Revert "crypto/rsa,crypto/ecdsa,crypto/ed25519: implement PublicKey.Equal"

Bryan C. Mills · Bryan C. Mills · commit fb2a6343defa · 2020-03-23T21:15:27.000Z
This reverts CL 223754. Reason for revert: new tests are failing on all longtest builders. Change-Id: I2257d106c132f3a02c0af6b20061d4f9a8093c4f Reviewed-on: https://go-review.googlesource.com/c/go/+/225077 Run-TryBot: Bryan C. Mills <bcmills@google.com> Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org> Reviewed-by: Katie Hockman <katie@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org>
diff --git a/src/crypto/ecdsa/ecdsa.go b/src/crypto/ecdsa/ecdsa.go
@@ -62,24 +62,6 @@ type PublicKey struct {
 	X, Y *big.Int
 }
 
-// Equal reports whether pub and x have the same value.
-//
-// Two keys are only considered to have the same value if they have the same Curve value.
-// Note that for example elliptic.P256() and elliptic.P256().Params() are different
-// values, as the latter is a generic not constant time implementation.
-func (pub *PublicKey) Equal(x crypto.PublicKey) bool {
-	xx, ok := x.(*PublicKey)
-	if !ok {
-		return false
-	}
-	return pub.X.Cmp(xx.X) == 0 && pub.Y.Cmp(xx.Y) == 0 &&
-		// Standard library Curve implementations are singletons, so this check
-		// will work for those. Other Curves might be equivalent even if not
-		// singletons, but there is no definitive way to check for that, and
-		// better to err on the side of safety.
-		pub.Curve == xx.Curve
-}
-
 // PrivateKey represents an ECDSA private key.
 type PrivateKey struct {
 	PublicKey
diff --git a/src/crypto/ecdsa/equal_test.go b/src/crypto/ecdsa/equal_test.go
diff --git a/src/crypto/ed25519/ed25519.go b/src/crypto/ed25519/ed25519.go
@@ -40,15 +40,6 @@ const (
 // PublicKey is the type of Ed25519 public keys.
 type PublicKey []byte
 
-// Equal reports whether pub and x have the same value.
-func (pub PublicKey) Equal(x crypto.PublicKey) bool {
-	xx, ok := x.(PublicKey)
-	if !ok {
-		return false
-	}
-	return bytes.Equal(pub, xx)
-}
-
 // PrivateKey is the type of Ed25519 private keys. It implements crypto.Signer.
 type PrivateKey []byte
 
diff --git a/src/crypto/ed25519/ed25519_test.go b/src/crypto/ed25519/ed25519_test.go
@@ -88,22 +88,6 @@ func TestCryptoSigner(t *testing.T) {
 	}
 }
 
-func TestEqual(t *testing.T) {
-	public, private, _ := GenerateKey(rand.Reader)
-
-	if !public.Equal(public) {
-		t.Errorf("public key is not equal to itself: %q", public)
-	}
-	if !public.Equal(crypto.Signer(private).Public().(PublicKey)) {
-		t.Errorf("private.Public() is not Equal to public: %q", public)
-	}
-
-	other, _, _ := GenerateKey(rand.Reader)
-	if public.Equal(other) {
-		t.Errorf("different public keys are Equal")
-	}
-}
-
 func TestGolden(t *testing.T) {
 	// sign.input.gz is a selection of test cases from
 	// https://ed25519.cr.yp.to/python/sign.input
diff --git a/src/crypto/rsa/equal_test.go b/src/crypto/rsa/equal_test.go
diff --git a/src/crypto/rsa/rsa.go b/src/crypto/rsa/rsa.go
@@ -50,15 +50,6 @@ func (pub *PublicKey) Size() int {
 	return (pub.N.BitLen() + 7) / 8
 }
 
-// Equal reports whether pub and x have the same value.
-func (pub *PublicKey) Equal(x crypto.PublicKey) bool {
-	xx, ok := x.(*PublicKey)
-	if !ok {
-		return false
-	}
-	return pub.N.Cmp(xx.N) == 0 && pub.E == xx.E
-}
-
 // OAEPOptions is an interface for passing options to OAEP decryption using the
 // crypto.Decrypter interface.
 type OAEPOptions struct {
