pqcrypto/crypto_sign/dilithium2/clean/polyvec.c

#include <stddef.h>
#include <stdint.h>

#include "params.h"
#include "poly.h"
#include "polyvec.h"

/**************************************************************/
/************ Vectors of polynomials of length L **************/
/**************************************************************/

/*************************************************
* Name:        PQCLEAN_DILITHIUM2_CLEAN_polyvecl_freeze
*
* Description: Reduce coefficients of polynomials in vector of length L
*              to standard representatives.
*
* Arguments:   - polyvecl *v: pointer to input/output vector
**************************************************/
void PQCLEAN_DILITHIUM2_CLEAN_polyvecl_freeze(polyvecl *v) {
    for (size_t i = 0; i < L; ++i) {
        PQCLEAN_DILITHIUM2_CLEAN_poly_freeze(&v->vec[i]);
    }
}

/*************************************************
* Name:        PQCLEAN_DILITHIUM2_CLEAN_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 PQCLEAN_DILITHIUM2_CLEAN_polyvecl_add(
    polyvecl *w, const polyvecl *u, const polyvecl *v) {
    for (size_t i = 0; i < L; ++i) {
        PQCLEAN_DILITHIUM2_CLEAN_poly_add(&w->vec[i], &u->vec[i], &v->vec[i]);
    }
}

/*************************************************
* Name:        PQCLEAN_DILITHIUM2_CLEAN_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 PQCLEAN_DILITHIUM2_CLEAN_polyvecl_ntt(polyvecl *v) {
    for (size_t i = 0; i < L; ++i) {
        PQCLEAN_DILITHIUM2_CLEAN_poly_ntt(&v->vec[i]);
    }
}

/*************************************************
* Name:        PQCLEAN_DILITHIUM2_CLEAN_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 PQCLEAN_DILITHIUM2_CLEAN_polyvecl_pointwise_acc_invmontgomery(
    poly *w, const polyvecl *u, const polyvecl *v) {
    poly t;

    PQCLEAN_DILITHIUM2_CLEAN_poly_pointwise_invmontgomery(w, &u->vec[0], &v->vec[0]);

    for (size_t i = 1; i < L; ++i) {
        PQCLEAN_DILITHIUM2_CLEAN_poly_pointwise_invmontgomery(&t, &u->vec[i], &v->vec[i]);
        PQCLEAN_DILITHIUM2_CLEAN_poly_add(w, w, &t);
    }
}

/*************************************************
* Name:        PQCLEAN_DILITHIUM2_CLEAN_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 PQCLEAN_DILITHIUM2_CLEAN_polyvecl_chknorm(const polyvecl *v, uint32_t B)  {
    for (size_t i = 0; i < L; ++i) {
        if (PQCLEAN_DILITHIUM2_CLEAN_poly_chknorm(&v->vec[i], B)) {
            return 1;
        }
    }

    return 0;
}

/**************************************************************/
/************ Vectors of polynomials of length K **************/
/**************************************************************/


/*************************************************
* Name:        PQCLEAN_DILITHIUM2_CLEAN_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 PQCLEAN_DILITHIUM2_CLEAN_polyveck_reduce(polyveck *v) {
    for (size_t i = 0; i < K; ++i) {
        PQCLEAN_DILITHIUM2_CLEAN_poly_reduce(&v->vec[i]);
    }
}

/*************************************************
* Name:        PQCLEAN_DILITHIUM2_CLEAN_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 PQCLEAN_DILITHIUM2_CLEAN_polyveck_csubq(polyveck *v) {
    for (size_t i = 0; i < K; ++i) {
        PQCLEAN_DILITHIUM2_CLEAN_poly_csubq(&v->vec[i]);
    }
}

/*************************************************
* Name:        PQCLEAN_DILITHIUM2_CLEAN_polyveck_freeze
*
* Description: Reduce coefficients of polynomials in vector of length K
*              to standard representatives.
*
* Arguments:   - polyveck *v: pointer to input/output vector
**************************************************/
void PQCLEAN_DILITHIUM2_CLEAN_polyveck_freeze(polyveck *v)  {
    for (size_t i = 0; i < K; ++i) {
        PQCLEAN_DILITHIUM2_CLEAN_poly_freeze(&v->vec[i]);
    }
}

/*************************************************
* Name:        PQCLEAN_DILITHIUM2_CLEAN_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 PQCLEAN_DILITHIUM2_CLEAN_polyveck_add(
    polyveck *w, const polyveck *u, const polyveck *v) {
    for (size_t i = 0; i < K; ++i) {
        PQCLEAN_DILITHIUM2_CLEAN_poly_add(&w->vec[i], &u->vec[i], &v->vec[i]);
    }
}

