// Establishes the Tao Channel for a client using the Program Key.
// This program does all the standard client side channel negotiation.
// After negotiation is complete. ms is the bi-directional confidentiality and
// integrity protected channel. OpenTaoChannel returns the stream (ms) for subsequent reads
// and writes as well as the server's Tao Principal Name.
func OpenTaoChannel(programObject *TaoProgramData, serverAddr *string) (
*util.MessageStream, *string, error) {
// Parse policy cert and make it the root of our
// hierarchy for verifying Tao Channel peer.
policyCert, err := x509.ParseCertificate(programObject.PolicyCert)
if err != nil {
return nil, nil, errors.New("OpenTaoChannel: Can't ParseCertificate")
}
pool := x509.NewCertPool()
pool.AddCert(policyCert)
// Open the Tao Channel using the Program key.
tlsc, err := tao.EncodeTLSCert(&programObject.ProgramKey)
if err != nil {
log.Fatalln("OpenTaoChannel, encode error: ", err)
}
// TODO(manferdelli): Replace this with tao.Dial
conn, err := tls.Dial("tcp", *serverAddr, &tls.Config{
RootCAs: pool,
Certificates: []tls.Certificate{*tlsc},
InsecureSkipVerify: false,
})
if err != nil {
fmt.Printf("OpenTaoChannel: Can't establish channel ", err, "\n")
return nil, nil, errors.New("OpenTaoChannel: Can't establish channel")
}
peerName := policyCert.Subject.OrganizationalUnit[0]
// Stream for Tao Channel.
ms := util.NewMessageStream(conn)
return ms, &peerName, nil
}
// This function sends a DomainServiceRequest of the type GET_CRL to the domain service,
// and deserializes the response into a pkix.CertificateList containing the revoked certificates.
func RequestCrl(network, addr string) (*pkix.CertificateList, error) {
reqType := DomainServiceRequest_GET_CRL
request := &DomainServiceRequest{
Type: &reqType}
conn, err := net.Dial(network, addr)
if err != nil {
return nil, err
}
ms := util.NewMessageStream(conn)
_, err = ms.WriteMessage(request)
if err != nil {
return nil, err
}
log.Printf("Sent crl request to Domain Service using network %s at address %s.",
network, addr)
var response DomainServiceResponse
err = ms.ReadMessage(&response)
if err != nil {
return nil, err
}
log.Println("Got response from Domain Service.")
if errStr := response.GetErrorMessage(); errStr != "" {
return nil, errors.New(errStr)
}
parsedCrl, err := x509.ParseCRL(response.GetCrl())
return parsedCrl, err
}
func HandleQuoteDomainRequest(conn net.Conn, policyKey *ecdsa.PrivateKey, derPolicyCert []byte) (bool, error) {
log.Printf("HandleQuoteDomainRequest\n")
// Expect a request with attestation from client.
ms := util.NewMessageStream(conn)
var request AttestCertRequest
err := ms.ReadMessage(&request)
if err != nil {
log.Printf("HandleQuoteDomainRequest: Couldn't read attest request from channel")
return false, err
}
resp, err := ProcessQuoteDomainRequest(request, policyKey, derPolicyCert)
if err != nil {
return false, err
}
_, err = ms.WriteMessage(resp)
if err != nil {
log.Printf("HandleQuoteDomainRequest: Couldn't return the attestation on the channel")
log.Printf("\n")
return false, err
}
return false, nil
}
// This function packages a certificate revoke request into a DomainServiceRequest of type
// REVOKE_CERTIFICATE and sends it to the domain service. It expects att to be an attestation
// signed by the domain policy key with a statement of the form:
// policyKey says revoke certificateSerialNumber
func RequestRevokeCertificate(att *tao.Attestation, network, addr string) error {
serAtt, err := proto.Marshal(att)
if err != nil {
return err
}
reqType := DomainServiceRequest_REVOKE_CERTIFICATE
request := &DomainServiceRequest{
Type: &reqType,
SerializedPolicyAttestation: serAtt}
conn, err := net.Dial(network, addr)
if err != nil {
return err
}
ms := util.NewMessageStream(conn)
_, err = ms.WriteMessage(request)
if err != nil {
return err
}
log.Printf("Sent cert revoke request to Domain Service using network %s at address %s.",
network, addr)
var response DomainServiceResponse
err = ms.ReadMessage(&response)
if err != nil {
return err
}
log.Println("Got response from Domain Service.")
if errStr := response.GetErrorMessage(); errStr != "" {
return errors.New(errStr)
}
return nil
}
// NewClientCodec returns a new rpc.ClientCodec using protobuf messages on conn.
func NewClientCodec(conn io.ReadWriteCloser) rpc.ClientCodec {
m, ok := conn.(*util.MessageStream)
if !ok {
// The given conn lacks framing, so add some.
m = util.NewMessageStream(conn)
}
return &clientCodec{m, sync.Mutex{}}
}
func serve(addr, fp string, cert []byte, signingKey *tao.Keys, policy *fileproxy.ProgramPolicy) error {
m := fileproxy.NewResourceMaster(fp)
policyCert, err := x509.ParseCertificate(cert)
if err != nil {
return err
}
conf, err := signingKey.TLSServerConfig(policyCert)
if err != nil {
return err
}
log.Println("fileserver listening")
sock, err := tls.Listen("tcp", addr, conf)
if err != nil {
return err
}
for {
// Accept and handle client connections one at a time.
conn, err := sock.Accept()
if err != nil {
return err
}
var clientName string
if err = conn.(*tls.Conn).Handshake(); err != nil {
log.Printf("fileserver: couldn't perform handshake: %s\n", err)
continue
}
peerCerts := conn.(*tls.Conn).ConnectionState().PeerCertificates
if peerCerts == nil {
log.Println("fileserver: couldn't get peer list")
continue
}
peerCert := conn.(*tls.Conn).ConnectionState().PeerCertificates[0]
if peerCert.Raw == nil {
log.Println("fileserver: couldn't get peer name")
continue
}
if peerCert.Subject.OrganizationalUnit != nil {
clientName = peerCert.Subject.OrganizationalUnit[0]
}
log.Printf("fileserver: peer name: '%s'\n", clientName)
ms := util.NewMessageStream(conn)
// TODO(tmroeder): support multiple simultaneous clients. This
// requires, e.g., adding locking to the ResourceMaster.
