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
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304

use core::convert::TryInto;
use digest::generic_array::typenum::U64;
use digest::generic_array::GenericArray;

pub const DIGEST_BUF_LEN: usize = 5;
pub const WORK_BUF_LEN: usize = 16;

pub const H0: [u32; DIGEST_BUF_LEN] = [
    0x6745_2301,
    0xefcd_ab89,
    0x98ba_dcfe,
    0x1032_5476,
    0xc3d2_e1f0,
];

type Block = GenericArray<u8, U64>;

macro_rules! round(
    ($a:expr, $b:expr, $c:expr, $d:expr, $e:expr,
     $x:expr, $bits:expr, $add:expr, $round:expr) => ({
        $a = $a.wrapping_add($round).wrapping_add($x).wrapping_add($add);
        $a = $a.rotate_left($bits).wrapping_add($e);
        $c = $c.rotate_left(10);
    });
);

macro_rules! process_block(
    ($h:ident, $data:expr,
     $( round1: h_ordering $f0:expr, $f1:expr, $f2:expr, $f3:expr, $f4:expr;
                data_index $data_index1:expr; roll_shift $bits1:expr )*;
     $( round2: h_ordering $g0:expr, $g1:expr, $g2:expr, $g3:expr, $g4:expr;
                data_index $data_index2:expr; roll_shift $bits2:expr )*;
     $( round3: h_ordering $h0:expr, $h1:expr, $h2:expr, $h3:expr, $h4:expr;
                data_index $data_index3:expr; roll_shift $bits3:expr )*;
     $( round4: h_ordering $i0:expr, $i1:expr, $i2:expr, $i3:expr, $i4:expr;
                data_index $data_index4:expr; roll_shift $bits4:expr )*;
     $( round5: h_ordering $j0:expr, $j1:expr, $j2:expr, $j3:expr, $j4:expr;
                data_index $data_index5:expr; roll_shift $bits5:expr )*;
     $( par_round1: h_ordering $pj0:expr, $pj1:expr, $pj2:expr, $pj3:expr, $pj4:expr;
                    data_index $pdata_index1:expr; roll_shift $pbits1:expr )*;
     $( par_round2: h_ordering $pi0:expr, $pi1:expr, $pi2:expr, $pi3:expr, $pi4:expr;
                    data_index $pdata_index2:expr; roll_shift $pbits2:expr )*;
     $( par_round3: h_ordering $ph0:expr, $ph1:expr, $ph2:expr, $ph3:expr, $ph4:expr;
                    data_index $pdata_index3:expr; roll_shift $pbits3:expr )*;
     $( par_round4: h_ordering $pg0:expr, $pg1:expr, $pg2:expr, $pg3:expr, $pg4:expr;
                    data_index $pdata_index4:expr; roll_shift $pbits4:expr )*;
     $( par_round5: h_ordering $pf0:expr, $pf1:expr, $pf2:expr, $pf3:expr, $pf4:expr;
                    data_index $pdata_index5:expr; roll_shift $pbits5:expr )*;
    ) => ({
        let mut bb = *$h;
        let mut bbb = *$h;

        // Round 1
        $( round!(bb[$f0], bb[$f1], bb[$f2], bb[$f3], bb[$f4],
                  $data[$data_index1], $bits1, 0x0000_0000,
                  bb[$f1] ^ bb[$f2] ^ bb[$f3]); )*

        // Round 2
        $( round!(bb[$g0], bb[$g1], bb[$g2], bb[$g3], bb[$g4],
                  $data[$data_index2], $bits2, 0x5a82_7999,
                  (bb[$g1] & bb[$g2]) | (!bb[$g1] & bb[$g3])); )*

        // Round 3
        $( round!(bb[$h0], bb[$h1], bb[$h2], bb[$h3], bb[$h4],
                  $data[$data_index3], $bits3, 0x6ed9_eba1,
                  (bb[$h1] | !bb[$h2]) ^ bb[$h3]); )*

