aboutsummaryrefslogtreecommitdiffstats
path: root/libhashsum_init_md2_hasher.c
blob: e3e929e71b24cba8b496d2c75077bf5a8e926e76 (plain) (blame)
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
/* See LICENSE file for copyright and license details. */
#include "common.h"


static const unsigned char S[] = {
	0x29, 0x2e, 0x43, 0xc9, 0xa2, 0xd8, 0x7c, 0x01, 0x3d, 0x36, 0x54, 0xa1, 0xec, 0xf0, 0x06, 0x13,
	0x62, 0xa7, 0x05, 0xf3, 0xc0, 0xc7, 0x73, 0x8c, 0x98, 0x93, 0x2b, 0xd9, 0xbc, 0x4c, 0x82, 0xca,
	0x1e, 0x9b, 0x57, 0x3c, 0xfd, 0xd4, 0xe0, 0x16, 0x67, 0x42, 0x6f, 0x18, 0x8a, 0x17, 0xe5, 0x12,
	0xbe, 0x4e, 0xc4, 0xd6, 0xda, 0x9e, 0xde, 0x49, 0xa0, 0xfb, 0xf5, 0x8e, 0xbb, 0x2f, 0xee, 0x7a,
	0xa9, 0x68, 0x79, 0x91, 0x15, 0xb2, 0x07, 0x3f, 0x94, 0xc2, 0x10, 0x89, 0x0b, 0x22, 0x5f, 0x21,
	0x80, 0x7f, 0x5d, 0x9a, 0x5a, 0x90, 0x32, 0x27, 0x35, 0x3e, 0xcc, 0xe7, 0xbf, 0xf7, 0x97, 0x03,
	0xff, 0x19, 0x30, 0xb3, 0x48, 0xa5, 0xb5, 0xd1, 0xd7, 0x5e, 0x92, 0x2a, 0xac, 0x56, 0xaa, 0xc6,
	0x4f, 0xb8, 0x38, 0xd2, 0x96, 0xa4, 0x7d, 0xb6, 0x76, 0xfc, 0x6b, 0xe2, 0x9c, 0x74, 0x04, 0xf1,
	0x45, 0x9d, 0x70, 0x59, 0x64, 0x71, 0x87, 0x20, 0x86, 0x5b, 0xcf, 0x65, 0xe6, 0x2d, 0xa8, 0x02,
	0x1b, 0x60, 0x25, 0xad, 0xae, 0xb0, 0xb9, 0xf6, 0x1c, 0x46, 0x61, 0x69, 0x34, 0x40, 0x7e, 0x0f,
	0x55, 0x47, 0xa3, 0x23, 0xdd, 0x51, 0xaf, 0x3a, 0xc3, 0x5c, 0xf9, 0xce, 0xba, 0xc5, 0xea, 0x26,
	0x2c, 0x53, 0x0d, 0x6e, 0x85, 0x28, 0x84, 0x09, 0xd3, 0xdf, 0xcd, 0xf4, 0x41, 0x81, 0x4d, 0x52,
	0x6a, 0xdc, 0x37, 0xc8, 0x6c, 0xc1, 0xab, 0xfa, 0x24, 0xe1, 0x7b, 0x08, 0x0c, 0xbd, 0xb1, 0x4a,
	0x78, 0x88, 0x95, 0x8b, 0xe3, 0x63, 0xe8, 0x6d, 0xe9, 0xcb, 0xd5, 0xfe, 0x3b, 0x00, 0x1d, 0x39,
	0xf2, 0xef, 0xb7, 0x0e, 0x66, 0x58, 0xd0, 0xe4, 0xa6, 0x77, 0x72, 0xf8, 0xeb, 0x75, 0x4b, 0x0a,
	0x31, 0x44, 0x50, 0xb4, 0x8f, 0xed, 0x1f, 0x1a, 0xdb, 0x99, 0x8d, 0x33, 0x9f, 0x11, 0x83, 0x14};


static void
process_block(const unsigned char *m, unsigned char *c, unsigned char *x)
{
	unsigned i, j, t;

	for (i = 0; i < 16U; i++) {
		x[i] = m[i];
		x[i + 16U] = m[i] ^ c[i];
	}

	t = 0;
	for (i = 0; i < 18U; i++) {
		for (j = 0; j < 16U; j++)
			t = c[j] ^= S[t];
		for (j = 0; j < 32U; j++)
			t = x[j] ^= S[t];
		t = (t + i) & 0xFFU;
	}
}


LIBHASHSUM_1_NONNULL_
static size_t
process(struct libhashsum_hasher *this, const void *data, size_t bytes)
{
	const unsigned char *m = data;
	size_t off = 0;
	unsigned i, t;

	t = this->state.md2.t;
	for (; bytes - off >= 16U; off += 16U) {
		process_block(&m[off], this->state.md2.sum, this->state.md2.x);
		for (i = 0; i < 16U; i++)
			t = this->state.md2.mz[i] ^= S[m[off + i] ^ t];
	}
	this->state.md2.t = t;

	return off;
}


LIBHASHSUM_1_NONNULL_
static int
finalise_common(struct libhashsum_hasher *this, unsigned char *m, size_t bytes, unsigned extra_bits)
{
	unsigned i, t;

	if (extra_bits) {
		errno = EINVAL;
		return -1;
	}

	memset(&m[bytes], 16 - (int)bytes, 16U - bytes);

	t = this->state.md2.t;
	process_block(m, this->state.md2.sum, this->state.md2.x);
	for (i = 0; i < 16U; i++)
		t = this->state.md2.mz[i] ^= S[m[i] ^ t];
	this->state.md2.t = t;

	process_block(this->state.md2.mz, this->state.md2.sum, this->state.md2.x);

	memset(this->state.md2.x, 0, sizeof(this->state.md2.x));
	memset(this->state.md2.mp, 0, sizeof(this->state.md2.mp));
	memset(this->state.md2.mz, 0, sizeof(this->state.md2.mz));
	this->state.md2.t = 0;

	this->hash_output = this->state.md2.sum;
	return 0;
}


LIBHASHSUM_1_NONNULL_
static int
finalise_const(struct libhashsum_hasher *this, const void *data, size_t bytes, unsigned extra_bits)
{
	const unsigned char *m = data;
	size_t r;

	r = process(this, m, bytes);
	m = &m[r];
	bytes -= r;

	memcpy(this->state.md2.mp, m, bytes + (size_t)(extra_bits > 0U));
	return finalise_common(this, this->state.md2.mp, bytes, extra_bits);
}


LIBHASHSUM_1_NONNULL_
static int
finalise(struct libhashsum_hasher *this, void *data, size_t bytes, unsigned extra_bits, size_t size)
{
	unsigned char *m = data;
	size_t r;

	r = process(this, m, bytes);
	m = &m[r];
	bytes -= r;
	size -= r;

	if (size < 16U) {
		memcpy(this->state.md2.mp, m, bytes + (size_t)(extra_bits > 0U));
		m = this->state.md2.mp;
	}
	return finalise_common(this, m, bytes, extra_bits);
}


int
libhashsum_init_md2_hasher(struct libhashsum_hasher *this)
{
	this->algorithm = LIBHASHSUM_MD2;
	this->input_block_size = 16U;
	this->hash_size = sizeof(this->state.md2.sum);
	this->hash_output = NULL;
	this->supports_non_whole_bytes = 0;
	this->process = &process;
	this->finalise_const = &finalise_const;
	this->finalise = &finalise;
	memset(&this->state.md2, 0, sizeof(this->state.md2));
	return 0;
}