aboutsummaryrefslogtreecommitdiffstats
path: root/src/lib/hash/keccak/keccak.cpp
blob: 39d0c822b5e3d23e7262c57e04dfa47dd12fa12f (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
195
/*
* Keccak
* (C) 2010 Jack Lloyd
*
* Botan is released under the Simplified BSD License (see license.txt)
*/

#include <botan/keccak.h>
#include <botan/parsing.h>
#include <botan/exceptn.h>

namespace Botan {

namespace {

void keccak_f_1600(u64bit A[25])
   {
   static const u64bit RC[24] = {
      0x0000000000000001, 0x0000000000008082, 0x800000000000808A,
      0x8000000080008000, 0x000000000000808B, 0x0000000080000001,
      0x8000000080008081, 0x8000000000008009, 0x000000000000008A,
      0x0000000000000088, 0x0000000080008009, 0x000000008000000A,
      0x000000008000808B, 0x800000000000008B, 0x8000000000008089,
      0x8000000000008003, 0x8000000000008002, 0x8000000000000080,
      0x000000000000800A, 0x800000008000000A, 0x8000000080008081,
      0x8000000000008080, 0x0000000080000001, 0x8000000080008008
   };

   for(size_t i = 0; i != 24; ++i)
      {
      const u64bit C0 = A[0] ^ A[5] ^ A[10] ^ A[15] ^ A[20];
      const u64bit C1 = A[1] ^ A[6] ^ A[11] ^ A[16] ^ A[21];
      const u64bit C2 = A[2] ^ A[7] ^ A[12] ^ A[17] ^ A[22];
      const u64bit C3 = A[3] ^ A[8] ^ A[13] ^ A[18] ^ A[23];
      const u64bit C4 = A[4] ^ A[9] ^ A[14] ^ A[19] ^ A[24];

      const u64bit D0 = rotate_left(C0, 1) ^ C3;
      const u64bit D1 = rotate_left(C1, 1) ^ C4;
      const u64bit D2 = rotate_left(C2, 1) ^ C0;
      const u64bit D3 = rotate_left(C3, 1) ^ C1;
      const u64bit D4 = rotate_left(C4, 1) ^ C2;

      const u64bit B00 = A[ 0] ^ D1;
      const u64bit B01 = rotate_left(A[ 6] ^ D2, 44);
      const u64bit B02 = rotate_left(A[12] ^ D3, 43);
      const u64bit B03 = rotate_left(A[18] ^ D4, 21);
      const u64bit B04 = rotate_left(A[24] ^ D0, 14);
      const u64bit B05 = rotate_left(A[ 3] ^ D4, 28);
      const u64bit B06 = rotate_left(A[ 9] ^ D0, 20);
      const u64bit B07 = rotate_left(A[10] ^ D1, 3);
      const u64bit B08 = rotate_left(A[16] ^ D2, 45);
      const u64bit B09 = rotate_left(A[22] ^ D3, 61);
      const u64bit B10 = rotate_left(A[ 1] ^ D2, 1);
      const u64bit B11 = rotate_left(A[ 7] ^ D3, 6);
      const u64bit B12 = rotate_left(A[13] ^ D4, 25);
      const u64bit B13 = rotate_left(A[19] ^ D0, 8);
      const u64bit B14 = rotate_left(A[20] ^ D1, 18);
      const u64bit B15 = rotate_left(A[ 4] ^ D0, 27);
      const u64bit B16 = rotate_left(A[ 5] ^ D1, 36);
      const u64bit B17 = rotate_left(A[11] ^ D2, 10);
      const u64bit B18 = rotate_left(A[17] ^ D3, 15);
      const u64bit B19 = rotate_left(A[23] ^ D4, 56);
      const u64bit B20 = rotate_left(A[ 2] ^ D3, 62);
      const u64bit B21 = rotate_left(A[ 8] ^ D4, 55);
      const u64bit B22 = rotate_left(A[14] ^ D0, 39);
      const u64bit B23 = rotate_left(A[15] ^ D1, 41);
      const u64bit B24 = rotate_left(A[21] ^ D2, 2);