        // Round 4
        $( round!(bb[$i0], bb[$i1], bb[$i2], bb[$i3], bb[$i4],
                  $data[$data_index4], $bits4, 0x8f1b_bcdc,
                  (bb[$i1] & bb[$i3]) | (bb[$i2] & !bb[$i3])); )*

        // Round 5
        $( round!(bb[$j0], bb[$j1], bb[$j2], bb[$j3], bb[$j4],
                  $data[$data_index5], $bits5, 0xa953_fd4e,
                  bb[$j1] ^ (bb[$j2] | !bb[$j3])); )*

        // Parallel rounds: these are the same as the previous five
        // rounds except that the constants have changed, we work
        // with the other buffer, and they are applied in reverse
        // order.

        // Parallel Round 1
        $( round!(bbb[$pj0], bbb[$pj1], bbb[$pj2], bbb[$pj3], bbb[$pj4],
                  $data[$pdata_index1], $pbits1, 0x50a2_8be6,
                  bbb[$pj1] ^ (bbb[$pj2] | !bbb[$pj3])); )*

        // Parallel Round 2
        $( round!(bbb[$pi0], bbb[$pi1], bbb[$pi2], bbb[$pi3], bbb[$pi4],
                  $data[$pdata_index2], $pbits2, 0x5c4d_d124,
                  (bbb[$pi1] & bbb[$pi3]) | (bbb[$pi2] & !bbb[$pi3])); )*

        // Parallel Round 3
        $( round!(bbb[$ph0], bbb[$ph1], bbb[$ph2], bbb[$ph3], bbb[$ph4],
                  $data[$pdata_index3], $pbits3, 0x6d70_3ef3,
                  (bbb[$ph1] | !bbb[$ph2]) ^ bbb[$ph3]); )*

        // Parallel Round 4
        $( round!(bbb[$pg0], bbb[$pg1], bbb[$pg2], bbb[$pg3], bbb[$pg4],
                  $data[$pdata_index4], $pbits4, 0x7a6d_76e9,
                  (bbb[$pg1] & bbb[$pg2]) | (!bbb[$pg1] & bbb[$pg3])); )*

        // Parallel Round 5
        $( round!(bbb[$pf0], bbb[$pf1], bbb[$pf2], bbb[$pf3], bbb[$pf4],
                  $data[$pdata_index5], $pbits5, 0x0000_0000,
                  bbb[$pf1] ^ bbb[$pf2] ^ bbb[$pf3]); )*

        // Combine results
        bbb[3] = bbb[3].wrapping_add($h[1]).wrapping_add(bb[2]);
        $h[1]   = $h[2].wrapping_add(bb[3]).wrapping_add(bbb[4]);
        $h[2]   = $h[3].wrapping_add(bb[4]).wrapping_add(bbb[0]);
        $h[3]   = $h[4].wrapping_add(bb[0]).wrapping_add(bbb[1]);
        $h[4]   = $h[0].wrapping_add(bb[1]).wrapping_add(bbb[2]);
        $h[0]   =                 bbb[3];
    });
);

