From 51a480129b7dc75f1e250113be7f76ba631ec119 Mon Sep 17 00:00:00 2001
From: Oliver Gugger <gugger@gmail.com>
Date: Thu, 12 May 2022 12:47:13 +0200
Subject: [PATCH] walletunlocker+keychain+config_builder: use new aezeed
 version

---
 config_builder.go              |  7 +++----
 keychain/derivation.go         | 26 +++++++++++++++++++++-----
 walletunlocker/service.go      |  2 +-
 walletunlocker/service_test.go |  2 +-
 4 files changed, 26 insertions(+), 11 deletions(-)

diff --git a/config_builder.go b/config_builder.go
index 71ab15611..18e9a3f6f 100644
--- a/config_builder.go
+++ b/config_builder.go
@@ -965,14 +965,13 @@ func waitForWalletPassword(cfg *Config,
 		// seed. If it's greater than the current key derivation
 		// version, then we'll return an error as we don't understand
 		// this.
-		const latestVersion = keychain.KeyDerivationVersion
 		if cipherSeed != nil &&
-			cipherSeed.InternalVersion != latestVersion {
+			!keychain.IsKnownVersion(cipherSeed.InternalVersion) {
 
 			return nil, fmt.Errorf("invalid internal "+
-				"seed version %v, current version is %v",
+				"seed version %v, current max version is %v",
 				cipherSeed.InternalVersion,
-				keychain.KeyDerivationVersion)
+				keychain.CurrentKeyDerivationVersion)
 		}
 
 		loader, err := btcwallet.NewWalletLoader(
diff --git a/keychain/derivation.go b/keychain/derivation.go
index 0d6a4ee5b..0e42ae966 100644
--- a/keychain/derivation.go
+++ b/keychain/derivation.go
@@ -8,11 +8,20 @@ import (
 )
 
 const (
-	// KeyDerivationVersion is the version of the key derivation schema
-	// defined below. We use a version as this means that we'll be able to
-	// accept new seed in the future and be able to discern if the software
-	// is compatible with the version of the seed.
-	KeyDerivationVersion = 0
+	// KeyDerivationVersionLegacy is the previous version of the key
+	// derivation schema defined below. We use a version as this means that
+	// we'll be able to accept new seed in the future and be able to discern
+	// if the software is compatible with the version of the seed.
+	KeyDerivationVersionLegacy = 0
+
+	// KeyDerivationVersionTaproot is the most recent version of the key
+	// derivation scheme that marks the introduction of the Taproot
+	// derivation with BIP0086 support.
+	KeyDerivationVersionTaproot = 1
+
+	// CurrentKeyDerivationVersion is the current default key derivation
+	// version that is used for new seeds.
+	CurrentKeyDerivationVersion = KeyDerivationVersionTaproot
 
 	// BIP0043Purpose is the "purpose" value that we'll use for the first
 	// version or our key derivation scheme. All keys are expected to be
@@ -25,6 +34,13 @@ const (
 	BIP0043Purpose = 1017
 )
 
+// IsKnownVersion returns true if the given version is one of the known
+// derivation scheme versions as defined by this package.
+func IsKnownVersion(internalVersion uint8) bool {
+	return internalVersion == KeyDerivationVersionLegacy ||
+		internalVersion == KeyDerivationVersionTaproot
+}
+
 var (
 	// MaxKeyRangeScan is the maximum number of keys that we'll attempt to
 	// scan with if a caller knows the public key, but not the KeyLocator
diff --git a/walletunlocker/service.go b/walletunlocker/service.go
index ce3997666..e473a0c5b 100644
--- a/walletunlocker/service.go
+++ b/walletunlocker/service.go
@@ -309,7 +309,7 @@ func (u *UnlockerService) GenSeed(_ context.Context,
 	// instance.
 	//
 	cipherSeed, err := aezeed.New(
-		keychain.KeyDerivationVersion, &entropy, time.Now(),
+		keychain.CurrentKeyDerivationVersion, &entropy, time.Now(),
 	)
 	if err != nil {
 		return nil, err
diff --git a/walletunlocker/service_test.go b/walletunlocker/service_test.go
index 88274459b..5c723d759 100644
--- a/walletunlocker/service_test.go
+++ b/walletunlocker/service_test.go
@@ -91,7 +91,7 @@ func createSeedAndMnemonic(t *testing.T,
 	pass []byte) (*aezeed.CipherSeed, aezeed.Mnemonic) {
 
 	cipherSeed, err := aezeed.New(
-		keychain.KeyDerivationVersion, &testEntropy, time.Now(),
+		keychain.CurrentKeyDerivationVersion, &testEntropy, time.Now(),
 	)
 	require.NoError(t, err)