Beispiel #1
0
func (client *clientImpl) validateTCert(tCertDER []byte) (*x509.Certificate, error) {
	client.node.log.Debug("Validating TCert [%s]", utils.EncodeBase64(tCertDER))

	// DER to x509
	x509Cert, err := utils.DERToX509Certificate(tCertDER)
	if err != nil {
		client.node.log.Debug("Failed parsing certificate: [%s].", err)

		return nil, err
	}

	// Handle Critical Extension TCertEncTCertIndex
	if _, err = utils.GetCriticalExtension(x509Cert, utils.TCertEncTCertIndex); err != nil {
		client.node.log.Error("Failed getting extension TCERT_ENC_TCERTINDEX [%s].", err.Error())

		return nil, err
	}

	// Verify certificate against root
	if _, err := utils.CheckCertAgainRoot(x509Cert, client.node.tcaCertPool); err != nil {
		client.node.log.Warning("Warning verifing certificate [%s].", err.Error())

		return nil, err
	}

	return x509Cert, nil
}
Beispiel #2
0
func (client *clientImpl) getTCertFromExternalDER(der []byte) (tCert, error) {
	// DER to x509
	x509Cert, err := utils.DERToX509Certificate(der)
	if err != nil {
		client.debug("Failed parsing certificate [% x]: [%s].", der, err)

		return nil, err
	}

	// Handle Critical Extension TCertEncTCertIndex
	if _, err = utils.GetCriticalExtension(x509Cert, utils.TCertEncTCertIndex); err != nil {
		client.error("Failed getting extension TCERT_ENC_TCERTINDEX [% x]: [%s].", der, err)

		return nil, err
	}

	// Verify certificate against root
	if _, err := utils.CheckCertAgainRoot(x509Cert, client.tcaCertPool); err != nil {
		client.warning("Warning verifing certificate [% x]: [%s].", der, err)

		return nil, err
	}

	return &tCertImpl{client, x509Cert, nil}, nil
}
Beispiel #3
0
func (validator *validatorImpl) getEnrollmentCertByHashFromECA(id []byte) ([]byte, []byte, error) {
	// Prepare the request
	validator.peer.node.log.Debug("Reading certificate for hash [%s]", utils.EncodeBase64(id))

	req := &obcca.Hash{Hash: id}
	responce, err := validator.peer.node.callECAReadCertificateByHash(context.Background(), req)
	if err != nil {
		validator.peer.node.log.Error("Failed requesting enrollment certificate [%s].", err.Error())

		return nil, nil, err
	}

	validator.peer.node.log.Debug("Certificate for hash [%s] = [%s][%s]", utils.EncodeBase64(id), utils.EncodeBase64(responce.Sign), utils.EncodeBase64(responce.Enc))

	// Verify responce.Sign
	x509Cert, err := utils.DERToX509Certificate(responce.Sign)
	if err != nil {
		validator.peer.node.log.Error("Failed parsing signing enrollment certificate for encrypting: [%s]", err)

		return nil, nil, err
	}

	// Check role
	roleRaw, err := utils.GetCriticalExtension(x509Cert, ECertSubjectRole)
	if err != nil {
		validator.peer.node.log.Error("Failed parsing ECertSubjectRole in enrollment certificate for signing: [%s]", err)

		return nil, nil, err
	}

	role, err := strconv.ParseInt(string(roleRaw), 10, len(roleRaw)*8)
	if err != nil {
		validator.peer.node.log.Error("Failed parsing ECertSubjectRole in enrollment certificate for signing: [%s]", err)

		return nil, nil, err
	}

	if obcca.Role(role) != obcca.Role_VALIDATOR {
		validator.peer.node.log.Error("Invalid ECertSubjectRole in enrollment certificate for signing. Not a validator: [%s]", err)

		return nil, nil, err
	}

	return responce.Sign, responce.Enc, nil
}
Beispiel #4
0
func (node *nodeImpl) getEnrollmentCertificateFromECA(id, pw string) (interface{}, []byte, []byte, error) {
	// Get a new ECA Client
	sock, ecaP, err := node.getECAClient()
	defer sock.Close()