pub fn process_msg_block(h: &mut [u32; DIGEST_BUF_LEN], data: &Block) {
    let mut w = [0u32; WORK_BUF_LEN];
    for (o, chunk) in w.iter_mut().zip(data.chunks_exact(4)) {
        *o = u32::from_le_bytes(chunk.try_into().unwrap());
    }
    process_block!(h, w[..],
    // Round 1
        round1: h_ordering 0, 1, 2, 3, 4; data_index  0; roll_shift 11
        round1: h_ordering 4, 0, 1, 2, 3; data_index  1; roll_shift 14
        round1: h_ordering 3, 4, 0, 1, 2; data_index  2; roll_shift 15
        round1: h_ordering 2, 3, 4, 0, 1; data_index  3; roll_shift 12
        round1: h_ordering 1, 2, 3, 4, 0; data_index  4; roll_shift  5
        round1: h_ordering 0, 1, 2, 3, 4; data_index  5; roll_shift  8
        round1: h_ordering 4, 0, 1, 2, 3; data_index  6; roll_shift  7
        round1: h_ordering 3, 4, 0, 1, 2; data_index  7; roll_shift  9
        round1: h_ordering 2, 3, 4, 0, 1; data_index  8; roll_shift 11
        round1: h_ordering 1, 2, 3, 4, 0; data_index  9; roll_shift 13
        round1: h_ordering 0, 1, 2, 3, 4; data_index 10; roll_shift 14
        round1: h_ordering 4, 0, 1, 2, 3; data_index 11; roll_shift 15
        round1: h_ordering 3, 4, 0, 1, 2; data_index 12; roll_shift  6
        round1: h_ordering 2, 3, 4, 0, 1; data_index 13; roll_shift  7
        round1: h_ordering 1, 2, 3, 4, 0; data_index 14; roll_shift  9
        round1: h_ordering 0, 1, 2, 3, 4; data_index 15; roll_shift  8;

    // Round 2
        round2: h_ordering 4, 0, 1, 2, 3; data_index  7; roll_shift  7
        round2: h_ordering 3, 4, 0, 1, 2; data_index  4; roll_shift  6
        round2: h_ordering 2, 3, 4, 0, 1; data_index 13; roll_shift  8
        round2: h_ordering 1, 2, 3, 4, 0; data_index  1; roll_shift 13
        round2: h_ordering 0, 1, 2, 3, 4; data_index 10; roll_shift 11
        round2: h_ordering 4, 0, 1, 2, 3; data_index  6; roll_shift  9
        round2: h_ordering 3, 4, 0, 1, 2; data_index 15; roll_shift  7
        round2: h_ordering 2, 3, 4, 0, 1; data_index  3; roll_shift 15
        round2: h_ordering 1, 2, 3, 4, 0; data_index 12; roll_shift  7
        round2: h_ordering 0, 1, 2, 3, 4; data_index  0; roll_shift 12
        round2: h_ordering 4, 0, 1, 2, 3; data_index  9; roll_shift 15
        round2: h_ordering 3, 4, 0, 1, 2; data_index  5; roll_shift  9
        round2: h_ordering 2, 3, 4, 0, 1; data_index  2; roll_shift 11
        round2: h_ordering 1, 2, 3, 4, 0; data_index 14; roll_shift  7
        round2: h_ordering 0, 1, 2, 3, 4; data_index 11; roll_shift 13
        round2: h_ordering 4, 0, 1, 2, 3; data_index  8; roll_shift 12;

    // Round 3
        round3: h_ordering 3, 4, 0, 1, 2; data_index  3; roll_shift 11
        round3: h_ordering 2, 3, 4, 0, 1; data_index 10; roll_shift 13
        round3: h_ordering 1, 2, 3, 4, 0; data_index 14; roll_shift  6
        round3: h_ordering 0, 1, 2, 3, 4; data_index  4; roll_shift  7
        round3: h_ordering 4, 0, 1, 2, 3; data_index  9; roll_shift 14
        round3: h_ordering 3, 4, 0, 1, 2; data_index 15; roll_shift  9
        round3: h_ordering 2, 3, 4, 0, 1; data_index  8; roll_shift 13
        round3: h_ordering 1, 2, 3, 4, 0; data_index  1; roll_shift 15
        round3: h_ordering 0, 1, 2, 3, 4; data_index  2; roll_shift 14
        round3: h_ordering 4, 0, 1, 2, 3; data_index  7; roll_shift  8
        round3: h_ordering 3, 4, 0, 1, 2; data_index  0; roll_shift 13
        round3: h_ordering 2, 3, 4, 0, 1; data_index  6; roll_shift  6
        round3: h_ordering 1, 2, 3, 4, 0; data_index 13; roll_shift  5
        round3: h_ordering 0, 1, 2, 3, 4; data_index 11; roll_shift 12
        round3: h_ordering 4, 0, 1, 2, 3; data_index  5; roll_shift  7
        round3: h_ordering 3, 4, 0, 1, 2; data_index 12; roll_shift  5;

