mat.go

Documentation: github.com/cloudflare/circl/pke/kyber/kyber1024/internal

     1  // Code generated from kyber512/internal/mat.go by gen.go
     2  
     3  package internal
     4  
     5  import (
     6  	"github.com/cloudflare/circl/pke/kyber/internal/common"
     7  )
     8  
     9  // A k by k matrix of polynomials.
    10  type Mat [K]Vec
    11  
    12  // Expands the given seed to the corresponding matrix A or its transpose Aᵀ.
    13  func (m *Mat) Derive(seed *[32]byte, transpose bool) {
    14  	if !common.DeriveX4Available {
    15  		if transpose {
    16  			for i := 0; i < K; i++ {
    17  				for j := 0; j < K; j++ {
    18  					m[i][j].DeriveUniform(seed, uint8(i), uint8(j))
    19  				}
    20  			}
    21  		} else {
    22  			for i := 0; i < K; i++ {
    23  				for j := 0; j < K; j++ {
    24  					m[i][j].DeriveUniform(seed, uint8(j), uint8(i))
    25  				}
    26  			}
    27  		}
    28  		return
    29  	}
    30  
    31  	var ps [4]*common.Poly
    32  	var xs [4]uint8
    33  	var ys [4]uint8
    34  	x := uint8(0)
    35  	y := uint8(0)
    36  
    37  	for x != K {
    38  		idx := 0
    39  		for ; idx < 4; idx++ {
    40  			ps[idx] = &m[x][y]
    41  
    42  			if transpose {
    43  				xs[idx] = x
    44  				ys[idx] = y
    45  			} else {
    46  				xs[idx] = y
    47  				ys[idx] = x
    48  			}
    49  
    50  			y++
    51  			if y == K {
    52  				x++
    53  				y = 0
    54  
    55  				if x == K {
    56  					if idx == 0 {
    57  						// If there is just one left, then a plain DeriveUniform
    58  						// is quicker than the X4 variant.
    59  						ps[0].DeriveUniform(seed, xs[0], ys[0])
    60  						return
    61  					}
    62  
    63  					for idx++; idx < 4; idx++ {
    64  						ps[idx] = nil
    65  					}
    66  
    67  					break
    68  				}
    69  			}
    70  		}
    71  
    72  		common.PolyDeriveUniformX4(ps, seed, xs, ys)
    73  	}
    74  }
    75  
    76  // Transposes A in place.
    77  func (m *Mat) Transpose() {
    78  	for i := 0; i < K-1; i++ {
    79  		for j := i + 1; j < K; j++ {
    80  			t := m[i][j]
    81  			m[i][j] = m[j][i]
    82  			m[j][i] = t
    83  		}
    84  	}
    85  }
    86
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