Added an OTA keybox provisioner.

[ Merge of http://go/wvgerrit/133729 ] The OtaKeyboxProvisioner is a system-wide provisioner for sharing the provisioning workflow between CDM engines. Bug: 189232882 Test: GtsMediaTestCases Change-Id: I873af3087cc05e1831bdd1d2c14fb002b73e6902 Added keybox provisioning proto fields. [ Merge of http://go/wvgerrit/133730 and http://go/ag/15113032 ] This CL copies over the required license_protocol.proto changes that are required for OTA keybox provisioning. These fields are defined in the server-side certificate_provisioning.proto, defined in http://cl/377533774. Note, changes are slightly different from server proto due to the RVC version of license_protocol.proto being out of date with SC and newer changes. Bug: 189232882 Test: run_x86_64_tests Change-Id: I55fcf6a7ac2ba4b6026b9acc63e822ff33c431d9 Added OTA keybox provisioning device files. [ Merge of http://go/wvgerrit/133743 and http://go/ag/15421141 ] This change adds a new set of proto messages/fields the CDM's device files for recording device and engine information around OTA keybox provisioning (OKP). To make cleanup and thread protection possible, there is a single file which will contain all the information for the device as a whole and each CDM engine tied to an app/origin. Bug: 189232882 Test: Linux unit tests Change-Id: Iaf80cd6342f32657e04416750d9b278d935821a5 Client ID for OKP requests. [ Merge of http://go/wvgerrit/133744 and http://go/ag/15645331 ] Extended the CDM ClientIdentification class to support a subset of client info used for OKP requests. Bug: 189232882 Test: Android unit tests Merged-In: I6aafb4f2164efe69bc733ece0a912f0e91893b91 Change-Id: I6aafb4f2164efe69bc733ece0a912f0e91893b91
2021-09-15 02:56:19 -07:00
parent 44ba42f5cc
commit 52bd1d206e
13 changed files with 586 additions and 30 deletions
--- a/libwvdrmengine/cdm/Android.bp
+++ b/libwvdrmengine/cdm/Android.bp
@@ -54,6 +54,7 @@ cc_library_static {
        CORE_SRC_DIR + "/license.cpp",
        CORE_SRC_DIR + "/license_key_status.cpp",
        CORE_SRC_DIR + "/oemcrypto_adapter_dynamic.cpp",
+        CORE_SRC_DIR + "/ota_keybox_provisioner.cpp",
        CORE_SRC_DIR + "/policy_engine.cpp",
        CORE_SRC_DIR + "/policy_timers.cpp",
        CORE_SRC_DIR + "/policy_timers_v15.cpp",
--- a/libwvdrmengine/cdm/core/include/certificate_provisioning.h
+++ b/libwvdrmengine/cdm/core/include/certificate_provisioning.h
@@ -67,6 +67,11 @@ class CertificateProvisioning {
  static bool ExtractAndDecodeSignedMessageForTesting(
      const std::string& provisioning_response, std::string* result);

+  // Retrieve the provisioning server URL used for certificate
+  // provisioning. This will be the same value as returned in
+  // |default_url| by GetProvisioningRequest().
+  static void GetProvisioningServerUrl(std::string* default_url);
+
 private:
  CdmResponseType GetProvisioningRequestInternal(
      SecurityLevel requested_security_level, CdmCertificateType cert_type,
--- a/libwvdrmengine/cdm/core/include/client_identification.h
+++ b/libwvdrmengine/cdm/core/include/client_identification.h
@@ -5,33 +5,35 @@
 #ifndef WVCDM_CORE_CLIENT_IDENTIFICATION_H_
 #define WVCDM_CORE_CLIENT_IDENTIFICATION_H_

+#include <string>
+
 // ClientIdentification fills in the ClientIdentification portion
 // of the License or Provisioning request messages.
-
 #include "disallow_copy_and_assign.h"
 #include "license_protocol.pb.h"
 #include "wv_cdm_types.h"

 namespace wvcdm {
-
 class CryptoSession;

 class ClientIdentification {
 public:
-  ClientIdentification() : is_license_request_(true) {}
+  ClientIdentification() {}
  virtual ~ClientIdentification() {}

  // Call this method when used with provisioning requests
-  CdmResponseType Init(CryptoSession* crypto_session);
+  CdmResponseType InitForProvisioning(CryptoSession* crypto_session);

  // Use in conjunction with license requests
  // |client_token| must be provided
  // |crypto_session| input parameter, mandatory
-  CdmResponseType Init(const std::string& client_token,
-                       CryptoSession* crypto_session);
+  CdmResponseType InitForLicenseRequest(const std::string& client_token,
+                                        CryptoSession* crypto_session);

-  // Fill the ClientIdentification portion of the license or provisioning
-  // request
+  CdmResponseType InitForOtaKeyboxProvisioning(CryptoSession* crypto_session);
+
+  // Fill the ClientIdentification portion of the license, DRM cert
+  // provisioning or OTA keybox provisioning request.
  // |app_parameters| parameters provided by client/app to be included in
  //                  provisioning/license request. optional, only used
  //                  if |is_license_request| is true
@@ -49,13 +51,13 @@ class ClientIdentification {
  bool GetProvisioningTokenType(
      video_widevine::ClientIdentification::TokenType* token_type);

