aboutsummaryrefslogtreecommitdiffstats
path: root/contrib/restricted/aws/s2n/pq-crypto/kyber_90s_r2/polyvec.c
blob: 8d90e7e0c72818429019f678a2562026a6025944 (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
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
#include "polyvec.h"

#include "poly.h"

#include <stddef.h>
#include <stdint.h>
/*************************************************
* Name:        polyvec_compress
*
* Description: Compress and serialize vector of polynomials
*
* Arguments:   - uint8_t *r: pointer to output byte array (needs space for KYBER_POLYVECCOMPRESSEDBYTES)
*              - const polyvec *a: pointer to input vector of polynomials
**************************************************/
void PQCLEAN_KYBER51290S_CLEAN_polyvec_compress(uint8_t *r, polyvec *a) {
    PQCLEAN_KYBER51290S_CLEAN_polyvec_csubq(a);

    uint16_t t[4];
    for (size_t i = 0; i < KYBER_K; i++) {
        for (size_t j = 0; j < KYBER_N / 4; j++) {
            for (size_t k = 0; k < 4; k++) {
                t[k] = ((((uint32_t)a->vec[i].coeffs[4 * j + k] << 10) + KYBER_Q / 2) / KYBER_Q) & 0x3ff;
            }

            r[5 * j + 0] = (uint8_t)t[0];
            r[5 * j + 1] = (uint8_t)((t[0] >>  8) | ((t[1] & 0x3f) << 2));
            r[5 * j + 2] = (uint8_t)((t[1] >>  6) | ((t[2] & 0x0f) << 4));
            r[5 * j + 3] = (uint8_t)((t[2] >>  4) | ((t[3] & 0x03) << 6));
            r[5 * j + 4] = (uint8_t)((t[3] >>  2));
        }
        r += 320;
    }
}

/*************************************************
* Name:        polyvec_decompress
*
* Description: De-serialize and decompress vector of polynomials;
*              approximate inverse of polyvec_compress
*
* Arguments:   - polyvec *r:       pointer to output vector of polynomials
*              - uint8_t *a: pointer to input byte array (of length KYBER_POLYVECCOMPRESSEDBYTES)
**************************************************/
void PQCLEAN_KYBER51290S_CLEAN_polyvec_decompress(polyvec *r, const uint8_t *a) {
    for (size_t i = 0; i < KYBER_K; i++) {
        for (size_t j = 0; j < KYBER_N / 4; j++) {
            r->vec[i].coeffs[4 * j + 0] = (int16_t)( (((a[5 * j + 0]       | (((uint32_t)a[5 * j + 1] & 0x03) << 8)) * KYBER_Q) + 512) >> 10);
            r->vec[i].coeffs[4 * j + 1] = (int16_t)(((((a[5 * j + 1] >> 2) | (((uint32_t)a[5 * j + 2] & 0x0f) << 6)) * KYBER_Q) + 512) >> 10);
            r->vec[i].coeffs[4 * j + 2] = (int16_t)(((((a[5 * j + 2] >> 4) | (((uint32_t)a[5 * j + 3] & 0x3f) << 4)) * KYBER_Q) + 512) >> 10);
            r->vec[i].coeffs[4 * j + 3] = (int16_t)(((((a[5 * j + 3] >> 6) | (((uint32_t)a[5 * j + 4] & 0xff) << 2)) * KYBER_Q) + 512) >> 10);
        }
        a += 320;
    }
}

/*************************************************
* Name:        polyvec_tobytes
*
* Description: Serialize vector of polynomials
*
* Arguments:   - uint8_t *r: pointer to output byte array (needs space for KYBER_POLYVECBYTES)
*              - const polyvec *a: pointer to input vector of polynomials
**************************************************/
void PQCLEAN_KYBER51290S_CLEAN_polyvec_tobytes(uint8_t *r, polyvec *a) {
    for (size_t i = 0; i < KYBER_K; i++) {
        PQCLEAN_KYBER51290S_CLEAN_poly_tobytes(r + i * KYBER_POLYBYTES, &a->vec[i]);
    }
}

