import/export accounts

- cli: add passwordfile flag
- cli: change unlock flag only takes account
- cli: with unlock you are prompted for password or use passfile with password flag
- cli: unlockAccount used in normal client start (run) and accountExport
- cli: getPassword used in accountCreate and accountImport
- accounts: Manager.Import, Manager.Export
- crypto: SaveECDSA (to complement LoadECDSA) to save to file
- crypto: NewKeyFromECDSA added (used in accountImport and New = generated constructor)

2 files changed, 16 insertions, 7 deletions

diff --git a/crypto/crypto.go b/crypto/crypto.go
index c3d47b629..2d26dd25e 100644
--- a/crypto/crypto.go
+++ b/crypto/crypto.go
@@ -139,6 +139,11 @@ func LoadECDSA(file string) (*ecdsa.PrivateKey, error) {
 	return ToECDSA(buf), nil
 }
 
+// SaveECDSA saves a secp256k1 private key from the given file.
+func SaveECDSA(file string, key *ecdsa.PrivateKey) error {
+	return common.WriteFile(file, FromECDSA(key))
+}
+
 func GenerateKey() (*ecdsa.PrivateKey, error) {
 	return ecdsa.GenerateKey(S256(), rand.Reader)
 }
diff --git a/crypto/key.go b/crypto/key.go
index 9dbf37467..0b84bfec1 100644
--- a/crypto/key.go
+++ b/crypto/key.go
@@ -85,6 +85,16 @@ func (k *Key) UnmarshalJSON(j []byte) (err error) {
 	return err
 }
 
+func NewKeyFromECDSA(privateKeyECDSA *ecdsa.PrivateKey) *Key {
+	id := uuid.NewRandom()
+	key := &Key{
+		Id:         id,
+		Address:    PubkeyToAddress(privateKeyECDSA.PublicKey),
+		PrivateKey: privateKeyECDSA,
+	}
+	return key
+}
+
 func NewKey(rand io.Reader) *Key {
 	randBytes := make([]byte, 64)
 	_, err := rand.Read(randBytes)
@@ -97,11 +107,5 @@ func NewKey(rand io.Reader) *Key {
 		panic("key generation: ecdsa.GenerateKey failed: " + err.Error())
 	}
 
-	id := uuid.NewRandom()
-	key := &Key{
-		Id:         id,
-		Address:    PubkeyToAddress(privateKeyECDSA.PublicKey),
-		PrivateKey: privateKeyECDSA,
-	}
-	return key
+	return NewKeyFromECDSA(privateKeyECDSA)
 }