From c689f38cb587be1d4681c19e7ebea7ec8e35794e Mon Sep 17 00:00:00 2001
From: Christopher Goes <cwgoes@protonmail.ch>
Date: Wed, 30 May 2018 22:07:20 +0200
Subject: [PATCH] Implement PubKeyLedgerEd25519

---
 amino.go          |  4 +++
 ledger_ed25519.go |  2 +-
 ledger_pub_key.go | 68 +++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 73 insertions(+), 1 deletion(-)
 create mode 100644 ledger_pub_key.go

diff --git a/amino.go b/amino.go
index 2af765434..b78a15ed9 100644
--- a/amino.go
+++ b/amino.go
@@ -19,6 +19,8 @@ func RegisterAmino(cdc *amino.Codec) {
 	cdc.RegisterInterface((*PubKey)(nil), nil)
 	cdc.RegisterConcrete(PubKeyEd25519{},
 		"tendermint/PubKeyEd25519", nil)
+	cdc.RegisterConcrete(PubKeyLedgerEd25519{},
+		"tendermint/PubKeyLedgerEd25519", nil)
 	cdc.RegisterConcrete(PubKeySecp256k1{},
 		"tendermint/PubKeySecp256k1", nil)
 
@@ -29,6 +31,8 @@ func RegisterAmino(cdc *amino.Codec) {
 		"tendermint/PrivKeySecp256k1", nil)
 	cdc.RegisterConcrete(PrivKeyLedgerSecp256k1{},
 		"tendermint/PrivKeyLedgerSecp256k1", nil)
+	cdc.RegisterConcrete(PrivKeyLedgerEd25519{},
+		"tendermint/PrivKeyLedgerEd25519", nil)
 
 	cdc.RegisterInterface((*Signature)(nil), nil)
 	cdc.RegisterConcrete(SignatureEd25519{},
diff --git a/ledger_ed25519.go b/ledger_ed25519.go
index 0c9cd157f..2110b8871 100644
--- a/ledger_ed25519.go
+++ b/ledger_ed25519.go
@@ -13,7 +13,7 @@ func pubkeyLedgerEd25519(device *ledger.Ledger, path DerivationPath) (pub PubKey
 	if err != nil {
 		return pub, fmt.Errorf("Error fetching public key: %v", err)
 	}
-	var p PubKeyEd25519
+	var p PubKeyLedgerEd25519
 	copy(p[:], key[0:32])
 	return p, err
 }
diff --git a/ledger_pub_key.go b/ledger_pub_key.go
new file mode 100644
index 000000000..0a5222577
--- /dev/null
+++ b/ledger_pub_key.go
@@ -0,0 +1,68 @@
+package crypto
+
+import (
+	"bytes"
+	"crypto/sha512"
+	"fmt"
+
+	"github.com/tendermint/ed25519"
+	"github.com/tendermint/ed25519/extra25519"
+	"golang.org/x/crypto/ripemd160"
+)
+
+var _ PubKey = PubKeyLedgerEd25519{}
+
+// Implements PubKeyInner
+type PubKeyLedgerEd25519 [32]byte
+
+func (pubKey PubKeyLedgerEd25519) Address() Address {
+	// append type byte
+	hasher := ripemd160.New()
+	hasher.Write(pubKey.Bytes()) // does not error
+	return Address(hasher.Sum(nil))
+}
+
+func (pubKey PubKeyLedgerEd25519) Bytes() []byte {
+	bz, err := cdc.MarshalBinaryBare(pubKey)
+	if err != nil {
+		panic(err)
+	}
+	return bz
+}
+
+func (pubKey PubKeyLedgerEd25519) VerifyBytes(msg []byte, sig_ Signature) bool {
+	// must verify sha512 hash of msg, no padding, for Ledger compatibility
+	sig, ok := sig_.(SignatureEd25519)
+	if !ok {
+		return false
+	}
+	pubKeyBytes := [32]byte(pubKey)
+	sigBytes := [64]byte(sig)
+	h := sha512.New()
+	h.Write(msg)
+	digest := h.Sum(nil)
+	return ed25519.Verify(&pubKeyBytes, digest, &sigBytes)
+}
+
+// For use with golang/crypto/nacl/box
+// If error, returns nil.
+func (pubKey PubKeyLedgerEd25519) ToCurve25519() *[32]byte {
+	keyCurve25519, pubKeyBytes := new([32]byte), [32]byte(pubKey)
+	ok := extra25519.PublicKeyToCurve25519(keyCurve25519, &pubKeyBytes)
+	if !ok {
+		return nil
+	}
+	return keyCurve25519
+}
+
+func (pubKey PubKeyLedgerEd25519) String() string {
+	return fmt.Sprintf("PubKeyLedgerEd25519{%X}", pubKey[:])
+}
+
+func (pubKey PubKeyLedgerEd25519) Equals(other PubKey) bool {
+	if otherEd, ok := other.(PubKeyLedgerEd25519); ok {
+		return bytes.Equal(pubKey[:], otherEd[:])
+	} else {
+		return false
+	}
+}