From 59beaf58f7d050a5b425802ce391995b322002c6 Mon Sep 17 00:00:00 2001
From: Austin Chandra <austinchandra@berkeley.edu>
Date: Wed, 30 Nov 2022 11:37:42 -0800
Subject: [PATCH] Add random opcode using consensus hash

---
 x/evm/keeper/state_transition.go | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/x/evm/keeper/state_transition.go b/x/evm/keeper/state_transition.go
index 3103a45cad..20f9645747 100644
--- a/x/evm/keeper/state_transition.go
+++ b/x/evm/keeper/state_transition.go
@@ -79,6 +79,10 @@ func (k *Keeper) NewEVM(
 	tracer vm.EVMLogger,
 	stateDB vm.StateDB,
 ) evm.EVM {
+	header := ctx.BlockHeader()
+	// Use EvidenceHash (parallel to MixDigest on Ethereum block)
+	random := common.BytesToHash(header.EvidenceHash)
+
 	blockCtx := vm.BlockContext{
 		CanTransfer: core.CanTransfer,
 		Transfer:    core.Transfer,
@@ -86,9 +90,10 @@ func (k *Keeper) NewEVM(
 		Coinbase:    cfg.CoinBase,
 		GasLimit:    ethermint.BlockGasLimit(ctx),
 		BlockNumber: big.NewInt(ctx.BlockHeight()),
-		Time:        big.NewInt(ctx.BlockHeader().Time.Unix()),
+		Time:        big.NewInt(header.Time.Unix()),
 		Difficulty:  big.NewInt(0), // unused. Only required in PoW context
 		BaseFee:     cfg.BaseFee,
+		Random:      &random,
 	}
 
 	txCtx := core.NewEVMTxContext(msg)