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Diffstat (limited to 'src/sha1.cpp')
-rw-r--r-- | src/sha1.cpp | 161 |
1 files changed, 161 insertions, 0 deletions
diff --git a/src/sha1.cpp b/src/sha1.cpp new file mode 100644 index 0000000..8270c3b --- /dev/null +++ b/src/sha1.cpp | |||
@@ -0,0 +1,161 @@ | |||
1 | #include <stdio.h> | ||
2 | #include <string.h> | ||
3 | #include <stdlib.h> | ||
4 | |||
5 | #include "sha1.h" | ||
6 | |||
7 | Sha1::Sha1() : | ||
8 | H0( 0x67452301 ), | ||
9 | H1( 0xefcdab89 ), | ||
10 | H2( 0x98badcfe ), | ||
11 | H3( 0x10325476 ), | ||
12 | H4( 0xc3d2e1f0 ), | ||
13 | unprocessedBytes( 0 ), | ||
14 | size( 0 ) | ||
15 | { | ||
16 | } | ||
17 | |||
18 | Sha1::~Sha1() | ||
19 | { | ||
20 | } | ||
21 | |||
22 | void Sha1::process() | ||
23 | { | ||
24 | int t; | ||
25 | uint32_t a, b, c, d, e, K, f, W[80]; | ||
26 | |||
27 | // starting values | ||
28 | a = H0; | ||
29 | b = H1; | ||
30 | c = H2; | ||
31 | d = H3; | ||
32 | e = H4; | ||
33 | |||
34 | // copy and expand the message block | ||
35 | for( t = 0; t < 16; t++ ) W[t] = (bytes[t*4] << 24) | ||
36 | +(bytes[t*4 + 1] << 16) | ||
37 | +(bytes[t*4 + 2] << 8) | ||
38 | + bytes[t*4 + 3]; | ||
39 | for(; t< 80; t++ ) W[t] = lrot( W[t-3]^W[t-8]^W[t-14]^W[t-16], 1 ); | ||
40 | |||
41 | /* main loop */ | ||
42 | uint32_t temp; | ||
43 | for( t = 0; t < 80; t++ ) | ||
44 | { | ||
45 | if( t < 20 ) { | ||
46 | K = 0x5a827999; | ||
47 | f = (b & c) | ((~b) & d); | ||
48 | } else if( t < 40 ) { | ||
49 | K = 0x6ed9eba1; | ||
50 | f = b ^ c ^ d; | ||
51 | } else if( t < 60 ) { | ||
52 | K = 0x8f1bbcdc; | ||
53 | f = (b & c) | (b & d) | (c & d); | ||
54 | } else { | ||
55 | K = 0xca62c1d6; | ||
56 | f = b ^ c ^ d; | ||
57 | } | ||
58 | temp = lrot(a,5) + f + e + W[t] + K; | ||
59 | e = d; | ||
60 | d = c; | ||
61 | c = lrot(b,30); | ||
62 | b = a; | ||
63 | a = temp; | ||
64 | //printf( "t=%d %08x %08x %08x %08x %08x\n",t,a,b,c,d,e ); | ||
65 | } | ||
66 | |||
67 | /* add variables */ | ||
68 | H0 += a; | ||
69 | H1 += b; | ||
70 | H2 += c; | ||
71 | H3 += d; | ||
72 | H4 += e; | ||
73 | |||
74 | //printf( "Current: %08x %08x %08x %08x %08x\n",H0,H1,H2,H3,H4 ); | ||
75 | /* all bytes have been processed */ | ||
76 | unprocessedBytes = 0; | ||
77 | } | ||
78 | |||
79 | void Sha1::update( const char* data, int num ) | ||
80 | { | ||
81 | // add these bytes to the running total | ||
82 | size += num; | ||
83 | |||
84 | // repeat until all data is processed | ||
85 | while( num > 0 ) | ||
86 | { | ||
87 | // number of bytes required to complete block | ||
88 | int needed = 64 - unprocessedBytes; | ||
89 | |||
90 | // number of bytes to copy (use smaller of two) | ||
91 | int toCopy = (num < needed) ? num : needed; | ||
92 | |||
93 | // Copy the bytes | ||
94 | memcpy( bytes + unprocessedBytes, data, toCopy ); | ||
95 | |||
96 | // Bytes have been copied | ||
97 | num -= toCopy; | ||
98 | data += toCopy; | ||
99 | unprocessedBytes += toCopy; | ||
100 | |||
101 | // there is a full block | ||
102 | if( unprocessedBytes == 64 ) process(); | ||
103 | } | ||
104 | } | ||
105 | |||
106 | unsigned char* Sha1::getDigest() | ||
107 | { | ||
108 | // save the message size | ||
109 | uint32_t totalBitsL = size << 3; | ||
110 | uint32_t totalBitsH = size >> 29; | ||
111 | |||
112 | // add 0x80 to the message | ||
113 | update( "\x80", 1 ); | ||
114 | |||
115 | unsigned char footer[64] = { | ||
116 | 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, | ||
117 | 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, | ||
118 | 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, | ||
119 | 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 }; | ||
120 | |||
121 | // block has no room for 8-byte filesize, so finish it | ||
122 | if( unprocessedBytes > 56 ) | ||
123 | update( (char*)footer, 64 - unprocessedBytes); | ||
124 | |||
125 | // how many zeros do we need | ||
126 | int neededZeros = 56 - unprocessedBytes; | ||
127 | |||
128 | // store file size (in bits) in big-endian format | ||
129 | toBigEndian( totalBitsH, footer + neededZeros ); | ||
130 | toBigEndian( totalBitsL, footer + neededZeros + 4 ); | ||
131 | |||
132 | // finish the final block | ||
133 | update( (char*)footer, neededZeros + 8 ); | ||
134 | |||
135 | // allocate memory for the digest bytes | ||
136 | unsigned char* digest = new unsigned char[20]; | ||
137 | |||
138 | // copy the digest bytes | ||
139 | toBigEndian( H0, digest ); | ||
140 | toBigEndian( H1, digest + 4 ); | ||
141 | toBigEndian( H2, digest + 8 ); | ||
142 | toBigEndian( H3, digest + 12 ); | ||
143 | toBigEndian( H4, digest + 16 ); | ||
144 | |||
145 | // return the digest | ||
146 | return digest; | ||
147 | } | ||
148 | |||
149 | uint32_t Sha1::lrot( uint32_t x, int bits ) | ||
150 | { | ||
151 | return (x<<bits) | (x>>(32 - bits)); | ||
152 | }; | ||
153 | |||
154 | void Sha1::toBigEndian( uint32_t num, unsigned char* byte ) | ||
155 | { | ||
156 | byte[0] = (unsigned char)(num>>24); | ||
157 | byte[1] = (unsigned char)(num>>16); | ||
158 | byte[2] = (unsigned char)(num>>8); | ||
159 | byte[3] = (unsigned char)num; | ||
160 | } | ||
161 | |||