Catch exceptions during peer storage deserialization

In some cases, the peer storage we receive could be empty or truncated.
We want to be safe and correctly catch every exception possible when
deserializing, because we don't want the app to crash and the user to
be stuck.

Author: t-bast

modules/core/src/commonMain/kotlin/fr/acinq/lightning/serialization/channel/Encryption.kt

@@ -90,22 +90,25 @@ object Encryption {
     }
 
     private fun fromEncryptedPeerStorageCurrent(key: PrivateKey, encryptedPeerStorage: EncryptedPeerStorage): Result<Serialization.PeerStorageDeserializationResult> {
-        // data is prefixed by 1 byte of serialization meta-info
-        return runCatching { decrypt(key.value, encryptedPeerStorage.data.drop(1).toByteArray()) }
-            .map { Serialization.deserializePeerStorage(encryptedPeerStorage.data[0], it) }
+        // Data should be prefixed by 1 byte of serialization meta-info, if this is a recent peer storage.
+        return runCatching {
+            val decrypted = decrypt(key.value, encryptedPeerStorage.data.drop(1).toByteArray())
+            Serialization.deserializePeerStorage(encryptedPeerStorage.data[0], decrypted)
+        }
     }
 
     /**
-     * Backward compatibility for an older backup mechanism where each channel data was stored individually, and restored from channel_reestablish messages.
+     * Backwards-compatibility for an older backup mechanism where each channel data was stored individually, and restored from channel_reestablish messages.
      */
     private fun fromEncryptedPeerStorageLegacyChannelData(key: PrivateKey, encryptedPeerStorage: EncryptedPeerStorage): Result<Serialization.PeerStorageDeserializationResult> {
-        // The blob is a list of individually encrypted channel data (because each of them was previously stored separately)
+        // The blob should be a list of individually encrypted channel data (because each of them was previously stored separately).
         val input = ByteArrayInput(encryptedPeerStorage.data.toByteArray())
-        val encryptedChannelDatas = input.readCollection { input.readDelimitedByteArray() }.toList()
-        val res: List<Result<Serialization.DeserializationResult>> = encryptedChannelDatas.map { data ->
+        val encryptedChannelDatas = runCatching { input.readCollection { input.readDelimitedByteArray() }.toList() }
+            .getOrDefault(listOf())
+        val res = encryptedChannelDatas.map { data ->
             runCatching { decrypt(key.value, data.drop(2).toByteArray()) }
                 .recoverCatching { decrypt(key.value, data) }
-                .map { Serialization.deserialize(it) }
+                .mapCatching { Serialization.deserialize(it) }
         }
 
         val states = res.mapNotNull { it.getOrNull() }.filterIsInstance<Serialization.DeserializationResult.Success>().map { it.state }