aboutsummaryrefslogtreecommitdiff
path: root/src/sha1.cpp
blob: a206a7899e3f8babae3bbefb1775fdcefd1d4f0e (plain)
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
/*
 * Copyright (C) 2007-2010 Xagasoft, All rights reserved.
 *
 * This file is part of the libbu++ library and is released under the
 * terms of the license contained in the file LICENSE.
 */

#include <string.h>

#include "bu/stream.h"

#include "bu/sha1.h"

Bu::Sha1::Sha1() :
	uH0( 0x67452301 ),
	uH1( 0xefcdab89 ),
	uH2( 0x98badcfe ),
	uH3( 0x10325476 ),
	uH4( 0xc3d2e1f0 ),
	iUnprocessedBytes( 0 ),
	uTotalBytes( 0 )
{
	reset();
}

Bu::Sha1::~Sha1()
{
}

void Bu::Sha1::reset()
{
	uH0 = 0x67452301;
	uH1 = 0xefcdab89;
	uH2 = 0x98badcfe;
	uH3 = 0x10325476;
	uH4 = 0xc3d2e1f0;
	iUnprocessedBytes = 0;
	uTotalBytes = 0;
}

void Bu::Sha1::setSalt( const Bu::FString & /*sSalt*/ )
{
}

void Bu::Sha1::addData( const void *sDataRaw, int iSize )
{
	const unsigned char *sData = (const unsigned char *)sDataRaw;
	// add these bytes to the running total
	uTotalBytes += iSize;

	// repeat until all data is processed
	while( iSize > 0 )
	{
		// number of bytes required to complete block
		int iNeeded = 64 - iUnprocessedBytes;

		// number of bytes to copy (use smaller of two)
		int iToCopy = (iSize < iNeeded) ? iSize : iNeeded;

		// Copy the bytes
		memcpy( uBytes + iUnprocessedBytes, sData, iToCopy );

		// Bytes have been copied
		iSize -= iToCopy;
		sData += iToCopy;
		iUnprocessedBytes += iToCopy;
		
		// there is a full block
		if( iUnprocessedBytes == 64 )
		{
			process();
		}
	}
}

Bu::FString Bu::Sha1::getResult()
{
	// save the message size
	uint32_t totalBitsL = uTotalBytes << 3;
	uint32_t totalBitsH = uTotalBytes >> 29;

	// add 0x80 to the message
	addData( "\x80", 1 );
	
	unsigned char footer[64] = {
		0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
		0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
		0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
		0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };

	// block has no room for 8-byte filesize, so finish it
	if( iUnprocessedBytes > 56 )
		addData( (char*)footer, 64 - iUnprocessedBytes);

	// how many zeros do we need
	int iNeededZeros = 56 - iUnprocessedBytes;

	// store file size (in bits) in big-endian format
	toBigEndian( totalBitsH, footer + iNeededZeros );
	toBigEndian( totalBitsL, footer + iNeededZeros + 4 );

	// finish the final block
	addData( (char*)footer, iNeededZeros + 8 );

	Bu::FString sRet( 20 );

	unsigned char *digest = (unsigned char *)sRet.getStr();

	// copy the digest bytes
	toBigEndian( uH0, digest );
	toBigEndian( uH1, digest + 4 );
	toBigEndian( uH2, digest + 8 );
	toBigEndian( uH3, digest + 12 );
	toBigEndian( uH4, digest + 16 );

	// return the digest
	return sRet;
}

void Bu::Sha1::writeResult( Bu::Stream &sOut )
{
	sOut.write( getResult() );
}

void Bu::Sha1::process()
{
	int t;
	uint32_t a, b, c, d, e, K, f, W[80];

	// starting values
	a = uH0;
	b = uH1;
	c = uH2;
	d = uH3;
	e = uH4;

	// copy and expand the message block
	for( t = 0; t < 16; t++ ) W[t] = (uBytes[t*4] << 24)
									+(uBytes[t*4 + 1] << 16)
									+(uBytes[t*4 + 2] << 8)
									+ uBytes[t*4 + 3];
	for(; t< 80; t++ ) W[t] = lrot( W[t-3]^W[t-8]^W[t-14]^W[t-16], 1 );
	
	/* main loop */
	uint32_t temp;
	for( t = 0; t < 80; t++ )
	{
		if( t < 20 ) {
			K = 0x5a827999;
			f = (b & c) | ((~b) & d);
		} else if( t < 40 ) {
			K = 0x6ed9eba1;
			f = b ^ c ^ d;
		} else if( t < 60 ) {
			K = 0x8f1bbcdc;
			f = (b & c) | (b & d) | (c & d);
		} else {
			K = 0xca62c1d6;
			f = b ^ c ^ d;
		}
		temp = lrot(a,5) + f + e + W[t] + K;
		e = d;
		d = c;
		c = lrot(b,30);
		b = a;
		a = temp;
		//printf( "t=%d %08x %08x %08x %08x %08x\n",t,a,b,c,d,e );
	}

	/* add variables */
	uH0 += a;
	uH1 += b;
	uH2 += c;
	uH3 += d;
	uH4 += e;

	//printf( "Current: %08x %08x %08x %08x %08x\n",H0,H1,H2,H3,H4 );
	/* all bytes have been processed */
	iUnprocessedBytes = 0;
}

uint32_t Bu::Sha1::lrot( uint32_t x, int bits )
{
	return (x<<bits) | (x>>(32 - bits));
}

void Bu::Sha1::toBigEndian( uint32_t num, unsigned char* byte )
{
	byte[0] = (unsigned char)(num>>24);
	byte[1] = (unsigned char)(num>>16);
	byte[2] = (unsigned char)(num>>8);
	byte[3] = (unsigned char)num;
}