From 661d0fd7e8055b9710a73a3967041cb14363a6d0 Mon Sep 17 00:00:00 2001
From: Ethan Buchman <ethan@coinculture.info>
Date: Sun, 11 Mar 2018 00:57:39 +0100
Subject: [PATCH] types: StdSignDoc includes sequence for each sig

---
 examples/basecoin/app/app_test.go | 14 +++++++-------
 types/tx_msg.go                   | 19 ++++++++++---------
 x/auth/ante.go                    | 12 +++++++-----
 3 files changed, 24 insertions(+), 21 deletions(-)

diff --git a/examples/basecoin/app/app_test.go b/examples/basecoin/app/app_test.go
index 595d75f380..148f0411fc 100644
--- a/examples/basecoin/app/app_test.go
+++ b/examples/basecoin/app/app_test.go
@@ -69,9 +69,9 @@ func TestMsgs(t *testing.T) {
 	}
 
 	chainID := ""
-	sequence := int64(0)
+	sequences := []int64{0}
 	for i, m := range msgs {
-		sig := priv1.Sign(sdk.StdSignBytes(chainID, sequence, m.msg))
+		sig := priv1.Sign(sdk.StdSignBytes(chainID, sequences, m.msg))
 		tx := sdk.NewStdTx(m.msg, []sdk.StdSignature{{
 			PubKey:    priv1.PubKey(),
 			Signature: sig,
@@ -169,8 +169,8 @@ func TestSendMsgWithAccounts(t *testing.T) {
 
 	// Sign the tx
 	chainID := "" // TODO: InitChain should get the ChainID
-	sequence := int64(0)
-	sig := priv1.Sign(sdk.StdSignBytes(chainID, sequence, sendMsg))
+	sequences := []int64{0}
+	sig := priv1.Sign(sdk.StdSignBytes(chainID, sequences, sendMsg))
 	tx := sdk.NewStdTx(sendMsg, []sdk.StdSignature{{
 		PubKey:    priv1.PubKey(),
 		Signature: sig,
@@ -197,13 +197,13 @@ func TestSendMsgWithAccounts(t *testing.T) {
 	assert.Equal(t, sdk.CodeInvalidSequence, res.Code, res.Log)
 
 	// bumping the txnonce number without resigning should be an auth error
-	sequence += 1
-	tx.Signatures[0].Sequence = sequence
+	tx.Signatures[0].Sequence = 1
 	res = bapp.Deliver(tx)
 	assert.Equal(t, sdk.CodeUnauthorized, res.Code, res.Log)
 
 	// resigning the tx with the bumped sequence should work
-	sig = priv1.Sign(sdk.StdSignBytes(chainID, sequence, tx.Msg))
+	sequences = []int64{1}
+	sig = priv1.Sign(sdk.StdSignBytes(chainID, sequences, tx.Msg))
 	tx.Signatures[0].Signature = sig
 	res = bapp.Deliver(tx)
 	assert.Equal(t, sdk.CodeOK, res.Code, res.Log)
diff --git a/types/tx_msg.go b/types/tx_msg.go
index c88107c518..63f9347265 100644
--- a/types/tx_msg.go
+++ b/types/tx_msg.go
@@ -71,19 +71,20 @@ func (tx StdTx) GetSignatures() []StdSignature { return tx.Signatures }
 // StdSignDoc is replay-prevention structure.
 // It includes the result of msg.GetSignBytes(),
 // as well as the ChainID (prevent cross chain replay)
-// and the Sequence (prevent inchain replay).
+// and the Sequence numbers for each signature (prevent
+// inchain replay and enforce tx ordering per account).
 type StdSignDoc struct {
-	ChainID  string `json:"chain_id"`
-	Sequence int64  `json:"sequence"`
-	MsgBytes []byte `json:"msg_bytes"`
-	AltBytes []byte `json:"alt_bytes"` // TODO: do we really want this ?
+	ChainID   string  `json:"chain_id"`
+	Sequences []int64 `json:"sequences"`
+	MsgBytes  []byte  `json:"msg_bytes"`
+	AltBytes  []byte  `json:"alt_bytes"` // TODO: do we really want this ?
 }
 
-func StdSignBytes(chainID string, sequence int64, msg Msg) []byte {
+func StdSignBytes(chainID string, sequences []int64, msg Msg) []byte {
 	bz, err := json.Marshal(StdSignDoc{
-		ChainID:  chainID,
-		Sequence: sequence,
-		MsgBytes: msg.GetSignBytes(),
+		ChainID:   chainID,
+		Sequences: sequences,
+		MsgBytes:  msg.GetSignBytes(),
 	})
 	if err != nil {
 		panic(err)
diff --git a/x/auth/ante.go b/x/auth/ante.go
index 7ab677e88d..f54435e21a 100644
--- a/x/auth/ante.go
+++ b/x/auth/ante.go
@@ -31,15 +31,17 @@ func NewAnteHandler(accountMapper sdk.AccountMapper) sdk.AnteHandler {
 		// Collect accounts to set in the context
 		var signerAccs = make([]sdk.Account, len(signerAddrs))
 
-		// First sig is the fee payer.
-		// signBytes uses the sequence of the fee payer
-		// (ie. the first account)
-		payerAddr, payerSig := signerAddrs[0], sigs[0]
-		signBytes := sdk.StdSignBytes(ctx.ChainID(), payerSig.Sequence, msg)
+		// Get the sign bytes by collecting all sequence numbers
+		sequences := make([]int64, len(signerAddrs))
+		for i := 0; i < len(signerAddrs); i++ {
+			sequences[i] = sigs[i].Sequence
+		}
+		signBytes := sdk.StdSignBytes(ctx.ChainID(), sequences, msg)
 
 		// Check fee payer sig and nonce, and deduct fee.
 		// This is done first because it only
 		// requires fetching 1 account.
+		payerAddr, payerSig := signerAddrs[0], sigs[0]
 		payerAcc, res := processSig(ctx, accountMapper, payerAddr, payerSig, signBytes)
 		if !res.IsOK() {
 			return ctx, res, true