Move ledger keychain implementation to dedicated package

utils/crypto/keychain/keychain.go

@@ -4,23 +4,10 @@
 package keychain
 
 import (
-	"errors"
-	"fmt"
-
 	"github.com/ava-labs/avalanchego/ids"
 	"github.com/ava-labs/avalanchego/utils/set"
 )
 
-var (
-	_ Keychain = (*ledgerKeychain)(nil)
-	_ Signer   = (*ledgerSigner)(nil)
-
-	ErrInvalidIndicesLength    = errors.New("number of indices should be greater than 0")
-	ErrInvalidNumAddrsToDerive = errors.New("number of addresses to derive should be greater than 0")
-	ErrInvalidNumAddrsDerived  = errors.New("incorrect number of ledger derived addresses")
-	ErrInvalidNumSignatures    = errors.New("incorrect number of signatures")
-)
-
 // Signer implements functions for a keychain to return its main address and
 // to sign a hash
 type Signer interface {
@@ -38,128 +25,3 @@ type Keychain interface {
 	// signer
 	Addresses() set.Set[ids.ShortID]
 }
-
-// ledgerKeychain is an abstraction of the underlying ledger hardware device,
-// to be able to get a signer from a finite set of derived signers
-type ledgerKeychain struct {
-	ledger    Ledger
-	addrs     set.Set[ids.ShortID]
-	addrToIdx map[ids.ShortID]uint32
-}
-
-// ledgerSigner is an abstraction of the underlying ledger hardware device,
-// to be able sign for a specific address
-type ledgerSigner struct {
-	ledger Ledger
-	idx    uint32
-	addr   ids.ShortID
-}
-
-// NewLedgerKeychain creates a new Ledger with [numToDerive] addresses.
-func NewLedgerKeychain(l Ledger, numToDerive int) (Keychain, error) {
-	if numToDerive < 1 {
-		return nil, ErrInvalidNumAddrsToDerive
-	}
-
-	indices := make([]uint32, numToDerive)
-	for i := range indices {
-		indices[i] = uint32(i)
-	}
-
-	return NewLedgerKeychainFromIndices(l, indices)
-}
-
-// NewLedgerKeychainFromIndices creates a new Ledger with addresses taken from the given [indices].
-func NewLedgerKeychainFromIndices(l Ledger, indices []uint32) (Keychain, error) {
-	if len(indices) == 0 {
-		return nil, ErrInvalidIndicesLength
-	}
-
-	addrs, err := l.Addresses(indices)
-	if err != nil {
-		return nil, err
-	}
-
-	if len(addrs) != len(indices) {
-		return nil, fmt.Errorf(
-			"%w. expected %d, got %d",
-			ErrInvalidNumAddrsDerived,
-			len(indices),
-			len(addrs),
-		)
-	}
-
-	addrsSet := set.Of(addrs...)
-
-	addrToIdx := map[ids.ShortID]uint32{}
-	for i := range indices {
-		addrToIdx[addrs[i]] = indices[i]
-	}
-
-	return &ledgerKeychain{
-		ledger:    l,
-		addrs:     addrsSet,
-		addrToIdx: addrToIdx,
-	}, nil
-}
-
-func (l *ledgerKeychain) Addresses() set.Set[ids.ShortID] {
-	return l.addrs
-}
-
-func (l *ledgerKeychain) Get(addr ids.ShortID) (Signer, bool) {
-	idx, ok := l.addrToIdx[addr]
-	if !ok {
-		return nil, false
-	}
-
-	return &ledgerSigner{
-		ledger: l.ledger,
-		idx:    idx,
-		addr:   addr,
-	}, 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.
-	sigs, err := l.ledger.SignHash(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], nil
-}
-
-// 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], nil
-}
-
-func (l *ledgerSigner) Address() ids.ShortID {
-	return l.addr
-}

utils/crypto/keychain/ledger.go → utils/crypto/keychain/ledger/ledger.go

@@ -1,10 +1,11 @@
 // Copyright (C) 2019-2025, Ava Labs, Inc. All rights reserved.
 // See the file LICENSE for licensing terms.
 
