1 #include "polyvec.h"
2
3 #include "poly.h"
4
5 #include <stddef.h>
6 #include <stdint.h>
7 /*************************************************
8 * Name: polyvec_compress
9 *
10 * Description: Compress and serialize vector of polynomials
11 *
12 * Arguments: - uint8_t *r: pointer to output byte array (needs space for KYBER_POLYVECCOMPRESSEDBYTES)
13 * - const polyvec *a: pointer to input vector of polynomials
14 **************************************************/
PQCLEAN_KYBER51290S_CLEAN_polyvec_compress(uint8_t * r,polyvec * a)15 void PQCLEAN_KYBER51290S_CLEAN_polyvec_compress(uint8_t *r, polyvec *a) {
16 PQCLEAN_KYBER51290S_CLEAN_polyvec_csubq(a);
17
18 uint16_t t[4];
19 for (size_t i = 0; i < KYBER_K; i++) {
20 for (size_t j = 0; j < KYBER_N / 4; j++) {
21 for (size_t k = 0; k < 4; k++) {
22 t[k] = ((((uint32_t)a->vec[i].coeffs[4 * j + k] << 10) + KYBER_Q / 2) / KYBER_Q) & 0x3ff;
23 }
24
25 r[5 * j + 0] = (uint8_t)t[0];
26 r[5 * j + 1] = (uint8_t)((t[0] >> 8) | ((t[1] & 0x3f) << 2));
27 r[5 * j + 2] = (uint8_t)((t[1] >> 6) | ((t[2] & 0x0f) << 4));
28 r[5 * j + 3] = (uint8_t)((t[2] >> 4) | ((t[3] & 0x03) << 6));
29 r[5 * j + 4] = (uint8_t)((t[3] >> 2));
30 }
31 r += 320;
32 }
33 }
34
35 /*************************************************
36 * Name: polyvec_decompress
37 *
38 * Description: De-serialize and decompress vector of polynomials;
39 * approximate inverse of polyvec_compress
40 *
41 * Arguments: - polyvec *r: pointer to output vector of polynomials
42 * - uint8_t *a: pointer to input byte array (of length KYBER_POLYVECCOMPRESSEDBYTES)
43 **************************************************/
PQCLEAN_KYBER51290S_CLEAN_polyvec_decompress(polyvec * r,const uint8_t * a)44 void PQCLEAN_KYBER51290S_CLEAN_polyvec_decompress(polyvec *r, const uint8_t *a) {
45 for (size_t i = 0; i < KYBER_K; i++) {
46 for (size_t j = 0; j < KYBER_N / 4; j++) {
47 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);
48 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);
49 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);
50 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);
51 }
52 a += 320;
53 }
54 }
55
56 /*************************************************
57 * Name: polyvec_tobytes
58 *
59 * Description: Serialize vector of polynomials
60 *
61 * Arguments: - uint8_t *r: pointer to output byte array (needs space for KYBER_POLYVECBYTES)
62 * - const polyvec *a: pointer to input vector of polynomials
63 **************************************************/
PQCLEAN_KYBER51290S_CLEAN_polyvec_tobytes(uint8_t * r,polyvec * a)64 void PQCLEAN_KYBER51290S_CLEAN_polyvec_tobytes(uint8_t *r, polyvec *a) {
65 for (size_t i = 0; i < KYBER_K; i++) {
66 PQCLEAN_KYBER51290S_CLEAN_poly_tobytes(r + i * KYBER_POLYBYTES, &a->vec[i]);
67 }
68 }
69
70 /*************************************************
71 * Name: polyvec_frombytes
72 *
73 * Description: De-serialize vector of polynomials;
74 * inverse of polyvec_tobytes
75 *
76 * Arguments: - uint8_t *r: pointer to output byte array
77 * - const polyvec *a: pointer to input vector of polynomials (of length KYBER_POLYVECBYTES)
78 **************************************************/
PQCLEAN_KYBER51290S_CLEAN_polyvec_frombytes(polyvec * r,const uint8_t * a)79 void PQCLEAN_KYBER51290S_CLEAN_polyvec_frombytes(polyvec *r, const uint8_t *a) {
80 for (size_t i = 0; i < KYBER_K; i++) {
81 PQCLEAN_KYBER51290S_CLEAN_poly_frombytes(&r->vec[i], a + i * KYBER_POLYBYTES);
82 }
83 }
84
85 /*************************************************
86 * Name: polyvec_ntt
87 *
88 * Description: Apply forward NTT to all elements of a vector of polynomials
89 *
90 * Arguments: - polyvec *r: pointer to in/output vector of polynomials
