use AttestationClient to get key info in MachineCertificateUploader.

We are deprecating attestation methods by CryptohomeClient.

This CL also includes a simplied flow by consolidating
TpmAttestationDoesKeyExist and TpmAttestationGetCertificate, of which
results come from the same methods of attestation service anyway.

BUG=b:158955123
TEST=unit_tests.

Change-Id: I36933b4ee20e86fd6946644d957ab70459609482
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2515801
Commit-Queue: Leo Lai <cylai@google.com>
Reviewed-by: Maksim Ivanov <emaxx@chromium.org>
Cr-Commit-Position: refs/heads/master@{#823899}

chrome/browser/chromeos/attestation/machine_certificate_uploader_impl.cc

@@ -44,51 +44,6 @@ const int kExpiryThresholdInDays = 30;
 const int kRetryDelay = 5;  // Seconds.
 const int kRetryLimit = 100;
 
-// A dbus callback which handles a boolean result.
-//
-// Parameters
-//   on_true - Called when status=success and value=true.
-//   on_false - Called when status=success and value=false.
-//   status - The dbus operation status.
-//   result - The value returned by the dbus operation.
-void DBusBoolRedirectCallback(const base::RepeatingClosure& on_true,
-                              const base::RepeatingClosure& on_false,
-                              const base::RepeatingClosure& on_failure,
-                              const base::Location& from_here,
-                              base::Optional<bool> result) {
-  if (!result.has_value()) {
-    LOG(ERROR) << "Cryptohome DBus method failed: " << from_here.ToString();
-    if (!on_failure.is_null())
-      on_failure.Run();
-    return;
-  }
-  const base::RepeatingClosure& task = result.value() ? on_true : on_false;
-  if (!task.is_null())
-    task.Run();
-}
-
-// A dbus callback which handles a string result.
-//
-// Parameters
-//   on_success - Called when status=success and result=true.
-//   status - The dbus operation status.
-//   result - The result returned by the dbus operation.
-//   data - The data returned by the dbus operation.
-void DBusStringCallback(
-    const base::RepeatingCallback<void(const std::string&)> on_success,
-    const base::RepeatingClosure& on_failure,
-    const base::Location& from_here,
-    base::Optional<chromeos::CryptohomeClient::TpmAttestationDataResult>
-        result) {
-  if (!result.has_value() || !result->success) {
-    LOG(ERROR) << "Cryptohome DBus method failed: " << from_here.ToString();
-    if (!on_failure.is_null())
-      on_failure.Run();
-    return;
-  }
-  on_success.Run(result->data);
-}
-
 void DBusPrivacyCACallback(
     const base::RepeatingCallback<void(const std::string&)> on_success,
     const base::RepeatingCallback<
@@ -181,22 +136,13 @@ void MachineCertificateUploaderImpl::Start() {
     return;
   }
 
-  // Start a dbus call to check if an Enterprise Machine Key already exists.
-  base::RepeatingClosure on_does_not_exist =
-      base::BindRepeating(&MachineCertificateUploaderImpl::GetNewCertificate,
-                          weak_factory_.GetWeakPtr());
-  base::RepeatingClosure on_does_exist = base::BindRepeating(
-      &MachineCertificateUploaderImpl::GetExistingCertificate,
-      weak_factory_.GetWeakPtr());
-  cryptohome_client_->TpmAttestationDoesKeyExist(
-      KEY_DEVICE,
-      cryptohome::AccountIdentifier(),  // Not used.
-      kEnterpriseMachineKey,
-      base::BindOnce(
-          DBusBoolRedirectCallback, on_does_exist, on_does_not_exist,
-          base::BindRepeating(&MachineCertificateUploaderImpl::Reschedule,
-                              weak_factory_.GetWeakPtr()),
-          FROM_HERE));
+  ::attestation::GetKeyInfoRequest request;
+  request.set_username("");
+  request.set_key_label(kEnterpriseMachineKey);
+  AttestationClient::Get()->GetKeyInfo(
+      request,
+      base::BindOnce(&MachineCertificateUploaderImpl::OnGetExistingCertificate,
+                     weak_factory_.GetWeakPtr()));
 }
 
 void MachineCertificateUploaderImpl::GetNewCertificate() {
@@ -224,23 +170,26 @@ void MachineCertificateUploaderImpl::GetNewCertificate() {
           FROM_HERE));
 }
 
