From 11a79f11e03076172d6dbaa2f375aaebee7d8190 Mon Sep 17 00:00:00 2001
From: Jae Kwon <jkwon.work@gmail.com>
Date: Fri, 3 Oct 2014 17:59:54 -0700
Subject: [PATCH] ...

---
 state/account.go      | 46 ++++++++++++++++++++++++++++++++++++-------
 state/account_test.go | 28 ++++++++++++++++++++++++++
 state/state.go        | 11 +++++------
 3 files changed, 72 insertions(+), 13 deletions(-)
 create mode 100644 state/account_test.go

diff --git a/state/account.go b/state/account.go
index 3270dd489..6a94b8b8a 100644
--- a/state/account.go
+++ b/state/account.go
@@ -3,10 +3,11 @@ package state
 import (
 	. "github.com/tendermint/tendermint/binary"
 	. "github.com/tendermint/tendermint/blocks"
+	. "github.com/tendermint/tendermint/common"
+	"github.com/tendermint/tendermint/crypto"
 	"io"
 )
 
-// NOTE: consensus/Validator embeds this, so..
 type Account struct {
 	Id     uint64 // Numeric id of account, incrementing.
 	PubKey []byte
@@ -19,11 +20,24 @@ func ReadAccount(r io.Reader, n *int64, err *error) *Account {
 	}
 }
 
-func (self *Account) Verify(msg []byte, sig Signature) bool {
-	if sig.SignerId != self.Id {
-		return false
+func (account *Account) Verify(msg []byte, sig Signature) bool {
+	if sig.SignerId != account.Id {
+		panic("Account.Id doesn't match sig.SignerId")
 	}
-	return false
+	v1 := &crypto.Verify{
+		Message:   msg,
+		PubKey:    account.PubKey,
+		Signature: sig.Bytes,
+	}
+	ok := crypto.VerifyBatch([]*crypto.Verify{v1})
+	return ok
+}
+
+//-----------------------------------------------------------------------------
+
+type AccountBalance struct {
+	Account
+	Balance uint64
 }
 
 //-----------------------------------------------------------------------------
@@ -33,6 +47,24 @@ type PrivAccount struct {
 	PrivKey []byte
 }
 
-func (self *PrivAccount) Sign(msg []byte) Signature {
-	return Signature{}
+// Generates a new account with private key.
+// The Account.Id is empty since it isn't in the blockchain.
+func GenPrivAccount() *PrivAccount {
+	privKey := RandBytes(32)
+	pubKey := crypto.MakePubKey(privKey)
+	return &PrivAccount{
+		Account: Account{
+			Id:     uint64(0),
+			PubKey: pubKey,
+		},
+		PrivKey: privKey,
+	}
+}
+
+func (pa *PrivAccount) Sign(msg []byte) Signature {
+	signature := crypto.SignMessage(msg, pa.PrivKey, pa.PubKey)
+	return Signature{
+		SignerId: pa.Id,
+		Bytes:    signature,
+	}
 }
diff --git a/state/account_test.go b/state/account_test.go
new file mode 100644
index 000000000..78abec04d
--- /dev/null
+++ b/state/account_test.go
@@ -0,0 +1,28 @@
+package state
+
+import (
+	. "github.com/tendermint/tendermint/common"
+	"testing"
+)
+
+func TestSignAndValidate(t *testing.T) {
+
+	privAccount := GenPrivAccount()
+	account := &privAccount.Account
+
+	msg := RandBytes(128)
+	sig := privAccount.Sign(msg)
+	t.Logf("msg: %X, sig: %X", msg, sig)
+
+	// Test the signature
+	if !account.Verify(msg, sig) {
+		t.Errorf("Account message signature verification failed")
+	}
+
+	// Mutate the signature, just one bit.
+	sig.Bytes[0] ^= byte(0x01)
+
+	if account.Verify(msg, sig) {
+		t.Errorf("Account message signature verification should have failed but passed instead")
+	}
+}
diff --git a/state/state.go b/state/state.go
index 10eee0dd1..06d44ee35 100644
--- a/state/state.go
+++ b/state/state.go
@@ -28,15 +28,14 @@ type State struct {
 	validators *ValidatorSet
 }
 
+func GenesisState(commitTime time.Time, accounts merkle.Tree, validators *ValidatorSet) *State {
+}
+
 func LoadState(db db_.Db) *State {
 	s := &State{}
 	buf := db.Get(stateKey)
 	if len(buf) == 0 {
-		s.height = uint32(0)
-		s.commitTime = time.Unix(0, 0)      // XXX BOOTSTRAP
-		s.blockHash = nil                   // XXX BOOTSTRAP
-		s.accounts = merkle.NewIAVLTree(db) // XXX BOOTSTRAP
-		s.validators = NewValidatorSet(nil) // XXX BOOTSTRAP
+		return nil
 	} else {
 		reader := bytes.NewReader(buf)
 		var n int64
@@ -112,7 +111,7 @@ func (s *State) commitTx(tx Tx) error {
 			return ErrStateInvalidSequenceNumber
 		}
 	*/
-	// TODO commit the tx
+	// XXX commit the tx
 	panic("Implement CommitTx()")
 	return nil
 }