w=rol(w,30);
42: #define R1(v,w,x,y,z,i) z+=((w&(x^y))^y)+blk(i)+0x5A827999+rol(v,5);w=rol(w,30);
43: #define R2(v,w,x,y,z,i) z+=(w^x^y)+blk(i)+0x6ED9EBA1+rol(v,5);w=rol(w,30);
44: #define R3(v,w,x,y,z,i) z+=(((w|x)&y)|(w&x))+blk(i)+0x8F1BBCDC+rol(v,5);w=rol(w,30);
45: #define R4(v,w,x,y,z,i) z+=(w^x^y)+blk(i)+0xCA62C1D6+rol(v,5);w=rol(w,30);
46:
47: /* Hash a single 512-bit block. This is the core of the algorithm. */
48:
49: void
50: SHA1Transform(u_int32_t state[5], unsigned char buffer[SHA1_BLOCK_LENGTH])
51: {
52: u_int32_t a, b, c, d, e;
53: typedef union {
54: unsigned char c[64];
55: unsigned int l[16];
56: } CHAR64LONG16;
57: CHAR64LONG16* block;
58: #ifdef SHA1HANDSOFF
59: unsigned char workspace[SHA1_BLOCK_LENGTH];
60:
61: block = (CHAR64LONG16 *)workspace;
62: bcopy(buffer, block, SHA1_BLOCK_LENGTH);
63: #else
64: block = (CHAR64LONG16 *)buffer;
65: #endif
66: /* Copy context->state[] to working vars */
67: a = state[0];
68: b = state[1];
69: c = state[2];
70: d = state[3];
71: e = state[4];
72:
73: /* 4 rounds of 20 operations each. Loop unrolled. */
74: R0(a,b,c,d,e, 0); R0(e,a,b,c,d, 1); R0(d,e,a,b,c, 2); R0(c,d,e,a,b, 3);
75: R0(b,c,d,e,a, 4); R0(a,b,c,d,e, 5); R0(e,a,b,c,d, 6); R0(d,e,a,b,c, 7);
76: R0(c,d,e,a,b, 8); R0(b,c,d,e,a, 9); R0(a,b,c,d,e,10); R0(e,a,b,c,d,11);
77: R0(d,e,a,b,c,12); R0(c,d,e,a,b,13); R0(b,c,d,e,a,14); R0(a,b,c,d,e,15);
78: R1(e,a,b,c,d,16); R1(d,e,a,b,c,17); R1(c,d,e,a,b,18); R1(b,c,d,e,a,19);
79: R2(a,b,c,d,e,20); R2(e,a,b,c,d,21); R2(d,e,a,b,c,22); R2(c,d,e,a,b,23);
80: R2(b,c,d,e,a,24); R2(a,b,c,d,e,25); R2(e,a,b,c,d,26); R2(d,e,a,b,c,27);
81: R2(c,d,e,a,b,28); R2(b,c,d,e,a,29); R2(a,b,c,d,e,30); R2(e,a,b,c,d,31);
82: R2(d,e,a,b,c,32); R2(c,d,e,a,b,33); R2(b,c,d,e,a,34); R2(a,b,c,d,e,35);
83: R2(e,a,b,c,d,36); R2(d,e,a,b,c,37); R2(c,d,e,a,b,38); R2(b,c,d,e,a,39);
84: R3(a,b,c,d,e,40); R3(e,a,b,c,d,41); R3(d,e,a,b,c,42); R3(c,d,e,a,b,43);
85: R3(b,c,d,e,a,44); R3(a,b,c,d,e,45); R3(e,a,b,c,d,46); R3(d,e,a,b,c,47);
86: R3(c,d,e,a,b,48); R3(b,c,d,e,a,49); R3(a,b,c,d,e,50); R3(e,a,b,c,d,51);
87: R3(d,e,a,b,c,52); R3(c,d,e,a,b,53); R3(b,c,d,e,a,54); R3(a,b,c,d,e,55);
88: R3(e,a,b,c,d,56); R3(d,e,a,b,c,57); R3(c,d,e,a,b,58); R3(b,c,d,e,a,59);
89: R4(a,b,c,d,e,60); R4(e,a,b,c,d,61); R4(d,e,a,b,c,62); R4(c,d,e,a,b,63);
90: R4(b,c,d,e,a,64); R4(a,b,c,d,e,65); R4(e,a,b,c,d,66); R4(d,e,a,b,c,67);
91: R4(c,d,e,a,b,68); R4(b,c,d,e,a,69); R4(a,b,c,d,e,70); R4(e,a,b,c,d,71);
92: R4(d,e,a,b,c,72); R4(c,d,e,a,b,73); R4(b,c,d,e,a,74); R4(a,b,c,d,e,75);