-  bool is_license_request_;
+  bool is_license_request_ = false;
+  bool is_okp_request_ = false;
  std::string client_token_;
-  CryptoSession* crypto_session_;
+  std::string device_id_;
+  CryptoSession* crypto_session_ = nullptr;

  CORE_DISALLOW_COPY_AND_ASSIGN(ClientIdentification);
 };
-
 }  // namespace wvcdm
-
 #endif  // WVCDM_CORE_CLIENT_IDENTIFICATION_H_
--- a/libwvdrmengine/cdm/core/include/crypto_session.h
+++ b/libwvdrmengine/cdm/core/include/crypto_session.h
@@ -26,6 +26,7 @@ namespace wvcdm {

 class CryptoKey;
 class CryptoSessionFactory;
+class OtaKeyboxProvisioner;
 class UsageTableHeader;

 using CryptoKeyMap = std::map<std::string, CryptoKey*>;
@@ -41,6 +42,7 @@ OEMCrypto_Substring GetSubstring(const std::string& message = "",
                                 bool set_zero = false);
 OEMCryptoCipherMode ToOEMCryptoCipherMode(CdmCipherMode cipher_mode);

+
 class CryptoSession {
 public:
  using HdcpCapability = OEMCrypto_HDCP_Capability;
@@ -288,7 +290,14 @@ class CryptoSession {
      SecurityLevel requested_security_level, CdmClientTokenType* token_type);

  // OTA Provisioning
-  // TODO(sigquit): include rest of http://go/wvgerrit/126004
+
+  bool needs_keybox_provisioning() const { return needs_keybox_provisioning_; }
+
+  // Returns a system-wide singleton instance of OtaKeyboxProvisioner
+  // to be used for OTA provisioning requests/responses across apps.
+  // Returns a null pointer if OTA provisioning is NOT supported, or
+  // if the device has already been provisioned.
+  virtual OtaKeyboxProvisioner* GetOtaKeyboxProvisioner();

  // Generates an OTA provisioning request.
  // This should only be called by an instance of OtaKeyboxProvisioner.
@@ -504,6 +513,11 @@ class CryptoSession {
  static std::mutex factory_mutex_;
  static std::unique_ptr<CryptoSessionFactory> factory_;

+  // A singleton instance of OtaKeyboxProvisioner.  Only one will
+  // be created for the system if OTA keybox provisioning is both
+  // required and supported by L1.
+  static std::unique_ptr<OtaKeyboxProvisioner> ota_keybox_provisioner_l1_;
+
  CORE_DISALLOW_COPY_AND_ASSIGN(CryptoSession);
 };  // class CryptoSession

--- a/libwvdrmengine/cdm/core/include/ota_keybox_provisioner.h
+++ b/libwvdrmengine/cdm/core/include/ota_keybox_provisioner.h
@@ -0,0 +1,68 @@
+// Copyright 2021 Google LLC. All Rights Reserved. This file and proprietary
+// source code may only be used and distributed under the Widevine License
+// Agreement.
+#ifndef WVCDM_CORE_OTA_KEYBOX_PROVISIONER_H_
+#define WVCDM_CORE_OTA_KEYBOX_PROVISIONER_H_
+
+#include <memory>
+#include <mutex>
+#include <string>
+
+#include "disallow_copy_and_assign.h"
+#include "wv_cdm_types.h"
+
+namespace wvcdm {
+class CryptoSession;
+
+// Wrapper around an OEMCrypto system-wide OTA keybox provisioning
+// workflow.
+class OtaKeyboxProvisioner {
+ public:
+  // Creates a new OTA keybox provisioner.  This should only be
+  // created once and object ownership belongs to the CryptoSession
+  // module.
+  static std::unique_ptr<OtaKeyboxProvisioner> Create();
+
+  ~OtaKeyboxProvisioner();
+
+  // === Request/response API ===
+
+  // Returns true if a provisioning response has been provided
+  // and accepted by OEMCrytpo.
+  bool IsProvisioned() const { return is_provisioned_; }
+
+  uint32_t request_count() const { return request_count_; }
+  uint32_t response_count() const { return response_count_; }
+
+  // Generates an OTA provisioning request.
+  // Generating a request will succeed so long as OTA provisioning
+  // is supported and no valid response has been provided.
+  CdmResponseType GenerateProvisioningRequest(CryptoSession* crypto_session,
+                                              std::string* request);
+
+  // Accepts a provisioning response from the OTA provisioning
+  // server.  The first response which is successfully loaded is
+  // is used.  Any subsequent response after the first successful
+  // response is silently discarded.
+  CdmResponseType HandleProvisioningResponse(CryptoSession* crypto_session,
+                                             const std::string& response);
+
+ private:
+  OtaKeyboxProvisioner();
+
+  bool is_provisioned_ = false;
+
+  // These counters are for debugging purposes.
+  // Number of requests generated.
+  uint32_t request_count_ = 0;
+  // Number of responses provided.
+  uint32_t response_count_ = 0;
+
+  // It is expected that multiple CDM engines may interact with the
+  // OtaKeyboxProvisioner instance simultaneously.
+  mutable std::mutex mutex_;
+
+  CORE_DISALLOW_COPY_AND_ASSIGN(OtaKeyboxProvisioner);
+};  // class OtaKeyboxProvisioner
+}  // namespace wvcdm
+#endif  // WVCDM_CORE_OTA_KEYBOX_PROVISIONER_H_
--- a/libwvdrmengine/cdm/core/src/certificate_provisioning.cpp
+++ b/libwvdrmengine/cdm/core/src/certificate_provisioning.cpp
@@ -118,6 +118,16 @@ using video_widevine::SignedProvisioningMessage;
 using video_widevine::
    SignedProvisioningMessage_ProvisioningProtocolVersion_VERSION_1_1;