	// Run the protocol

	signPriv, err := utils.NewECDSAKey()
	if err != nil {
		node.log.Error("Failed generating ECDSA key [%s].", err.Error())

		return nil, nil, nil, err
	}
	signPub, err := x509.MarshalPKIXPublicKey(&signPriv.PublicKey)
	if err != nil {
		node.log.Error("Failed mashalling ECDSA key [%s].", err.Error())

		return nil, nil, nil, err
	}

	encPriv, err := utils.NewECDSAKey()
	if err != nil {
		node.log.Error("Failed generating Encryption key [%s].", err.Error())

		return nil, nil, nil, err
	}
	encPub, err := x509.MarshalPKIXPublicKey(&encPriv.PublicKey)
	if err != nil {
		node.log.Error("Failed marshalling Encryption key [%s].", err.Error())

		return nil, nil, nil, err
	}

	req := &obcca.ECertCreateReq{&protobuf.Timestamp{Seconds: time.Now().Unix(), Nanos: 0},
		&obcca.Identity{id},
		&obcca.Token{Tok: []byte(pw)},
		&obcca.PublicKey{obcca.CryptoType_ECDSA, signPub},
		&obcca.PublicKey{obcca.CryptoType_ECDSA, encPub},
		nil}

	resp, err := ecaP.CreateCertificatePair(context.Background(), req)
	if err != nil {
		node.log.Error("Failed invoking CreateCertficatePair [%s].", err.Error())

		return nil, nil, nil, err
	}

	//out, err := rsa.DecryptPKCS1v15(rand.Reader, encPriv, resp.Tok.Tok)
	spi := ecies.NewSPI()
	eciesKey, err := spi.NewPrivateKey(nil, encPriv)
	if err != nil {
		node.log.Error("Failed parsing decrypting key [%s].", err.Error())

		return nil, nil, nil, err
	}

	ecies, err := spi.NewAsymmetricCipherFromPublicKey(eciesKey)
	if err != nil {
		node.log.Error("Failed creating asymmetrinc cipher [%s].", err.Error())

		return nil, nil, nil, err
	}

	out, err := ecies.Process(resp.Tok.Tok)
	if err != nil {
		node.log.Error("Failed decrypting toke [%s].", err.Error())

		return nil, nil, nil, err
	}

	req.Tok.Tok = out
	req.Sig = nil

	hash := utils.NewHash()
	raw, _ := proto.Marshal(req)
	hash.Write(raw)

	r, s, err := ecdsa.Sign(rand.Reader, signPriv, hash.Sum(nil))
	if err != nil {
		node.log.Error("Failed signing [%s].", err.Error())

		return nil, nil, nil, err
	}
	R, _ := r.MarshalText()
	S, _ := s.MarshalText()
	req.Sig = &obcca.Signature{obcca.CryptoType_ECDSA, R, S}

	resp, err = ecaP.CreateCertificatePair(context.Background(), req)
	if err != nil {
		node.log.Error("Failed invoking CreateCertificatePair [%s].", err.Error())

		return nil, nil, nil, err
	}

	// Verify response

	// Verify cert for signing
	node.log.Debug("Enrollment certificate for signing [%s]", utils.EncodeBase64(utils.Hash(resp.Certs.Sign)))

	x509SignCert, err := utils.DERToX509Certificate(resp.Certs.Sign)
	if err != nil {
		node.log.Error("Failed parsing signing enrollment certificate for signing: [%s]", err)

		return nil, nil, nil, err
	}

	_, err = utils.GetCriticalExtension(x509SignCert, ECertSubjectRole)
	if err != nil {
		node.log.Error("Failed parsing ECertSubjectRole in enrollment certificate for signing: [%s]", err)

		return nil, nil, nil, err
	}

	err = utils.CheckCertAgainstSKAndRoot(x509SignCert, signPriv, node.ecaCertPool)
	if err != nil {
		node.log.Error("Failed checking signing enrollment certificate for signing: [%s]", err)