-void MachineCertificateUploaderImpl::GetExistingCertificate() {
-  cryptohome_client_->TpmAttestationGetCertificate(
-      KEY_DEVICE,
-      cryptohome::AccountIdentifier(),  // Not used.
-      kEnterpriseMachineKey,
-      base::BindOnce(
-          DBusStringCallback,
-          base::BindRepeating(
-              &MachineCertificateUploaderImpl::CheckCertificateExpiry,
-              weak_factory_.GetWeakPtr()),
-          base::BindRepeating(&MachineCertificateUploaderImpl::Reschedule,
-                              weak_factory_.GetWeakPtr()),
-          FROM_HERE));
+void MachineCertificateUploaderImpl::OnGetExistingCertificate(
+    const ::attestation::GetKeyInfoReply& reply) {
+  if (reply.status() != ::attestation::STATUS_SUCCESS &&
+      reply.status() != ::attestation::STATUS_INVALID_PARAMETER) {
+    LOG(ERROR) << "Error getting the existing certificate; status: "
+               << reply.status();
+    Reschedule();
+    return;
+  }
+  // Get a new certificate if not exists.
+  if (reply.status() == ::attestation::STATUS_INVALID_PARAMETER) {
+    GetNewCertificate();
+    return;
+  }
+  CheckCertificateExpiry(reply);
 }
 
 void MachineCertificateUploaderImpl::CheckCertificateExpiry(
-    const std::string& pem_certificate_chain) {
+    const ::attestation::GetKeyInfoReply& reply) {
+  const std::string& pem_certificate_chain = reply.certificate();
   int num_certificates = 0;
   net::PEMTokenizer pem_tokenizer(pem_certificate_chain, {"CERTIFICATE"});
   while (pem_tokenizer.GetNext()) {
@@ -270,13 +219,7 @@ void MachineCertificateUploaderImpl::CheckCertificateExpiry(
   if (num_certificates == 0) {
     LOG(WARNING) << "Failed to parse certificate chain, cannot check expiry.";
   }
-  ::attestation::GetKeyInfoRequest request;
-  request.set_username("");
-  request.set_key_label(kEnterpriseMachineKey);
-  AttestationClient::Get()->GetKeyInfo(
-      request,
-      base::BindOnce(&MachineCertificateUploaderImpl::CheckIfUploaded,
-                     weak_factory_.GetWeakPtr(), pem_certificate_chain));
+  CheckIfUploaded(reply);
 }
 
 void MachineCertificateUploaderImpl::UploadCertificate(
@@ -289,9 +232,12 @@ void MachineCertificateUploaderImpl::UploadCertificate(
 }
 
 void MachineCertificateUploaderImpl::CheckIfUploaded(
-    const std::string& pem_certificate_chain,
     const ::attestation::GetKeyInfoReply& reply) {
+  // The caller in the entire flow should have checked the reply status already.
   if (reply.status() != ::attestation::STATUS_SUCCESS) {
+    LOG(DFATAL) << "Checking key payload in a bad reply from attestation "
+                   "service; status: "
+                << reply.status();
     Reschedule();
     return;
   }
@@ -304,7 +250,7 @@ void MachineCertificateUploaderImpl::CheckIfUploaded(
     RunCallbacks(certificate_uploaded_.value());
     return;
   }
-  UploadCertificate(pem_certificate_chain);
+  UploadCertificate(reply.certificate());
 }
 
 void MachineCertificateUploaderImpl::OnUploadComplete(bool status) {
@@ -333,6 +279,10 @@ void MachineCertificateUploaderImpl::WaitForUploadComplete(
 
 void MachineCertificateUploaderImpl::MarkAsUploaded(
     const ::attestation::GetKeyInfoReply& reply) {
+  if (reply.status() != ::attestation::STATUS_SUCCESS) {
+    LOG(WARNING) << "Failed to get existing payload.";
+    return;
+  }
   AttestationKeyPayload payload_pb;
   if (!reply.payload().empty())
     payload_pb.ParseFromString(reply.payload());

chrome/browser/chromeos/attestation/machine_certificate_uploader_impl.h

@@ -67,19 +67,23 @@ class MachineCertificateUploaderImpl : public MachineCertificateUploader {
   // Gets a new certificate for the Enterprise Machine Key (EMK).
   void GetNewCertificate();
 
-  // Gets the existing EMK certificate and sends it to CheckCertificateExpiry.
-  void GetExistingCertificate();
+  // Called when `GetKeyInfo()` returned to check the existing certificate.
+  // There are 3 cases by the status replied from attestation service:
+  //     1. If the existing EMK is found, calls `CheckCertificateExpiry()`.
+  //     2. If the key does not exist, calls `GetNewCertificate()`.
+  //     3. Otherwise, there is an error and `Reschedule()` is called to retry.
+  void OnGetExistingCertificate(const ::attestation::GetKeyInfoReply& reply);
 
