From bca3728a10fcaf88d8a899063608986fdd084712 Mon Sep 17 00:00:00 2001
From: Luke Parker <lukeparker5132@gmail.com>
Date: Sat, 23 Mar 2024 00:09:23 -0400
Subject: [PATCH] Randomly select an addr from the authority discovery

---
 Cargo.lock                |  1 +
 substrate/node/Cargo.toml |  1 +
 substrate/node/src/rpc.rs | 15 +++++++++++----
 3 files changed, 13 insertions(+), 4 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index 9c5d097e..1ae1d463 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -7625,6 +7625,7 @@ dependencies = [
  "hex",
  "jsonrpsee",
  "pallet-transaction-payment-rpc",
+ "rand_core",
  "sc-authority-discovery",
  "sc-basic-authorship",
  "sc-cli",
diff --git a/substrate/node/Cargo.toml b/substrate/node/Cargo.toml
index f66a9705..12ba4d17 100644
--- a/substrate/node/Cargo.toml
+++ b/substrate/node/Cargo.toml
@@ -23,6 +23,7 @@ name = "serai-node"
 zeroize = "1"
 hex = "0.4"
 
+rand_core = "0.6"
 schnorrkel = "0.11"
 
 sp-core = { git = "https://github.com/serai-dex/substrate" }
diff --git a/substrate/node/src/rpc.rs b/substrate/node/src/rpc.rs
index f5ed2582..d07778cc 100644
--- a/substrate/node/src/rpc.rs
+++ b/substrate/node/src/rpc.rs
@@ -1,5 +1,7 @@
 use std::{sync::Arc, collections::HashSet};
 
+use rand_core::{RngCore, OsRng};
+
 use sp_blockchain::{Error as BlockchainError, HeaderBackend, HeaderMetadata};
 use sp_block_builder::BlockBuilder;
 use sp_api::ProvideRuntimeApi;
@@ -72,14 +74,19 @@ where
             .get_addresses_by_authority_id(validator.into())
             .await
             .unwrap_or_else(HashSet::new)
-            .into_iter();
-          // Only take a single address
+            .into_iter()
+            .collect::<Vec<_>>();
+          // Randomly select an address
           // There should be one, there may be two if their IP address changed, and more should only
           // occur if they have multiple proxies/an IP address changing frequently/some issue
           // preventing consistent self-identification
           // It isn't beneficial to use multiple addresses for a single peer here
-          if let Some(address) = returned_addresses.next() {
-            all_p2p_addresses.push(address);
+          if !returned_addresses.is_empty() {
+            all_p2p_addresses.push(
+              returned_addresses.remove(
+                usize::try_from(OsRng.next_u64() >> 32).unwrap() % returned_addresses.len(),
+              ),
+            );
           }
         }
         Ok(all_p2p_addresses)