Remove cost and just use defaultCost

bcrypt/verifier.go

@@ -7,9 +7,7 @@ import (
 )
 
 // Verifier verifys passwords using Bcrypt.
-type Verifier struct {
-	cost int
-}
+type Verifier struct{}
 
 // Verify verifys a Password.
 func (bv *Verifier) Verify(password string, hashOnDB string) error {
@@ -23,7 +21,7 @@ func (bv *Verifier) Verify(password string, hashOnDB string) error {
 
 // Hash calculates a hash to be stored on the database.
 func (bv *Verifier) Hash(password string) (string, error) {
-	hash, err := bcrypt.GenerateFromPassword([]byte(password), bv.cost)
+	hash, err := bcrypt.GenerateFromPassword([]byte(password), bcrypt.DefaultCost)
 	if err != nil {
 		return "", fmt.Errorf("hash password: %w", err)
 	}