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comparison toys/other/sha1sum.c @ 676:522ec2aad996

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Simplify sha1sum a little.
author Rob Landley <rob@landley.net>
date Mon, 08 Oct 2012 21:27:58 -0500
parents 7e846e281e38
children
comparison
equal deleted inserted replaced
675:fa858a67e231 676:522ec2aad996
29 unsigned char c[64]; 29 unsigned char c[64];
30 uint32_t i[16]; 30 uint32_t i[16];
31 } buffer; 31 } buffer;
32 ) 32 )
33 33
34 #define rol(value, bits) (((value) << (bits)) | ((value) >> (32 - (bits))))
35 34
36 // blk0() and blk() perform the initial expand. 35 static const unsigned rconsts[]={0x5A827999,0x6ED9EBA1,0x8F1BBCDC,0xCA62C1D6};
37 // The idea of expanding during the round function comes from SSLeay
38 #if 1
39 #define blk0(i) (block[i] = (rol(block[i],24)&0xFF00FF00) \
40 |(rol(block[i],8)&0x00FF00FF))
41 #else // big endian?
42 #define blk0(i) block[i]
43 #endif
44 #define blk(i) (block[i&15] = rol(block[(i+13)&15]^block[(i+8)&15] \
45 ^block[(i+2)&15]^block[i&15],1))
46
47 static const uint32_t rconsts[]={0x5A827999,0x6ED9EBA1,0x8F1BBCDC,0xCA62C1D6};
48 36
49 // Hash a single 512-bit block. This is the core of the algorithm. 37 // Hash a single 512-bit block. This is the core of the algorithm.
50 38
39 #define rol(value, bits) (((value) << (bits)) | ((value) >> (32 - (bits))))
51 static void sha1_transform(void) 40 static void sha1_transform(void)
52 { 41 {
53 int i, j, k, count; 42 int i, j, k, count;
54 uint32_t *block = TT.buffer.i; 43 unsigned *block = TT.buffer.i;
55 uint32_t *rot[5], *temp; 44 unsigned *rot[5], *temp;
56 45
57 // Copy context->state[] to working vars 46 // Copy context->state[] to working vars
58 for (i=0; i<5; i++) { 47 for (i=0; i<5; i++) {
59 TT.oldstate[i] = TT.state[i]; 48 TT.oldstate[i] = TT.state[i];
60 rot[i] = TT.state + i; 49 rot[i] = TT.state + i;
61 } 50 }
62 // 4 rounds of 20 operations each. 51 // 4 rounds of 20 operations each.
63 for (i=count=0; i<4; i++) { 52 for (i=count=0; i<4; i++) {
64 for (j=0; j<20; j++) { 53 for (j=0; j<20; j++) {
65 uint32_t work; 54 unsigned work;
66 55
67 work = *rot[2] ^ *rot[3]; 56 work = *rot[2] ^ *rot[3];
68 if (!i) work = (work & *rot[1]) ^ *rot[3]; 57 if (!i) work = (work & *rot[1]) ^ *rot[3];
69 else { 58 else {
70 if (i==2) 59 if (i==2)
71 work = ((*rot[1]|*rot[2])&*rot[3])|(*rot[1]&*rot[2]); 60 work = ((*rot[1]|*rot[2])&*rot[3])|(*rot[1]&*rot[2]);
72 else work ^= *rot[1]; 61 else work ^= *rot[1];
73 } 62 }
74 if (!i && j<16) work += blk0(count); 63
75 else work += blk(count); 64 if (!i && j<16) work += block[count] = (rol(block[count],24)&0xFF00FF00) | (rol(block[count],8)&0x00FF00FF);
65 else work += block[count&15] = rol(block[(count+13)&15]^block[(count+8)&15]^block[(count+2)&15]^block[count&15],1);
76 *rot[4] += work + rol(*rot[0],5) + rconsts[i]; 66 *rot[4] += work + rol(*rot[0],5) + rconsts[i];
77 *rot[1] = rol(*rot[1],30); 67 *rot[1] = rol(*rot[1],30);
78 68
79 // Rotate by one for next time. 69 // Rotate by one for next time.
80 temp = rot[4]; 70 temp = rot[4];