mosquitto-go-auth/hashing/argon2id.go

108 lines
2.8 KiB
Go

package hashing
import (
"crypto/rand"
"crypto/subtle"
"encoding/base64"
"fmt"
"strconv"
"strings"
"github.com/pkg/errors"
log "github.com/sirupsen/logrus"
"golang.org/x/crypto/argon2"
)
type argon2IDHasher struct {
saltSize int
iterations int
keyLen int
memory uint32
parallelism uint8
}
func NewArgon2IDHasher(saltSize int, iterations int, keylen int, memory uint32, parallelism uint8) HashComparer {
return argon2IDHasher{
saltSize: saltSize,
iterations: iterations,
keyLen: keylen,
memory: memory,
parallelism: parallelism,
}
}
// Hash generates a hashed password using Argon2ID.
func (h argon2IDHasher) Hash(password string) (string, error) {
salt := make([]byte, h.saltSize)
_, err := rand.Read(salt)
if err != nil {
return "", errors.Wrap(err, "read random bytes error")
}
return h.hashWithSalt(password, salt, h.memory, h.iterations, h.parallelism, h.keyLen), nil
}
// Compare checks that an argon2 generated password matches the password hash.
func (h argon2IDHasher) Compare(password string, passwordHash string) bool {
hashSplit := strings.Split(passwordHash, "$")
if hashSplit[1] != "argon2id" {
log.Errorf("unknown hash format: %s", hashSplit[1])
}
if len(hashSplit) != 6 {
log.Errorf("invalid hash supplied, expected 6 elements, got: %d", len(hashSplit))
return false
}
version, err := strconv.ParseInt(strings.TrimPrefix(hashSplit[2], "v="), 10, 32)
if err != nil {
log.Errorf("argon2id version parse error: %s", err)
return false
}
if version != argon2.Version {
log.Errorf("unknown argon2id version: %d", version)
return false
}
var memory, iterations uint32
var parallelism uint8
_, err = fmt.Sscanf(hashSplit[3], "m=%d,t=%d,p=%d", &memory, &iterations, &parallelism)
if err != nil {
log.Errorf("argon2id parameters parse error: %s", err)
return false
}
salt, err := base64.RawStdEncoding.DecodeString(hashSplit[4])
if err != nil {
log.Errorf("base64 salt error: %s", err)
return false
}
extractedHash, err := base64.RawStdEncoding.DecodeString(hashSplit[5])
if err != nil {
log.Errorf("argon2id decoding error: %s", err)
return false
}
keylen := uint32(len(extractedHash))
newHash := argon2.IDKey([]byte(password), salt, iterations, memory, parallelism, keylen)
if subtle.ConstantTimeCompare(newHash, extractedHash) == 1 {
return true
}
return false
}
func (h argon2IDHasher) hashWithSalt(password string, salt []byte, memory uint32, iterations int, parallelism uint8, keylen int) string {
hashedPassword := argon2.IDKey([]byte(password), salt, uint32(iterations), memory, parallelism, uint32(keylen))
b64salt := base64.RawStdEncoding.EncodeToString(salt)
b64Hash := base64.RawStdEncoding.EncodeToString(hashedPassword)
return fmt.Sprintf("$argon2id$v=%d$m=%d,t=%d,p=%d$%s$%s", argon2.Version, h.memory, h.iterations, h.parallelism, b64salt, b64Hash)
}