93: R4(e,a,b,c,d,76); R4(d,e,a,b,c,77); R4(c,d,e,a,b,78); R4(b,c,d,e,a,79);
94:
95: /* Add the working vars back into context.state[] */
96: state[0] += a;
97: state[1] += b;
98: state[2] += c;
99: state[3] += d;
100: state[4] += e;
101: /* Wipe variables */
102: a = b = c = d = e = 0;
103: }
104:
105:
106: /* SHA1Init - Initialize new context */
107:
108: void
109: SHA1Init(SHA1_CTX *context)
110: {
111: /* SHA1 initialization constants */
112: context->count = 0;
113: context->state[0] = 0x67452301;
114: context->state[1] = 0xEFCDAB89;
115: context->state[2] = 0x98BADCFE;
116: context->state[3] = 0x10325476;
117: context->state[4] = 0xC3D2E1F0;
118: }
119:
120:
121: /* Run your data through this. */
122:
123: void
124: SHA1Update(SHA1_CTX *context, unsigned char *data, unsigned int len)
125: {
126: unsigned int i;
127: unsigned int j;
128:
129: j = (u_int32_t)((context->count >> 3) & 63);
130: context->count += (len << 3);
131: if ((j + len) > 63) {
132: bcopy(data, &context->buffer[j], (i = 64 - j));
133: SHA1Transform(context->state, context->buffer);
134: for ( ; i + 63 < len; i += 64) {
135: SHA1Transform(context->state, &data[i]);
136: }
137: j = 0;
138: }
139: else i = 0;
140: bcopy(&data[i], &context->buffer[j], len - i);
141: }
142:
143:
144: /* Add padding and return the message digest. */
145:
146: void
147: SHA1Final(unsigned char digest[SHA1_DIGEST_LENGTH], SHA1_CTX *context)
148: {
149: unsigned int i;
150: unsigned char finalcount[8];
151:
152: for (i = 0; i < 8; i++) {
153: finalcount[i] = (unsigned char)((context->count >>
154: ((7 - (i & 7)) * 8)) & 255); /* Endian independent */
155: }
156: SHA1Update(context, (unsigned char *)"\200", 1);
157: while ((context->count & 504) != 448) {
158: SHA1Update(context, (unsigned char *)"\0", 1);
159: }
160: SHA1Update(context, finalcount, 8); /* Should cause a SHA1Transform() */
161:
162: if (digest)
163: for (i = 0; i < SHA1_DIGEST_LENGTH; i++) {
164: digest[i] = (unsigned char)((context->state[i >> 2] >>
165: ((3 - (i & 3)) * 8)) & 255);
166: }
167: #if 0 /* We want to use this for "keyfill" */
168: /* Wipe variables */
169: i = 0;
170: bzero(context->buffer, 64);
171: bzero(context->state, 20);
172: bzero(context->count, 8);
173: bzero(&finalcount, 8);
174: #ifdef SHA1HANDSOFF /* make SHA1Transform overwrite its own static vars */
175: SHA1Transform(context->state, context->buffer);
176: #endif
177: #endif
178: }
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