if err := m.RunMessageLoop(ms, policy); err != nil {
log.Printf("fileserver: failed to run message loop: %s\n", err)
continue
}
log.Println("Finished handling the client messages")
}
}
func serve(serverAddr string, prin string, policyCert []byte, signingKey *tao.Keys, policy *fileproxy.ProgramPolicy, m *fileproxy.RollbackMaster) error {
pc, err := x509.ParseCertificate(policyCert)
if err != nil {
return err
}
conf, err := signingKey.TLSServerConfig(pc)
if err != nil {
return err
}
log.Println("Rollback server listening")
sock, err := tls.Listen("tcp", serverAddr, conf)
if err != nil {
return err
}
for {
conn, err := sock.Accept()
if err != nil {
return err
}
var clientName string
if err = conn.(*tls.Conn).Handshake(); err != nil {
log.Println("TLS handshake failed")
continue
}
peerCerts := conn.(*tls.Conn).ConnectionState().PeerCertificates
if peerCerts == nil {
log.Println("rollbackserver: can't get peer list")
continue
}
peerCert := conn.(*tls.Conn).ConnectionState().PeerCertificates[0]
if peerCert.Raw == nil {
log.Println("rollbackserver: can't get peer name")
continue
}
if peerCert.Subject.OrganizationalUnit == nil {
log.Println("No OrganizationalUnit name in the peer certificate. Refusing the connection")
continue
}
clientName = peerCert.Subject.OrganizationalUnit[0]
ms := util.NewMessageStream(conn)
// TODO(tmroeder): support multiple simultaneous clients.
// Add this program as a rollback program.
log.Printf("Adding a program with name '%s'\n", clientName)
_ = m.AddRollbackProgram(clientName)
if err := m.RunMessageLoop(ms, policy, clientName); err != nil {
log.Printf("rollbackserver: failed to run message loop: %s\n", err)
}
}
}
// Dial connects to a Tao TLS server, performs a TLS handshake, and verifies
// the Attestation value of the server, checking that the server is authorized
// to execute. If keys are provided (keys!=nil), then it sends an attestation
// of its identity to the peer.
func Dial(network, addr string, guard Guard, v *Verifier, keys *Keys) (net.Conn, error) {
tlsConfig := &tls.Config{
RootCAs: x509.NewCertPool(),
InsecureSkipVerify: true,
}
// Set up certificate for two-way authentication.
if keys != nil {
if keys.Cert == nil {
return nil, fmt.Errorf("client: can't dial with an empty client certificate\n")
}
tlsCert, err := EncodeTLSCert(keys)
if err != nil {
return nil, err
}
tlsConfig.Certificates = []tls.Certificate{*tlsCert}
}
conn, err := tls.Dial(network, addr, tlsConfig)
if err != nil {
return nil, err
}
ms := util.NewMessageStream(conn)
// Two-way Tao handshake: send client delegation.
if keys != nil {
if _, err = ms.WriteMessage(keys.Delegation); err != nil {
conn.Close()
return nil, err
}
}
// Tao handshake: read server delegation.
var a Attestation
if err := ms.ReadMessage(&a); err != nil {
conn.Close()
return nil, err
}
if err := AddEndorsements(guard, &a, v); err != nil {
conn.Close()
return nil, err
}
// Validate the peer certificate according to the guard.
peerCert := conn.ConnectionState().PeerCertificates[0]
if err := ValidatePeerAttestation(&a, peerCert, guard); err != nil {
conn.Close()
return nil, err
}
return conn, nil
}
// RequestDomainServiceCert requests the signed Program
// Certificate from simpledomainservice.
// TODO: This needs to change in a way that is tao supplier dependent.
// For tpm2 we need the ekCert and the tao and we need the data
// for ActivateCredential.
// For tpm1.2, we need the aikCert.
func RequestDomainServiceCert(network, addr string, requesting_key *tao.Keys,
v *tao.Verifier) (*domain_policy.DomainCertResponse, error) {
// Note requesting program key contains a self-signed cert to open channel.
if requesting_key.Cert == nil {
return nil, errors.New("RequestDomainServiceCert: Can't dial with an empty client certificate")
}
tlsCert, err := tao.EncodeTLSCert(requesting_key)
if err != nil {
return nil, err
}
conn, err := tls.Dial(network, addr, &tls.Config{
RootCAs: x509.NewCertPool(),
Certificates: []tls.Certificate{*tlsCert},
InsecureSkipVerify: true,
})
if err != nil {
return nil, err
}
defer conn.Close()
var request domain_policy.DomainCertRequest
request.Attestation, err = proto.Marshal(requesting_key.Delegation)
signer := requesting_key.SigningKey.GetSigner()
if signer == nil {
return nil, err
}
key_type := "ECDSA"
request.KeyType = &key_type
request.SubjectPublicKey, err = domain_policy.GetPublicDerFromEcdsaKey(&signer.PublicKey)
if err != nil {
return nil, err
}
// Tao handshake: send client delegation.
ms := util.NewMessageStream(conn)
_, err = ms.WriteMessage(&request)
if err != nil {
return nil, err
}
// Read the new cert
var response domain_policy.DomainCertResponse
err = ms.ReadMessage(&response)
if err != nil {
return nil, err
}
return &response, nil
}
// Handshake performs a Tao (and TLS) handshake. This occurs only once, before
// the first read or write. Users don't usually need to call this directly,
// since other functions call this as necessary.
func (conn *Conn) Handshake() error {
// Tao handshake protocol:
// 0. TLS handshake (executed automatically on first message)
// 1. Client -> Server: "delgation", Tao delegation for X.509 certificate.
