github.com/cloudflare/circl@v1.5.0/sign/dilithium/mode2/internal/mat.go (about)

     1  // Code generated from mode3/internal/mat.go by gen.go
     2  
     3  package internal
     4  
     5  import (
     6  	common "github.com/cloudflare/circl/sign/internal/dilithium"
     7  )
     8  
     9  // A k by l matrix of polynomials.
    10  type Mat [K]VecL
    11  
    12  // Expands the given seed to a complete matrix.
    13  //
    14  // This function is called ExpandA in the specification.
    15  func (m *Mat) Derive(seed *[32]byte) {
    16  	if !DeriveX4Available {
    17  		for i := uint16(0); i < K; i++ {
    18  			for j := uint16(0); j < L; j++ {
    19  				PolyDeriveUniform(&m[i][j], seed, (i<<8)+j)
    20  			}
    21  		}
    22  		return
    23  	}
    24  
    25  	idx := 0
    26  	var nonces [4]uint16
    27  	var ps [4]*common.Poly
    28  	for i := uint16(0); i < K; i++ {
    29  		for j := uint16(0); j < L; j++ {
    30  			nonces[idx] = (i << 8) + j
    31  			ps[idx] = &m[i][j]
    32  			idx++
    33  			if idx == 4 {
    34  				idx = 0
    35  				PolyDeriveUniformX4(ps, seed, nonces)
    36  			}
    37  		}
    38  	}
    39  	if idx != 0 {
    40  		for i := idx; i < 4; i++ {
    41  			ps[i] = nil
    42  		}
    43  		PolyDeriveUniformX4(ps, seed, nonces)
    44  	}
    45  }
    46  
    47  // Set p to the inner product of a and b using pointwise multiplication.
    48  //
    49  // Assumes a and b are in Montgomery form and their coefficients are
    50  // pairwise sufficiently small to multiply, see Poly.MulHat().  Resulting
    51  // coefficients are bounded by 2Lq.
    52  func PolyDotHat(p *common.Poly, a, b *VecL) {
    53  	var t common.Poly
    54  	*p = common.Poly{} // zero p
    55  	for i := 0; i < L; i++ {
    56  		t.MulHat(&a[i], &b[i])
    57  		p.Add(&t, p)
    58  	}
    59  }