Files
go-sdk/utils/hash.go
2025-10-18 21:00:52 +02:00

76 lines
1.8 KiB
Go

package utils
import (
"crypto/rand"
"crypto/subtle"
"encoding/base64"
"fmt"
"strings"
"golang.org/x/crypto/argon2"
)
var (
Time uint32 = 3
Memory uint32 = 64 * 1024 // 64 MiB (in KiB)
Threads uint8 = 4
KeyLen uint32 = 32
SaltLen int = 16
)
// HashPassword hashes a password using Argon2.
func HashPassword(password string) (string, error) {
salt := make([]byte, SaltLen)
if _, err := rand.Read(salt); err != nil {
return "", err
}
hash := argon2.IDKey([]byte(password), salt, Time, Memory, Threads, KeyLen)
// Encode salt and hash to base64
b64Salt := base64.RawStdEncoding.EncodeToString(salt)
b64Hash := base64.RawStdEncoding.EncodeToString(hash)
// Format is $argon2id$v=19$m=...,t=...,p=...$salt$hash
encodedHash := fmt.Sprintf("$argon2id$v=%d$m=%d,t=%d,p=%d$%s$%s",
argon2.Version, Memory, Time, Threads, b64Salt, b64Hash)
return encodedHash, nil
}
// ComparePassword verifies a password against an Argon2 hash.
func ComparePassword(password, encodedHash string) (bool, error) {
parts := strings.Split(encodedHash, "$")
if len(parts) != 6 {
return false, fmt.Errorf("invalid hash format")
}
var version, m, t, p int
_, err := fmt.Sscanf(parts[2], "v=%d", &version)
if err != nil {
return false, err
}
if version != argon2.Version {
return false, fmt.Errorf("incompatible version")
}
_, err = fmt.Sscanf(parts[3], "m=%d,t=%d,p=%d", &m, &t, &p)
if err != nil {
return false, err
}
salt, err := base64.RawStdEncoding.DecodeString(parts[4])
if err != nil {
return false, err
}
hash, err := base64.RawStdEncoding.DecodeString(parts[5])
if err != nil {
return false, err
}
otherHash := argon2.IDKey([]byte(password), salt, uint32(t), uint32(m), uint8(p), uint32(len(hash)))
return subtle.ConstantTimeCompare(hash, otherHash) == 1, nil
}