package ed25519_test

import (
	"testing"

	"github.com/cloudflare/circl/sign/ed25519"
)

type zeroReader struct{}

func (zeroReader) Read(buf []byte) (int, error) {
	for i := range buf {
		buf[i] = 0
	}
	return len(buf), nil
}

func TestMalleability(t *testing.T) {
	// https://tools.ietf.org/html/rfc8032#section-5.1.7 adds an additional test
	// that s be in [0, order). This prevents someone from adding a multiple of
	// order to s and obtaining a second valid signature for the same message.
	msg := []byte{0x54, 0x65, 0x73, 0x74}
	sig := []byte{
		0x7c, 0x38, 0xe0, 0x26, 0xf2, 0x9e, 0x14, 0xaa, 0xbd, 0x05, 0x9a,
		0x0f, 0x2d, 0xb8, 0xb0, 0xcd, 0x78, 0x30, 0x40, 0x60, 0x9a, 0x8b,
		0xe6, 0x84, 0xdb, 0x12, 0xf8, 0x2a, 0x27, 0x77, 0x4a, 0xb0, 0x67,
		0x65, 0x4b, 0xce, 0x38, 0x32, 0xc2, 0xd7, 0x6f, 0x8f, 0x6f, 0x5d,
		0xaf, 0xc0, 0x8d, 0x93, 0x39, 0xd4, 0xee, 0xf6, 0x76, 0x57, 0x33,
		0x36, 0xa5, 0xc5, 0x1e, 0xb6, 0xf9, 0x46, 0xb3, 0x1d,
	}
	publicKey := []byte{
		0x7d, 0x4d, 0x0e, 0x7f, 0x61, 0x53, 0xa6, 0x9b, 0x62, 0x42, 0xb5,
		0x22, 0xab, 0xbe, 0xe6, 0x85, 0xfd, 0xa4, 0x42, 0x0f, 0x88, 0x34,
		0xb1, 0x08, 0xc3, 0xbd, 0xae, 0x36, 0x9e, 0xf5, 0x49, 0xfa,
	}

	if ed25519.Verify(publicKey, msg, sig) {
		t.Fatal("non-canonical signature accepted")
	}
}

func TestPublic(t *testing.T) {
	var zero zeroReader
	pub, priv, err := ed25519.GenerateKey(zero)
	if err != nil {
		t.Fatal(err)
	}
	if !priv.Equal(priv) {
		t.FailNow()
	}
	if !pub.Equal(pub) {
		t.FailNow()
	}
	pub2 := priv.Public()
	if !pub.Equal(pub2) {
		t.FailNow()
	}
}

func BenchmarkKeyGeneration(b *testing.B) {
	var zero zeroReader
	for i := 0; i < b.N; i++ {
		if _, _, err := ed25519.GenerateKey(zero); err != nil {
			b.Fatal(err)
		}
	}
}

func BenchmarkNewKeyFromSeed(b *testing.B) {
	seed := make([]byte, ed25519.SeedSize)
	b.ReportAllocs()
	for i := 0; i < b.N; i++ {
		_ = ed25519.NewKeyFromSeed(seed)
	}
}

func BenchmarkSigning(b *testing.B) {
	var zero zeroReader
	_, priv, err := ed25519.GenerateKey(zero)
	if err != nil {
		b.Fatal(err)
	}
	message := []byte("Hello, world!")
	b.ReportAllocs()
	b.ResetTimer()
	for i := 0; i < b.N; i++ {
		ed25519.Sign(priv, message)
	}
}

func BenchmarkVerification(b *testing.B) {
	var zero zeroReader
	pub, priv, err := ed25519.GenerateKey(zero)
	if err != nil {
		b.Fatal(err)
	}
	message := []byte("Hello, world!")
	signature := ed25519.Sign(priv, message)
	b.ResetTimer()
	for i := 0; i < b.N; i++ {
		ed25519.Verify(pub, message, signature)
	}
}