Add ledger tx parsing support (ava-labs#2695)

utils/crypto/keychain/keychain.go

@@ -25,6 +25,7 @@ var (
 // to sign a hash
 type Signer interface {
 	SignHash([]byte) ([]byte, error)
+	Sign([]byte) ([]byte, error)
 	Address() ids.ShortID
 }
 
@@ -120,6 +121,7 @@ func (l *ledgerKeychain) Get(addr ids.ShortID) (Signer, bool) {
 	}, true
 }
 
+// expects to receive a hash of the unsigned tx bytes
 func (l *ledgerSigner) SignHash(b []byte) ([]byte, error) {
 	// Sign using the address with index l.idx on the ledger device. The number
 	// of returned signatures should be the same length as the provided indices.
@@ -139,6 +141,26 @@ func (l *ledgerSigner) SignHash(b []byte) ([]byte, error) {
 	return sigs[0], err
 }
 
+// expects to receive the unsigned tx bytes
+func (l *ledgerSigner) Sign(b []byte) ([]byte, error) {
+	// Sign using the address with index l.idx on the ledger device. The number
+	// of returned signatures should be the same length as the provided indices.
+	sigs, err := l.ledger.Sign(b, []uint32{l.idx})
+	if err != nil {
+		return nil, err
+	}
+
+	if sigsLen := len(sigs); sigsLen != 1 {
+		return nil, fmt.Errorf(
+			"%w. expected 1, got %d",
+			ErrInvalidNumSignatures,
+			sigsLen,
+		)
+	}
+
+	return sigs[0], err
+}
+
 func (l *ledgerSigner) Address() ids.ShortID {
 	return l.addr
 }

utils/crypto/keychain/ledger.go

@@ -14,6 +14,6 @@ type Ledger interface {
 	Address(displayHRP string, addressIndex uint32) (ids.ShortID, error)
 	Addresses(addressIndices []uint32) ([]ids.ShortID, error)
 	SignHash(hash []byte, addressIndices []uint32) ([][]byte, error)
-	// TODO: add SignTransaction
+	Sign(unsignedTxBytes []byte, addressIndices []uint32) ([][]byte, error)
 	Disconnect() error
 }

utils/crypto/ledger/ledger.go

@@ -10,10 +10,15 @@ import (
 
 	"github.com/ava-labs/avalanchego/ids"
 	"github.com/ava-labs/avalanchego/utils/crypto/keychain"
+	"github.com/ava-labs/avalanchego/utils/hashing"
 	"github.com/ava-labs/avalanchego/version"
 )
 
-const rootPath = "m/44'/9000'/0'"
+const (
+	rootPath          = "m/44'/9000'/0'"
+	ledgerBufferLimit = 8192
+	ledgerPathSize    = 9
+)
 
 var _ keychain.Ledger = (*Ledger)(nil)
 
@@ -79,6 +84,35 @@ func (l *Ledger) SignHash(hash []byte, addressIndices []uint32) ([][]byte, error
 	return responses, nil
 }
 
+func (l *Ledger) Sign(txBytes []byte, addressIndices []uint32) ([][]byte, error) {
+	// will pass to the ledger addressIndices both as signing paths and change paths
+	numSigningPaths := len(addressIndices)
+	numChangePaths := len(addressIndices)
+	if len(txBytes)+(numSigningPaths+numChangePaths)*ledgerPathSize > ledgerBufferLimit {
+		// There is a limit on the tx length that can be parsed by the ledger
+		// app. When the tx that is being signed is too large, we sign with hash
+		// instead.
+		//
+		// Ref: https://github.com/ava-labs/avalanche-wallet-sdk/blob/9a71f05e424e06b94eaccf21fd32d7983ed1b040/src/Wallet/Ledger/provider/ZondaxProvider.ts#L68
+		unsignedHash := hashing.ComputeHash256(txBytes)
+		return l.SignHash(unsignedHash, addressIndices)
+	}
+	strIndices := convertToSigningPaths(addressIndices)
+	response, err := l.device.Sign(rootPath, strIndices, txBytes, strIndices)
+	if err != nil {
+		return nil, fmt.Errorf("%w: unable to sign transaction", err)
+	}
+	responses := make([][]byte, len(strIndices))
+	for i, index := range strIndices {
+		sig, ok := response.Signature[index]
+		if !ok {
+			return nil, fmt.Errorf("missing signature %s", index)
+		}
+		responses[i] = sig
+	}
+	return responses, nil
+}
+
 func (l *Ledger) Version() (*version.Semantic, error) {
 	resp, err := l.device.GetVersion()
 	if err != nil {

wallet/chain/p/signer_visitor.go

@@ -14,7 +14,6 @@ import (
 	"github.com/ava-labs/avalanchego/utils/constants"
 	"github.com/ava-labs/avalanchego/utils/crypto/keychain"
 	"github.com/ava-labs/avalanchego/utils/crypto/secp256k1"
-	"github.com/ava-labs/avalanchego/utils/hashing"
 	"github.com/ava-labs/avalanchego/vms/components/avax"
 	"github.com/ava-labs/avalanchego/vms/components/verify"
 	"github.com/ava-labs/avalanchego/vms/platformvm/stakeable"
@@ -266,7 +265,6 @@ func sign(tx *txs.Tx, txSigners [][]keychain.Signer) error {
 	if err != nil {
 		return fmt.Errorf("couldn't marshal unsigned tx: %w", err)
 	}
-	unsignedHash := hashing.ComputeHash256(unsignedBytes)
 
 	if expectedLen := len(txSigners); expectedLen != len(tx.Creds) {
 		tx.Creds = make([]verify.Verifiable, expectedLen)
@@ -309,7 +307,7 @@ func sign(tx *txs.Tx, txSigners [][]keychain.Signer) error {
 				continue
 			}
 
-			sig, err := signer.SignHash(unsignedHash)
+			sig, err := signer.Sign(unsignedBytes)
 			if err != nil {
 				return fmt.Errorf("problem signing tx: %w", err)
 			}

wallet/chain/x/signer.go

@@ -13,7 +13,6 @@ import (
 	"github.com/ava-labs/avalanchego/ids"
 	"github.com/ava-labs/avalanchego/utils/crypto/keychain"
 	"github.com/ava-labs/avalanchego/utils/crypto/secp256k1"
-	"github.com/ava-labs/avalanchego/utils/hashing"
 	"github.com/ava-labs/avalanchego/vms/avm/fxs"
 	"github.com/ava-labs/avalanchego/vms/avm/txs"
 	"github.com/ava-labs/avalanchego/vms/components/avax"
@@ -262,7 +261,6 @@ func sign(tx *txs.Tx, creds []verify.Verifiable, txSigners [][]keychain.Signer)
 	if err != nil {
 		return fmt.Errorf("couldn't marshal unsigned tx: %w", err)
 	}
-	unsignedHash := hashing.ComputeHash256(unsignedBytes)
 
 	if expectedLen := len(txSigners); expectedLen != len(tx.Creds) {
 		tx.Creds = make([]*fxs.FxCredential, expectedLen)
@@ -318,7 +316,7 @@ func sign(tx *txs.Tx, creds []verify.Verifiable, txSigners [][]keychain.Signer)
 				continue
 			}
 
-			sig, err := signer.SignHash(unsignedHash)
+			sig, err := signer.Sign(unsignedBytes)
 			if err != nil {
 				return fmt.Errorf("problem signing tx: %w", err)
 			}