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 }
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 }
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 }
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 }
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 }
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) }
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 }