From 50e4d31149a2155ee205622ce67b39eb48c26d20 Mon Sep 17 00:00:00 2001
From: rigel rozanski <rigel.rozanski@gmail.com>
Date: Tue, 11 Jul 2017 20:00:39 -0400
Subject: [PATCH] working nonce module

---
 app/app.go                   |  2 ++
 cmd/basecli/commands/cmds.go |  4 +++
 modules/nonce/replaycheck.go | 45 +++++++++++++++++++++++
 modules/nonce/tx.go          | 69 ++++++++++++++++++++++++++++++++++++
 4 files changed, 120 insertions(+)
 create mode 100644 modules/nonce/replaycheck.go
 create mode 100644 modules/nonce/tx.go

diff --git a/app/app.go b/app/app.go
index 836e8c66f..313c71933 100644
--- a/app/app.go
+++ b/app/app.go
@@ -15,6 +15,7 @@ import (
 	"github.com/tendermint/basecoin/modules/base"
 	"github.com/tendermint/basecoin/modules/coin"
 	"github.com/tendermint/basecoin/modules/fee"
+	"github.com/tendermint/basecoin/modules/nonce"
 	"github.com/tendermint/basecoin/stack"
 	sm "github.com/tendermint/basecoin/state"
 	"github.com/tendermint/basecoin/version"
@@ -61,6 +62,7 @@ func DefaultHandler(feeDenom string) basecoin.Handler {
 		base.Logger{},
 		stack.Recovery{},
 		auth.Signatures{},
+		nonce.ReplayCheck{},
 		base.Chain{},
 		fee.NewSimpleFeeMiddleware(coin.Coin{feeDenom, 0}, fee.Bank),
 	).Use(d)
diff --git a/cmd/basecli/commands/cmds.go b/cmd/basecli/commands/cmds.go
index 631c371d6..d069a838a 100644
--- a/cmd/basecli/commands/cmds.go
+++ b/cmd/basecli/commands/cmds.go
@@ -17,6 +17,7 @@ import (
 	"github.com/tendermint/basecoin/modules/base"
 	"github.com/tendermint/basecoin/modules/coin"
 	"github.com/tendermint/basecoin/modules/fee"
+	"github.com/tendermint/basecoin/modules/nonce"
 )
 
 //-------------------------
@@ -74,6 +75,9 @@ func doSendTx(cmd *cobra.Command, args []string) error {
 		return err
 	}
 
+	// XXX - what is the nonceAccount here!!!
+	tx = nonce.NewTx(tx, viper.GetInt(FlagSequence), nonceAccount)
+
 	// Note: this is single sig (no multi sig yet)
 	stx := auth.NewSig(tx)
 
diff --git a/modules/nonce/replaycheck.go b/modules/nonce/replaycheck.go
new file mode 100644
index 000000000..9e75f0b18
--- /dev/null
+++ b/modules/nonce/replaycheck.go
@@ -0,0 +1,45 @@
+package nonce
+
+import (
+	"github.com/tendermint/basecoin"
+	"github.com/tendermint/basecoin/stack"
+	"github.com/tendermint/basecoin/state"
+)
+
+//nolint
+const (
+	NameNonce = "nonce"
+)
+
+// ReplayCheck parses out go-crypto signatures and adds permissions to the
+// context for use inside the application
+type ReplayCheck struct {
+	stack.PassOption
+}
+
+// Name of the module - fulfills Middleware interface
+func (ReplayCheck) Name() string {
+	return NameNonce
+}
+
+var _ stack.Middleware = ReplayCheck{}
+
+// CheckTx verifies the signatures are correct - fulfills Middlware interface
+func (ReplayCheck) CheckTx(ctx basecoin.Context, store state.KVStore, tx basecoin.Tx, next basecoin.Checker) (res basecoin.Result, err error) {
+	sigs, tnext, err := getSigners(tx)
+	if err != nil {
+		return res, err
+	}
+	ctx2 := addSigners(ctx, sigs)
+	return next.CheckTx(ctx2, store, tnext)
+}
+
+// DeliverTx verifies the signatures are correct - fulfills Middlware interface
+func (ReplayCheck) DeliverTx(ctx basecoin.Context, store state.KVStore, tx basecoin.Tx, next basecoin.Deliver) (res basecoin.Result, err error) {
+	sigs, tnext, err := getSigners(tx)
+	if err != nil {
+		return res, err
+	}
+	ctx2 := addSigners(ctx, sigs)
+	return next.DeliverTx(ctx2, store, tnext)
+}
diff --git a/modules/nonce/tx.go b/modules/nonce/tx.go
new file mode 100644
index 000000000..741340cfd
--- /dev/null
+++ b/modules/nonce/tx.go
@@ -0,0 +1,69 @@
+/*
+Package nonce XXX
+*/
+package nonce
+
+import (
+	"github.com/tendermint/basecoin/state"
+
+	"github.com/tendermint/basecoin"
+)
+
+// nolint
+const (
+	// for signatures
+	ByteSingleTx = 0x16
+	ByteMultiSig = 0x17
+)
+
+/**** Registration ****/
+
+//func init() {
+//basecoin.TxMapper.RegisterImplementation(&Tx{}, TypeSingleTx, ByteSingleTx)
+//}
+
+// Tx - XXX fill in
+type Tx struct {
+	Tx       basecoin.Tx `json:p"tx"`
+	Sequence uint32
+	Signers  []basecoin.Actor // or simple []data.Bytes (they are only pubkeys...)
+}
+
+var _ basecoin.TxInner = &Tx{}
+
+// NewTx wraps the tx with a signable nonce
+func NewTx(tx basecoin.Tx, sequence uint32, signers []basecoin.Actor) *Tx {
+	return &Tx{
+		Tx:       tx,
+		Sequence: sequence,
+		Signers:  signers,
+	}
+}
+
+//nolint
+func (n *Tx) Wrap() basecoin.Tx {
+	return basecoin.Tx{s}
+}
+func (n *Tx) ValidateBasic() error {
+	return s.Tx.ValidateBasic()
+}
+
+// CheckSequence - XXX fill in
+func (n *Tx) CheckSequence(ctx basecoin.Context, store state.KVStore) error {
+
+	// check the current state
+	h := hash(Sort(n.Signers))
+	cur := loadSeq(store, h)
+	if n.Sequence != cur+1 {
+		return ErrBadNonce()
+	}
+
+	// make sure they all signed
+	for _, s := range n.Signers {
+		if !ctx.HasPermission(s) {
+			return ErrNotMember()
+		}
+	}
+
+	return nil
+}