Use 8 bytes to hash UpgradeConfig

nytzuga · nytzuga · commit a3a6471b9498 · 2023-09-08T02:42:59.000-04:00
8 bytes is generally enough to fingerprint the UpgradeConfig changes, so nodes can exchange the hash as part of the handshake[1] [1] https://stackoverflow.com/questions/18134627/how-much-of-a-git-sha-is-generally-considered-necessary-to-uniquely-identify-a
diff --git a/plugin/evm/message/handshake/upgrade_config.go b/plugin/evm/message/handshake/upgrade_config.go
@@ -111,6 +111,9 @@ func (r *UpgradeConfig) Bytes() []byte {
 	return r.bytes
 }
 
-func (r *UpgradeConfig) Hash() [32]byte {
-	return sha256.Sum256(r.bytes)
+func (r *UpgradeConfig) Hash() [8]byte {
+	hash := sha256.Sum256(r.bytes)
+	var firstBytes [8]byte
+	copy(firstBytes[:], hash[:8])
+	return firstBytes
 }

Original file line number	Diff line number	Diff line change
`@@ -111,6 +111,9 @@ func (r *UpgradeConfig) Bytes() []byte {`
`111`	`111`	`return r.bytes`
`112`	`112`	`}`
`113`	`113`
`114`		`-func (r *UpgradeConfig) Hash() [32]byte {`
`115`		`- return sha256.Sum256(r.bytes)`
	`114`	`+func (r *UpgradeConfig) Hash() [8]byte {`
	`115`	`+ hash := sha256.Sum256(r.bytes)`
	`116`	`+ var firstBytes [8]byte`
	`117`	`+ copy(firstBytes[:], hash[:8])`
	`118`	`+ return firstBytes`
`116`	`119`	`}`