-  // Checks if any certificate in the given pem_certificate_chain is expired
-  // and, if so, gets a new one. If not renewing, calls CheckIfUploaded.
-  void CheckCertificateExpiry(const std::string& pem_certificate_chain);
+  // Checks if any certificate in the given `reply` is expired and, if so, gets
+  // a new one. If not renewing, calls `CheckIfUploaded()`.
+  void CheckCertificateExpiry(const ::attestation::GetKeyInfoReply& reply);
 
   // Uploads a machine certificate to the policy server.
   void UploadCertificate(const std::string& pem_certificate_chain);
 
-  // Checks if a certificate has already been uploaded and, if not, upload.
-  void CheckIfUploaded(const std::string& pem_certificate_chain,
-                       const ::attestation::GetKeyInfoReply& reply);
+  // Checks if a certificate in `reply` has already been uploaded and, if not,
+  // upload.
+  void CheckIfUploaded(const ::attestation::GetKeyInfoReply& reply);
 
   // Called when a certificate upload operation completes.  On success, |status|
   // will be true.

chromeos/dbus/attestation/attestation_client.h

@@ -135,6 +135,11 @@ class COMPONENT_EXPORT(CHROMEOS_DBUS_ATTESTATION) AttestationClient {
     virtual ::attestation::GetKeyInfoReply* GetMutableKeyInfoReply(
         const std::string& username,
         const std::string& label) = 0;
+    // Sets the returned status of `GetKeyInfo()` to be D-Bus error for
+    // `count` times to emulate D-Bus late availability.
+    virtual void set_key_info_dbus_error_count(int count) = 0;
+    // Gets the remaining count of `GetKeyInfo()` replying D-Bus error.
+    virtual int key_info_dbus_error_count() const = 0;
 
     // Verifies if `signed_data` is signed against `challenge`.
     virtual bool VerifySimpleChallengeResponse(

chromeos/dbus/attestation/fake_attestation_client.cc

@@ -76,11 +76,16 @@ void FakeAttestationClient::GetKeyInfo(
     const ::attestation::GetKeyInfoRequest& request,
     GetKeyInfoCallback callback) {
   ::attestation::GetKeyInfoReply reply;
-  auto iter = key_info_database_.find(request);
-  if (iter != key_info_database_.end()) {
-    reply = iter->second;
+  if (key_info_dbus_error_count_ > 0) {
+    reply.set_status(::attestation::STATUS_DBUS_ERROR);
+    key_info_dbus_error_count_--;
   } else {
-    reply.set_status(::attestation::STATUS_INVALID_PARAMETER);
+    auto iter = key_info_database_.find(request);
+    if (iter != key_info_database_.end()) {
+      reply = iter->second;
+    } else {
+      reply.set_status(::attestation::STATUS_INVALID_PARAMETER);
+    }
   }
 
   PostProtoResponse(std::move(callback), reply);
@@ -413,6 +418,14 @@ void FakeAttestationClient::set_enrollment_id_dbus_error_count(int count) {
   return &(key_info_database_[request]);
 }
 
+void FakeAttestationClient::set_key_info_dbus_error_count(int count) {
+  key_info_dbus_error_count_ = count;
+}
+
+int FakeAttestationClient::key_info_dbus_error_count() const {
+  return key_info_dbus_error_count_;
+}
+
 bool FakeAttestationClient::VerifySimpleChallengeResponse(
     const std::string& challenge,
     const ::attestation::SignedData& signed_data) {

chromeos/dbus/attestation/fake_attestation_client.h

@@ -121,6 +121,8 @@ class COMPONENT_EXPORT(CHROMEOS_DBUS_ATTESTATION) FakeAttestationClient
   ::attestation::GetKeyInfoReply* GetMutableKeyInfoReply(
       const std::string& username,
       const std::string& label) override;
+  void set_key_info_dbus_error_count(int count) override;
+  int key_info_dbus_error_count() const override;
   bool VerifySimpleChallengeResponse(
       const std::string& challenge,
       const ::attestation::SignedData& signed_data) override;
@@ -189,6 +191,7 @@ class COMPONENT_EXPORT(CHROMEOS_DBUS_ATTESTATION) FakeAttestationClient
            ::attestation::GetKeyInfoReply,
            GetKeyInfoRequestComparator>
       key_info_database_;
+  int key_info_dbus_error_count_ = 0;
 
   // The status returned by `SignSimpleChallenge()`.
   ::attestation::AttestationStatus sign_simple_challenge_status_ =