    // Round 4
        round4: h_ordering 2, 3, 4, 0, 1; data_index  1; roll_shift 11
        round4: h_ordering 1, 2, 3, 4, 0; data_index  9; roll_shift 12
        round4: h_ordering 0, 1, 2, 3, 4; data_index 11; roll_shift 14
        round4: h_ordering 4, 0, 1, 2, 3; data_index 10; roll_shift 15
        round4: h_ordering 3, 4, 0, 1, 2; data_index  0; roll_shift 14
        round4: h_ordering 2, 3, 4, 0, 1; data_index  8; roll_shift 15
        round4: h_ordering 1, 2, 3, 4, 0; data_index 12; roll_shift  9
        round4: h_ordering 0, 1, 2, 3, 4; data_index  4; roll_shift  8
        round4: h_ordering 4, 0, 1, 2, 3; data_index 13; roll_shift  9
        round4: h_ordering 3, 4, 0, 1, 2; data_index  3; roll_shift 14
        round4: h_ordering 2, 3, 4, 0, 1; data_index  7; roll_shift  5
        round4: h_ordering 1, 2, 3, 4, 0; data_index 15; roll_shift  6
        round4: h_ordering 0, 1, 2, 3, 4; data_index 14; roll_shift  8
        round4: h_ordering 4, 0, 1, 2, 3; data_index  5; roll_shift  6
        round4: h_ordering 3, 4, 0, 1, 2; data_index  6; roll_shift  5
        round4: h_ordering 2, 3, 4, 0, 1; data_index  2; roll_shift 12;

    // Round 5
        round5: h_ordering 1, 2, 3, 4, 0; data_index  4; roll_shift  9
        round5: h_ordering 0, 1, 2, 3, 4; data_index  0; roll_shift 15
        round5: h_ordering 4, 0, 1, 2, 3; data_index  5; roll_shift  5
        round5: h_ordering 3, 4, 0, 1, 2; data_index  9; roll_shift 11
        round5: h_ordering 2, 3, 4, 0, 1; data_index  7; roll_shift  6
        round5: h_ordering 1, 2, 3, 4, 0; data_index 12; roll_shift  8
        round5: h_ordering 0, 1, 2, 3, 4; data_index  2; roll_shift 13
        round5: h_ordering 4, 0, 1, 2, 3; data_index 10; roll_shift 12
        round5: h_ordering 3, 4, 0, 1, 2; data_index 14; roll_shift  5
        round5: h_ordering 2, 3, 4, 0, 1; data_index  1; roll_shift 12
        round5: h_ordering 1, 2, 3, 4, 0; data_index  3; roll_shift 13
        round5: h_ordering 0, 1, 2, 3, 4; data_index  8; roll_shift 14
        round5: h_ordering 4, 0, 1, 2, 3; data_index 11; roll_shift 11
        round5: h_ordering 3, 4, 0, 1, 2; data_index  6; roll_shift  8
        round5: h_ordering 2, 3, 4, 0, 1; data_index 15; roll_shift  5
        round5: h_ordering 1, 2, 3, 4, 0; data_index 13; roll_shift  6;

