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

vendor/github.com/boombuler/barcode/utils/galoisfield.go

@@ -0,0 +1,65 @@
+package utils
+
+// GaloisField encapsulates galois field arithmetics
+type GaloisField struct {
+	Size    int
+	Base    int
+	ALogTbl []int
+	LogTbl  []int
+}
+
+// NewGaloisField creates a new galois field
+func NewGaloisField(pp, fieldSize, b int) *GaloisField {
+	result := new(GaloisField)
+
+	result.Size = fieldSize
+	result.Base = b
+	result.ALogTbl = make([]int, fieldSize)
+	result.LogTbl = make([]int, fieldSize)
+
+	x := 1
+	for i := 0; i < fieldSize; i++ {
+		result.ALogTbl[i] = x
+		x = x * 2
+		if x >= fieldSize {
+			x = (x ^ pp) & (fieldSize - 1)
+		}
+	}
+
+	for i := 0; i < fieldSize; i++ {
+		result.LogTbl[result.ALogTbl[i]] = int(i)
+	}
+
+	return result
+}
+
+func (gf *GaloisField) Zero() *GFPoly {
+	return NewGFPoly(gf, []int{0})
+}
+
+// AddOrSub add or substract two numbers
+func (gf *GaloisField) AddOrSub(a, b int) int {
+	return a ^ b
+}
+
+// Multiply multiplys two numbers
+func (gf *GaloisField) Multiply(a, b int) int {
+	if a == 0 || b == 0 {
+		return 0
+	}
+	return gf.ALogTbl[(gf.LogTbl[a]+gf.LogTbl[b])%(gf.Size-1)]
+}
+
+// Divide divides two numbers
+func (gf *GaloisField) Divide(a, b int) int {
+	if b == 0 {
+		panic("divide by zero")
+	} else if a == 0 {
+		return 0
+	}
+	return gf.ALogTbl[(gf.LogTbl[a]-gf.LogTbl[b])%(gf.Size-1)]
+}
+
+func (gf *GaloisField) Invers(num int) int {
+	return gf.ALogTbl[(gf.Size-1)-gf.LogTbl[num]]
+}