// 2. Server: checks for a Tao-authorized program.
// 3. Server -> Client: "delgation", Tao delegation for X.509 certificate.
// 4. Client: checks for a Tao-authorized program.
//
// Alternate steps 1 and 2 if client authentication is not needed:
// 1'. Client -> Server: "anonymous"
// 2'. Server: checks if policy allows anonymous connections
//
// Alternate steps 3 and 4 if server authentication is not needed:
// 3'. Server -> Client: "anonymous"
// 4'. Client: checks if policy allows anonymous connections
if !conn.handshakeComplete {
if conn.T != nil {
conn.T.Start()
}
// Use a new framing stream on the underlying tls to avoid recursing.
ms := util.NewMessageStream(conn.Conn)
if conn.isServer {
conn.sendCredentials(ms)
if conn.T != nil {
conn.T.Sample("sent tao creds")
}
conn.recvCredentials(ms)
} else {
conn.sendCredentials(ms)
if conn.T != nil {
conn.T.Sample("sent tao creds")
}
conn.recvCredentials(ms)
}
conn.handshakeComplete = true
conn.handshakeErr = ms.Err()
if conn.handshakeErr != nil {
conn.Close()
conn.SetErr(conn.handshakeErr)
}
if conn.T != nil {
conn.T.Sample("done tao handshake")
}
}
return conn.handshakeErr
}
// RequestACLSet requests the policy from a TaoCA running an ACLGuard. Verify
// the signature with the public policy key `v`.
func RequestACLSet(network, addr string, v *Verifier) (*ACLSet, error) {
// Establish connection wtih the CA.
conn, err := net.Dial(network, addr)
if err != nil {
return nil, err
}
defer conn.Close()
// Create a CArequest.
req := &CARequest{
Type: CAType_ACL_POLICY.Enum(),
}
// Send request.
ms := util.NewMessageStream(conn)
if _, err = ms.WriteMessage(req); err != nil {
return nil, err
}
// Receive response.
var resp CAResponse
if err := ms.ReadMessage(&resp); err != nil {
return nil, err
}
// Verify signature.
ok, err := v.Verify(resp.SignedAclSet.SerializedAclset,
ACLGuardSigningContext, resp.SignedAclSet.Signature)
if !ok {
return nil, errVerifyFailed
} else if err != nil {
return nil, err
}
if *resp.Type != CAType_ACL_POLICY {
return nil, errInvalidResponse
}
var db ACLSet
if err := proto.Unmarshal(resp.SignedAclSet.SerializedAclset, &db); err != nil {
return nil, err
}
return &db, nil
}
// HandleCARequest checks a request from a program and responds with a truncated
// delegation signed by the policy key.
func HandleCARequest(conn net.Conn, s *Signer, guard Guard) {
defer conn.Close() // TODO(cjpatton) This should be managed by calling function.
// Get request.
ms := util.NewMessageStream(conn)
var req CARequest
if err := ms.ReadMessage(&req); err != nil {
fmt.Fprintln(os.Stderr, "Couldn't read from channel:", err)
return
}
resp := respond(&req, s, guard)
if _, err := ms.WriteMessage(resp); err != nil {
fmt.Fprintln(os.Stderr, "Couldn't write to the channel:", err)
}
}
// RequestDomainQuoteCert requests the Quote Cert
func RequestDomainQuoteCert(network, addr string, endorsementCert []byte, tpmDevice io.ReadWriter,
quoteHandle Handle, endorsementHandle Handle, taoName string,
ownerPw string) ([]byte, error) {
requestingKey, derChannelCert, err := CreateTemporaryChannelKey()
if err != nil || requestingKey == nil {
return nil, err
}
channelCert, err := x509.ParseCertificate(derChannelCert)
if err != nil || channelCert == nil {
return nil, err
}
// Contact domain service.
conn, err := tls.Dial(network, addr, &tls.Config{
RootCAs: x509.NewCertPool(),
// Certificates: []tls.Certificate{tls.Certificate(*channelCert)},
InsecureSkipVerify: true,
})
if err != nil {
return nil, err
}
defer conn.Close()
// Build request.
request, err := BuildAttestCertRequest(tpmDevice, quoteHandle, endorsementHandle, endorsementCert, taoName, ownerPw)
if err != nil {
return nil, err
}
// Send request
ms := util.NewMessageStream(conn)
_, err = ms.WriteMessage(request)
if err != nil {
return nil, err
}
// Read the new cert
var response AttestCertResponse
err = ms.ReadMessage(&response)
if err != nil {
return nil, err
}
return GetCertFromAttestResponse(tpmDevice, quoteHandle, endorsementHandle, ownerPw, response)
}
// Accept waits for a connect, accepts it using the underlying Conn and checks
// the attestations and the statement.
func (l *anonymousListener) Accept() (net.Conn, error) {
c, err := l.gl.Accept()
if err != nil {
return nil, err
}
// One-way Tao handshake Protocol:
// 0. TLS handshake (executed automatically on first message)
// 1. Server -> Client: Tao delegation for X.509 certificate.
// 2. Client: checks for a Tao-authorized program.
ms := util.NewMessageStream(c)
if _, err := ms.WriteMessage(l.delegation); err != nil {
c.Close()
return nil, err
}
return c, nil
}
func TestInvalidRequest(t *testing.T) {
cal, err := net.Listen("tcp", "127.0.0.1:0")
caAddr := cal.Addr()
guard, keys, tmpDir, err := makeDatalogGuard()
if err != nil {
os.RemoveAll(tmpDir)
t.Fatal(err)
}
defer os.RemoveAll(tmpDir)
ch := make(chan bool)
// Test an invalid request.
go runTCCA(t, cal, keys, guard, ch)
conn, err := net.Dial("tcp", caAddr.String())
if err != nil {
t.Fatal("Failed to connect to TaoCA.")