91 **************************************************/
PQCLEAN_KYBER51290S_CLEAN_polyvec_ntt(polyvec * r)92 void PQCLEAN_KYBER51290S_CLEAN_polyvec_ntt(polyvec *r) {
93 for (size_t i = 0; i < KYBER_K; i++) {
94 PQCLEAN_KYBER51290S_CLEAN_poly_ntt(&r->vec[i]);
95 }
96 }
97
98 /*************************************************
99 * Name: polyvec_invntt
100 *
101 * Description: Apply inverse NTT to all elements of a vector of polynomials
102 *
103 * Arguments: - polyvec *r: pointer to in/output vector of polynomials
104 **************************************************/
PQCLEAN_KYBER51290S_CLEAN_polyvec_invntt(polyvec * r)105 void PQCLEAN_KYBER51290S_CLEAN_polyvec_invntt(polyvec *r) {
106 for (size_t i = 0; i < KYBER_K; i++) {
107 PQCLEAN_KYBER51290S_CLEAN_poly_invntt(&r->vec[i]);
108 }
109 }
110
111 /*************************************************
112 * Name: polyvec_pointwise_acc
113 *
114 * Description: Pointwise multiply elements of a and b and accumulate into r
115 *
116 * Arguments: - poly *r: pointer to output polynomial
117 * - const polyvec *a: pointer to first input vector of polynomials
118 * - const polyvec *b: pointer to second input vector of polynomials
119 **************************************************/
PQCLEAN_KYBER51290S_CLEAN_polyvec_pointwise_acc(poly * r,const polyvec * a,const polyvec * b)120 void PQCLEAN_KYBER51290S_CLEAN_polyvec_pointwise_acc(poly *r, const polyvec *a, const polyvec *b) {
121 poly t;
122
123 PQCLEAN_KYBER51290S_CLEAN_poly_basemul(r, &a->vec[0], &b->vec[0]);
124 for (size_t i = 1; i < KYBER_K; i++) {
125 PQCLEAN_KYBER51290S_CLEAN_poly_basemul(&t, &a->vec[i], &b->vec[i]);
126 PQCLEAN_KYBER51290S_CLEAN_poly_add(r, r, &t);
127 }
128
129 PQCLEAN_KYBER51290S_CLEAN_poly_reduce(r);
130 }
131
132 /*************************************************
133 * Name: polyvec_reduce
134 *
135 * Description: Applies Barrett reduction to each coefficient
136 * of each element of a vector of polynomials
137 * for details of the Barrett reduction see comments in reduce.c
138 *
139 * Arguments: - poly *r: pointer to input/output polynomial
140 **************************************************/
PQCLEAN_KYBER51290S_CLEAN_polyvec_reduce(polyvec * r)141 void PQCLEAN_KYBER51290S_CLEAN_polyvec_reduce(polyvec *r) {
142 for (size_t i = 0; i < KYBER_K; i++) {
143 PQCLEAN_KYBER51290S_CLEAN_poly_reduce(&r->vec[i]);
144 }
145 }
146
147 /*************************************************
148 * Name: polyvec_csubq
149 *
150 * Description: Applies conditional subtraction of q to each coefficient
151 * of each element of a vector of polynomials
152 * for details of conditional subtraction of q see comments in reduce.c
153 *
154 * Arguments: - poly *r: pointer to input/output polynomial
155 **************************************************/
PQCLEAN_KYBER51290S_CLEAN_polyvec_csubq(polyvec * r)156 void PQCLEAN_KYBER51290S_CLEAN_polyvec_csubq(polyvec *r) {
157 for (size_t i = 0; i < KYBER_K; i++) {
158 PQCLEAN_KYBER51290S_CLEAN_poly_csubq(&r->vec[i]);
159 }
160 }
161
162 /*************************************************
163 * Name: polyvec_add
164 *
165 * Description: Add vectors of polynomials
166 *
167 * Arguments: - polyvec *r: pointer to output vector of polynomials
168 * - const polyvec *a: pointer to first input vector of polynomials
169 * - const polyvec *b: pointer to second input vector of polynomials
170 **************************************************/
PQCLEAN_KYBER51290S_CLEAN_polyvec_add(polyvec * r,const polyvec * a,const polyvec * b)171 void PQCLEAN_KYBER51290S_CLEAN_polyvec_add(polyvec *r, const polyvec *a, const polyvec *b) {
172 for (size_t i = 0; i < KYBER_K; i++) {
173 PQCLEAN_KYBER51290S_CLEAN_poly_add(&r->vec[i], &a->vec[i], &b->vec[i]);
174 }
175 }
176