Final adjustments on the use of XChaCha

app/src/main/java/com/vitorpamplona/amethyst/service/CryptoUtils.kt

@@ -93,12 +93,12 @@ object CryptoUtils {
         )
     }
 
-    fun decryptXChaCha(encryptedInfo: EncryptedInfo, privateKey: ByteArray, pubKey: ByteArray): String {
+    fun decryptXChaCha(encryptedInfo: EncryptedInfo, privateKey: ByteArray, pubKey: ByteArray): String? {
         val sharedSecret = getSharedSecretXChaCha(privateKey, pubKey)
         return decryptXChaCha(encryptedInfo, sharedSecret)
     }
 
-    fun decryptXChaCha(encryptedInfo: EncryptedInfo, sharedSecret: ByteArray): String {
+    fun decryptXChaCha(encryptedInfo: EncryptedInfo, sharedSecret: ByteArray): String? {
         val lazySodium = LazySodiumAndroid(SodiumAndroid(), Base64MessageEncoder())
 
         val key = Key.fromBytes(sharedSecret)
@@ -111,7 +111,7 @@ object CryptoUtils {
             key = key
         )
 
-        return cipher.decodeToString()
+        return cipher?.decodeToString()
     }
 
     fun verifySignature(
@@ -221,9 +221,9 @@ private fun LazySodium.cryptoStreamXChaCha20Xor(
     messageBytes: ByteArray,
     nonce: ByteArray,
     key: Key
-): ByteArray {
+): ByteArray? {
     val mLen = messageBytes.size
     val cipher = ByteArray(mLen)
-    cryptoStreamXChaCha20Xor(cipher, messageBytes, mLen.toLong(), nonce, key.asBytes)
-    return cipher
+    val sucessful = cryptoStreamXChaCha20Xor(cipher, messageBytes, mLen.toLong(), nonce, key.asBytes)
+    return if (sucessful) cipher else null
 }

app/src/main/java/com/vitorpamplona/amethyst/service/model/GiftWrapEvent.kt

@@ -32,7 +32,7 @@ class GiftWrapEvent(
     fun unwrap(privKey: ByteArray) = try {
         plainContent(privKey)?.let { fromJson(it, Client.lenient) }
     } catch (e: Exception) {
-        Log.e("UnwrapError", "Couldn't Decrypt the content", e)
+        // Log.e("UnwrapError", "Couldn't Decrypt the content", e)
         null
     }
 

app/src/main/java/com/vitorpamplona/amethyst/service/model/SealedGossipEvent.kt

@@ -38,7 +38,7 @@ class SealedGossipEvent(
         if (content.isBlank()) return null
 
         return try {
-            val sharedSecret = CryptoUtils.getSharedSecret(privKey, pubKey.hexToByteArray())
+            val sharedSecret = CryptoUtils.getSharedSecretXChaCha(privKey, pubKey.hexToByteArray())
 
             val toDecrypt = gson.fromJson<EncryptedInfo>(
                 content,
@@ -71,7 +71,7 @@ class SealedGossipEvent(
             privateKey: ByteArray,
             createdAt: Long = TimeUtils.now()
         ): SealedGossipEvent {
-            val sharedSecret = CryptoUtils.getSharedSecret(privateKey, encryptTo.hexToByteArray())
+            val sharedSecret = CryptoUtils.getSharedSecretXChaCha(privateKey, encryptTo.hexToByteArray())
 
             val content = gson.toJson(
                 CryptoUtils.encryptXChaCha(