+// static
+void CertificateProvisioning::GetProvisioningServerUrl(
+    std::string* default_url) {
+  if (default_url == nullptr) {
+    LOGE("Output |default_url| is null");
+    return;
+  }
+  default_url->assign(kProvisioningServerUrl);
+}
+
 CdmResponseType CertificateProvisioning::Init(
    const std::string& service_certificate) {
  std::string certificate = service_certificate.empty()
@@ -221,7 +231,7 @@ CdmResponseType CertificateProvisioning::GetProvisioningRequestInternal(
  ProvisioningRequest provisioning_request;

  wvcdm::ClientIdentification id;
-  status = id.Init(crypto_session_.get());
+  status = id.InitForProvisioning(crypto_session_.get());
  if (status != NO_ERROR) return status;

  video_widevine::ClientIdentification client_id;
--- a/libwvdrmengine/cdm/core/src/client_identification.cpp
+++ b/libwvdrmengine/cdm/core/src/client_identification.cpp
@@ -66,35 +66,44 @@ using video_widevine::ProvisioningRequest;
 using video_widevine::ProvisioningResponse;
 using video_widevine::SignedProvisioningMessage;

-CdmResponseType ClientIdentification::Init(CryptoSession* crypto_session) {
+CdmResponseType ClientIdentification::InitForProvisioning(
+    CryptoSession* crypto_session) {
  if (crypto_session == nullptr) {
    LOGE("Crypto session not provided");
    return PARAMETER_NULL;
  }
-
  is_license_request_ = false;
  crypto_session_ = crypto_session;
  return NO_ERROR;
 }

-CdmResponseType ClientIdentification::Init(const std::string& client_token,
-                                           CryptoSession* crypto_session) {
+CdmResponseType ClientIdentification::InitForLicenseRequest(
+    const std::string& client_token, CryptoSession* crypto_session) {
  if (crypto_session == nullptr) {
    LOGE("Crypto session not provided");
    return PARAMETER_NULL;
  }
-
  if (client_token.empty()) {
    LOGE("Client token is empty");
    return PARAMETER_NULL;
  }
-
  is_license_request_ = true;
  client_token_ = client_token;
  crypto_session_ = crypto_session;
  return NO_ERROR;
 }

+CdmResponseType ClientIdentification::InitForOtaKeyboxProvisioning(
+    CryptoSession* crypto_session) {
+  if (crypto_session == nullptr) {
+    LOGE("Crypto session not provided");
+    return PARAMETER_NULL;
+  }
+  is_okp_request_ = true;
+  crypto_session_ = crypto_session;
+  return NO_ERROR;
+}
+
 /*
 * Return the ClientIdentification message token type for provisioning request.
 * NOTE: a DRM Cert should never be presented to the provisioning server.
@@ -107,7 +116,7 @@ CdmResponseType ClientIdentification::Prepare(
    client_id->set_type(
        video_widevine::ClientIdentification::DRM_DEVICE_CERTIFICATE);
    client_id->set_token(client_token_);
-  } else {
+  } else if (!is_okp_request_) {
    video_widevine::ClientIdentification::TokenType token_type;
    if (!GetProvisioningTokenType(&token_type)) {
      LOGE("Failed to get provisioning token type");
@@ -189,6 +198,11 @@ CdmResponseType ClientIdentification::Prepare(
    client_id->set_provider_client_token(provider_client_token);
  }

+  if (is_okp_request_) {
+    // Capabilities is not important for OTA keybox provisionining.
+    return NO_ERROR;
+  }
+
  ClientCapabilities* client_capabilities =
      client_id->mutable_client_capabilities();

--- a/libwvdrmengine/cdm/core/src/crypto_session.cpp
+++ b/libwvdrmengine/cdm/core/src/crypto_session.cpp
@@ -20,6 +20,7 @@
 #include "crypto_key.h"
 #include "entitlement_key_session.h"
 #include "log.h"
+#include "ota_keybox_provisioner.h"
 #include "platform.h"
 #include "privacy_crypto.h"
 #include "properties.h"
@@ -178,6 +179,7 @@ std::unique_ptr<UsageTableHeader> CryptoSession::usage_table_header_l1_;
 std::unique_ptr<UsageTableHeader> CryptoSession::usage_table_header_l3_;
 std::recursive_mutex CryptoSession::usage_table_mutex_;
 std::atomic<uint64_t> CryptoSession::request_id_index_source_(0);
+std::unique_ptr<OtaKeyboxProvisioner> CryptoSession::ota_keybox_provisioner_l1_;