/*************************************************
* Name:        polyvec_frombytes
*
* Description: De-serialize vector of polynomials;
*              inverse of polyvec_tobytes
*
* Arguments:   - uint8_t *r: pointer to output byte array
*              - const polyvec *a: pointer to input vector of polynomials (of length KYBER_POLYVECBYTES)
**************************************************/
void PQCLEAN_KYBER51290S_CLEAN_polyvec_frombytes(polyvec *r, const uint8_t *a) {
    for (size_t i = 0; i < KYBER_K; i++) {
        PQCLEAN_KYBER51290S_CLEAN_poly_frombytes(&r->vec[i], a + i * KYBER_POLYBYTES);
    }
}

/*************************************************
* Name:        polyvec_ntt
*
* Description: Apply forward NTT to all elements of a vector of polynomials
*
* Arguments:   - polyvec *r: pointer to in/output vector of polynomials
**************************************************/
void PQCLEAN_KYBER51290S_CLEAN_polyvec_ntt(polyvec *r) {
    for (size_t i = 0; i < KYBER_K; i++) {
        PQCLEAN_KYBER51290S_CLEAN_poly_ntt(&r->vec[i]);
    }
}

/*************************************************
* Name:        polyvec_invntt
*
* Description: Apply inverse NTT to all elements of a vector of polynomials
*
* Arguments:   - polyvec *r: pointer to in/output vector of polynomials
**************************************************/
void PQCLEAN_KYBER51290S_CLEAN_polyvec_invntt(polyvec *r) {
    for (size_t i = 0; i < KYBER_K; i++) {
        PQCLEAN_KYBER51290S_CLEAN_poly_invntt(&r->vec[i]);
    }
}

/*************************************************
* Name:        polyvec_pointwise_acc
*
* Description: Pointwise multiply elements of a and b and accumulate into r
*
* Arguments: - poly *r:          pointer to output polynomial
*            - const polyvec *a: pointer to first input vector of polynomials
*            - const polyvec *b: pointer to second input vector of polynomials
**************************************************/
void PQCLEAN_KYBER51290S_CLEAN_polyvec_pointwise_acc(poly *r, const polyvec *a, const polyvec *b) {
    poly t;

    PQCLEAN_KYBER51290S_CLEAN_poly_basemul(r, &a->vec[0], &b->vec[0]);
    for (size_t i = 1; i < KYBER_K; i++) {
        PQCLEAN_KYBER51290S_CLEAN_poly_basemul(&t, &a->vec[i], &b->vec[i]);
        PQCLEAN_KYBER51290S_CLEAN_poly_add(r, r, &t);
    }

    PQCLEAN_KYBER51290S_CLEAN_poly_reduce(r);
}

/*************************************************
* Name:        polyvec_reduce
*
* Description: Applies Barrett reduction to each coefficient
*              of each element of a vector of polynomials
*              for details of the Barrett reduction see comments in reduce.c
*
* Arguments:   - poly *r:       pointer to input/output polynomial
**************************************************/
void PQCLEAN_KYBER51290S_CLEAN_polyvec_reduce(polyvec *r) {
    for (size_t i = 0; i < KYBER_K; i++) {
        PQCLEAN_KYBER51290S_CLEAN_poly_reduce(&r->vec[i]);
    }
}

/*************************************************
* Name:        polyvec_csubq
*
* Description: Applies conditional subtraction of q to each coefficient
*              of each element of a vector of polynomials
*              for details of conditional subtraction of q see comments in reduce.c
*
* Arguments:   - poly *r:       pointer to input/output polynomial
**************************************************/
void PQCLEAN_KYBER51290S_CLEAN_polyvec_csubq(polyvec *r) {
    for (size_t i = 0; i < KYBER_K; i++) {
        PQCLEAN_KYBER51290S_CLEAN_poly_csubq(&r->vec[i]);
    }
}

/*************************************************
* Name:        polyvec_add
*
* Description: Add vectors of polynomials
*
* Arguments: - polyvec *r:       pointer to output vector of polynomials
*            - const polyvec *a: pointer to first input vector of polynomials
*            - const polyvec *b: pointer to second input vector of polynomials
**************************************************/
void PQCLEAN_KYBER51290S_CLEAN_polyvec_add(polyvec *r, const polyvec *a, const polyvec *b) {
    for (size_t i = 0; i < KYBER_K; i++) {
        PQCLEAN_KYBER51290S_CLEAN_poly_add(&r->vec[i], &a->vec[i], &b->vec[i]);
    }
}