Add accounts package and refactor key stores

* Add initial UserAccount and AccountManager structs
* Add NewAccount, Sign and Accounts functions
* Refactor key stores to use key address as main identifier
  while keeping the UUID.
* Use key address as file/dir names instead of UUID

2 files changed, 118 insertions, 0 deletions

diff --git a/accounts/account_manager.go b/accounts/account_manager.go
new file mode 100644
index 000000000..b5a0c4f87
--- /dev/null
+++ b/accounts/account_manager.go
@@ -0,0 +1,99 @@
+/*
+	This file is part of go-ethereum
+
+	go-ethereum is free software: you can redistribute it and/or modify
+	it under the terms of the GNU Lesser General Public License as published by
+	the Free Software Foundation, either version 3 of the License, or
+	(at your option) any later version.
+
+	go-ethereum is distributed in the hope that it will be useful,
+	but WITHOUT ANY WARRANTY; without even the implied warranty of
+	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+	GNU General Public License for more details.
+
+	You should have received a copy of the GNU Lesser General Public License
+	along with go-ethereum.  If not, see <http://www.gnu.org/licenses/>.
+*/
+/**
+ * @authors
+ * 	Gustav Simonsson <gustav.simonsson@gmail.com>
+ * @date 2015
+ *
+ */
+/*
+
+This abstracts part of a user's interaction with an account she controls.
+It's not an abstraction of core Ethereum accounts data type / logic -
+for that see the core processing code of blocks / txs.
+
+Currently this is pretty much a passthrough to the KeyStore2 interface,
+and accounts persistence is derived from stored keys' addresses
+
+*/
+package accounts
+
+import (
+	crand "crypto/rand"
+	"github.com/ethereum/go-ethereum/crypto"
+	"github.com/ethereum/go-ethereum/crypto/secp256k1"
+)
+
+// TODO: better name for this struct?
+type UserAccount struct {
+	Addr []byte
+}
+
+type AccountManager struct {
+	keyStore crypto.KeyStore2
+}
+
+// TODO: get key by addr - modify KeyStore2 GetKey to work with addr
+
+// TODO: pass through passphrase for APIs which require access to private key?
+func NewAccountManager(keyStore crypto.KeyStore2) AccountManager {
+	am := &AccountManager{
+		keyStore: keyStore,
+	}
+	return *am
+}
+
+func (am *AccountManager) Sign(fromAddr []byte, keyAuth string, toSign []byte) (signature []byte, err error) {
+	key, err := am.keyStore.GetKey(fromAddr, keyAuth)
+	if err != nil {
+		return nil, err
+	}
+	privKey := crypto.FromECDSA(key.PrivateKey)
+	// TODO: what is second value?
+	signature, err = secp256k1.Sign(toSign, privKey)
+	return signature, err
+}
+
+func (am AccountManager) NewAccount(auth string) (*UserAccount, error) {
+	key, err := am.keyStore.GenerateNewKey(crand.Reader, auth)
+	if err != nil {
+		return nil, err
+	}
+	ua := &UserAccount{
+		Addr: key.Address,
+	}
+	return ua, err
+}
+
+// set of accounts == set of keys in given key store
+// TODO: do we need persistence of accounts as well?
+func (am *AccountManager) Accounts() ([]UserAccount, error) {
+	addresses, err := am.keyStore.GetKeyAddresses()
+	if err != nil {
+		return nil, err
+	}
+
+	accounts := make([]UserAccount, len(addresses))
+
+	for i, addr := range addresses {
+		ua := &UserAccount{
+			Addr: addr,
+		}
+		accounts[i] = *ua
+	}
+	return accounts, err
+}
diff --git a/accounts/accounts_test.go b/accounts/accounts_test.go
new file mode 100644
index 000000000..381657718
--- /dev/null
+++ b/accounts/accounts_test.go
@@ -0,0 +1,19 @@
+package accounts
+
+import (
+	"github.com/ethereum/go-ethereum/crypto"
+	"testing"
+)
+
+func TestAccountManager(t *testing.T) {
+	ks := crypto.NewKeyStorePlain(crypto.DefaultDataDir())
+	am := NewAccountManager(ks)
+	pass := "" // not used but required by API
+	a1, err := am.NewAccount(pass)
+	toSign := make([]byte, 4, 4)
+	toSign = []byte{0, 1, 2, 3}
+	_, err = am.Sign(a1.Addr, pass, toSign)
+	if err != nil {
+		t.Fatal(err)
+	}
+}