		return nil, nil, nil, err
	}

	// Verify cert for encrypting
	node.log.Debug("Enrollment certificate for encrypting [%s]", utils.EncodeBase64(utils.Hash(resp.Certs.Enc)))

	x509EncCert, err := utils.DERToX509Certificate(resp.Certs.Enc)
	if err != nil {
		node.log.Error("Failed parsing signing enrollment certificate for encrypting: [%s]", err)

		return nil, nil, nil, err
	}

	_, err = utils.GetCriticalExtension(x509EncCert, ECertSubjectRole)
	if err != nil {
		node.log.Error("Failed parsing ECertSubjectRole in enrollment certificate for encrypting: [%s]", err)

		return nil, nil, nil, err
	}

	err = utils.CheckCertAgainstSKAndRoot(x509EncCert, encPriv, node.ecaCertPool)
	if err != nil {
		node.log.Error("Failed checking signing enrollment certificate for encrypting: [%s]", err)

		return nil, nil, nil, err
	}

	// END

	return signPriv, resp.Certs.Sign, resp.Chain.Tok, nil
}
Beispiel #5
0
func (client *clientImpl) getTCertsFromTCA(num int) ([][]byte, error) {
	client.node.log.Debug("Get [%d] certificates from the TCA...", num)

	// Contact the TCA
	TCertOwnerKDFKey, certDERs, err := client.callTCACreateCertificateSet(num)
	if err != nil {
		client.node.log.Debug("Failed contacting TCA [%s].", err.Error())

		return nil, err
	}

	//	client.node.log.Debug("TCertOwnerKDFKey [%s].", utils.EncodeBase64(TCertOwnerKDFKey))

	// Store TCertOwnerKDFKey and checks that every time it is always the same key
	if client.tCertOwnerKDFKey != nil {
		// Check that the keys are the same
		equal := bytes.Equal(client.tCertOwnerKDFKey, TCertOwnerKDFKey)
		if !equal {
			return nil, errors.New("Failed reciving kdf key from TCA. The keys are different.")
		}
	} else {
		client.tCertOwnerKDFKey = TCertOwnerKDFKey

		// TODO: handle this situation more carefully
		if err := client.storeTCertOwnerKDFKey(); err != nil {
			client.node.log.Error("Failed storing TCertOwnerKDFKey [%s].", err.Error())

			return nil, err
		}
	}

	// Validate the Certificates obtained

	TCertOwnerEncryptKey := utils.HMACTruncated(TCertOwnerKDFKey, []byte{1}, utils.AESKeyLength)
	ExpansionKey := utils.HMAC(TCertOwnerKDFKey, []byte{2})

	resCert := make([][]byte, num)

	j := 0
	for i := 0; i < num; i++ {
		client.node.log.Debug("Validating certificate [%d], [%s]", i, utils.EncodeBase64(certDERs[i]))

		// DER to x509
		x509Cert, err := utils.DERToX509Certificate(certDERs[i])
		if err != nil {
			client.node.log.Debug("Failed parsing certificate: [%s].", err)

			continue
		}

		// Handle Critical Extenstion TCertEncTCertIndex
		tCertIndexCT, err := utils.GetCriticalExtension(x509Cert, utils.TCertEncTCertIndex)
		if err != nil {
			client.node.log.Error("Failed getting extension TCERT_ENC_TCERTINDEX [%s].", err.Error())

			continue
		}

		// Verify certificate against root
		if _, err := utils.CheckCertAgainRoot(x509Cert, client.node.tcaCertPool); err != nil {
			client.node.log.Warning("Warning verifing certificate [%s].", err.Error())

			continue
		}

		// Verify public key

		// 384-bit ExpansionValue = HMAC(Expansion_Key, TCertIndex)
		// Let TCertIndex = Timestamp, RandValue, 1,2,…
		// Timestamp assigned, RandValue assigned and counter reinitialized to 1 per batch