    // Parallel Round 1
        par_round1: h_ordering 0, 1, 2, 3, 4; data_index  5; roll_shift  8
        par_round1: h_ordering 4, 0, 1, 2, 3; data_index 14; roll_shift  9
        par_round1: h_ordering 3, 4, 0, 1, 2; data_index  7; roll_shift  9
        par_round1: h_ordering 2, 3, 4, 0, 1; data_index  0; roll_shift 11
        par_round1: h_ordering 1, 2, 3, 4, 0; data_index  9; roll_shift 13
        par_round1: h_ordering 0, 1, 2, 3, 4; data_index  2; roll_shift 15
        par_round1: h_ordering 4, 0, 1, 2, 3; data_index 11; roll_shift 15
        par_round1: h_ordering 3, 4, 0, 1, 2; data_index  4; roll_shift  5
        par_round1: h_ordering 2, 3, 4, 0, 1; data_index 13; roll_shift  7
        par_round1: h_ordering 1, 2, 3, 4, 0; data_index  6; roll_shift  7
        par_round1: h_ordering 0, 1, 2, 3, 4; data_index 15; roll_shift  8
        par_round1: h_ordering 4, 0, 1, 2, 3; data_index  8; roll_shift 11
        par_round1: h_ordering 3, 4, 0, 1, 2; data_index  1; roll_shift 14
        par_round1: h_ordering 2, 3, 4, 0, 1; data_index 10; roll_shift 14
        par_round1: h_ordering 1, 2, 3, 4, 0; data_index  3; roll_shift 12
        par_round1: h_ordering 0, 1, 2, 3, 4; data_index 12; roll_shift  6;

    // Parallel Round 2
        par_round2: h_ordering 4, 0, 1, 2, 3; data_index  6; roll_shift  9
        par_round2: h_ordering 3, 4, 0, 1, 2; data_index 11; roll_shift 13
        par_round2: h_ordering 2, 3, 4, 0, 1; data_index  3; roll_shift 15
        par_round2: h_ordering 1, 2, 3, 4, 0; data_index  7; roll_shift  7
        par_round2: h_ordering 0, 1, 2, 3, 4; data_index  0; roll_shift 12
        par_round2: h_ordering 4, 0, 1, 2, 3; data_index 13; roll_shift  8
        par_round2: h_ordering 3, 4, 0, 1, 2; data_index  5; roll_shift  9
        par_round2: h_ordering 2, 3, 4, 0, 1; data_index 10; roll_shift 11
        par_round2: h_ordering 1, 2, 3, 4, 0; data_index 14; roll_shift  7
        par_round2: h_ordering 0, 1, 2, 3, 4; data_index 15; roll_shift  7
        par_round2: h_ordering 4, 0, 1, 2, 3; data_index  8; roll_shift 12
        par_round2: h_ordering 3, 4, 0, 1, 2; data_index 12; roll_shift  7
        par_round2: h_ordering 2, 3, 4, 0, 1; data_index  4; roll_shift  6
        par_round2: h_ordering 1, 2, 3, 4, 0; data_index  9; roll_shift 15
        par_round2: h_ordering 0, 1, 2, 3, 4; data_index  1; roll_shift 13
        par_round2: h_ordering 4, 0, 1, 2, 3; data_index  2; roll_shift 11;

    // Parallel Round 3
        par_round3: h_ordering 3, 4, 0, 1, 2; data_index 15; roll_shift  9
        par_round3: h_ordering 2, 3, 4, 0, 1; data_index  5; roll_shift  7
        par_round3: h_ordering 1, 2, 3, 4, 0; data_index  1; roll_shift 15
        par_round3: h_ordering 0, 1, 2, 3, 4; data_index  3; roll_shift 11
        par_round3: h_ordering 4, 0, 1, 2, 3; data_index  7; roll_shift  8
        par_round3: h_ordering 3, 4, 0, 1, 2; data_index 14; roll_shift  6
        par_round3: h_ordering 2, 3, 4, 0, 1; data_index  6; roll_shift  6
        par_round3: h_ordering 1, 2, 3, 4, 0; data_index  9; roll_shift 14
        par_round3: h_ordering 0, 1, 2, 3, 4; data_index 11; roll_shift 12
        par_round3: h_ordering 4, 0, 1, 2, 3; data_index  8; roll_shift 13
        par_round3: h_ordering 3, 4, 0, 1, 2; data_index 12; roll_shift  5
        par_round3: h_ordering 2, 3, 4, 0, 1; data_index  2; roll_shift 14
        par_round3: h_ordering 1, 2, 3, 4, 0; data_index 10; roll_shift 13
        par_round3: h_ordering 0, 1, 2, 3, 4; data_index  0; roll_shift 13
        par_round3: h_ordering 4, 0, 1, 2, 3; data_index  4; roll_shift  7
        par_round3: h_ordering 3, 4, 0, 1, 2; data_index 13; roll_shift  5;

