From 9c2ac6fbd5a12b3f30feb78f3d358dca31603a86 Mon Sep 17 00:00:00 2001
From: Felix Lange <fjl@twurst.com>
Date: Fri, 31 Jul 2020 16:20:31 +0200
Subject: [PATCH] rpc: remove silly use of ReadVarint in subscription ID
 generator (#21391)

Found by @protolambda
---
 rpc/subscription.go | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/rpc/subscription.go b/rpc/subscription.go
index f9d60dcb98..233215d792 100644
--- a/rpc/subscription.go
+++ b/rpc/subscription.go
@@ -17,7 +17,6 @@
 package rpc
 
 import (
-	"bufio"
 	"container/list"
 	"context"
 	crand "crypto/rand"
@@ -51,10 +50,14 @@ func NewID() ID {
 
 // randomIDGenerator returns a function generates a random IDs.
 func randomIDGenerator() func() ID {
-	seed, err := binary.ReadVarint(bufio.NewReader(crand.Reader))
-	if err != nil {
+	var buf = make([]byte, 8)
+	var seed int64
+	if _, err := crand.Read(buf); err == nil {
+		seed = int64(binary.BigEndian.Uint64(buf))
+	} else {
 		seed = int64(time.Now().Nanosecond())
 	}
+
 	var (
 		mu  sync.Mutex
 		rng = rand.New(rand.NewSource(seed))