		// Decrypt ct to TCertIndex (TODO: || EnrollPub_Key || EnrollID ?)
		pt, err := utils.CBCPKCS7Decrypt(TCertOwnerEncryptKey, tCertIndexCT)
		if err != nil {
			client.node.log.Error("Failed decrypting extension TCERT_ENC_TCERTINDEX [%s].", err.Error())

			continue
		}

		// Compute ExpansionValue based on TCertIndex
		TCertIndex := pt
		//		TCertIndex := []byte(strconv.Itoa(i))

		client.node.log.Debug("TCertIndex: [%s].", utils.EncodeBase64(TCertIndex))
		mac := hmac.New(utils.NewHash, ExpansionKey)
		mac.Write(TCertIndex)
		ExpansionValue := mac.Sum(nil)

		// Derive tpk and tsk accordingly to ExapansionValue from enrollment pk,sk
		// Computable by TCA / Auditor: TCertPub_Key = EnrollPub_Key + ExpansionValue G
		// using elliptic curve point addition per NIST FIPS PUB 186-4- specified P-384

		// Compute temporary secret key
		tempSK := &ecdsa.PrivateKey{
			PublicKey: ecdsa.PublicKey{
				Curve: client.node.enrollPrivKey.Curve,
				X:     new(big.Int),
				Y:     new(big.Int),
			},
			D: new(big.Int),
		}

		var k = new(big.Int).SetBytes(ExpansionValue)
		var one = new(big.Int).SetInt64(1)
		n := new(big.Int).Sub(client.node.enrollPrivKey.Params().N, one)
		k.Mod(k, n)
		k.Add(k, one)

		tempSK.D.Add(client.node.enrollPrivKey.D, k)
		tempSK.D.Mod(tempSK.D, client.node.enrollPrivKey.PublicKey.Params().N)

		// Compute temporary public key
		tempX, tempY := client.node.enrollPrivKey.PublicKey.ScalarBaseMult(k.Bytes())
		tempSK.PublicKey.X, tempSK.PublicKey.Y =
			tempSK.PublicKey.Add(
				client.node.enrollPrivKey.PublicKey.X, client.node.enrollPrivKey.PublicKey.Y,
				tempX, tempY,
			)

		// Verify temporary public key is a valid point on the reference curve
		isOn := tempSK.Curve.IsOnCurve(tempSK.PublicKey.X, tempSK.PublicKey.Y)
		if !isOn {
			client.node.log.Error("Failed temporary public key IsOnCurve check.")

			continue
		}

		// Check that the derived public key is the same as the one in the certificate
		certPK := x509Cert.PublicKey.(*ecdsa.PublicKey)

		cmp := certPK.X.Cmp(tempSK.PublicKey.X)
		if cmp != 0 {
			client.node.log.Error("Derived public key is different on X")

			continue
		}

		cmp = certPK.Y.Cmp(tempSK.PublicKey.Y)
		if cmp != 0 {
			client.node.log.Error("Derived public key is different on Y")

			continue
		}

		// Verify the signing capability of tempSK
		err = utils.VerifySignCapability(tempSK, x509Cert.PublicKey)
		if err != nil {
			client.node.log.Error("Failed verifing signing capability [%s].", err.Error())

			continue
		}

		// Marshall certificate and secret key to be stored in the database
		resCert[j] = certDERs[i]
		if err != nil {
			client.node.log.Error("Failed marshalling private key [%s].", err.Error())

			continue
		}

		if err := utils.CheckCertPKAgainstSK(x509Cert, interface{}(tempSK)); err != nil {
			client.node.log.Error("Failed checking TCA cert PK against private key [%s].", err.Error())

			continue
		}

		client.node.log.Debug("Sub index [%d]", j)
		j++
		client.node.log.Debug("Certificate [%d] validated.", i)
	}

	if j == 0 {
		client.node.log.Error("No valid TCert was sent")

		return nil, errors.New("No valid TCert was sent.")
	}

	return resCert[:j], nil
}
Beispiel #6
0
func (client *clientImpl) signUsingTCertX509(tCert *x509.Certificate, msg []byte) ([]byte, error) {
	// Extract the signing key from the tCert
	TCertOwnerEncryptKey := utils.HMACTruncated(client.tCertOwnerKDFKey, []byte{1}, utils.AESKeyLength)
	ExpansionKey := utils.HMAC(client.tCertOwnerKDFKey, []byte{2})

