From 0947bd185bd9da6cffd937505ec24cbb52310677 Mon Sep 17 00:00:00 2001
From: Fred Gylys-Colwell <fredgc@google.com>
Date: Wed, 26 Feb 2020 13:14:20 -0800
Subject: [PATCH] Fix nonce problem in license renewal

Merge from Widevine repo of http://go/wvgerrit/94523

For OEMCrypto v16, a renewal does not get a new nonce.

Bug: 149856581
Test: WvCdmRequestLicenseTest.StreamingLicenseRenewal
Change-Id: I258f0bcb9c9a417310785f130d32d66fa7430185
---
 libwvdrmengine/cdm/core/src/license.cpp | 34 +++++++++++++++----------
 1 file changed, 20 insertions(+), 14 deletions(-)

diff --git a/libwvdrmengine/cdm/core/src/license.cpp b/libwvdrmengine/cdm/core/src/license.cpp
index 9549f0cd..d8c8c4a9 100644
--- a/libwvdrmengine/cdm/core/src/license.cpp
+++ b/libwvdrmengine/cdm/core/src/license.cpp
@@ -457,19 +457,25 @@ CdmResponseType CdmLicense::PrepareKeyUpdateRequest(
     current_license->set_seconds_since_last_played(seconds_since_last_played);
   }
 
-  // Get/set the nonce.  This value will be reflected in the Key Control Block
-  // of the license response.
-  uint32_t nonce;
-  CdmResponseType status = crypto_session_->GenerateNonce(&nonce);
-
-  switch (status) {
-    case NO_ERROR:
-      break;
-    case SESSION_LOST_STATE_ERROR:
-    case SYSTEM_INVALIDATED_ERROR:
-      return status;
-    default:
-      return LICENSE_RENEWAL_NONCE_GENERATION_ERROR;
+  uint32_t api_version = 0;
+  if (!crypto_session_->GetApiVersion(&api_version)) {
+    LOGW("Unknown API Version");
+    api_version = 15;
+  }
+  uint32_t nonce = 0;
+  if (api_version < 16) {
+    // For a pre-v16 license, get/set the nonce.  This value will be reflected
+    // in the Key Control Block of the license response.
+    const CdmResponseType status = crypto_session_->GenerateNonce(&nonce);
+    switch (status) {
+      case NO_ERROR:
+        break;
+      case SESSION_LOST_STATE_ERROR:
+      case SYSTEM_INVALIDATED_ERROR:
+        return status;
+      default:
+        return LICENSE_RENEWAL_NONCE_GENERATION_ERROR;
+    }
   }
   license_request.set_key_control_nonce(nonce);
   LOGD("nonce = %u", nonce);
@@ -482,7 +488,7 @@ CdmResponseType CdmLicense::PrepareKeyUpdateRequest(
   // Construct signature and core message.
   std::string core_message;
   std::string license_request_signature;
-  status = crypto_session_->PrepareAndSignRenewalRequest(
+  const CdmResponseType status = crypto_session_->PrepareAndSignRenewalRequest(
       serialized_license_req, &core_message, &license_request_signature);
   if (status != NO_ERROR) return status;