    // Parallel Round 4
        par_round4: h_ordering 2, 3, 4, 0, 1; data_index  8; roll_shift 15
        par_round4: h_ordering 1, 2, 3, 4, 0; data_index  6; roll_shift  5
        par_round4: h_ordering 0, 1, 2, 3, 4; data_index  4; roll_shift  8
        par_round4: h_ordering 4, 0, 1, 2, 3; data_index  1; roll_shift 11
        par_round4: h_ordering 3, 4, 0, 1, 2; data_index  3; roll_shift 14
        par_round4: h_ordering 2, 3, 4, 0, 1; data_index 11; roll_shift 14
        par_round4: h_ordering 1, 2, 3, 4, 0; data_index 15; roll_shift  6
        par_round4: h_ordering 0, 1, 2, 3, 4; data_index  0; roll_shift 14
        par_round4: h_ordering 4, 0, 1, 2, 3; data_index  5; roll_shift  6
        par_round4: h_ordering 3, 4, 0, 1, 2; data_index 12; roll_shift  9
        par_round4: h_ordering 2, 3, 4, 0, 1; data_index  2; roll_shift 12
        par_round4: h_ordering 1, 2, 3, 4, 0; data_index 13; roll_shift  9
        par_round4: h_ordering 0, 1, 2, 3, 4; data_index  9; roll_shift 12
        par_round4: h_ordering 4, 0, 1, 2, 3; data_index  7; roll_shift  5
        par_round4: h_ordering 3, 4, 0, 1, 2; data_index 10; roll_shift 15
        par_round4: h_ordering 2, 3, 4, 0, 1; data_index 14; roll_shift  8;

    // Parallel Round 5
        par_round5: h_ordering 1, 2, 3, 4, 0; data_index 12; roll_shift  8
        par_round5: h_ordering 0, 1, 2, 3, 4; data_index 15; roll_shift  5
        par_round5: h_ordering 4, 0, 1, 2, 3; data_index 10; roll_shift 12
        par_round5: h_ordering 3, 4, 0, 1, 2; data_index  4; roll_shift  9
        par_round5: h_ordering 2, 3, 4, 0, 1; data_index  1; roll_shift 12
        par_round5: h_ordering 1, 2, 3, 4, 0; data_index  5; roll_shift  5
        par_round5: h_ordering 0, 1, 2, 3, 4; data_index  8; roll_shift 14
        par_round5: h_ordering 4, 0, 1, 2, 3; data_index  7; roll_shift  6
        par_round5: h_ordering 3, 4, 0, 1, 2; data_index  6; roll_shift  8
        par_round5: h_ordering 2, 3, 4, 0, 1; data_index  2; roll_shift 13
        par_round5: h_ordering 1, 2, 3, 4, 0; data_index 13; roll_shift  6
        par_round5: h_ordering 0, 1, 2, 3, 4; data_index 14; roll_shift  5
        par_round5: h_ordering 4, 0, 1, 2, 3; data_index  0; roll_shift 15
        par_round5: h_ordering 3, 4, 0, 1, 2; data_index  3; roll_shift 13
        par_round5: h_ordering 2, 3, 4, 0, 1; data_index  9; roll_shift 11
        par_round5: h_ordering 1, 2, 3, 4, 0; data_index 11; roll_shift 11;
    );
}