	// TODO: retrieve TCertIndex from the ciphertext encrypted under the TCertOwnerEncryptKey
	ct, err := utils.GetCriticalExtension(tCert, utils.TCertEncTCertIndex)
	if err != nil {
		client.node.log.Error("Failed getting extension TCERT_ENC_TCERTINDEX [%s].", err.Error())

		return nil, err
	}

	// Decrypt ct to TCertIndex (TODO: || EnrollPub_Key || EnrollID ?)
	decryptedTCertIndex, err := utils.CBCPKCS7Decrypt(TCertOwnerEncryptKey, ct)
	if err != nil {
		client.node.log.Error("Failed decrypting extension TCERT_ENC_TCERTINDEX [%s].", err.Error())

		return nil, err
	}

	// Compute ExpansionValue based on TCertIndex
	TCertIndex := decryptedTCertIndex

	client.node.log.Debug("TCertIndex [%s].", utils.EncodeBase64(TCertIndex))
	mac := hmac.New(utils.NewHash, ExpansionKey)
	mac.Write(TCertIndex)
	ExpansionValue := mac.Sum(nil)

	// Derive tpk and tsk accordingly to ExapansionValue from enrollment pk,sk
	// Computable by TCA / Auditor: TCertPub_Key = EnrollPub_Key + ExpansionValue G
	// using elliptic curve point addition per NIST FIPS PUB 186-4- specified P-384

	// Compute temporary secret key
	tempSK := &ecdsa.PrivateKey{
		PublicKey: ecdsa.PublicKey{
			Curve: client.node.enrollPrivKey.Curve,
			X:     new(big.Int),
			Y:     new(big.Int),
		},
		D: new(big.Int),
	}

	var k = new(big.Int).SetBytes(ExpansionValue)
	var one = new(big.Int).SetInt64(1)
	n := new(big.Int).Sub(client.node.enrollPrivKey.Params().N, one)
	k.Mod(k, n)
	k.Add(k, one)

	tempSK.D.Add(client.node.enrollPrivKey.D, k)
	tempSK.D.Mod(tempSK.D, client.node.enrollPrivKey.PublicKey.Params().N)

	// Compute temporary public key
	tempX, tempY := client.node.enrollPrivKey.PublicKey.ScalarBaseMult(k.Bytes())
	tempSK.PublicKey.X, tempSK.PublicKey.Y =
		tempSK.PublicKey.Add(
			client.node.enrollPrivKey.PublicKey.X, client.node.enrollPrivKey.PublicKey.Y,
			tempX, tempY,
		)

	return client.node.sign(tempSK, msg)
}
Beispiel #7
0
func (client *clientImpl) getTCertFromDER(der []byte) (tCert tCert, err error) {
	if client.tCertOwnerKDFKey == nil {
		return nil, fmt.Errorf("KDF key not initialized yet")
	}

	TCertOwnerEncryptKey := utils.HMACTruncated(client.tCertOwnerKDFKey, []byte{1}, utils.AESKeyLength)
	ExpansionKey := utils.HMAC(client.tCertOwnerKDFKey, []byte{2})

	// DER to x509
	x509Cert, err := utils.DERToX509Certificate(der)
	if err != nil {
		client.debug("Failed parsing certificate [% x]: [%s].", der, err)

		return
	}

	// Handle Critical Extenstion TCertEncTCertIndex
	tCertIndexCT, err := utils.GetCriticalExtension(x509Cert, utils.TCertEncTCertIndex)
	if err != nil {
		client.error("Failed getting extension TCERT_ENC_TCERTINDEX [%s].", err.Error())

		return
	}

	// Verify certificate against root
	if _, err = utils.CheckCertAgainRoot(x509Cert, client.tcaCertPool); err != nil {
		client.warning("Warning verifing certificate [%s].", err.Error())

		return
	}

	// Verify public key

	// 384-bit ExpansionValue = HMAC(Expansion_Key, TCertIndex)
	// Let TCertIndex = Timestamp, RandValue, 1,2,…
	// Timestamp assigned, RandValue assigned and counter reinitialized to 1 per batch

