1/*
 2    Copyright 2018 0KIMS association.
 3
 4    This file is part of circom (Zero Knowledge Circuit Compiler).
 5
 6    circom is a free software: you can redistribute it and/or modify it
 7    under the terms of the GNU General Public License as published by
 8    the Free Software Foundation, either version 3 of the License, or
 9    (at your option) any later version.
10
11    circom is distributed in the hope that it will be useful, but WITHOUT
12    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
13    or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public
14    License for more details.
15
16    You should have received a copy of the GNU General Public License
17    along with circom. If not, see <https://www.gnu.org/licenses/>.
18*/
19
20/* Maj function for sha256
21
22out = a&b ^ a&c ^ b&c  =>
23
24out = a*b   +  a*c  +  b*c  -  2*a*b*c  =>
25
26out = a*( b + c - 2*b*c ) + b*c =>
27
28mid = b*c
29out = a*( b + c - 2*mid ) + mid
30
31*/
32pragma circom 2.0.0;
33
34template Maj_t(n) {
35    signal input a[n];
36    signal input b[n];
37    signal input c[n];
38    signal output out[n];
39    signal mid[n];
40
41    for (var k=0; k<n; k++) {
42        mid[k] <== b[k]*c[k];
43        out[k] <== a[k] * (b[k]+c[k]-2*mid[k]) + mid[k];
44    }
45}