Improve backup handling for unexpected GameCenter certificates. (26087f4b) · Commits · public-projects / Nakama

social/social.go

+13 −10

Original line number	Diff line number	Diff line
		@@ -297,7 +297,7 @@ func (c Client) CheckGoogleToken(idToken string) (GoogleProfile, error) {
		func (c *Client) CheckGameCenterID(playerID string, bundleID string, timestamp int64, salt string, signature string, publicKeyURL string) (bool, error) {
		pub, err := url.Parse(publicKeyURL)
		if err != nil {
		return false, err
		return false, fmt.Errorf("gamecenter check error: invalid public key url: %v", err.Error())
		} else if pub.Scheme != "https" {
		return false, errors.New("gamecenter check error: invalid public key url scheme")
		} else if pub.Path == "" \|\| pub.Path == "/" {
		@@ -307,11 +307,11 @@ func (c *Client) CheckGameCenterID(playerID string, bundleID string, timestamp i
		}
		slt, err := base64.StdEncoding.DecodeString(salt)
		if err != nil {
		return false, err
		return false, errors.New("gamecenter check error: error decoding salt")
		}
		sig, err := base64.StdEncoding.DecodeString(signature)
		if err != nil {
		return false, err
		return false, errors.New("gamecenter check error: error decoding signature")
		}

		body, err := c.requestRaw("apple public key url", publicKeyURL, nil)
		@@ -320,24 +320,27 @@ func (c *Client) CheckGameCenterID(playerID string, bundleID string, timestamp i
		}

		// Parse the public key, check issuer, check signature.
		pubBlock, _ := pem.Decode([]byte(body))
		pubBlock, rest := pem.Decode([]byte(body))
		if pubBlock == nil {
		pubBlock, rest = pem.Decode([]byte("\n-----BEGIN CERTIFICATE-----\n" + base64.StdEncoding.EncodeToString(rest) + "\n-----END CERTIFICATE-----"))
		if pubBlock == nil {
		return false, errors.New("gamecenter check error: error decoding public key")
		}
		}
		pubCert, err := x509.ParseCertificate(pubBlock.Bytes)
		if err != nil {
		return false, err
		return false, fmt.Errorf("gamecenter check error: error parsing public block: %v", err.Error())
		}
		err = pubCert.CheckSignatureFrom(c.gamecenterCaCert)
		if err != nil {
		return false, err
		return false, fmt.Errorf("gamecenter check error: bad public key signature: %v", err.Error())
		}
		ts := make([]byte, 8)
		binary.LittleEndian.PutUint64(ts, uint64(timestamp))
		binary.BigEndian.PutUint64(ts, uint64(timestamp))
		payload := [][]byte{[]byte(playerID), []byte(bundleID), ts, slt}
		err = pubCert.CheckSignature(x509.SHA256WithRSA, bytes.Join(payload, make([]byte, 0)), sig)
		err = pubCert.CheckSignature(x509.SHA256WithRSA, bytes.Join(payload, []byte{}), sig)
		if err != nil {
		return false, err
		return false, fmt.Errorf("gamecenter check error: signature mismatch: %v", err.Error())
		}
		return true, nil
		}