go-x25519/x25519_test.go

package x25519

import (
	"bytes"
	"encoding/hex"
	"testing"
)

var (
	// Test vector from https://tools.ietf.org/html/rfc7748#section-6.1
	aliceSK      = "77076d0a7318a57d3c16c17251b26645df4c2f87ebc0992ab177fba51db92c2a"
	alicePK      = "8520f0098930a754748b7ddcb43ef75a0dbf3a0d26381af4eba4a98eaa9b4e6a"
	bobSK        = "5dab087e624a8a4b79e17f8b83800ee66f3bb1292618b6fd1c2f8b27ff88e0eb"
	bobPK        = "de9edb7d7b7dc1b4d35b61c2ece435373f8343c85b78674dadfc7e146f882b4f"
	sharedSecret = "4a5d9d5ba4ce2de1728e3bf480350f25e07e21c947d19e3376f09b3c1e161742"
)

func TestGenerateKey(t *testing.T) {
	askhex, err := hex.DecodeString(aliceSK)
	if err != nil {
		t.Fatal(err)
	}

	ask := NewSecretKey(askhex)
	apk := ask.Public()
	if alicePK != hex.EncodeToString(apk[:]) {
		t.Fatal("public key failed")
	}

	bskhex, err := hex.DecodeString(bobSK)
	if err != nil {
		t.Fatal(err)
	}

	bsk := NewSecretKey(bskhex)
	bpk := bsk.Public()
	if bobPK != hex.EncodeToString(bpk[:]) {
		t.Fatal("public key failed")
	}

	s1 := new([32]byte)
	s2 := new([32]byte)
	ask.Shared(s1, bpk)
	bsk.Shared(s2, apk)
	if !bytes.Equal(s1[:], s2[:]) {
		t.Fatal("shared secret failed")
	}
	if hex.EncodeToString(s1[:]) != sharedSecret {
		t.Fatal("shared secret failed")
	}
}

func TestGenerateKey2(t *testing.T) {
	ourSK, _ := GenerateKey(nil)
	theirSK, _ := GenerateKey(nil)

	t.Logf("our secret = %0x", ourSK)
	t.Logf("our public = %0x", ourSK.Public())
	t.Logf("their secret = %0x", theirSK)
	t.Logf("their public = %0x", theirSK.Public())

	s1 := new([32]byte)
	s2 := new([32]byte)
	ourSK.Shared(s1, theirSK.Public())
	theirSK.Shared(s2, ourSK.Public())
	if !bytes.Equal(s1[:], s2[:]) {
		t.Fatal("computed shared secrets differs")
	}
	t.Logf("shared secret = %0x", s1)
}