Implemented conn.go and hanshake.go + unit tests

handshake_test.go

@@ -0,0 +1,132 @@
+package ownwire_sdk_test
+
+import (
+	"context"
+	"crypto/ecdh"
+	"crypto/rand"
+	"encoding/base64"
+
+	. "github.com/onsi/ginkgo/v2"
+	. "github.com/onsi/gomega"
+
+	sdk "ownwire.net/ownwire-sdk"
+)
+
+var _ = Describe("Handshaker", func() {
+	It("sends /create when no resume session_id is provided and derives shared key", func() {
+		ctx := context.Background()
+		conn := sdk_test_new_inmem_conn()
+
+		client_kp, err := sdk.GenClientKey()
+		Expect(err).To(BeNil())
+
+		h := sdk.Handshaker{
+			GenClientKeyF: func() (sdk.Keypair, error) {
+				return client_kp, nil
+			},
+		}
+
+		curve := ecdh.P256()
+		server_priv, err := curve.GenerateKey(rand.Reader)
+		Expect(err).To(BeNil())
+		server_pub_raw := server_priv.PublicKey().Bytes()
+		server_pub_b64 := base64.StdEncoding.EncodeToString(server_pub_raw)
+
+		salt_raw := make([]byte, 32)
+		_, err = rand.Read(salt_raw)
+		Expect(err).To(BeNil())
+		salt_b64 := base64.StdEncoding.EncodeToString(salt_raw)
+
+		session_id := "cb653f53-6f7d-4aeb-ba0d-d2b17c290d8a"
+
+		go func() {
+			written := <-conn.write_ch
+			Expect(written).To(HavePrefix("/create:"))
+
+			conn.read_ch <- "/session:" + session_id + ":" + server_pub_b64 + ":" + salt_b64 + ":12:34"
+		}()
+
+		state, pending, err := h.Run(ctx, conn, "")
+		Expect(err).To(BeNil())
+		Expect(pending).To(BeEmpty())
+
+		Expect(state.SessionId).To(Equal(session_id))
+		Expect(state.ClientPubKeyB64).ToNot(BeEmpty())
+
+		want_key, err := sdk.DeriveSharedKey(session_id, client_kp.ClientPriv, server_pub_raw, salt_raw)
+		Expect(err).To(BeNil())
+		Expect(state.SharedKey).To(Equal(want_key))
+
+		Expect(state.SeqOut).To(Equal(uint64(34)))
+		Expect(state.SeqInMax).To(Equal(uint64(12)))
+	})
+
+	It("sends /open when resume session_id is provided", func() {
+		ctx := context.Background()
+		conn := sdk_test_new_inmem_conn()
+
+		client_kp, err := sdk.GenClientKey()
+		Expect(err).To(BeNil())
+
+		h := sdk.Handshaker{
+			GenClientKeyF: func() (sdk.Keypair, error) {
+				return client_kp, nil
+			},
+		}
+
+		curve := ecdh.P256()
+		server_priv, err := curve.GenerateKey(rand.Reader)
+		Expect(err).To(BeNil())
+		server_pub_raw := server_priv.PublicKey().Bytes()
+		server_pub_b64 := base64.StdEncoding.EncodeToString(server_pub_raw)
+
+		salt_raw := make([]byte, 32)
+		_, err = rand.Read(salt_raw)
+		Expect(err).To(BeNil())
+		salt_b64 := base64.StdEncoding.EncodeToString(salt_raw)
+
+		session_id := "cb653f53-6f7d-4aeb-ba0d-d2b17c290d8a"
+
+		go func() {
+			written := <-conn.write_ch
+			Expect(written).To(HavePrefix("/open:" + session_id + ":"))
+
+			conn.read_ch <- "/session:" + session_id + ":" + server_pub_b64 + ":" + salt_b64 + ":1:2"
+		}()
+
+		_, pending, err := h.Run(ctx, conn, session_id)
+		Expect(err).To(BeNil())
+		Expect(pending).To(BeEmpty())
+	})
+})
+
+func sdk_test_new_inmem_conn() *sdk_test_inmem_conn {
+	return &sdk_test_inmem_conn{
+		write_ch: make(chan string, 16),
+		read_ch:  make(chan string, 16),
+	}
+}
+
+type sdk_test_inmem_conn struct {
+	write_ch chan string
+	read_ch  chan string
+}
+
+func (c *sdk_test_inmem_conn) WriteText(ctx context.Context, s string) error {
+	select {
+	case c.write_ch <- s:
+		return nil
+	case <-ctx.Done():
+		return ctx.Err()
+	}
+}
+
+func (c *sdk_test_inmem_conn) ReadText(ctx context.Context) (string, error) {
+	select {
+	case s := <-c.read_ch:
+		return s, nil
+	case <-ctx.Done():
+		return "", ctx.Err()
+	}
+}
+