vikunja-api/vendor/github.com/boombuler/barcode/utils/reedsolomon.go
konrad 24904585a2 Add 2fa for authentification (#383)
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: https://kolaente.dev/vikunja/api/pulls/383
2020-04-17 19:25:35 +00:00

44 lines
1.1 KiB
Go

package utils
import (
"sync"
)
type ReedSolomonEncoder struct {
gf *GaloisField
polynomes []*GFPoly
m *sync.Mutex
}
func NewReedSolomonEncoder(gf *GaloisField) *ReedSolomonEncoder {
return &ReedSolomonEncoder{
gf, []*GFPoly{NewGFPoly(gf, []int{1})}, new(sync.Mutex),
}
}
func (rs *ReedSolomonEncoder) getPolynomial(degree int) *GFPoly {
rs.m.Lock()
defer rs.m.Unlock()
if degree >= len(rs.polynomes) {
last := rs.polynomes[len(rs.polynomes)-1]
for d := len(rs.polynomes); d <= degree; d++ {
next := last.Multiply(NewGFPoly(rs.gf, []int{1, rs.gf.ALogTbl[d-1+rs.gf.Base]}))
rs.polynomes = append(rs.polynomes, next)
last = next
}
}
return rs.polynomes[degree]
}
func (rs *ReedSolomonEncoder) Encode(data []int, eccCount int) []int {
generator := rs.getPolynomial(eccCount)
info := NewGFPoly(rs.gf, data)
info = info.MultByMonominal(eccCount, 1)
_, remainder := info.Divide(generator)
result := make([]int, eccCount)
numZero := int(eccCount) - len(remainder.Coefficients)
copy(result[numZero:], remainder.Coefficients)
return result
}