 size_t GetOffset(std::string message, std::string field) {
  size_t pos = message.find(field);
@@ -360,8 +362,15 @@ void CryptoSession::Init() {
    LOGD("OEMCrypto version (L3 security level): %s.%s", api_version.c_str(),
         api_minor_version.c_str());
    if (needs_keybox_provisioning_) {
-      LOGE("OEMCrypto needs provisioning");
-      // TODO(fredgc,sigquit,rfrias): handle provisioning.
+      WithStaticFieldWriteLock("OtaKeyboxProvisioner", [&] {
+        if (!ota_keybox_provisioner_l1_) {
+          LOGD("OEMCrypto needs keybox provisioning");
+          // Only create once.  Possible that OEMCrypto is initialized
+          // and terminated many times over the life cycle of the OTA
+          // keybox provisioning process.
+          ota_keybox_provisioner_l1_ = OtaKeyboxProvisioner::Create();
+        }
+      });
    }
  }
 }
@@ -3011,11 +3020,20 @@ OEMCryptoResult CryptoSession::LegacyDecryptInChunks(
    remaining_input_data -= chunk_size;
    AdvanceDestBuffer(&fake_sample.buffers.output_descriptor, chunk_size);
  }
-
  return sts;
 }

-// TODO(sigquit): include rest of http://go/wvgerrit/126004
+OtaKeyboxProvisioner* CryptoSession::GetOtaKeyboxProvisioner() {
+  const auto getter = [&]() -> OtaKeyboxProvisioner* {
+    // If not set, then OTA keybox provisioning is not supported or
+    // not needed.
+    if (!ota_keybox_provisioner_l1_) return nullptr;
+    // May have already been initialized.
+    if (ota_keybox_provisioner_l1_->IsProvisioned()) return nullptr;
+    return ota_keybox_provisioner_l1_.get();
+  };
+  return WithStaticFieldReadLock("GetOtaKeyboxProvisioner", getter);
+}

 CdmResponseType CryptoSession::PrepareOtaProvisioningRequest(
    bool use_test_key, std::string* request) {
@@ -3026,17 +3044,25 @@ CdmResponseType CryptoSession::PrepareOtaProvisioningRequest(
  if (status != OEMCrypto_ERROR_SHORT_BUFFER)
    return MapOEMCryptoResult(status, UNKNOWN_ERROR,
                              "PrepareOtaProvisioningRequest");
-  std::string temp_buffer(buffer_length, '\0');
-  uint8_t* buf = reinterpret_cast<uint8_t*>(&temp_buffer[0]);
+  if (buffer_length == 0) {
+    LOGE("OTA request size is zero");
+    return UNKNOWN_ERROR;
+  }
+  request->resize(buffer_length);
+  uint8_t* buf = reinterpret_cast<uint8_t*>(&request->front());
  status = OEMCrypto_GenerateOTARequest(buf, &buffer_length, use_test_key);
-  if (OEMCrypto_SUCCESS == status) request->assign(temp_buffer);
+  if (OEMCrypto_SUCCESS != status) {
+    request->clear();
+  } else if (buffer_length != request->size()) {
+    request->resize(buffer_length);
+  }
  return MapOEMCryptoResult(status, UNKNOWN_ERROR,
                            "PrepareOtaProvisioningRequest");
 }

 CdmResponseType CryptoSession::LoadOtaProvisioning(
    bool use_test_key, const std::string& response) {
-  OEMCryptoResult status = OEMCrypto_ProcessOTAKeybox(
+  const OEMCryptoResult status = OEMCrypto_ProcessOTAKeybox(
      reinterpret_cast<const uint8_t*>(response.data()), response.size(),
      use_test_key);
  return MapOEMCryptoResult(status, UNKNOWN_ERROR, "LoadOtaProvisioning");
--- a/libwvdrmengine/cdm/core/src/device_files.proto
+++ b/libwvdrmengine/cdm/core/src/device_files.proto
@@ -125,6 +125,71 @@ message UsageTableInfo {
  optional bool use_lru = 3 [default = false];
 }