	// Decrypt ct to TCertIndex (TODO: || EnrollPub_Key || EnrollID ?)
	pt, err := utils.CBCPKCS7Decrypt(TCertOwnerEncryptKey, tCertIndexCT)
	if err != nil {
		client.error("Failed decrypting extension TCERT_ENC_TCERTINDEX [%s].", err.Error())

		return
	}

	// Compute ExpansionValue based on TCertIndex
	TCertIndex := pt
	//		TCertIndex := []byte(strconv.Itoa(i))

	client.debug("TCertIndex: [% x].", TCertIndex)
	mac := hmac.New(utils.NewHash, ExpansionKey)
	mac.Write(TCertIndex)
	ExpansionValue := mac.Sum(nil)

	// Derive tpk and tsk accordingly to ExapansionValue from enrollment pk,sk
	// Computable by TCA / Auditor: TCertPub_Key = EnrollPub_Key + ExpansionValue G
	// using elliptic curve point addition per NIST FIPS PUB 186-4- specified P-384

	// Compute temporary secret key
	tempSK := &ecdsa.PrivateKey{
		PublicKey: ecdsa.PublicKey{
			Curve: client.enrollPrivKey.Curve,
			X:     new(big.Int),
			Y:     new(big.Int),
		},
		D: new(big.Int),
	}

	var k = new(big.Int).SetBytes(ExpansionValue)
	var one = new(big.Int).SetInt64(1)
	n := new(big.Int).Sub(client.enrollPrivKey.Params().N, one)
	k.Mod(k, n)
	k.Add(k, one)

	tempSK.D.Add(client.enrollPrivKey.D, k)
	tempSK.D.Mod(tempSK.D, client.enrollPrivKey.PublicKey.Params().N)

	// Compute temporary public key
	tempX, tempY := client.enrollPrivKey.PublicKey.ScalarBaseMult(k.Bytes())
	tempSK.PublicKey.X, tempSK.PublicKey.Y =
		tempSK.PublicKey.Add(
			client.enrollPrivKey.PublicKey.X, client.enrollPrivKey.PublicKey.Y,
			tempX, tempY,
		)

	// Verify temporary public key is a valid point on the reference curve
	isOn := tempSK.Curve.IsOnCurve(tempSK.PublicKey.X, tempSK.PublicKey.Y)
	if !isOn {
		client.error("Failed temporary public key IsOnCurve check.")

		return nil, fmt.Errorf("Failed temporary public key IsOnCurve check.")
	}

	// Check that the derived public key is the same as the one in the certificate
	certPK := x509Cert.PublicKey.(*ecdsa.PublicKey)

	if certPK.X.Cmp(tempSK.PublicKey.X) != 0 {
		client.error("Derived public key is different on X")

		return nil, fmt.Errorf("Derived public key is different on X")
	}

	if certPK.Y.Cmp(tempSK.PublicKey.Y) != 0 {
		client.error("Derived public key is different on Y")

		return nil, fmt.Errorf("Derived public key is different on Y")
	}

	// Verify the signing capability of tempSK
	err = utils.VerifySignCapability(tempSK, x509Cert.PublicKey)
	if err != nil {
		client.error("Failed verifing signing capability [%s].", err.Error())

		return
	}

	// Marshall certificate and secret key to be stored in the database
	if err != nil {
		client.error("Failed marshalling private key [%s].", err.Error())

		return
	}

	if err = utils.CheckCertPKAgainstSK(x509Cert, interface{}(tempSK)); err != nil {
		client.error("Failed checking TCA cert PK against private key [%s].", err.Error())

		return
	}

	tCert = &tCertImpl{client, x509Cert, tempSK}

	return
}