pqc/crypto_sign/dilithium-iii/clean/polyvec.c
2019-01-16 11:02:32 +01:00

339 lines
12 KiB
C

#include "polyvec.h"
#include "params.h"
#include "poly.h"
#include <stdint.h>
/**************************************************************/
/************ Vectors of polynomials of length L **************/
/**************************************************************/
/*************************************************
* Name: polyvecl_freeze
*
* Description: Reduce coefficients of polynomials in vector of length L
* to standard representatives.
*
* Arguments: - polyvecl *v: pointer to input/output vector
**************************************************/
void polyvecl_freeze(polyvecl *v) {
unsigned int i;
for (i = 0; i < L; ++i)
poly_freeze(v->vec + i);
}
/*************************************************
* Name: polyvecl_add
*
* Description: Add vectors of polynomials of length L.
* No modular reduction is performed.
*
* Arguments: - polyvecl *w: pointer to output vector
* - const polyvecl *u: pointer to first summand
* - const polyvecl *v: pointer to second summand
**************************************************/
void polyvecl_add(polyvecl *w, const polyvecl *u, const polyvecl *v) {
unsigned int i;
for (i = 0; i < L; ++i)
poly_add(w->vec + i, u->vec + i, v->vec + i);
}
/*************************************************
* Name: polyvecl_ntt
*
* Description: Forward NTT of all polynomials in vector of length L. Output
* coefficients can be up to 16*Q larger than input coefficients.
*
* Arguments: - polyvecl *v: pointer to input/output vector
**************************************************/
void polyvecl_ntt(polyvecl *v) {
unsigned int i;
for (i = 0; i < L; ++i)
poly_ntt(v->vec + i);
}
/*************************************************
* Name: polyvecl_pointwise_acc_invmontgomery
*
* Description: Pointwise multiply vectors of polynomials of length L, multiply
* resulting vector by 2^{-32} and add (accumulate) polynomials
* in it. Input/output vectors are in NTT domain representation.
* Input coefficients are assumed to be less than 22*Q. Output
* coeffcient are less than 2*L*Q.
*
* Arguments: - poly *w: output polynomial
* - const polyvecl *u: pointer to first input vector
* - const polyvecl *v: pointer to second input vector
**************************************************/
void polyvecl_pointwise_acc_invmontgomery(poly *w, const polyvecl *u,
const polyvecl *v) {
unsigned int i;
poly t;
poly_pointwise_invmontgomery(w, u->vec + 0, v->vec + 0);
for (i = 1; i < L; ++i) {
poly_pointwise_invmontgomery(&t, u->vec + i, v->vec + i);
poly_add(w, w, &t);
}
}
/*************************************************
* Name: polyvecl_chknorm
*
* Description: Check infinity norm of polynomials in vector of length L.
* Assumes input coefficients to be standard representatives.
*
* Arguments: - const polyvecl *v: pointer to vector
* - uint32_t B: norm bound
*
* Returns 0 if norm of all polynomials is strictly smaller than B and 1
* otherwise.
**************************************************/
int polyvecl_chknorm(const polyvecl *v, uint32_t bound) {
unsigned int i;
int ret = 0;
for (i = 0; i < L; ++i)
ret |= poly_chknorm(v->vec + i, bound);
return ret;
}
/**************************************************************/
/************ Vectors of polynomials of length K **************/
/**************************************************************/
/*************************************************
* Name: polyveck_reduce
*
* Description: Reduce coefficients of polynomials in vector of length K
* to representatives in [0,2*Q[.
*
* Arguments: - polyveck *v: pointer to input/output vector
**************************************************/
void polyveck_reduce(polyveck *v) {
unsigned int i;
for (i = 0; i < K; ++i)
poly_reduce(v->vec + i);
}
/*************************************************
* Name: polyveck_csubq
*
* Description: For all coefficients of polynomials in vector of length K
* subtract Q if coefficient is bigger than Q.
*
* Arguments: - polyveck *v: pointer to input/output vector
**************************************************/
void polyveck_csubq(polyveck *v) {
unsigned int i;
for (i = 0; i < K; ++i)
poly_csubq(v->vec + i);
}
/*************************************************
* Name: polyveck_freeze
*
* Description: Reduce coefficients of polynomials in vector of length K
* to standard representatives.
*
* Arguments: - polyveck *v: pointer to input/output vector
**************************************************/
void polyveck_freeze(polyveck *v) {
unsigned int i;
for (i = 0; i < K; ++i)
poly_freeze(v->vec + i);
}
/*************************************************
* Name: polyveck_add
*
* Description: Add vectors of polynomials of length K.
* No modular reduction is performed.
*
* Arguments: - polyveck *w: pointer to output vector
* - const polyveck *u: pointer to first summand
* - const polyveck *v: pointer to second summand
**************************************************/
void polyveck_add(polyveck *w, const polyveck *u, const polyveck *v) {
unsigned int i;
for (i = 0; i < K; ++i)
poly_add(w->vec + i, u->vec + i, v->vec + i);
}
/*************************************************
* Name: polyveck_sub
*
* Description: Subtract vectors of polynomials of length K.
* Assumes coefficients of polynomials in second input vector
* to be less than 2*Q. No modular reduction is performed.
