From bdb6566076a614c45a207c21ef3ac0e27cf51798 Mon Sep 17 00:00:00 2001
From: Olaoluwa Osuntokun <laolu32@gmail.com>
Date: Fri, 12 Aug 2016 15:03:18 -0700
Subject: [PATCH] channeldb: only store public keys for multi-sig + commitment
 keys

This commit removes the storage+encryption of private keys within
channeldb. We no longer need to encrypt these secrets before storing as
the base wallet is now expected to retain full control of these secrets
rather than the database.

As a result, we now only store public keys within the database.
---
 channeldb/channel.go      | 32 +++++++++-----------------------
 channeldb/channel_test.go | 12 ++++++------
 2 files changed, 15 insertions(+), 29 deletions(-)

diff --git a/channeldb/channel.go b/channeldb/channel.go
index 6ec88ae0..742ce2ef 100644
--- a/channeldb/channel.go
+++ b/channeldb/channel.go
@@ -106,7 +106,7 @@ type OpenChannel struct {
 	//ReserveAmount btcutil.Amount
 
 	// Keys for both sides to be used for the commitment transactions.
-	OurCommitKey   *btcec.PrivateKey
+	OurCommitKey   *btcec.PublicKey
 	TheirCommitKey *btcec.PublicKey
 
 	// Tracking total channel capacity, and the amount of funds allocated
@@ -123,7 +123,7 @@ type OpenChannel struct {
 	// The outpoint of the final funding transaction.
 	FundingOutpoint *wire.OutPoint
 
-	OurMultiSigKey      *btcec.PrivateKey
+	OurMultiSigKey      *btcec.PublicKey
 	TheirMultiSigKey    *btcec.PublicKey
 	FundingRedeemScript []byte
 
@@ -809,12 +809,7 @@ func putChanCommitKeys(nodeChanBucket *bolt.Bucket, channel *OpenChannel) error
 		return err
 	}
 
-	encryptedPriv, err := ed.Encrypt(channel.OurCommitKey.Serialize())
-	if err != nil {
-		return err
-	}
-
-	if _, err := b.Write(encryptedPriv); err != nil {
+	if _, err := b.Write(channel.OurCommitKey.SerializeCompressed()); err != nil {
 		return err
 	}
 
@@ -848,12 +843,7 @@ func fetchChanCommitKeys(nodeChanBucket *bolt.Bucket, channel *OpenChannel) erro
 		return err
 	}
 
-	decryptedPriv, err := ed.Decrypt(keyBytes[33:])
-	if err != nil {
-		return err
-	}
-
-	channel.OurCommitKey, _ = btcec.PrivKeyFromBytes(btcec.S256(), decryptedPriv)
+	channel.OurCommitKey, err = btcec.ParsePubKey(keyBytes[33:], btcec.S256())
 	if err != nil {
 		return err
 	}
@@ -952,11 +942,8 @@ func putChanFundingInfo(nodeChanBucket *bolt.Bucket, channel *OpenChannel) error
 		return err
 	}
 
-	encryptedPriv, err := ed.Encrypt(channel.OurMultiSigKey.Serialize())
-	if err != nil {
-		return err
-	}
-	if err := wire.WriteVarBytes(&b, 0, encryptedPriv); err != nil {
+	ourSerKey := channel.OurMultiSigKey.SerializeCompressed()
+	if err := wire.WriteVarBytes(&b, 0, ourSerKey); err != nil {
 		return err
 	}
 	theirSerKey := channel.TheirMultiSigKey.SerializeCompressed()
@@ -1002,17 +989,16 @@ func fetchChanFundingInfo(nodeChanBucket *bolt.Bucket, channel *OpenChannel) err
 		return err
 	}
 
-	encryptedPrivBytes, err := wire.ReadVarBytes(infoBytes, 0, 100, "")
+	ourKeyBytes, err := wire.ReadVarBytes(infoBytes, 0, 34, "")
 	if err != nil {
 		return err
 	}
-	decryptedPriv, err := ed.Decrypt(encryptedPrivBytes)
+	channel.OurMultiSigKey, err = btcec.ParsePubKey(ourKeyBytes, btcec.S256())
 	if err != nil {
 		return err
 	}
-	channel.OurMultiSigKey, _ = btcec.PrivKeyFromBytes(btcec.S256(), decryptedPriv)
 
-	theirKeyBytes, err := wire.ReadVarBytes(infoBytes, 0, 33, "")
+	theirKeyBytes, err := wire.ReadVarBytes(infoBytes, 0, 34, "")
 	if err != nil {
 		return err
 	}
diff --git a/channeldb/channel_test.go b/channeldb/channel_test.go
index c46efdef..b7ce9345 100644
--- a/channeldb/channel_test.go
+++ b/channeldb/channel_test.go
@@ -126,7 +126,7 @@ func TestOpenChannelPutGetDelete(t *testing.T) {
 		TheirLNID:                  key,
 		ChanID:                     id,
 		MinFeePerKb:                btcutil.Amount(5000),
-		OurCommitKey:               privKey,
+		OurCommitKey:               privKey.PubKey(),
 		TheirCommitKey:             pubKey,
 		Capacity:                   btcutil.Amount(10000),
 		OurBalance:                 btcutil.Amount(3000),
@@ -136,7 +136,7 @@ func TestOpenChannelPutGetDelete(t *testing.T) {
 		LocalElkrem:                sender,
 		RemoteElkrem:               receiver,
 		FundingOutpoint:            testOutpoint,
-		OurMultiSigKey:             privKey,
+		OurMultiSigKey:             privKey.PubKey(),
 		TheirMultiSigKey:           privKey.PubKey(),
 		FundingRedeemScript:        script,
 		TheirCurrentRevocation:     privKey.PubKey(),
@@ -177,8 +177,8 @@ func TestOpenChannelPutGetDelete(t *testing.T) {
 		t.Fatalf("fee/kb doens't match")
 	}
 
-	if !bytes.Equal(state.OurCommitKey.Serialize(),
-		newState.OurCommitKey.Serialize()) {
+	if !bytes.Equal(state.OurCommitKey.SerializeCompressed(),
+		newState.OurCommitKey.SerializeCompressed()) {
 		t.Fatalf("our commit key dont't match")
 	}
 	if !bytes.Equal(state.TheirCommitKey.SerializeCompressed(),
@@ -216,8 +216,8 @@ func TestOpenChannelPutGetDelete(t *testing.T) {
 		t.Fatalf("funding outpoint doesn't match")
 	}
 
-	if !bytes.Equal(state.OurMultiSigKey.Serialize(),
-		newState.OurMultiSigKey.Serialize()) {
+	if !bytes.Equal(state.OurMultiSigKey.SerializeCompressed(),
+		newState.OurMultiSigKey.SerializeCompressed()) {
 		t.Fatalf("our multisig key doesn't match")
 	}
 	if !bytes.Equal(state.TheirMultiSigKey.SerializeCompressed(),