Add delegated xchacha20poly1305 decrypt

multiplatform-crypto-delegated/src/jsMain/kotlin/com/ionspin/kotlin/crypto/JsSodiumInterface.kt

@@ -50,6 +50,7 @@ interface JsSodiumInterface {
 
     //decrypt
     fun crypto_secretstream_xchacha20poly1305_init_pull(header: Uint8Array, key: Uint8Array) : dynamic
+    fun crypto_secretstream_xchacha20poly1305_pull(state: dynamic, ciphertext: Uint8Array, additionalData: Uint8Array) : dynamic
 
 
 }

multiplatform-crypto-delegated/src/jsMain/kotlin/com/ionspin/kotlin/crypto/authenticated/XChaCha20Poly1305Delegated.kt

@@ -1,6 +1,8 @@
 package com.ionspin.kotlin.crypto.authenticated
 
+import com.ionspin.kotlin.crypto.InvalidTagException
 import com.ionspin.kotlin.crypto.getSodium
+import com.ionspin.kotlin.crypto.util.hexColumsPrint
 import ext.libsodium.com.ionspin.kotlin.crypto.toUByteArray
 import ext.libsodium.com.ionspin.kotlin.crypto.toUInt8Array
 import org.khronos.webgl.Uint8Array
@@ -84,7 +86,15 @@ actual class XChaCha20Poly1305Delegated internal actual constructor() {
     }
 
     actual fun decrypt(data: UByteArray, additionalData: UByteArray): UByteArray {
-        TODO("not implemented yet")
+        val decryptedWithTag = getSodium().crypto_secretstream_xchacha20poly1305_pull(state, data.toUInt8Array(), additionalData.toUInt8Array())
+        val decrypted = decryptedWithTag.message as Uint8Array
+        val validTag = decryptedWithTag.tag as UInt
+
+        if (validTag != 0U) {
+            println("Tag validation failed")
+            throw InvalidTagException()
+        }
+        return decrypted.toUByteArray()
     }