-package keychain
+package ledger
 
 import (
 	"github.com/ava-labs/avalanchego/ids"
+	"github.com/ava-labs/avalanchego/utils/crypto/ledger"
 	"github.com/ava-labs/avalanchego/version"
 )
 
@@ -17,3 +18,6 @@ type Ledger interface {
 	Sign(unsignedTxBytes []byte, addressIndices []uint32) ([][]byte, error)
 	Disconnect() error
 }
+
+// Verify that the ledger implementation satisfies the interface
+var _ Ledger = (*ledger.Ledger)(nil)

utils/crypto/keychain/ledger/ledger_keychain.go

@@ -0,0 +1,153 @@
+// Copyright (C) 2019-2025, Ava Labs, Inc. All rights reserved.
+// See the file LICENSE for licensing terms.
+
+package ledger
+
+import (
+	"errors"
+	"fmt"
+
+	"github.com/ava-labs/avalanchego/ids"
+	"github.com/ava-labs/avalanchego/utils/crypto/keychain"
+	"github.com/ava-labs/avalanchego/utils/set"
+)
+
+var (
+	_ keychain.Keychain = (*KeyChain)(nil)
+	_ keychain.Signer   = (*ledgerSigner)(nil)
+
+	ErrInvalidIndicesLength    = errors.New("number of indices should be greater than 0")
+	ErrInvalidNumAddrsToDerive = errors.New("number of addresses to derive should be greater than 0")
+	ErrInvalidNumAddrsDerived  = errors.New("incorrect number of ledger derived addresses")
+	ErrInvalidNumSignatures    = errors.New("incorrect number of signatures")
+)
+
+// KeyChain is an abstraction of the underlying ledger hardware device,
+// to be able to get a signer from a finite set of derived signers
+type KeyChain struct {
+	ledger    Ledger
+	addrs     set.Set[ids.ShortID]
+	addrToIdx map[ids.ShortID]uint32
+}
+
+// NewKeychain creates a new Ledger with [numToDerive] addresses.
+func NewKeychain(l Ledger, numToDerive int) (*KeyChain, error) {
+	if numToDerive < 1 {
+		return nil, ErrInvalidNumAddrsToDerive
+	}
+
+	indices := make([]uint32, numToDerive)
+	for i := range indices {
+		indices[i] = uint32(i)
+	}
+
+	return NewKeychainFromIndices(l, indices)
+}
+
+// NewKeychainFromIndices creates a new Ledger with addresses taken from the given [indices].
+func NewKeychainFromIndices(l Ledger, indices []uint32) (*KeyChain, error) {
+	if len(indices) == 0 {
+		return nil, ErrInvalidIndicesLength
+	}
+
+	addrs, err := l.Addresses(indices)
+	if err != nil {
+		return nil, err
+	}
+
+	if len(addrs) != len(indices) {
+		return nil, fmt.Errorf(
+			"%w. expected %d, got %d",
+			ErrInvalidNumAddrsDerived,
+			len(indices),
+			len(addrs),
+		)
+	}
+
+	addrsSet := set.Of(addrs...)
+
+	addrToIdx := map[ids.ShortID]uint32{}
+	for i := range indices {
+		addrToIdx[addrs[i]] = indices[i]
+	}
+
+	return &KeyChain{
+		ledger:    l,
+		addrs:     addrsSet,
+		addrToIdx: addrToIdx,
+	}, nil
+}
+
+// Addresses returns the set of addresses that this keychain can sign for.
+func (l *KeyChain) Addresses() set.Set[ids.ShortID] {
+	return l.addrs
+}
+
+// Get returns a signer for the given address, if it exists in this keychain.
+func (l *KeyChain) Get(addr ids.ShortID) (keychain.Signer, bool) {
+	idx, ok := l.addrToIdx[addr]
+	if !ok {
+		return nil, false
+	}
+
+	return &ledgerSigner{
+		ledger: l.ledger,
+		idx:    idx,
+		addr:   addr,
+	}, true
+}
+
+// ledgerSigner is an abstraction of the underlying ledger hardware device,
+// to be able sign for a specific address
+type ledgerSigner struct {
+	ledger Ledger
+	idx    uint32
+	addr   ids.ShortID
+}
+
+// SignHash signs the provided hash using the Ledger device.
+// It expects to receive a hash of the unsigned transaction 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.
+	sigs, err := l.ledger.SignHash(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], nil
+}
+
+// Sign signs the provided unsigned transaction bytes using the Ledger device.
+// It expects to receive the unsigned transaction bytes and returns the signature.
+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], nil
+}
+
+// Address returns the address associated with this signer.
+func (l *ledgerSigner) Address() ids.ShortID {
+	return l.addr
+}