Extract common server encryption logic (#65)

* refactor: extract common message encryption logic
* refactor: move letsencrypt logic to common
* refactor: rename common package to encryption
* test: add encryption tests

encryption/encryption_test.go

@@ -0,0 +1,60 @@
+package encryption_test
+
+import (
+	. "github.com/onsi/ginkgo"
+	. "github.com/onsi/gomega"
+	"github.com/wiretrustee/wiretrustee/encryption"
+	"github.com/wiretrustee/wiretrustee/encryption/testprotos"
+	"golang.zx2c4.com/wireguard/wgctrl/wgtypes"
+)
+
+const ()
+
+var _ = Describe("Encryption", func() {
+
+	var (
+		encryptionKey wgtypes.Key
+		decryptionKey wgtypes.Key
+	)
+
+	BeforeEach(func() {
+		var err error
+		encryptionKey, err = wgtypes.GenerateKey()
+		Expect(err).NotTo(HaveOccurred())
+		decryptionKey, err = wgtypes.GenerateKey()
+		Expect(err).NotTo(HaveOccurred())
+	})
+
+	Context("decrypting a plain message", func() {
+		Context("when it was encrypted with Wireguard keys", func() {
+			Specify("should be successful", func() {
+				msg := "message"
+				encryptedMsg, err := encryption.Encrypt([]byte(msg), decryptionKey.PublicKey(), encryptionKey)
+				Expect(err).NotTo(HaveOccurred())
+
+				decryptedMsg, err := encryption.Decrypt(encryptedMsg, encryptionKey.PublicKey(), decryptionKey)
+				Expect(err).NotTo(HaveOccurred())
+
+				Expect(string(decryptedMsg)).To(BeEquivalentTo(msg))
+			})
+		})
+	})
+
+	Context("decrypting a protobuf message", func() {
+		Context("when it was encrypted with Wireguard keys", func() {
+			Specify("should be successful", func() {
+
+				protoMsg := &testprotos.TestMessage{Body: "message"}
+				encryptedMsg, err := encryption.EncryptMessage(decryptionKey.PublicKey(), encryptionKey, protoMsg)
+				Expect(err).NotTo(HaveOccurred())
+
+				decryptedMsg := &testprotos.TestMessage{}
+				err = encryption.DecryptMessage(encryptionKey.PublicKey(), decryptionKey, encryptedMsg, decryptedMsg)
+				Expect(err).NotTo(HaveOccurred())
+
+				Expect(decryptedMsg.GetBody()).To(BeEquivalentTo(protoMsg.GetBody()))
+			})
+		})
+	})
+
+})