Add tests for welcome packet

mtglib/internal/faketls/welcome_test.go

@@ -0,0 +1,82 @@
+package faketls_test
+
+import (
+	"bytes"
+	"crypto/hmac"
+	"crypto/sha256"
+	"math/rand"
+	"testing"
+	"time"
+
+	"github.com/9seconds/mtg/v2/mtglib"
+	"github.com/9seconds/mtg/v2/mtglib/internal/faketls"
+	"github.com/9seconds/mtg/v2/mtglib/internal/faketls/record"
+	"github.com/stretchr/testify/suite"
+)
+
+type WelcomeTestSuite struct {
+	suite.Suite
+
+	h      *faketls.ClientHello
+	buf    *bytes.Buffer
+	secret mtglib.Secret
+}
+
+func (suite *WelcomeTestSuite) SetupTest() {
+	suite.h = &faketls.ClientHello{
+		Time:        time.Now(),
+		Host:        "google.com",
+		CipherSuite: 4867,
+		SessionID:   make([]byte, 32),
+	}
+
+	_, err := rand.Read(suite.h.SessionID)
+	suite.NoError(err)
+
+	_, err = rand.Read(suite.h.Random[:])
+	suite.NoError(err)
+
+	suite.buf = &bytes.Buffer{}
+
+	suite.secret = mtglib.GenerateSecret("google.com")
+}
+
+func (suite *WelcomeTestSuite) TestOk() {
+	suite.NoError(faketls.SendWelcomePacket(suite.buf, suite.secret.Key[:], *suite.h))
+
+	welcomePacket := []byte{}
+	welcomePacket = append(welcomePacket, suite.buf.Bytes()...)
+
+	rec := record.AcquireRecord()
+	defer record.ReleaseRecord(rec)
+
+	suite.NoError(rec.Read(suite.buf))
+	suite.Equal(record.TypeHandshake, rec.Type)
+	suite.Equal(record.Version12, rec.Version)
+
+	suite.NoError(rec.Read(suite.buf))
+	suite.Equal(record.TypeChangeCipherSpec, rec.Type)
+	suite.Equal(record.Version12, rec.Version)
+
+	suite.NoError(rec.Read(suite.buf))
+	suite.Equal(record.TypeApplicationData, rec.Type)
+	suite.Equal(record.Version12, rec.Version)
+	suite.Empty(suite.buf.Bytes())
+
+	random := make([]byte, 32)
+	copy(random, welcomePacket[11:])
+
+	empty := make([]byte, 32)
+	copy(welcomePacket[11:], empty)
+
+	mac := hmac.New(sha256.New, suite.secret.Key[:])
+	mac.Write(suite.h.Random[:])
+	mac.Write(welcomePacket)
+
+	suite.Equal(random, mac.Sum(nil))
+}
+
+func TestWelcome(t *testing.T) {
+	t.Parallel()
+	suite.Run(t, &WelcomeTestSuite{})
+}