+// Stores information related to a device's experience with OTA Keybox
+// Provisioning (OKP).  Only devices which both support OKP and require
+// OKP should create this file.  Otherwise, this information is not
+// needed.
+message OtaKeyboxProvisioningInfo {
+  // Engine-specific information about OKP.
+  message OkpEngineInfo {
+    // Engine identifier.
+    optional bytes app_id = 1;
+    optional bytes origin = 2;
+    reserved 3 to 5;  // Reserved for future engine composite keys.
+    // Counters for engine-specific OKP events.
+    // These counters are reset after a certain amount of time
+    // (OKP period) since the last event.
+    // Number of calls to openSession() where it is recommended
+    // to the app to try keybox provisioning.
+    optional uint32 try_okp_counter = 6;
+    // Number of calls to getProvisionRequest().
+    optional uint32 generate_request_counter = 7;
+    // Number of failed calls to provideProvisionRequest().
+    optional uint32 failed_response_counter = 8;
+
+    // The value of |last_event_time| and |backoff_start_time| are set
+    // using the system's wall-clock in epoch seconds.  A value of
+    // zero indicates it's not set.
+
+    // Time of the last engine OKP event (change of the above counters;
+    // the beginning of the current OKP period).
+    // Zero indicates no event has yet occurred.
+    optional int64 last_event_time = 9;
+    // Beginning of an app/origin backoff period.
+    // Zero indicates that engine is not in a backoff state.
+    optional int64 backoff_start_time = 10;
+    // Intended length of “backoff period”.  This will be assigned a
+    // random duration initially, then double each time an engine
+    // enters a backoff state.  This is base on Google's recommended
+    // exponential backoff rules.
+    // Value of 0 indicates that backoff has not yet occurred.
+    optional int64 backoff_duration = 11;
+  }
+
+  enum OkpDeviceState {
+    // Not yet checked for provisioning state.  This should be a
+    // transitory state only.  Device which do not need OTA Keybox
+    // Provisioning should simply not store this file.
+    OKP_UNKNOWN = 0;
+    // OEMCrypto has reported that keybox provisioning is required and
+    // that the device supports OKP.  Device may or may not be in the
+    // process of performing provisioning.
+    OKP_NEEDS_PROVISIONING = 1;
+    // The device has successfully provisioned its keybox.
+    OKP_PROVISIONED = 2;
+  }
+  // Device-wide OKP state.
+  optional OkpDeviceState state = 1;
+  // Time when the CDM service first discovers that it needs to
+  // provision the L1 keybox.
+  optional int64 first_checked_time = 2;
+  // System time of when a successful provisioning request has been
+  // received.  Only relevant if |state| is OKP_PROVISIONED.
+  optional int64 provisioning_time = 3;
+  // A list of all records for each identifiable engine.
+  repeated OkpEngineInfo engine_infos = 4;
+}
+
 message File {
  enum FileType {
    DEVICE_CERTIFICATE = 1;
@@ -132,6 +197,7 @@ message File {
    USAGE_INFO = 3;
    HLS_ATTRIBUTES = 4;
    USAGE_TABLE_INFO = 5;
+    OKP_INFO = 6;
  }

  enum FileVersion { VERSION_1 = 1; }
@@ -143,6 +209,7 @@ message File {
  optional UsageInfo usage_info = 5;
  optional HlsAttributes hls_attributes = 6;
  optional UsageTableInfo usage_table_info = 7;
+  optional OtaKeyboxProvisioningInfo okp_info = 8;
 }

 message HashedFile {
--- a/libwvdrmengine/cdm/core/src/license.cpp
+++ b/libwvdrmengine/cdm/core/src/license.cpp
@@ -1046,7 +1046,8 @@ CdmResponseType CdmLicense::PrepareClientId(
    return CLIENT_TOKEN_NOT_SET;
  }

-  CdmResponseType status = id.Init(client_token_, crypto_session_);
+  CdmResponseType status =
+      id.InitForLicenseRequest(client_token_, crypto_session_);
  if (status != NO_ERROR) return status;

  video_widevine::ClientIdentification* client_id =
--- a/libwvdrmengine/cdm/core/src/license_protocol.proto
+++ b/libwvdrmengine/cdm/core/src/license_protocol.proto
@@ -532,6 +532,14 @@ message ProvisioningRequest {
    // Serialized, encrypted session keys.  Required.
    optional bytes encrypted_session_keys = 2;
  }
+  // This message contains the custom serialized message for OTA provisioning
+  // using Android Attestation and a device id as authentication.
+  message AndroidAttestationOtaKeyboxRequest {
+    // The request contains custom serialized and signed data for the
+    // Android Attestation OTA request.
+    optional bytes ota_request = 1;
+  }
+
  oneof clear_or_encrypted_client_id {
    // Device root of trust and other client identification. Required.
    ClientIdentification client_id = 1;
@@ -555,6 +563,8 @@ message ProvisioningRequest {
  // SessionKeys encrypted using a service cert public key.
  // Required for keybox provisioning.
  optional EncryptedSessionKeys encrypted_session_keys = 8;
+  // The custom request for Android Attestation OTA.
+  optional AndroidAttestationOtaKeyboxRequest android_ota_keybox_request = 9;
 }

 // Provisioning response sent by the provisioning server to client devices.
@@ -579,6 +589,14 @@ message ProvisioningResponse {
    // Devices in this series have been revoked. Provisioning is not possible.
    REVOKED_DEVICE_SERIES = 2;
  }
+  // This message contains the custom response for Android Attestation OTA
+  // provisioning which uses the Android Attestation keybox and a device id
+  // from the chip set.
+  message AndroidAttestationOtaKeyboxResponse {
+    // The response contains custom serialized and signed data for the
+    // Android Attestation OTA keybox provisioning.
+    optional bytes ota_response = 1;
+  }

  // AES-128 encrypted device private RSA key. PKCS#1 ASN.1 DER-encoded.
  // Required. For X.509 certificates, the private RSA key may also include
@@ -603,6 +621,9 @@ message ProvisioningResponse {
  // than |status| may be empty and should be ignored if the |status|
  // is present and not NO_ERROR
  optional ProvisioningStatus status = 7;
+  // The Android Attestation OTA response. Only populated if the request
+  // was an Android Attestation OTA request.
+  optional AndroidAttestationOtaKeyboxResponse android_ota_keybox_response = 8;
 }

