func main() {
domain, err := tao.LoadDomain(*configPath, []byte(*domainPass))
if domain == nil {
log.Printf("domainserver: no domain path - %s, pass - %s, err - %s\n",
*configPath, *domainPass, err)
} else if err != nil {
log.Printf("domainserver: Couldn't load the config path %s: %s\n",
*configPath, err)
}
policyKey, policyCert := domain.Keys, domain.Keys.Cert
if policyCert == nil {
log.Fatalln("Policy cert not found")
}
hostKey, hostAtt := generateAttestation(policyKey, hostName)
programKey, programAtt := generateAttestation(hostKey, programName)
rawEnd1, err := proto.Marshal(hostAtt)
if err != nil {
log.Fatalln("Error serializing attestation.")
}
programAtt.SerializedEndorsements = [][]byte{rawEnd1}
cert, err := domain_service.RequestProgramCert(programAtt, programKey.VerifyingKey,
*network, *addr)
if err != nil {
log.Fatalln("Error:", err)
}
rootCerts := x509.NewCertPool()
rootCerts.AddCert(domain.Keys.Cert)
options := x509.VerifyOptions{Roots: rootCerts}
_, err = cert.Verify(options)
if err != nil {
log.Fatalln("Program cert fails verification check.", err)
}
ver, err := tao.FromX509(cert)
if err != nil {
log.Fatalln("Error getting verifier from Program cert", err)
}
if v := programKey.VerifyingKey; !v.Equals(cert) {
log.Fatalf("Key in Program cert %v differs from expected value %v.", ver, v)
}
// Test Certificate Revocation.
serialNumber := cert.SerialNumber
says := auth.Says{
Speaker: domain.Keys.SigningKey.ToPrincipal(),
Message: auth.Pred{
Name: "revoke",
Arg: []auth.Term{auth.Bytes(serialNumber.Bytes())}}}
att, err := tao.GenerateAttestation(domain.Keys.SigningKey, nil, says)
if err != nil {
log.Fatalln("Error generating attestation for certificate revocation.")
}
err = domain_service.RequestRevokeCertificate(att, *network, *addr)
if err != nil {
log.Fatalln("Error revoking certificate: ", err)
}
crl, err := domain_service.RequestCrl(*network, *addr)
if err != nil {
log.Fatalln("Error getting CRL: ", err)
}
revokedCerts := crl.TBSCertList.RevokedCertificates
if len(revokedCerts) != 1 {
log.Fatalf("Revoked 1 cert and got back CRL with %v revoked certs", len(revokedCerts))
}
if num := revokedCerts[0].SerialNumber.Int64(); num != serialNumber.Int64() {
log.Fatalf("Serial number %v doesnt match expected value %v", num, serialNumber)
}
log.Println("YAY!")
}
// AuthenticatePrincipal runs a synchronous protocol to authenticate a single
// principal on a single channel. In this toy implementation, it is assumed that
// there are no other principals on the channel and that there are no other
// simultaneous channels.
func (m *ResourceMaster) AuthenticatePrincipal(ms util.MessageStream, msg *Message, programPolicy *ProgramPolicy) ([]byte, error) {
// The certificate message is passed in by the caller as the first
// message.
// Process the certificate. For AUTH_CERT, the data is just the
// certificate.
cert, err := x509.ParseCertificate([]byte(msg.Data))
if err != nil {
log.Printf("couldn't Parse Certificate in AuthenticatePrincipal\n")
return nil, err
}
// Set up a nonce challenge for the reply. For NONCE_CHALL, the data is
// also just the message itself.
reply := &Message{
Type: MessageType_NONCE_CHALL.Enum(),
Data: make([]byte, NonceSize),
}
if _, err = rand.Read(reply.Data); err != nil {
return nil, err
}
// Step 1: Send a nonce to the principal.
if _, err := ms.WriteMessage(reply); err != nil {
return nil, err
}
// Step 2: Wait for the signed response.
var s Message
if err := ms.ReadMessage(&s); err != nil {
return nil, err
}
if *s.Type != MessageType_SIGNED_NONCE {
return nil, fmt.Errorf("received message was not SIGNED_NONCE")
}
// Verify the certificate against the root.
// TODO(tmroeder): move the VerifyOptions up into the ResourceMaster.
var opts x509.VerifyOptions
roots := x509.NewCertPool()
policyCert, err := x509.ParseCertificate(programPolicy.PolicyCert)
if err != nil || policyCert == nil {
return nil, err
}
roots.AddCert(policyCert)
opts.Roots = roots
chains, err := cert.Verify(opts)
if chains == nil || err != nil {
return nil, err
}
v, err := tao.FromX509(cert)
if err != nil {
return nil, err
}
ok, err := v.Verify(reply.Data, ChallengeContext, s.Data)
if err != nil {
return nil, err
}
if err := sendResult(ms, ok); err != nil {
return nil, fmt.Errorf("failed to return a result to the client")
}
if !ok {
return nil, fmt.Errorf("the nonce signature did not pass verification")
}
return msg.Data, nil
}
// This function performs the following checks on a secret disclosure directive.
