crypto/rsa: check RSA private/public key size before using it

src/crypto/rsa/pkcs1v15.go

@@ -292,6 +292,9 @@ func SignPKCS1v15(random io.Reader, priv *PrivateKey, hash crypto.Hash, hashed [
 
 	tLen := len(prefix) + hashLen
 	k := priv.Size()
+	if k == 0 {
+		return nil, errPrivateKeySizeZero
+	}
 	if k < tLen+11 {
 		return nil, ErrMessageTooLong
 	}

src/crypto/rsa/pkcs1v15_test.go

@@ -213,6 +213,19 @@ func TestSignPKCS1v15(t *testing.T) {
 	}
 }
 
+func TestSignPKCS1v15WithPrivateKeySizeZero(t *testing.T) {
+	h := sha1.New()
+	h.Write([]byte("key"))
+	digest := h.Sum(nil)
+	_, err := SignPKCS1v15(nil, &PrivateKey{}, crypto.SHA1, digest)
+	if err == nil {
+		t.Error("expected error but got nil")
+	}
+	if err != nil && err.Error() != "crypto/rsa: private key size zero" {
+		t.Errorf("unexpected error: %v", err)
+	}
+}
+
 func TestVerifyPKCS1v15(t *testing.T) {
 	for i, test := range signPKCS1v15Tests {
 		h := sha1.New()

src/crypto/rsa/rsa.go

@@ -89,6 +89,8 @@ var (
 	errPublicModulus       = errors.New("crypto/rsa: missing public modulus")
 	errPublicExponentSmall = errors.New("crypto/rsa: public exponent too small")
 	errPublicExponentLarge = errors.New("crypto/rsa: public exponent too large")
+	errPublicKeySizeZero   = errors.New("crypto/rsa: public key size zero")
+	errPrivateKeySizeZero  = errors.New("crypto/rsa: private key size zero")
 )
 
 // checkPub sanity checks the public key before we use it.
@@ -106,6 +108,9 @@ func checkPub(pub *PublicKey) error {
 	if pub.E > 1<<31-1 {
 		return errPublicExponentLarge
 	}
+	if pub.Size() == 0 {
+		return errPublicKeySizeZero
+	}
 	return nil
 }
 

src/crypto/rsa/rsa_test.go

@@ -654,6 +654,17 @@ func TestEncryptOAEP(t *testing.T) {
 	}
 }
 
+func TestEncryptOAEPWithPublicKeySizeZero(t *testing.T) {
+	sha1 := sha1.New()
+	_, err := EncryptOAEP(sha1, nil, &PublicKey{}, nil, nil)
+	if err == nil {
+		t.Error("expected error but got nil")
+	}
+	if err != nil && err.Error() != "crypto/rsa: public key size zero" {
+		t.Errorf("unexpected error: %v", err)
+	}
+}
+
 func TestDecryptOAEP(t *testing.T) {
 	random := rand.Reader