}
defer conn.Close()
// Bad CArequest, no value for bad_req.Attesation
badReq := new(CARequest)
badReq.Type = CAType_ATTESTATION.Enum()
ms := util.NewMessageStream(conn)
if _, err = ms.WriteMessage(badReq); err != nil {
t.Logf("Failed to write to message stream: %s", err)
}
// Receive response.
var resp CAResponse
if err := ms.ReadMessage(&resp); err != nil {
t.Fatalf("Failed to read from message stream: %s", err)
}
if *resp.Type != CAType_UNDEFINED {
t.Fatalf("Response should have been UNDEFINED, got %s", resp.Type.String())
}
<-ch
}
// RequestAttestation connects to a CA and gets an attestation back from it.
// This might be a truncated attestation (in which case, the right next step is
// to verify the truncated attesation, as in RequestTruncatedAttestation), or it
// might be some other kind of attestation (like a KeyNegoServer attestation,
// which provides a policy-key-signed X.509 certificate for the auth name of
// this program).
func RequestAttestation(network, addr string, keys *Keys, v *Verifier) (*Attestation, error) {
// Establish connection wtih the CA.
conn, err := net.Dial(network, addr)
if err != nil {
return nil, err
}
defer conn.Close()
// Create a CARequest.
req := &CARequest{
Type: CAType_ATTESTATION.Enum(),
Attestation: keys.Delegation,
}
// Tao handshake: send client delegation.
ms := util.NewMessageStream(conn)
if _, err = ms.WriteMessage(req); err != nil {
return nil, err
}
// Read the truncated attestation and check it.
var resp CAResponse
if err := ms.ReadMessage(&resp); err != nil {
return nil, err
}
ok, err := v.Verify(resp.Attestation.SerializedStatement,
AttestationSigningContext, resp.Attestation.Signature)
if !ok {
return nil, errVerifyFailed
} else if err != nil {
return nil, err
}
if *resp.Type != CAType_ATTESTATION {
return nil, errInvalidResponse
}
return resp.Attestation, nil
}
// This function packages a host attestation into a DomainServiceRequest of the type
// DOMAIN_CERT_REQUEST, sends it to the domain service and deserializes the response
// into an attestation that contains the domain program certificate.
func RequestProgramCert(hostAtt *tao.Attestation, verifier *tao.Verifier,
network string, addr string) (*x509.Certificate, error) {
serAtt, err := proto.Marshal(hostAtt)
if err != nil {
return nil, err
}
reqType := DomainServiceRequest_DOMAIN_CERT_REQUEST
request := &DomainServiceRequest{
Type: &reqType,
SerializedHostAttestation: serAtt,
ProgramKey: verifier.MarshalKey(),
}
conn, err := net.Dial(network, addr)
if err != nil {
return nil, err
}
ms := util.NewMessageStream(conn)
_, err = ms.WriteMessage(request)
if err != nil {
return nil, err
}
log.Printf("Sent Program cert request to Domain Service using network %s at address %s.",
network, addr)
var response DomainServiceResponse
err = ms.ReadMessage(&response)
if err != nil {
return nil, err
}
log.Println("Got response from Domain Service.")
if errStr := response.GetErrorMessage(); errStr != "" {
return nil, errors.New(errStr)
}
cert, err := x509.ParseCertificate(response.GetDerProgramCert())
if err != nil {
return nil, err
}
return cert, nil
}
// Submit sends a CSR to a certificate authority server. The keys are used to
// authenticate to the server.
func (server *Server) Submit(keys *tao.Keys, csr *CSR) ([]*x509.Certificate, error) {
addr := net.JoinHostPort(server.Host, server.Port)
conn, err := tao.Dial("tcp", addr, nil /* guard */, nil /* verifier */, keys, nil)
if err != nil {
return nil, err
}
defer conn.Close()
ms := util.NewMessageStream(conn)
req := &Request{CSR: csr}
_, err = ms.WriteMessage(req)
if err != nil {
return nil, err
}
var resp Response
if err := ms.ReadMessage(&resp); err != nil {
return nil, err
}
if *resp.Status != ResponseStatus_TAOCA_OK {
detail := "unknown error"
if resp.ErrorDetail != nil {
detail = *resp.ErrorDetail
}
return nil, fmt.Errorf("%s: %s", resp.Status, detail)
}
if len(resp.Cert) == 0 {
return nil, fmt.Errorf("no certificates in CA response")
}
certs := make([]*x509.Certificate, len(resp.Cert))
for i, c := range resp.Cert {
cert, err := x509.ParseCertificate(c.X509Cert)
if err != nil {
return nil, err
}
certs[i] = cert
}
return certs, nil
}
// Return attest certificate
func (tt *TPM2Tao) Tpm2Certify(network, addr string, keyName string) ([]byte, error) {
// Establish connection wtih the CA.
conn, err := net.Dial(network, addr)
if err != nil {
return nil, err
}
defer conn.Close()
rk, err := tt.loadRoot()
if err != nil {
return nil, err
}
defer tpm2.FlushContext(tt.rw, rk)
qh, err := tt.loadQuote()
if err != nil {
return nil, err
}
defer tpm2.FlushContext(tt.rw, qh)
ms := util.NewMessageStream(conn)
programCertMessage, err := Tpm2ConstructClientRequest(tt.rw,
tt.rootCert, tt.pcrs,
qh, "", tt.password, keyName)
_, err = ms.WriteMessage(programCertMessage)
if err != nil {
return nil, err
}
var resp tpm2.ProgramCertResponseMessage
err = ms.ReadMessage(&resp)
if err != nil {
return nil, err
}
attestCert, err := Tpm2ClientDecodeServerResponse(tt.rw, rk, qh,
tt.password, resp)
return attestCert, nil
}
// Accept waits for a connect, accepts it using the underlying Conn and checks
// the attestations and the statement.
func (l *listener) Accept() (net.Conn, error) {
c, err := l.gl.Accept()
if err != nil {
return nil, err
}
// Tao handshake Protocol:
// 0. TLS handshake (executed automatically on first message)
// 1. Client -> Server: Tao delegation for X.509 certificate.
