Key Manager

- keypair, keyring:
-- consistent naming of methods
-- error propagation
-- no panic
- keyManager: persist, import, export, initialize and (re)set keyring
- no global public "singleton" keyring, instead interface via keyManager
- keys test
- KeyStore interface, DB and File store implementations

1 files changed, 121 insertions, 0 deletions

diff --git a/ethcrypto/key_manager.go b/ethcrypto/key_manager.go
new file mode 100644
index 000000000..dcbc7b77e
--- /dev/null
+++ b/ethcrypto/key_manager.go
@@ -0,0 +1,121 @@
+package ethcrypto
+
+import (
+	"fmt"
+	"github.com/ethereum/eth-go/ethutil"
+	"sync"
+)
+
+type KeyManager struct {
+	keyRing  *KeyRing
+	session  string
+	keyStore KeyStore            // interface
+	keyRings map[string]*KeyRing // cache
+	keyPair  *KeyPair
+}
+
+func NewDBKeyManager(db ethutil.Database) *KeyManager {
+	return &KeyManager{keyStore: &DBKeyStore{db: db}, keyRings: make(map[string]*KeyRing)}
+}
+
+func NewFileKeyManager(basedir string) *KeyManager {
+	return &KeyManager{keyStore: &FileKeyStore{basedir: basedir}, keyRings: make(map[string]*KeyRing)}
+}
+
+func (k *KeyManager) KeyPair() *KeyPair {
+	return k.keyPair
+}
+
+func (k *KeyManager) KeyRing() *KeyPair {
+	return k.keyPair
+}
+
+func (k *KeyManager) PrivateKey() []byte {
+	return k.keyPair.PrivateKey
+}
+
+func (k *KeyManager) PublicKey() []byte {
+	return k.keyPair.PublicKey
+}
+
+func (k *KeyManager) Address() []byte {
+	return k.keyPair.Address()
+}
+
+func (k *KeyManager) save(session string, keyRing *KeyRing) error {
+	err := k.keyStore.Save(session, keyRing)
+	if err != nil {
+		return err
+	}
+	k.keyRings[session] = keyRing
+	return nil
+}
+
+func (k *KeyManager) load(session string) (*KeyRing, error) {
+	keyRing, found := k.keyRings[session]
+	if !found {
+		var err error
+		keyRing, err = k.keyStore.Load(session)
+		if err != nil {
+			return nil, err
+		}
+	}
+	return keyRing, nil
+}
+
+func cursorError(cursor int, len int) error {
+	return fmt.Errorf("cursor %d out of range (0..%d)", cursor, len)
+}
+
+func (k *KeyManager) reset(session string, cursor int, keyRing *KeyRing) error {
+	if cursor >= keyRing.Len() {
+		return cursorError(cursor, keyRing.Len())
+	}
+	lock := &sync.Mutex{}
+	lock.Lock()
+	defer lock.Unlock()
+	err := k.save(session, keyRing)
+	if err != nil {
+		return err
+	}
+	k.session = session
+	k.keyRing = keyRing
+	k.keyPair = keyRing.GetKeyPair(cursor)
+	return nil
+}
+
+func (k *KeyManager) SetCursor(cursor int) error {
+	if cursor >= k.keyRing.Len() {
+		return cursorError(cursor, k.keyRing.Len())
+	}
+	k.keyPair = k.keyRing.GetKeyPair(cursor)
+	return nil
+}
+
+func (k *KeyManager) Init(session string, cursor int, force bool) error {
+	var keyRing *KeyRing
+	if !force {
+		var err error
+		keyRing, err = k.load(session)
+		if err != nil {
+			return err
+		}
+	}
+	if keyRing == nil {
+		keyRing = NewGeneratedKeyRing(1)
+	}
+	return k.reset(session, cursor, keyRing)
+}
+
+func (k *KeyManager) InitFromSecretsFile(session string, cursor int, secretsfile string) error {
+	keyRing, err := NewKeyRingFromFile(secretsfile)
+	if err != nil {
+		return err
+	}
+	return k.reset(session, cursor, keyRing)
+}
+
+func (k *KeyManager) Export(dir string) error {
+	fileKeyStore := FileKeyStore{dir}
+	return fileKeyStore.Save(k.session, k.keyRing)
+}