Add password hashing with argon2

internal/crypto/crypto.go

@@ -0,0 +1,21 @@
+package crypto
+
+import (
+	"crypto/rand"
+	"encoding/base64"
+	"log"
+
+	"golang.org/x/crypto/argon2"
+)
+
+func PasswordHash(password, salt string) string {
+	return string(argon2.Key([]byte(password), []byte(salt), 3, 32*1024, 4, 32))
+}
+
+func GenerateKey() string {
+	key := [32]byte{}
+	if _, err := rand.Read(key[:]); err != nil {
+		log.Fatal("can't generate a vaild key", err)
+	}
+	return base64.StdEncoding.EncodeToString(key[:])
+}