make handshake and crypto internal packages

internal/crypto/source_address_token_test.go

@@ -0,0 +1,41 @@
+package crypto
+
+import (
+	. "github.com/onsi/ginkgo"
+	. "github.com/onsi/gomega"
+)
+
+var _ = Describe("Source Address Tokens", func() {
+	It("should generate the encryption key", func() {
+		Expect(deriveKey([]byte("TESTING"))).To(Equal([]byte{0xee, 0x71, 0x18, 0x9, 0xfd, 0xb8, 0x9a, 0x79, 0x19, 0xfc, 0x5e, 0x1a, 0x97, 0x20, 0xb2, 0x6}))
+	})
+
+	Context("tokens", func() {
+		var source *stkSource
+
+		BeforeEach(func() {
+			sourceI, err := NewStkSource()
+			source = sourceI.(*stkSource)
+			Expect(err).NotTo(HaveOccurred())
+		})
+
+		It("serializes", func() {
+			token, err := source.NewToken([]byte("foobar"))
+			Expect(err).ToNot(HaveOccurred())
+			data, err := source.DecodeToken(token)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(data).To(Equal([]byte("foobar")))
+		})
+
+		It("rejects invalid tokens", func() {
+			_, err := source.DecodeToken([]byte("invalid source address token"))
+			Expect(err).To(HaveOccurred())
+			Expect(err.Error()).To(ContainSubstring("message authentication failed"))
+		})
+
+		It("rejects tokens of wrong size", func() {
+			_, err := source.DecodeToken(nil)
+			Expect(err).To(MatchError("STK too short: 0"))
+		})
+	})
+})