cmd/lncli: move commands and export

We want to export some of our CLI code to re-use in other projects. But
in Golang you cannot import code from a `main` package.
So we need to move the actual code into its own package and only have
the `func main()` in the `main` package.

cmd/commands/macaroon_jar_test.go

@@ -0,0 +1,102 @@
+package commands
+
+import (
+	"encoding/hex"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+	"gopkg.in/macaroon.v2"
+)
+
+var (
+	dummyMacStr = "0201047465737402067788991234560000062052d26ed139ea5af8" +
+		"3e675500c4ccb2471f62191b745bab820f129e5588a255d2"
+	dummyMac, _    = hex.DecodeString(dummyMacStr)
+	encryptedEntry = &macaroonEntry{
+		Name: "encryptedMac",
+		Data: "snacl:exX8xbUOb6Gih88ybL2jZGo+DBDPU2tYKkvo0eVVmbDGDoFP" +
+			"zlv5xvqNK5eml0LKLcB8LdZRw43qXK1W2OLs/gBAAAAAAAAACAAA" +
+			"AAAAAAABAAAAAAAAAA==:C8TN/aDOvSLiBCX+IdoPTx+UUWhVdGj" +
+			"NQvbcaWp+KXQWqPfpRZpjJQ6B2PDx5mJxImcezJGPx8ShAqMdxWe" +
+			"l2precU+1cOjk7HQFkYuu943eJ00s6JerAY+ssg==",
+	}
+	plaintextEntry = &macaroonEntry{
+		Name: "plaintextMac",
+		Data: dummyMacStr,
+	}
+
+	testPassword = []byte("S3curePazzw0rd")
+	pwCallback   = func(string) ([]byte, error) {
+		return testPassword, nil
+	}
+	noPwCallback = func(string) ([]byte, error) {
+		return nil, nil
+	}
+)
+
+// TestMacaroonJarEncrypted tests that a macaroon can be stored and retrieved
+// safely by encrypting/decrypting it with a password.
+func TestMacaroonJarEncrypted(t *testing.T) {
+	// Create a new macaroon entry from the dummy macaroon and encrypt it
+	// with the test password.
+	newEntry := &macaroonEntry{
+		Name: "encryptedMac",
+	}
+	err := newEntry.storeMacaroon(toMacaroon(t, dummyMac), testPassword)
+	require.NoError(t, err)
+
+	// Now decrypt it again and make sure we get the same content back.
+	mac, err := newEntry.loadMacaroon(pwCallback)
+	require.NoError(t, err)
+	macBytes, err := mac.MarshalBinary()
+	require.NoError(t, err)
+	require.Equal(t, dummyMac, macBytes)
+
+	// The encrypted data of the entry we just created shouldn't be the
+	// same as our test entry because of the salt snacl uses.
+	require.NotEqual(t, encryptedEntry.Data, newEntry.Data)
+
+	// Decrypt the hard coded test entry and make sure the decrypted content
+	// matches our created entry.
+	mac, err = encryptedEntry.loadMacaroon(pwCallback)
+	require.NoError(t, err)
+	macBytes, err = mac.MarshalBinary()
+	require.NoError(t, err)
+	require.Equal(t, dummyMac, macBytes)
+}
+
+// TestMacaroonJarPlaintext tests that a macaroon can be stored and retrieved
+// as plaintext as well.
+func TestMacaroonJarPlaintext(t *testing.T) {
+	// Create a new macaroon entry from the dummy macaroon and encrypt it
+	// with the test password.
+	newEntry := &macaroonEntry{
+		Name: "plaintextMac",
+	}
+	err := newEntry.storeMacaroon(toMacaroon(t, dummyMac), nil)
+	require.NoError(t, err)
+
+	// Now decrypt it again and make sure we get the same content back.
+	mac, err := newEntry.loadMacaroon(noPwCallback)
+	require.NoError(t, err)
+	macBytes, err := mac.MarshalBinary()
+	require.NoError(t, err)
+	require.Equal(t, dummyMac, macBytes)
+	require.Equal(t, plaintextEntry.Data, newEntry.Data)
+
+	// Load the hard coded plaintext test entry and make sure the loaded
+	// content matches our created entry.
+	mac, err = plaintextEntry.loadMacaroon(noPwCallback)
+	require.NoError(t, err)
+	macBytes, err = mac.MarshalBinary()
+	require.NoError(t, err)
+	require.Equal(t, dummyMac, macBytes)
+}
+
+func toMacaroon(t *testing.T, macData []byte) *macaroon.Macaroon {
+	mac := &macaroon.Macaroon{}
+	err := mac.UnmarshalBinary(macData)
+	require.NoError(t, err)
+
+	return mac
+}