// 2. Server: checks for a Tao-authorized program.
// 3. Server -> Client: Tao delegation for X.509 certificate.
// 4. Client: checks for a Tao-authorized program.
ms := util.NewMessageStream(c)
var a Attestation
if err := ms.ReadMessage(&a); err != nil {
c.Close()
return nil, err
}
if err := AddEndorsements(l.guard, &a, l.verifier); err != nil {
return nil, err
}
peerCert := c.(*tls.Conn).ConnectionState().PeerCertificates[0]
if err := ValidatePeerAttestation(&a, peerCert, l.guard); err != nil {
c.Close()
return nil, err
}
if _, err := ms.WriteMessage(l.delegation); err != nil {
c.Close()
return nil, err
}
return c, nil
}
func main() {
flag.Parse()
var domain *tao.Domain
var rootCerts *x509.CertPool
var err error
if *createDomainFlag {
log.Println("Creating new domain...")
domain, rootCerts, err = createDomain()
} else {
log.Println("Loading domain info...")
domain, rootCerts, err = loadDomain()
}
if err != nil {
log.Fatalln("domain_server: could not load domain:", err)
}
ln, err := net.Listen(*network, *addr)
if err != nil {
log.Fatalln("domain_server: could not listen at port:", err)
}
for {
conn, err := ln.Accept()
if err != nil {
log.Fatalln("domain_server: could not accept connection:", err)
}
// switch case
ms := util.NewMessageStream(conn)
var request domain_service.DomainServiceRequest
if err := ms.ReadMessage(&request); err != nil {
log.Printf("domain_server: Couldn't read request from channel: %s\n", err)
continue
}
switch *request.Type {
case domain_service.DomainServiceRequest_DOMAIN_CERT_REQUEST:
_, kPrin, prog, err := domain_service.VerifyHostAttestation(
request.GetSerializedHostAttestation(), domain, rootCerts)
if err != nil {
log.Printf("domain_server: Error verifying host att: %s\n", err)
sendError(err, ms)
continue
}
programKeyBytes := request.GetProgramKey()
verifier, err := tao.UnmarshalKey(programKeyBytes)
if err != nil {
log.Printf("domain_server: Error parsing program key: %v\n", err)
sendError(err, ms)
continue
}
if !verifier.ToPrincipal().Identical(kPrin) {
log.Printf("domain_server: Program key in request does not match key being attested to.")
sendError(err, ms)
continue
}
cert, err := domain_service.GenerateProgramCert(domain, serialNumber, prog,
verifier, time.Now(), time.Now().AddDate(1, 0, 0))
if err != nil {
log.Printf("domain_server: Error generating program cert: %s\n", err)
sendError(err, ms)
continue
}
resp := &domain_service.DomainServiceResponse{
DerProgramCert: cert.Raw}
if _, err := ms.WriteMessage(resp); err != nil {
log.Printf("domain_server: Error sending cert on the channel: %s\n ",
err)
continue
}
case domain_service.DomainServiceRequest_MANAGE_POLICY:
// TODO(sidtelang)
case domain_service.DomainServiceRequest_REVOKE_CERTIFICATE:
revokedCertificates, err = domain_service.RevokeCertificate(
request.GetSerializedPolicyAttestation(), revokedCertificates, domain)
if err != nil {
log.Printf("domain_server: Error revoking certificate: %s\n", err)
}
sendError(err, ms)
case domain_service.DomainServiceRequest_GET_CRL:
nowTime := time.Now()
expireTime := time.Now().AddDate(1, 0, 0)
crl, err := domain.Keys.SigningKey.CreateCRL(domain.Keys.Cert,
revokedCertificates, nowTime, expireTime)
resp := domain_service.DomainServiceResponse{}
if err != nil {
errStr := err.Error()
resp.ErrorMessage = &errStr
} else {
resp.Crl = crl
}
if _, err := ms.WriteMessage(&resp); err != nil {
log.Printf("domain_server: Error sending response on the channel: %s\n ", err)
}
}
}
}
// First return is terminate flag.
func handleRequest(conn net.Conn, policyKey *tao.Keys, guard tao.Guard) error {
// Expect an attestation from the client.