 // Protocol-specific context data used to hold the state of the server in
@@ -654,6 +675,8 @@ message SignedProvisioningMessage {
    PROVISIONING_20 = 2;              // Keybox factory-provisioned devices.
    PROVISIONING_30 = 3;     // OEM certificate factory-provisioned devices.
    ARCPP_PROVISIONING = 4;  // ChromeOS/Arc++ devices.
+    // Android-Attestation-based OTA keyboxes.
+    ANDROID_ATTESTATION_KEYBOX_OTA = 6;
    INTEL_SIGMA_101 = 101;   // Intel Sigma 1.0.1 protocol.
  }

--- a/libwvdrmengine/cdm/core/src/ota_keybox_provisioner.cpp
+++ b/libwvdrmengine/cdm/core/src/ota_keybox_provisioner.cpp
@@ -0,0 +1,83 @@
+// Copyright 2021 Google LLC. All Rights Reserved. This file and proprietary
+// source code may only be used and distributed under the Widevine License
+// Agreement.
+#include "ota_keybox_provisioner.h"
+
+#include <utility>
+
+#include "crypto_session.h"
+#include "log.h"
+#include "string_conversions.h"
+
+namespace wvcdm {
+using UniqueLock = std::unique_lock<std::mutex>;
+namespace {
+// Indicates not to use the test keybox for OTA provisioning.
+constexpr bool kProductionKeybox = false;
+}  // namespace
+
+// static
+std::unique_ptr<OtaKeyboxProvisioner> OtaKeyboxProvisioner::Create() {
+  return std::unique_ptr<OtaKeyboxProvisioner>(new OtaKeyboxProvisioner());
+}
+
+OtaKeyboxProvisioner::OtaKeyboxProvisioner() : mutex_() {}
+
+OtaKeyboxProvisioner::~OtaKeyboxProvisioner() {}
+
+CdmResponseType OtaKeyboxProvisioner::GenerateProvisioningRequest(
+    CryptoSession* crypto_session, std::string* request) {
+  if (crypto_session == nullptr) {
+    LOGE("Input |crypto_session| is null");
+    return PARAMETER_NULL;
+  }
+  if (request == nullptr) {
+    LOGE("Output |request| is null");
+    return PARAMETER_NULL;
+  }
+  UniqueLock lock(mutex_);
+  // Do not generate new requests if already provisioned.
+  if (IsProvisioned()) {
+    LOGW("Already provisioned");
+    // TODO(sigquit): Use a response code that will indicate to the
+    // caller that the system is already provisioned.
+    return UNKNOWN_ERROR;
+  }
+  const CdmResponseType result =
+      crypto_session->PrepareOtaProvisioningRequest(kProductionKeybox, request);
+  if (result != NO_ERROR) {
+    return result;
+  }
+  LOGV("OTA request generated: request = %s", b2a_hex(*request).c_str());
+  request_count_++;
+  return NO_ERROR;
+}
+
+CdmResponseType OtaKeyboxProvisioner::HandleProvisioningResponse(
+    CryptoSession* crypto_session, const std::string& response) {
+  if (crypto_session == nullptr) {
+    LOGE("Input |crypto_session| is null");
+    return PARAMETER_NULL;
+  }
+  if (response.empty()) {
+    LOGE("OTA provisioning response is empty");
+    return EMPTY_PROVISIONING_RESPONSE;
+  }
+  UniqueLock lock(mutex_);
+  if (IsProvisioned()) {
+    // Response already received, silently dropping.
+    response_count_++;
+    return NO_ERROR;
+  }
+  const CdmResponseType result =
+      crypto_session->LoadOtaProvisioning(kProductionKeybox, response);
+  if (result != NO_ERROR) {
+    return result;
+  }
+  LOGD("OTA response successfully processed: response = %s",
+       b2a_hex(response).c_str());
+  is_provisioned_ = true;
+  response_count_ = 1;
+  return NO_ERROR;
+}
+}  // namespace wvcdm
--- a/libwvdrmengine/cdm/core/test/ota_keybox_provisioner_test.cpp
+++ b/libwvdrmengine/cdm/core/test/ota_keybox_provisioner_test.cpp
@@ -0,0 +1,242 @@
+// Copyright 2021 Google LLC. All Rights Reserved. This file and proprietary
+// source code may only be used and distributed under the Widevine License
+// Agreement.
+#include "ota_keybox_provisioner.h"
+
+#include <gmock/gmock.h>
+#include <gtest/gtest.h>
+
+#include "crypto_session.h"
+
+namespace wvcdm {
+using ::testing::DoAll;
+using ::testing::NotNull;
+using ::testing::Return;
+using ::testing::SetArgPointee;
+namespace {
+const std::string kEmptyString;
+const std::string kFakeOtaProvisioningRequest =
+    "Totally real device ID, not fake"   // Device ID : 32 bytes
+    "Totally real model ID, also real"   // Model ID : 32 bytes
+    "Super secure key"                   // Encryped session key : 16 bytes
+    "Undoubtedly authentic signature!";  // Signature : 32 bytes
+
+const std::string kFakeOtaProvisioningResponse =
+    "Definitely an IV"  // IV : 16 bytes
