From 665a44646e9453e37c8a73bdd2c94ba7dc1e7c0a Mon Sep 17 00:00:00 2001
From: obscuren <geffobscura@gmail.com>
Date: Wed, 29 Oct 2014 10:29:22 +0100
Subject: [PATCH] Generic hashing method

---
 ethchain/derive_sha.go | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)
 create mode 100644 ethchain/derive_sha.go

diff --git a/ethchain/derive_sha.go b/ethchain/derive_sha.go
new file mode 100644
index 000000000..b41252e39
--- /dev/null
+++ b/ethchain/derive_sha.go
@@ -0,0 +1,20 @@
+package ethchain
+
+import (
+	"github.com/ethereum/go-ethereum/ethtrie"
+	"github.com/ethereum/go-ethereum/ethutil"
+)
+
+type DerivableList interface {
+	Len() int
+	GetRlp(i int) []byte
+}
+
+func DeriveSha(list DerivableList) []byte {
+	trie := ethtrie.New(ethutil.Config.Db, "")
+	for i := 0; i < list.Len(); i++ {
+		trie.Update(string(ethutil.NewValue(i).Encode()), string(list.GetRlp(i)))
+	}
+
+	return trie.GetRoot()
+}