ms := util.NewMessageStream(conn)
var a tao.Attestation
if err := ms.ReadMessage(&a); err != nil {
return err
}
peerCert := conn.(*tls.Conn).ConnectionState().PeerCertificates[0]
p, err := tao.ValidatePeerAttestation(&a, peerCert)
if err != nil {
return err
}
// TODO(kwalsh) most of this duplicates the work of tao.Conn
if !guard.IsAuthorized(p, "Execute", nil) {
return fmt.Errorf("peer is not authorized to execute, hence not authorized to connect either")
}
// Sign cert and put it in attestation statement
// a consists of serialized statement, sig and SignerInfo
// a is a says speaksfor, Delegate of speaksfor is cert and should be DER encoded
// Get underlying says
f, err := auth.UnmarshalForm(a.SerializedStatement)
if err != nil {
return err
}
var saysStatement *auth.Says
if ptr, ok := f.(*auth.Says); ok {
saysStatement = ptr
} else if val, ok := f.(auth.Says); ok {
saysStatement = &val
}
sf, ok := saysStatement.Message.(auth.Speaksfor)
if ok != true {
return fmt.Errorf("keynegoserver: says doesn't have a speaksfor message\n")
}
kprin, ok := sf.Delegate.(auth.Prin)
if ok != true {
return fmt.Errorf("keynegoserver: speaksfor Delegate is not auth.Prin\n")
}
subjectPrin, ok := sf.Delegator.(auth.Prin)
if ok != true {
return fmt.Errorf("keynegoserver: can't get subject principal\n")
}
subjectName := subjectPrin.String()
details := &tao.X509Details{
Country: proto.String("US"),
Organization: proto.String("Google"),
OrganizationalUnit: proto.String(subjectName),
CommonName: proto.String("localhost"),
}
subjectname := tao.NewX509Name(details)
SerialNumber = SerialNumber + 1
verifier, err := tao.FromPrincipal(kprin)
if err != nil {
return errors.New("can't get principal from kprin")
}
template := policyKey.SigningKey.X509Template(subjectname)
template.IsCA = false
clientCert, err := policyKey.CreateSignedX509(verifier, template, "default")
if err != nil {
return fmt.Errorf("keynegoserver: can't create client certificate: %s\n", err)
}
clientDERCert := clientCert.Raw
err = ioutil.WriteFile("ClientCert", clientDERCert, os.ModePerm)
nowTime := time.Now().UnixNano()
expireTime := time.Now().AddDate(1, 0, 0).UnixNano()
// Replace self signed cert in attest request
newSpeaksFor := &auth.Speaksfor{
Delegate: auth.Bytes(clientDERCert),
Delegator: sf.Delegator,
}
keyNegoSays := auth.Says{
Speaker: policyKey.SigningKey.ToPrincipal(),
Time: &nowTime,
Expiration: &expireTime,
Message: newSpeaksFor,
}
delegator, ok := sf.Delegator.(auth.Prin)
if !ok {
return fmt.Errorf("keynegoserver: the delegator must be a principal")
}
found := false
for _, sprin := range delegator.Ext {
if !found && (sprin.Name == "Program") {
found = true
}
if found {
kprin.Ext = append(kprin.Ext, sprin)
}
}
ra, err := tao.GenerateAttestation(policyKey.SigningKey, nil, keyNegoSays)
if err != nil {
return fmt.Errorf("Couldn't attest to the new says statement: %s", err)
}
if _, err := ms.WriteMessage(ra); err != nil {
return fmt.Errorf("Couldn't return the attestation on the channel: %s", err)
}
return nil
}
// First return is terminate flag.
func DomainRequest(conn net.Conn, policyKey *tao.Keys, guard tao.Guard) (bool, error) {
fmt.Printf("DomainRequest\n")
log.Printf("DomainRequest\n")
// Expect a request with attestation from client.
ms := util.NewMessageStream(conn)
var request domain_policy.DomainCertRequest
err := ms.ReadMessage(&request)
if err != nil {
log.Printf("DomainRequest: Couldn't read attestation from channel:", err)
log.Printf("\n")
return false, err
}
var a tao.Attestation
err = proto.Unmarshal(request.Attestation, &a)
if request.KeyType == nil {
log.Printf("Domain: Empty key type")
return false, errors.New("Empty key type")
}
if *request.KeyType != "ECDSA" {
log.Printf("Domain: bad key type")
return false, errors.New("Domain: bad key type")
}
subjectPublicKey, err := domain_policy.GetEcdsaKeyFromDer(request.SubjectPublicKey)
if err != nil {
log.Printf("DomainRequest: can't get key from der")
return false, errors.New("DomainRequest: can't get key from der")
}
// Get hash of the public key subject.
serializedKey, err := domain_policy.SerializeEcdsaKeyToInternalName(subjectPublicKey.(*ecdsa.PublicKey))
if err != nil || serializedKey == nil {
log.Printf("DomainRequest: Can't serialize key to internal format\n")
return false, errors.New("DomainRequest: Can't serialize key to internal format")
}
subjectKeyHash := domain_policy.GetKeyHash(serializedKey)
peerCert := conn.(*tls.Conn).ConnectionState().PeerCertificates[0]
err = tao.ValidatePeerAttestation(&a, peerCert, guard)
/*
if err != nil {
log.Printf("Domain: RequestCouldn't validate peer attestation:", err)
return false, err
}
fmt.Printf("DomainRequest, peerCert: %x\n", peerCert)
*/
// Sign cert
// Get Program name and key info from delegation.
f, err := auth.UnmarshalForm(a.SerializedStatement)
if err != nil {
log.Printf("DomainRequest: Can't unmarshal a.SerializedStatement\n")
return false, err
}
var saysStatement *auth.Says
if ptr, ok := f.(*auth.Says); ok {
saysStatement = ptr
} else if val, ok := f.(auth.Says); ok {
saysStatement = &val
}
sf, ok := saysStatement.Message.(auth.Speaksfor)
if ok != true {
log.Printf("DomainRequest: says doesnt have speaksfor message\n")
return false, err
}
// this in the new key principal
clientKeyPrincipal, ok := sf.Delegate.(auth.Prin)
if ok != true {
log.Printf("DomainRequest: speaksfor Delegate is not auth.Prin\n")
return false, err
}
programPrincipal, ok := sf.Delegator.(auth.Prin)
if ok != true {
log.Printf("DomainRequest: Can't get subject principal\n")
return false, errors.New("Can't get principal name from verifier")
}
programPrincipalName := programPrincipal.String()
verified := IsAuthenticationValid(&programPrincipalName)
if !verified {
log.Printf("DomainRequest: name verification failed\n")
return false, err
}
fmt.Printf("\nSimpleDomainService: key principal: %s, program principal: %s\n", clientKeyPrincipal, programPrincipalName)
// Is the delegate the same key as was presented in the name in the request?
namedHash := clientKeyPrincipal.KeyHash.(auth.Bytes)
fmt.Printf("\nkeyhash: %x\n", namedHash)
if bytes.Compare(subjectKeyHash[:], namedHash) != 0 {
log.Printf("DomainRequest: named hash is wrong\n")
fmt.Printf("DomainRequest: named hash is wrong, named: %x, computed: %x\n",
namedHash, subjectKeyHash)
return false, errors.New("DomainRequest: named hash is wrong")
}
// Sign program certificate.
