forked from vikunja/vikunja
konrad
24904585a2
Fix user tests Add swagger docs Fix lint Add totp check when logging in Make totp enrollment work Add migration for totp table go mod vendor Add routes for totp routes Add route handler for totp routes Add basic implementation to enroll a user in totp Co-authored-by: kolaente <k@knt.li> Reviewed-on: vikunja/api#383
104 lines
2.8 KiB
Go
104 lines
2.8 KiB
Go
package utils
|
|
|
|
type GFPoly struct {
|
|
gf *GaloisField
|
|
Coefficients []int
|
|
}
|
|
|
|
func (gp *GFPoly) Degree() int {
|
|
return len(gp.Coefficients) - 1
|
|
}
|
|
|
|
func (gp *GFPoly) Zero() bool {
|
|
return gp.Coefficients[0] == 0
|
|
}
|
|
|
|
// GetCoefficient returns the coefficient of x ^ degree
|
|
func (gp *GFPoly) GetCoefficient(degree int) int {
|
|
return gp.Coefficients[gp.Degree()-degree]
|
|
}
|
|
|
|
func (gp *GFPoly) AddOrSubstract(other *GFPoly) *GFPoly {
|
|
if gp.Zero() {
|
|
return other
|
|
} else if other.Zero() {
|
|
return gp
|
|
}
|
|
smallCoeff := gp.Coefficients
|
|
largeCoeff := other.Coefficients
|
|
if len(smallCoeff) > len(largeCoeff) {
|
|
largeCoeff, smallCoeff = smallCoeff, largeCoeff
|
|
}
|
|
sumDiff := make([]int, len(largeCoeff))
|
|
lenDiff := len(largeCoeff) - len(smallCoeff)
|
|
copy(sumDiff, largeCoeff[:lenDiff])
|
|
for i := lenDiff; i < len(largeCoeff); i++ {
|
|
sumDiff[i] = int(gp.gf.AddOrSub(int(smallCoeff[i-lenDiff]), int(largeCoeff[i])))
|
|
}
|
|
return NewGFPoly(gp.gf, sumDiff)
|
|
}
|
|
|
|
func (gp *GFPoly) MultByMonominal(degree int, coeff int) *GFPoly {
|
|
if coeff == 0 {
|
|
return gp.gf.Zero()
|
|
}
|
|
size := len(gp.Coefficients)
|
|
result := make([]int, size+degree)
|
|
for i := 0; i < size; i++ {
|
|
result[i] = int(gp.gf.Multiply(int(gp.Coefficients[i]), int(coeff)))
|
|
}
|
|
return NewGFPoly(gp.gf, result)
|
|
}
|
|
|
|
func (gp *GFPoly) Multiply(other *GFPoly) *GFPoly {
|
|
if gp.Zero() || other.Zero() {
|
|
return gp.gf.Zero()
|
|
}
|
|
aCoeff := gp.Coefficients
|
|
aLen := len(aCoeff)
|
|
bCoeff := other.Coefficients
|
|
bLen := len(bCoeff)
|
|
product := make([]int, aLen+bLen-1)
|
|
for i := 0; i < aLen; i++ {
|
|
ac := int(aCoeff[i])
|
|
for j := 0; j < bLen; j++ {
|
|
bc := int(bCoeff[j])
|
|
product[i+j] = int(gp.gf.AddOrSub(int(product[i+j]), gp.gf.Multiply(ac, bc)))
|
|
}
|
|
}
|
|
return NewGFPoly(gp.gf, product)
|
|
}
|
|
|
|
func (gp *GFPoly) Divide(other *GFPoly) (quotient *GFPoly, remainder *GFPoly) {
|
|
quotient = gp.gf.Zero()
|
|
remainder = gp
|
|
fld := gp.gf
|
|
denomLeadTerm := other.GetCoefficient(other.Degree())
|
|
inversDenomLeadTerm := fld.Invers(int(denomLeadTerm))
|
|
for remainder.Degree() >= other.Degree() && !remainder.Zero() {
|
|
degreeDiff := remainder.Degree() - other.Degree()
|
|
scale := int(fld.Multiply(int(remainder.GetCoefficient(remainder.Degree())), inversDenomLeadTerm))
|
|
term := other.MultByMonominal(degreeDiff, scale)
|
|
itQuot := NewMonominalPoly(fld, degreeDiff, scale)
|
|
quotient = quotient.AddOrSubstract(itQuot)
|
|
remainder = remainder.AddOrSubstract(term)
|
|
}
|
|
return
|
|
}
|
|
|
|
func NewMonominalPoly(field *GaloisField, degree int, coeff int) *GFPoly {
|
|
if coeff == 0 {
|
|
return field.Zero()
|
|
}
|
|
result := make([]int, degree+1)
|
|
result[0] = coeff
|
|
return NewGFPoly(field, result)
|
|
}
|
|
|
|
func NewGFPoly(field *GaloisField, coefficients []int) *GFPoly {
|
|
for len(coefficients) > 1 && coefficients[0] == 0 {
|
|
coefficients = coefficients[1:]
|
|
}
|
|
return &GFPoly{field, coefficients}
|
|
}
|