Added to hex and to base64 and from conversions

multiplatform-crypto-libsodium-bindings/src/commonMain/kotlin/com.ionspin.kotlin.crypto/util/LibsodiumUtil.kt

@@ -5,6 +5,11 @@ package com.ionspin.kotlin.crypto.util
  * ugljesa.jovanovic@ionspin.com
  * on 31-Aug-2020
  */
+
+enum class Base64Variants(val value: Int) {
+    ORIGINAL(1), ORIGINAL_NO_PADDING(3), URLSAFE(5), URLSAFE_NO_PADDING(7)
+}
+
 expect object LibsodiumUtil {
 
     fun memcmp(first: UByteArray, second: UByteArray) : Boolean
@@ -13,11 +18,11 @@ expect object LibsodiumUtil {
     fun pad(unpaddedData : UByteArray, blocksize: Int) : UByteArray
     fun unpad(paddedData: UByteArray, blocksize: Int) : UByteArray
 
-    fun toBase64(data: UByteArray) : String
+    fun toBase64(data: UByteArray, variant : Base64Variants = Base64Variants.URLSAFE_NO_PADDING) : String
     fun toHex(data: UByteArray) : String
     fun toString(data : UByteArray) : String
 
-    fun fromBase64(data: String) : UByteArray
+    fun fromBase64(data: String, variant : Base64Variants = Base64Variants.URLSAFE_NO_PADDING) : UByteArray
     fun fromHex(data: String) : UByteArray
     fun fromString(data: String) : UByteArray
 }