// (1) the directive signature is valid with respect to signerKey of directive
// (2) Either
// - policyKey matches the signerKey of directive
// - directive cert is a valid program cert (signed by policyKey) certifying the signerKey
// of directive as belonging to 'delegator'
// (3) the directive message is a statement of the form:
// 'policyKey/'delegator' says delegate can read protectedObjectId'
// where delegate is a Tao Principal and protectedObjectId is a (serialized) protected
// object message id.
func VerifySecretDisclosureDirective(policyKey *tao.Keys, directive *DirectiveMessage) (*auth.Prin,
*auth.Prin, *string, *po.ObjectIdMessage, error) {
// Check type of directive
if directive.Type == nil || *(directive.Type) != DirectiveMessage_SECRET_DISCLOSURE {
return nil, nil, nil, nil, errors.New(
"secret_disclosure: directive not of secret disclosure type.")
}
var verifier *tao.Verifier
var delegatorStr string
// Check directive signer matches policy key.
if bytes.Compare(
auth.Marshal(policyKey.SigningKey.ToPrincipal()), directive.GetSigner()) == 0 {
verifier = policyKey.SigningKey.GetVerifier()
delegatorStr = verifier.ToPrincipal().String()
} else {
// Check if program cert is valid, signed by policy key,
// cert public key matches signer and cert name matches speaker
// of says statement.
cert, err := x509.ParseCertificate(directive.Cert)
if err != nil {
return nil, nil, nil, nil, errors.New(
"error parsing directive program cert")
}
rootCert := x509.NewCertPool()
rootCert.AddCert(policyKey.Cert)
verifyOptions := x509.VerifyOptions{Roots: rootCert}
_, err = cert.Verify(verifyOptions)
if err != nil {
return nil, nil, nil, nil, errors.New(
"program cert not valid")
}
verifier, err = tao.FromX509(cert)
delegatorStr = cert.Subject.CommonName
if err != nil {
return nil, nil, nil, nil, err
}
if bytes.Compare(auth.Marshal(verifier.ToPrincipal()), directive.GetSigner()) != 0 {
return nil, nil, nil, nil, errors.New(
"secret_disclosure: directive signer doesn't match program key.")
}
}
// Verify signature.
ok, err := verifier.Verify(directive.GetSerializedStatement(), SigningContext,
directive.GetSignature())
if err != nil {
return nil, nil, nil, nil, err
}
if !ok {
return nil, nil, nil, nil,
errors.New("secret_disclosure: directive signature check failed.")
}
// Validate and return statement.
statement, err := auth.UnmarshalForm(directive.GetSerializedStatement())
if err != nil {
return nil, nil, nil, nil, err
}
var saysStatement *auth.Says
if ptr, ok := statement.(*auth.Says); ok {
saysStatement = ptr
} else if val, ok := statement.(auth.Says); ok {
saysStatement = &val
} else {
return nil, nil, nil, nil,
errors.New("secret_disclosure: directive statement not a 'Says'")
}
stmtSpeaker, ok := saysStatement.Speaker.(auth.Prin)
if !ok {
return nil, nil, nil, nil,
errors.New("secret_disclosure: directive speaker not a 'Prin'")
}
if stmtSpeaker.String() != delegatorStr {
return nil, nil, nil, nil, errors.New(
"secret_disclosure: directive statement speaker does not match signer")
}
pred, ok := saysStatement.Message.(auth.Pred)
if !ok {
return nil, nil, nil, nil,
errors.New("secret_disclosure: directive message not a 'Pred'")
}
predName := pred.Name
if predName == "" {
return nil, nil, nil, nil,
errors.New("secret_disclosure: directive predicate name is empty")
}
if len(pred.Arg) != 2 {
return nil, nil, nil, nil,
errors.New("secret_disclosure: directive predicate doesn't have 2 terms")
}
delegateName, ok := pred.Arg[0].(auth.Prin)
if !ok {
return nil, nil, nil, nil, errors.New(
"secret_disclosure: directive delegateName Term not of type auth.Prin.")
}
serializedObjId, ok := pred.Arg[1].(auth.Bytes)
if !ok {
return nil, nil, nil, nil, errors.New(
"secret_disclosure: directive ObjId Term not of type []byte.")
}
protectedObjId := po.ObjectIdMessage{}
err = proto.Unmarshal(serializedObjId, &protectedObjId)
if err != nil {
return nil, nil, nil, nil, errors.New(
"secret_disclosure: error deserializing protected ObjId.")
}
return &stmtSpeaker, &delegateName, &predName, &protectedObjId, nil
}