+    // Keybox : 128 bytes
+    "I'm a keybox, look at my keys and box-like appearance [].  You might "
+    "be thinking 'you are not a real keybox', but you'd be wrong"
+    "Scribble scribble dot slash dot ";  // Signature : 32 bytes
+
+const std::string kAnotherFakeOtaProvisioningResponse =
+    "Looks like an IV"  // IV : 16 bytes
+    // Keybox : 128 bytes
+    "I am also a keybox.  It's so safe to assume I'm a real keybox that "
+    "attempting to verify that will look very embarrassing for you"
+    "A drawing of boat with dolphins ";  // Signature : 32 bytes
+
+class MockCryptoSession : public CryptoSession {
+ public:
+  MockCryptoSession() : CryptoSession(&crypto_metrics_) {}
+  ~MockCryptoSession() {}
+
+  bool IsOpen() override { return is_open_; }
+  void SetIsOpen(bool is_open) { is_open_ = is_open; }
+
+  MOCK_METHOD2(PrepareOtaProvisioningRequest,
+               CdmResponseType(bool, std::string*));
+  MOCK_METHOD2(LoadOtaProvisioning, CdmResponseType(bool, const std::string&));
+
+  void ExpectRequest(const std::string& request, CdmResponseType result) {
+    if (result == NO_ERROR) {
+      EXPECT_CALL(*this, PrepareOtaProvisioningRequest(false, NotNull()))
+          .WillOnce(DoAll(SetArgPointee<1>(request), Return(NO_ERROR)));
+    } else {
+      EXPECT_CALL(*this, PrepareOtaProvisioningRequest(false, NotNull()))
+          .WillOnce(Return(result));
+    }
+  }
+
+  void ExpectResponse(const std::string& response, CdmResponseType result) {
+    EXPECT_CALL(*this, LoadOtaProvisioning(false, response))
+        .WillOnce(Return(result));
+  }
+
+ private:
+  bool is_open_ = false;
+
+  static metrics::CryptoMetrics crypto_metrics_;
+};
+
+metrics::CryptoMetrics MockCryptoSession::crypto_metrics_;
+}  // namespace
+
+class OtaKeyboxProvisionerTest : public ::testing::Test {
+ protected:
+  void SetUp() override {
+    crypto_session_.reset(new MockCryptoSession());
+    provisioner_ = OtaKeyboxProvisioner::Create();
+  }
+
+  void TearDown() override {
+    crypto_session_.reset();
+    provisioner_.reset();
+  }
+
+  std::unique_ptr<MockCryptoSession> crypto_session_;
+  std::unique_ptr<OtaKeyboxProvisioner> provisioner_;
+};
+
+TEST_F(OtaKeyboxProvisionerTest, SingleRequestSingleResponse) {
+  // Pre-request conditions.
+  EXPECT_FALSE(provisioner_->IsProvisioned());
+  EXPECT_EQ(0u, provisioner_->request_count());
+  EXPECT_EQ(0u, provisioner_->response_count());
+
+  // Generate request.
+  crypto_session_->ExpectRequest(kFakeOtaProvisioningRequest, NO_ERROR);
+  std::string request;
+  EXPECT_EQ(NO_ERROR, provisioner_->GenerateProvisioningRequest(
+                          crypto_session_.get(), &request));
+  EXPECT_EQ(request, kFakeOtaProvisioningRequest);
+
+  // Post-request, pre-response conditions.
+  EXPECT_FALSE(provisioner_->IsProvisioned());
+  EXPECT_EQ(1u, provisioner_->request_count());
+  EXPECT_EQ(0u, provisioner_->response_count());
+
+  // Load response.
+  const std::string response = kFakeOtaProvisioningResponse;
+  crypto_session_->ExpectResponse(response, NO_ERROR);
+  EXPECT_EQ(NO_ERROR, provisioner_->HandleProvisioningResponse(
+                          crypto_session_.get(), response));
+
+  // Post-response conditions.
+  EXPECT_TRUE(provisioner_->IsProvisioned());
+  EXPECT_EQ(1u, provisioner_->request_count());
+  EXPECT_EQ(1u, provisioner_->response_count());
+}
+
+TEST_F(OtaKeyboxProvisionerTest, MultipleRequestsMultipleResponse) {
+  // Generate first request.
+  crypto_session_->ExpectRequest(kFakeOtaProvisioningRequest, NO_ERROR);
+  std::string first_request;
+  EXPECT_EQ(NO_ERROR, provisioner_->GenerateProvisioningRequest(
+                          crypto_session_.get(), &first_request));
+  EXPECT_EQ(first_request, kFakeOtaProvisioningRequest);
+
+  // Generate second request.
+  crypto_session_->ExpectRequest(kFakeOtaProvisioningRequest, NO_ERROR);
+  std::string second_request;
+  EXPECT_EQ(NO_ERROR, provisioner_->GenerateProvisioningRequest(
+                          crypto_session_.get(), &second_request));
+  EXPECT_EQ(second_request, kFakeOtaProvisioningRequest);
+
+  EXPECT_FALSE(provisioner_->IsProvisioned());
+  EXPECT_EQ(2u, provisioner_->request_count());
+  EXPECT_EQ(0u, provisioner_->response_count());
+
+  // Load first response.