notBefore := time.Now()
validFor := 365 * 24 * time.Hour
notAfter := notBefore.Add(validFor)
us := "US"
issuerName := "Google"
localhost := "localhost"
x509SubjectName := &pkix.Name{
Organization: []string{programPrincipalName},
OrganizationalUnit: []string{programPrincipalName},
CommonName: localhost,
Country: []string{us},
}
x509IssuerName := &pkix.Name{
Organization: []string{issuerName},
OrganizationalUnit: []string{issuerName},
CommonName: localhost,
Country: []string{us},
}
// issuerName := tao.NewX509Name(&details)
SerialNumber = SerialNumber + 1
var sn big.Int
certificateTemplate := x509.Certificate{
SerialNumber: &sn,
Issuer: *x509IssuerName,
Subject: *x509SubjectName,
NotBefore: notBefore,
NotAfter: notAfter,
KeyUsage: x509.KeyUsageCertSign |
x509.KeyUsageKeyAgreement | x509.KeyUsageDigitalSignature,
}
clientCert, err := x509.CreateCertificate(rand.Reader, &certificateTemplate,
policyKey.Cert, subjectPublicKey,
policyKey.SigningKey.GetSigner())
if err != nil {
fmt.Printf("Can't create client certificate: ", err, "\n")
return false, err
}
zero := int32(0)
var ra domain_policy.DomainCertResponse
ra.Error = &zero
ra.SignedCert = clientCert
// Add cert chain (just policy cert for now).
ra.CertChain = append(ra.CertChain, policyKey.Cert.Raw)
_, err = ms.WriteMessage(&ra)
if err != nil {
log.Printf("DomainRequest: Couldn't return the attestation on the channel: ", err)
log.Printf("\n")
return false, err
}
return false, nil
}
// This is the server. It implements the server Tao Channel negotiation corresponding
// to the client's taosupport.OpenTaoChannel. It's possible we should move this into
// taosupport/taosupport.go since it should not vary very much from implementation to
// implementation.
func server(serverAddr string, serverProgramData *taosupport.TaoProgramData) {
var sock net.Listener
// Set up the single root certificate for channel negotiation which is the
// policy key cert.
pool := x509.NewCertPool()
policyCert, err := x509.ParseCertificate(serverProgramData.PolicyCert)
if err != nil {
log.Printf("simpleserver, can't parse policyCert: ", err, "\n")
return
}
// Make the policy cert the unique root of the verification chain.
pool.AddCert(policyCert)
tlsc, err := tao.EncodeTLSCert(&serverProgramData.ProgramKey)
if err != nil {
log.Printf("simpleserver, encode error: ", err, "\n")
return
}
conf := &tls.Config{
RootCAs: pool,
Certificates: []tls.Certificate{*tlsc},
InsecureSkipVerify: false,
ClientAuth: tls.RequireAnyClientCert,
}
// Listen for clients.
log.Printf("simpleserver: Listening\n")
sock, err = tls.Listen("tcp", serverAddr, conf)
if err != nil {
log.Printf("simpleserver, listen error: ", err, "\n")
return
}
// Service client connections.
for {
log.Printf("server: at accept\n")
conn, err := sock.Accept()
if err != nil {
fmt.Printf("simpleserver: can't accept connection: %s\n", err.Error())
log.Printf("server: can't accept connection: %s\n", err.Error())
continue
}
var clientName string
err = conn.(*tls.Conn).Handshake()
if err != nil {
log.Printf("server: TLS handshake failed\n")
continue
}
peerCerts := conn.(*tls.Conn).ConnectionState().PeerCertificates
if peerCerts == nil {
log.Printf("server: can't get peer list\n")
continue
}
peerCert := conn.(*tls.Conn).ConnectionState().PeerCertificates[0]
if peerCert.Raw == nil {
log.Printf("server: can't get peer cert\n")
continue
}
if peerCert.Subject.OrganizationalUnit == nil {
log.Printf("server: can't get peer name\n")
continue
}
clientName = peerCert.Subject.OrganizationalUnit[0]
log.Printf("server, peer client name: %s\n", clientName)
ms := util.NewMessageStream(conn)
// At this point the handshake is complete and we fork a service thread
// to communicate with this simpleclient. ms is the bi-directional
// confidentiality and integrity protected channel corresponding to the
// channel opened by OpenTaoChannel.
go serviceThead(ms, clientName, serverProgramData)
}
}
func main() {
caAddr := flag.String("caAddr", "localhost:8124", "The address of the CA for setting up a certificate signed by the policy key")
hostcfg := flag.String("hostconfig", "tao.config", "path to host tao configuration")
serverHost := flag.String("host", "localhost", "address for client/server")
serverPort := flag.String("port", "8123", "port for client/server")
rollbackServerHost := flag.String("rollbackhost", "localhost", "address for rollback client/server")
rollbackServerPort := flag.String("rollbackport", "8129", "port for client/server")
fileClientPassword := flag.String("password", "BogusPass", "A password for unlocking the user certificates")
fileClientPath := flag.String("fileclient_files", "fileclient_files", "fileclient directory")
fileClientFilePath := flag.String("stored_files", "fileclient_files/stored_files", "fileclient file directory")
testFile := flag.String("test_file", "originalTestFile", "test file")
fileClientKeyPath := flag.String("usercreds", "usercreds", "user keys and certs")
country := flag.String("country", "US", "The country for the fileclient certificate")
org := flag.String("organization", "Google", "The organization for the fileclient certificate")
flag.Parse()
serverAddr := net.JoinHostPort(*serverHost, *serverPort)
hostDomain, err := tao.LoadDomain(*hostcfg, nil)
if err != nil {
log.Fatalln("fileclient: Can't load domain")
}
var derPolicyCert []byte
if hostDomain.Keys.Cert["default"] != nil {
derPolicyCert = hostDomain.Keys.Cert["default"].Raw
}
if derPolicyCert == nil {
log.Fatalln("fileclient: Can't retrieve policy cert")
}
parentTao := tao.Parent()
if err := hostDomain.ExtendTaoName(parentTao); err != nil {
log.Fatalln("fileclient: can't extend the Tao with the policy key")
}
e := auth.PrinExt{Name: "fileclient_version_1"}
if err = parentTao.ExtendTaoName(auth.SubPrin{e}); err != nil {
log.Fatalln("fileclient: couldn't extend the tao name with the policy key")
}
taoName, err := parentTao.GetTaoName()
if err != nil {
log.Fatalln("fileclient: Can't get tao name")
}
// Create or read the keys for fileclient.
