1 files changed, 75 insertions, 0 deletions
diff --git a/src/crypto/ecdsa/equal_test.go b/src/crypto/ecdsa/equal_test.go
new file mode 100644
index 0000000..53ac850
--- /dev/null
+++ b/src/crypto/ecdsa/equal_test.go
@@ -0,0 +1,75 @@
+// Copyright 2020 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package ecdsa_test
+
+import (
+	"crypto"
+	"crypto/ecdsa"
+	"crypto/elliptic"
+	"crypto/rand"
+	"crypto/x509"
+	"testing"
+)
+
+func testEqual(t *testing.T, c elliptic.Curve) {
+	private, _ := ecdsa.GenerateKey(c, rand.Reader)
+	public := &private.PublicKey
+
+	if !public.Equal(public) {
+		t.Errorf("public key is not equal to itself: %v", public)
+	}
+	if !public.Equal(crypto.Signer(private).Public().(*ecdsa.PublicKey)) {
+		t.Errorf("private.Public() is not Equal to public: %q", public)
+	}
+	if !private.Equal(private) {
+		t.Errorf("private key is not equal to itself: %v", private)
+	}
+
+	enc, err := x509.MarshalPKCS8PrivateKey(private)
+	if err != nil {
+		t.Fatal(err)
+	}
+	decoded, err := x509.ParsePKCS8PrivateKey(enc)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !public.Equal(decoded.(crypto.Signer).Public()) {
+		t.Errorf("public key is not equal to itself after decoding: %v", public)
+	}
+	if !private.Equal(decoded) {
+		t.Errorf("private key is not equal to itself after decoding: %v", private)
+	}
+
+	other, _ := ecdsa.GenerateKey(c, rand.Reader)
+	if public.Equal(other.Public()) {
+		t.Errorf("different public keys are Equal")
+	}
+	if private.Equal(other) {
+		t.Errorf("different private keys are Equal")
+	}
+
+	// Ensure that keys with the same coordinates but on different curves
+	// aren't considered Equal.
+	differentCurve := &ecdsa.PublicKey{}
+	*differentCurve = *public // make a copy of the public key
+	if differentCurve.Curve == elliptic.P256() {
+		differentCurve.Curve = elliptic.P224()
+	} else {
+		differentCurve.Curve = elliptic.P256()
+	}
+	if public.Equal(differentCurve) {
+		t.Errorf("public keys with different curves are Equal")
+	}
+}
+
+func TestEqual(t *testing.T) {
+	t.Run("P224", func(t *testing.T) { testEqual(t, elliptic.P224()) })
+	if testing.Short() {
+		return
+	}
+	t.Run("P256", func(t *testing.T) { testEqual(t, elliptic.P256()) })
+	t.Run("P384", func(t *testing.T) { testEqual(t, elliptic.P384()) })
+	t.Run("P521", func(t *testing.T) { testEqual(t, elliptic.P521()) })
+}