+  const std::string first_response = kFakeOtaProvisioningResponse;
+  crypto_session_->ExpectResponse(first_response, NO_ERROR);
+  EXPECT_EQ(NO_ERROR, provisioner_->HandleProvisioningResponse(
+                          crypto_session_.get(), first_response));
+
+  // Loading second response should be silently dropped.
+  // No call to CryptoSession.
+  const std::string second_response = kAnotherFakeOtaProvisioningResponse;
+  EXPECT_EQ(NO_ERROR, provisioner_->HandleProvisioningResponse(
+                          crypto_session_.get(), second_response));
+
+  // Post-response conditions.
+  EXPECT_TRUE(provisioner_->IsProvisioned());
+  EXPECT_EQ(2u, provisioner_->request_count());
+  EXPECT_EQ(2u, provisioner_->response_count());
+}
+
+TEST_F(OtaKeyboxProvisionerTest, NullRequestParameters) {
+  // Null CryptoSession
+  std::string request;
+  EXPECT_NE(NO_ERROR,
+            provisioner_->GenerateProvisioningRequest(nullptr, &request));
+
+  // Null request, no call to CryptoSession.
+  EXPECT_NE(NO_ERROR, provisioner_->GenerateProvisioningRequest(
+                          crypto_session_.get(), nullptr));
+  // Counter should not increase.
+  EXPECT_FALSE(provisioner_->IsProvisioned());
+  EXPECT_EQ(0u, provisioner_->request_count());
+  EXPECT_EQ(0u, provisioner_->response_count());
+}
+
+TEST_F(OtaKeyboxProvisionerTest, EmptyRequest) {
+  // Generate request.
+  crypto_session_->ExpectRequest(kFakeOtaProvisioningRequest, NO_ERROR);
+  std::string request;
+  EXPECT_EQ(NO_ERROR, provisioner_->GenerateProvisioningRequest(
+                          crypto_session_.get(), &request));
+
+  // Attempt to load empty response.  No call to CryptoSession.
+  const std::string response = "";
+  EXPECT_NE(NO_ERROR, provisioner_->HandleProvisioningResponse(
+                          crypto_session_.get(), response));
+
+  EXPECT_FALSE(provisioner_->IsProvisioned());
+  EXPECT_EQ(1u, provisioner_->request_count());
+  EXPECT_EQ(0u, provisioner_->response_count());
+}
+
+TEST_F(OtaKeyboxProvisionerTest, OtaProvisioningNotImplemented) {
+  // Generate request.
+  crypto_session_->ExpectRequest(kEmptyString, NOT_IMPLEMENTED_ERROR);
+  std::string request;
+  EXPECT_EQ(NOT_IMPLEMENTED_ERROR, provisioner_->GenerateProvisioningRequest(
+                                       crypto_session_.get(), &request));
+  // Counter should not increase.
+  EXPECT_FALSE(provisioner_->IsProvisioned());
+  EXPECT_EQ(0u, provisioner_->request_count());
+  EXPECT_EQ(0u, provisioner_->response_count());
+}
+
+TEST_F(OtaKeyboxProvisionerTest, ResponseRejected) {
+  // Generate request.
+  crypto_session_->ExpectRequest(kFakeOtaProvisioningRequest, NO_ERROR);
+  std::string request;
+  EXPECT_EQ(NO_ERROR, provisioner_->GenerateProvisioningRequest(
+                          crypto_session_.get(), &request));
+
+  // Attempt to load response.  OEMCrypto rejects response.
+  const std::string response = kFakeOtaProvisioningResponse;
+  crypto_session_->ExpectResponse(response, UNKNOWN_ERROR);
+  EXPECT_NE(NO_ERROR, provisioner_->HandleProvisioningResponse(
+                          crypto_session_.get(), response));
+
+  // Should not be provisioned.
+  EXPECT_FALSE(provisioner_->IsProvisioned());
+  EXPECT_EQ(1u, provisioner_->request_count());
+  EXPECT_EQ(0u, provisioner_->response_count());
+}
+
+TEST_F(OtaKeyboxProvisionerTest, GenerateRequestAfterProvisioning) {
+  // Generate request.
+  crypto_session_->ExpectRequest(kFakeOtaProvisioningRequest, NO_ERROR);
+  std::string first_request;
+  EXPECT_EQ(NO_ERROR, provisioner_->GenerateProvisioningRequest(
+                          crypto_session_.get(), &first_request));
+
+  // Load response.
+  const std::string response = kFakeOtaProvisioningResponse;
+  crypto_session_->ExpectResponse(response, NO_ERROR);
+  EXPECT_EQ(NO_ERROR, provisioner_->HandleProvisioningResponse(
+                          crypto_session_.get(), response));
+
+  // Attempt to generate second request.  Should fail.
+  std::string second_request;
+  EXPECT_NE(NO_ERROR, provisioner_->GenerateProvisioningRequest(
+                          crypto_session_.get(), &second_request));
+
+  EXPECT_TRUE(provisioner_->IsProvisioned());
+  EXPECT_EQ(1u, provisioner_->request_count());
+  EXPECT_EQ(1u, provisioner_->response_count());
+}
+}  // namespace wvcdm