// Set up a temporary cert for communication with keyNegoServer.
// TODO(kwalsh) This may no longer be needed. Is there a significance to
// this cert?
name := tao.NewX509Name(&tao.X509Details{
Country: proto.String(*country),
Organization: proto.String(*org),
CommonName: proto.String(taoName.String()),
})
fcKeys, err := tao.NewOnDiskTaoSealedKeys(tao.Signing|tao.Crypting, name, parentTao, *fileClientPath, tao.SealPolicyDefault)
if err != nil {
log.Fatalln("fileclient: couldn't set up the Tao-sealed keys:", err)
}
if err != nil {
log.Fatalln("fileclient: couldn't create a self-signed cert for fileclient keys:", err)
}
// Contact keyNegoServer for the certificate.
if err := fileproxy.EstablishCert("tcp", *caAddr, fcKeys, hostDomain.Keys.VerifyingKey); err != nil {
log.Fatalf("fileclient: couldn't establish a cert signed by the policy key: %s", err)
}
// Get the policy cert and set up TLS.
conf, err := fcKeys.TLSClientConfig(hostDomain.Keys.Cert["default"])
if err != nil {
log.Fatalln("fileclient, encode error: ", err)
}
conn, err := tls.Dial("tcp", serverAddr, conf)
if err != nil {
log.Fatalln("fileclient: can't establish channel: ", err)
}
ms := util.NewMessageStream(conn)
// Before doing any tests, create a simple file to send to the server.
testContents := `
This is a simple file to test
It has some new lines
And it doesn't have very much content.
`
if _, err := os.Stat(*fileClientFilePath); err != nil {
if err := os.MkdirAll(*fileClientFilePath, 0700); err != nil {
log.Fatalf("fileclient: couldn't create the file storage path %s: %s", *fileClientFilePath, err)
}
}
sentFileName := *testFile
sentFilePath := path.Join(*fileClientFilePath, sentFileName)
if err := ioutil.WriteFile(sentFilePath, []byte(testContents), 0600); err != nil {
log.Fatalf("fileclient: couldn't create a test file at %s: %s", sentFilePath, err)
}
// Authenticate user principal(s).
if _, err := os.Stat(*fileClientKeyPath); err != nil {
log.Fatalf("fileclient: couldn't get user credentials from %s: %s\n", *fileClientKeyPath, err)
}
// This method won't generate the right certificate in general for
// signing, which is why we check first to make sure the right directory
// already exists. But it will successfully read the signer and the
// certificate.
userKeys, err := tao.NewOnDiskPBEKeys(tao.Signing, []byte(*fileClientPassword), *fileClientKeyPath, nil)
if err != nil {
log.Fatalf("Couldn't read the keys from %s: %s\n", *fileClientKeyPath, err)
}
userCert := userKeys.Cert["default"].Raw
// Authenticate a key to use for requests to the server.
if err = fileproxy.AuthenticatePrincipal(ms, userKeys, userCert); err != nil {
log.Fatalf("fileclient: can't authenticate principal: %s", err)
}
// Create a file.
if err = fileproxy.CreateFile(ms, userCert, sentFileName); err != nil {
log.Fatalln("fileclient: can't create file:", err)
}
// Send File.
if err = fileproxy.WriteFile(ms, userCert, *fileClientFilePath, sentFileName); err != nil {
log.Fatalf("fileclient: couldn't write the file %s to the server: %s", sentFileName, err)
}
// Get file.
outputFileName := sentFileName + ".out"
if err = fileproxy.ReadFile(ms, userCert, *fileClientFilePath, sentFileName, outputFileName); err != nil {
log.Fatalf("fileclient: couldn't get file %s to output file %s: %s", sentFileName, outputFileName, err)
}
// TODO(tmroeder): compare the received file against the sent file.
// Set up a TLS connection to the rollback server, just like the one to
// the file server.
rollbackServerAddr := net.JoinHostPort(*rollbackServerHost, *rollbackServerPort)
rbconn, err := tls.Dial("tcp", rollbackServerAddr, conf)
if err != nil {
log.Fatalf("fileclient: can't establish rollback channel: %s", err)
}
newms := util.NewMessageStream(rbconn)
// Create a fake hash value, and set this value for an item.
hashLen := 32
hash := make([]byte, hashLen)
if _, err := rand.Read(hash); err != nil {
log.Fatalf("fileclient: failed to read a random value for the hash")
}
progName := taoName.String()
resName := "test_resource"
if err := fileproxy.SetHash(newms, resName, hash); err != nil {
log.Fatalf("Couldn't set the hash for program '%s', resource '%s', hash % x on the remote server: %s", progName, resName, hash, err)
}
// Set the counter to 10 and check that we get the same value back.
if err := fileproxy.SetCounter(newms, uint64(10)); err != nil {
log.Fatalf("fileclient: couldn't set the counter in the file client")
}
c, err := fileproxy.GetCounter(newms)
if err != nil {
log.Fatalf("fileclient: couldn't get the value of the counter from the rollback server")
}
// Get the hash verification value.
newHash, err := fileproxy.GetHashedVerifier(newms, resName)
if err != nil {
log.Fatalf("fileclient: couldn't get the hashed verifier from the rollback server")
}
// Try to recompute the hashed verifier directly to see if it matches.
sh := sha256.New()
vi := fileproxy.EncodeCounter(c)
sh.Write(vi)
sh.Write(hash)
sh.Write(vi)
computed := sh.Sum(nil)
if subtle.ConstantTimeCompare(newHash, computed) != 1 {
log.Fatalf("fileclient: the hashed verifier % x returned by the server didn't match the value % x computed locally", newHash, computed)
}
log.Println("All fileclient tests pass")
}
