Add new key_store interface and two new key stores

* Add new generic key_store interface
* Add new plaintext key store storing unprotected keys on disk
* Add new encrypted key store storing encrypted keys on disk
* Add new entropy mixing function using OS and go runtime sources

crypto/key_store_test.go

@@ -0,0 +1,118 @@
+package crypto
+
+import (
+	"fmt"
+	"reflect"
+	"testing"
+)
+
+func TestKeyStorePlaintext(t *testing.T) {
+	ks := new(KeyStorePlaintext)
+	ks.keysDirPath = DefaultDataDir()
+	pass := "" // not used but required by API
+	k1, err := ks.GenerateNewKey(pass)
+	if err != nil {
+		fmt.Println(err.Error())
+		t.FailNow()
+	}
+
+	k2 := new(Key)
+	k2, err = ks.GetKey(k1.Id, pass)
+	if err != nil {
+		fmt.Println(err.Error())
+		t.FailNow()
+	}
+
+	if !reflect.DeepEqual(k1.Id, k2.Id) {
+		fmt.Println("key Id mismatch")
+		t.FailNow()
+	}
+
+	if k1.Flags != k2.Flags {
+		fmt.Println("key Flags mismatch")
+		t.FailNow()
+	}
+
+	if !reflect.DeepEqual(k1.PrivateKey, k2.PrivateKey) {
+		fmt.Println("key PrivateKey mismatch")
+		t.FailNow()
+	}
+
+	err = ks.DeleteKey(k2.Id, pass)
+	if err != nil {
+		fmt.Println(err.Error())
+		t.FailNow()
+	}
+}
+
+func TestKeyStorePassphrase(t *testing.T) {
+	ks := new(KeyStorePassphrase)
+	ks.keysDirPath = DefaultDataDir()
+	pass := "foo"
+	k1, err := ks.GenerateNewKey(pass)
+	if err != nil {
+		fmt.Println(err.Error())
+		t.FailNow()
+	}
+
+	k2 := new(Key)
+	k2, err = ks.GetKey(k1.Id, pass)
+	if err != nil {
+		fmt.Println(err.Error())
+		t.FailNow()
+	}
+
+	if !reflect.DeepEqual(k1.Id, k2.Id) {
+		fmt.Println("key Id mismatch")
+		t.FailNow()
+	}
+
+	if k1.Flags != k2.Flags {
+		fmt.Println("key Flags mismatch")
+		t.FailNow()
+	}
+
+	if !reflect.DeepEqual(k1.PrivateKey, k2.PrivateKey) {
+		fmt.Println("key PrivateKey mismatch")
+		t.FailNow()
+	}
+
+	err = ks.DeleteKey(k2.Id, pass) // also to clean up created files
+	if err != nil {
+		fmt.Println(err.Error())
+		t.FailNow()
+	}
+}
+
+func TestKeyStorePassphraseDecryptionFail(t *testing.T) {
+	ks := new(KeyStorePassphrase)
+	ks.keysDirPath = DefaultDataDir()
+	pass := "foo"
+	k1, err := ks.GenerateNewKey(pass)
+	if err != nil {
+		fmt.Println(err.Error())
+		t.FailNow()
+	}
+
+	_, err = ks.GetKey(k1.Id, "bar") // wrong passphrase
+	// fmt.Println(err.Error())
+	if err == nil {
+		t.FailNow()
+	}
+
+	err = ks.DeleteKey(k1.Id, "bar") // wrong passphrase
+	if err == nil {
+		fmt.Println(err.Error())
+		t.FailNow()
+	}
+
+	err = ks.DeleteKey(k1.Id, pass) // to clean up
+	if err != nil {
+		fmt.Println(err.Error())
+		t.FailNow()
+	}
+}
+
+func TestKeyMixedEntropy(t *testing.T) {
+	GetEntropyTinFoilHat()
+}