      A[ 0] = B00 ^ (~B01 & B02);
      A[ 1] = B01 ^ (~B02 & B03);
      A[ 2] = B02 ^ (~B03 & B04);
      A[ 3] = B03 ^ (~B04 & B00);
      A[ 4] = B04 ^ (~B00 & B01);
      A[ 5] = B05 ^ (~B06 & B07);
      A[ 6] = B06 ^ (~B07 & B08);
      A[ 7] = B07 ^ (~B08 & B09);
      A[ 8] = B08 ^ (~B09 & B05);
      A[ 9] = B09 ^ (~B05 & B06);
      A[10] = B10 ^ (~B11 & B12);
      A[11] = B11 ^ (~B12 & B13);
      A[12] = B12 ^ (~B13 & B14);
      A[13] = B13 ^ (~B14 & B10);
      A[14] = B14 ^ (~B10 & B11);
      A[15] = B15 ^ (~B16 & B17);
      A[16] = B16 ^ (~B17 & B18);
      A[17] = B17 ^ (~B18 & B19);
      A[18] = B18 ^ (~B19 & B15);
      A[19] = B19 ^ (~B15 & B16);
      A[20] = B20 ^ (~B21 & B22);
      A[21] = B21 ^ (~B22 & B23);
      A[22] = B22 ^ (~B23 & B24);
      A[23] = B23 ^ (~B24 & B20);
      A[24] = B24 ^ (~B20 & B21);

      A[0] ^= RC[i];
      }
   }

}

Keccak_1600::Keccak_1600(size_t output_bits) :
   output_bits(output_bits),
   bitrate(1600 - 2*output_bits),
   S(25),
   S_pos(0)
   {
   // We only support the parameters for the SHA-3 proposal

   if(output_bits != 224 && output_bits != 256 &&
      output_bits != 384 && output_bits != 512)
      throw Invalid_Argument("Keccak_1600: Invalid output length " +
                             std::to_string(output_bits));
   }

std::string Keccak_1600::name() const
   {
   return "Keccak-1600(" + std::to_string(output_bits) + ")";
   }

HashFunction* Keccak_1600::clone() const
   {
   return new Keccak_1600(output_bits);
   }

void Keccak_1600::clear()
   {
   zeroise(S);
   S_pos = 0;
   }

void Keccak_1600::add_data(const byte input[], size_t length)
   {
   if(length == 0)
      return;

   while(length)
      {
      size_t to_take = std::min(length, bitrate / 8 - S_pos);

      length -= to_take;

      while(to_take && S_pos % 8)
         {
         S[S_pos / 8] ^= static_cast<u64bit>(input[0]) << (8 * (S_pos % 8));

         ++S_pos;
         ++input;
         --to_take;
         }

      while(to_take && to_take % 8 == 0)
         {
         S[S_pos / 8] ^= load_le<u64bit>(input, 0);
         S_pos += 8;
         input += 8;
         to_take -= 8;
         }

      while(to_take)
         {
         S[S_pos / 8] ^= static_cast<u64bit>(input[0]) << (8 * (S_pos % 8));

         ++S_pos;
         ++input;
         --to_take;
         }

      if(S_pos == bitrate / 8)
         {
         keccak_f_1600(S.data());
         S_pos = 0;
         }
      }
   }

void Keccak_1600::final_result(byte output[])
   {
   std::vector<byte> padding(bitrate / 8 - S_pos);

   padding[0] = 0x01;
   padding[padding.size()-1] |= 0x80;

   add_data(padding.data(), padding.size());

   /*
   * We never have to run the permutation again because we only support
   * limited output lengths
   */
   for(size_t i = 0; i != output_bits/8; ++i)
      output[i] = get_byte(7 - (i % 8), S[i/8]);

   clear();
   }

}