*
* Arguments: - polyveck *w: pointer to output vector
* - const polyveck *u: pointer to first input vector
* - const polyveck *v: pointer to second input vector to be
* subtracted from first input vector
**************************************************/
void polyveck_sub(polyveck *w, const polyveck *u, const polyveck *v) {
unsigned int i;
for (i = 0; i < K; ++i)
poly_sub(w->vec + i, u->vec + i, v->vec + i);
}
/*************************************************
* Name: polyveck_shiftl
*
* Description: Multiply vector of polynomials of Length K by 2^k without
*modular reduction. Assumes input coefficients to be less than 2^{32-k}.
*
* Arguments: - polyveck *v: pointer to input/output vector
* - unsigned int k: exponent
**************************************************/
void polyveck_shiftl(polyveck *v, unsigned int k) {
unsigned int i;
for (i = 0; i < K; ++i)
poly_shiftl(v->vec + i, k);
}
/*************************************************
* Name: polyveck_ntt
*
* Description: Forward NTT of all polynomials in vector of length K. Output
* coefficients can be up to 16*Q larger than input coefficients.
*
* Arguments: - polyveck *v: pointer to input/output vector
**************************************************/
void polyveck_ntt(polyveck *v) {
unsigned int i;
for (i = 0; i < K; ++i)
poly_ntt(v->vec + i);
}
/*************************************************
* Name: polyveck_invntt_montgomery
*
* Description: Inverse NTT and multiplication by 2^{32} of polynomials
* in vector of length K. Input coefficients need to be less
* than 2*Q.
*
* Arguments: - polyveck *v: pointer to input/output vector
**************************************************/
void polyveck_invntt_montgomery(polyveck *v) {
unsigned int i;
for (i = 0; i < K; ++i)
poly_invntt_montgomery(v->vec + i);
}
/*************************************************
* Name: polyveck_chknorm
*
* Description: Check infinity norm of polynomials in vector of length K.
* Assumes input coefficients to be standard representatives.
*
* Arguments: - const polyveck *v: pointer to vector
* - uint32_t B: norm bound
*
* Returns 0 if norm of all polynomials are strictly smaller than B and 1
* otherwise.
**************************************************/
int polyveck_chknorm(const polyveck *v, uint32_t bound) {
unsigned int i;
int ret = 0;
for (i = 0; i < K; ++i)
ret |= poly_chknorm(v->vec + i, bound);
return ret;
}
/*************************************************
* Name: polyveck_power2round
*
* Description: For all coefficients a of polynomials in vector of length K,
* compute a0, a1 such that a mod Q = a1*2^D + a0
* with -2^{D-1} < a0 <= 2^{D-1}. Assumes coefficients to be
* standard representatives.
*
* Arguments: - polyveck *v1: pointer to output vector of polynomials with
* coefficients a1
* - polyveck *v0: pointer to output vector of polynomials with
* coefficients Q + a0
* - const polyveck *v: pointer to input vector
**************************************************/
void polyveck_power2round(polyveck *v1, polyveck *v0, const polyveck *v) {
unsigned int i;
for (i = 0; i < K; ++i)
poly_power2round(v1->vec + i, v0->vec + i, v->vec + i);
}
/*************************************************
* Name: polyveck_decompose
*
* Description: For all coefficients a of polynomials in vector of length K,
* compute high and low bits a0, a1 such a mod Q = a1*ALPHA + a0
* with -ALPHA/2 < a0 <= ALPHA/2 except a1 = (Q-1)/ALPHA where we
* set a1 = 0 and -ALPHA/2 <= a0 = a mod Q - Q < 0.
* Assumes coefficients to be standard representatives.
*
* Arguments: - polyveck *v1: pointer to output vector of polynomials with
* coefficients a1
* - polyveck *v0: pointer to output vector of polynomials with
* coefficients Q + a0
* - const polyveck *v: pointer to input vector
**************************************************/
void polyveck_decompose(polyveck *v1, polyveck *v0, const polyveck *v) {
unsigned int i;
for (i = 0; i < K; ++i)
poly_decompose(v1->vec + i, v0->vec + i, v->vec + i);
}
/*************************************************
* Name: polyveck_make_hint
*
* Description: Compute hint vector.
*
* Arguments: - polyveck *h: pointer to output vector
* - const polyveck *u: pointer to first input vector
* - const polyveck *u: pointer to second input vector
*
* Returns number of 1 bits.
**************************************************/
unsigned int polyveck_make_hint(polyveck *h, const polyveck *u,
const polyveck *v) {
unsigned int i, s = 0;
for (i = 0; i < K; ++i)
s += poly_make_hint(h->vec + i, u->vec + i, v->vec + i);
return s;
}
/*************************************************
* Name: polyveck_use_hint
*
* Description: Use hint vector to correct the high bits of input vector.
*
* Arguments: - polyveck *w: pointer to output vector of polynomials with
* corrected high bits
* - const polyveck *u: pointer to input vector
* - const polyveck *h: pointer to input hint vector
**************************************************/
void polyveck_use_hint(polyveck *w, const polyveck *u, const polyveck *h) {
unsigned int i;
for (i = 0; i < K; ++i)
poly_use_hint(w->vec + i, u->vec + i, h->vec + i);
}