/*************************************************
* Name:        PQCLEAN_DILITHIUM2_CLEAN_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 PQCLEAN_DILITHIUM2_CLEAN_polyveck_sub(
    polyveck *w, const polyveck *u, const polyveck *v) {
    for (size_t i = 0; i < K; ++i) {
        PQCLEAN_DILITHIUM2_CLEAN_poly_sub(&w->vec[i], &u->vec[i], &v->vec[i]);
    }
}

/*************************************************
* Name:        PQCLEAN_DILITHIUM2_CLEAN_polyveck_shiftl
*
* Description: Multiply vector of polynomials of Length K by 2^D without modular
*              reduction. Assumes input coefficients to be less than 2^{32-D}.
*
* Arguments:   - polyveck *v: pointer to input/output vector
**************************************************/
void PQCLEAN_DILITHIUM2_CLEAN_polyveck_shiftl(polyveck *v) {
    for (size_t i = 0; i < K; ++i) {
        PQCLEAN_DILITHIUM2_CLEAN_poly_shiftl(&v->vec[i]);
    }
}

/*************************************************
* Name:        PQCLEAN_DILITHIUM2_CLEAN_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 PQCLEAN_DILITHIUM2_CLEAN_polyveck_ntt(polyveck *v) {
    for (size_t i = 0; i < K; ++i) {
        PQCLEAN_DILITHIUM2_CLEAN_poly_ntt(&v->vec[i]);
    }
}

/*************************************************
* Name:        PQCLEAN_DILITHIUM2_CLEAN_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 PQCLEAN_DILITHIUM2_CLEAN_polyveck_invntt_montgomery(polyveck *v) {
    for (size_t i = 0; i < K; ++i) {
        PQCLEAN_DILITHIUM2_CLEAN_poly_invntt_montgomery(&v->vec[i]);
    }
}

/*************************************************
* Name:        PQCLEAN_DILITHIUM2_CLEAN_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 PQCLEAN_DILITHIUM2_CLEAN_polyveck_chknorm(const polyveck *v, uint32_t B) {
    for (size_t i = 0; i < K; ++i) {
        if (PQCLEAN_DILITHIUM2_CLEAN_poly_chknorm(&v->vec[i], B)) {
            return 1;
        }
    }

    return 0;
}

/*************************************************
* Name:        PQCLEAN_DILITHIUM2_CLEAN_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 PQCLEAN_DILITHIUM2_CLEAN_polyveck_power2round(
    polyveck *v1, polyveck *v0, const polyveck *v) {
    for (size_t i = 0; i < K; ++i) {
        PQCLEAN_DILITHIUM2_CLEAN_poly_power2round(&v1->vec[i], &v0->vec[i], &v->vec[i]);
    }
}

/*************************************************
* Name:        PQCLEAN_DILITHIUM2_CLEAN_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 PQCLEAN_DILITHIUM2_CLEAN_polyveck_decompose(
    polyveck *v1, polyveck *v0, const polyveck *v) {
    for (size_t i = 0; i < K; ++i) {
        PQCLEAN_DILITHIUM2_CLEAN_poly_decompose(&v1->vec[i], &v0->vec[i], &v->vec[i]);
    }
}

/*************************************************
* Name:        PQCLEAN_DILITHIUM2_CLEAN_polyveck_make_hint
*
* Description: Compute hint vector.
*
* Arguments:   - polyveck *h: pointer to output vector
*              - const polyveck *v0: pointer to low part of input vector
*              - const polyveck *v1: pointer to high part of input vector
*
* Returns number of 1 bits.
**************************************************/
uint32_t PQCLEAN_DILITHIUM2_CLEAN_polyveck_make_hint(
    polyveck *h,
    const polyveck *v0,
    const polyveck *v1) {
    uint32_t s = 0;

    for (size_t i = 0; i < K; ++i) {
        s += PQCLEAN_DILITHIUM2_CLEAN_poly_make_hint(
                 &h->vec[i], &v0->vec[i], &v1->vec[i]);
    }

    return s;
}

/*************************************************
* Name:        PQCLEAN_DILITHIUM2_CLEAN_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 *v: pointer to input vector
*              - const polyveck *h: pointer to input hint vector
**************************************************/
void PQCLEAN_DILITHIUM2_CLEAN_polyveck_use_hint(
    polyveck *w, const polyveck *v, const polyveck *h) {
    for (size_t i = 0; i < K; ++i) {
        PQCLEAN_DILITHIUM2_CLEAN_poly_use_hint(
            &w->vec[i], &v->vec[i], &h->vec[i]);
    }
}