Files

45 lines
1.0 KiB
Go

package password
import (
"crypto/sha256"
"encoding/hex"
"errors"
"strings"
"unicode/utf8"
"golang.org/x/crypto/bcrypt"
)
const prefix = "bcrypt:v1:"
const minLength = 6
var ErrInvalidEncoding = errors.New("password hash encoding is invalid")
func Encode(value string) (string, error) {
length := utf8.RuneCountInString(value)
if !utf8.ValidString(value) || length < minLength || length > 1024 {
return "", ErrInvalidEncoding
}
hash, err := bcrypt.GenerateFromPassword(bcryptInput(value), bcrypt.DefaultCost)
if err != nil {
return "", err
}
return prefix + string(hash), nil
}
func Verify(encoded, value string) bool {
if !strings.HasPrefix(encoded, prefix) || !utf8.ValidString(value) || utf8.RuneCountInString(value) > 1024 {
return false
}
return bcrypt.CompareHashAndPassword([]byte(strings.TrimPrefix(encoded, prefix)), bcryptInput(value)) == nil
}
func bcryptInput(value string) []byte {
raw := []byte(value)
if len(raw) <= 72 {
return raw
}
digest := sha256.Sum256(raw)
return []byte("sha256:" + hex.EncodeToString(digest[:]))
}