diff --git a/libwvdrmengine/oemcrypto/ref/src/oemcrypto_auth_ref.cpp b/libwvdrmengine/oemcrypto/ref/src/oemcrypto_auth_ref.cpp
index 5b92ee0a..1473d3ea 100644
--- a/libwvdrmengine/oemcrypto/ref/src/oemcrypto_auth_ref.cpp
+++ b/libwvdrmengine/oemcrypto/ref/src/oemcrypto_auth_ref.cpp
@@ -177,6 +177,9 @@ static const uint8_t kTestRSAPKCS8PrivateKeyInfo2_2048[] = {
   0x72, 0x2c, 0xf7, 0xc1, 0x22, 0x36, 0xd9, 0x18,
   0x56, 0xfe, 0x39, 0x28, 0x33, 0xe0, 0xdb, 0x03
 };
+
+// Filler for returning vector references.
+const std::vector<uint8_t> kEmptyVector;
 }  // namespace
 
 bool AuthenticationRoot::Initialize(OEMCrypto_ProvisioningMethod method) {
@@ -184,12 +187,10 @@ bool AuthenticationRoot::Initialize(OEMCrypto_ProvisioningMethod method) {
     // If provisioning method is something other than ProvisioningError
     // indicates it has already been initialized before.  Must
     // existing data.
-    drm_cert_key_.reset();
-    test_drm_cert_key_.reset();
+    rsa_key_.reset();
+    test_rsa_key_.reset();
     keybox_.reset();
     test_keybox_.reset();
-    oem_cert_.reset();
-    oem_cert_key_.reset();
   }
   prov_method_ = method;
   switch (method) {
@@ -197,7 +198,7 @@ bool AuthenticationRoot::Initialize(OEMCrypto_ProvisioningMethod method) {
       std::unique_ptr<RsaPrivateKey> key =
           RsaPrivateKey::Load(kPrivateKey, kPrivateKeySize);
       if (key) {
-        drm_cert_key_ = std::move(key);
+        rsa_key_ = std::move(key);
       } else {
         // This error message is OK in unit tests which use test certificate.
         LOGE(
@@ -229,7 +230,8 @@ bool AuthenticationRoot::IsValid() const {
       return HasDeviceKey();
     }
     case OEMCrypto_OEMCertificate: {
-      return HasOemCertKey() && HasDeviceKey();
+      // TODO(sigquit): Add OEM Certificate validation.
+      return true;
     }
     default: {
       LOGE("Root of trust is not properly initialized");
@@ -249,11 +251,8 @@ OEMCryptoResult AuthenticationRoot::IsKeyboxOrOemCertValid() const {
       return kb->IsKeyboxValid();
     }
     case OEMCrypto_OEMCertificate: {
-      if (!oem_cert_) {
-        LOGW("OEM cert is not installed");
-        return OEMCrypto_ERROR_UNKNOWN_FAILURE;
-      }
-      return oem_cert_->IsCertificateValid();
+      LOGW("OEM certificate validation is not implemented");
+      return OEMCrypto_ERROR_NOT_IMPLEMENTED;
     }
     case OEMCrypto_DrmCertificate: {
       return OEMCrypto_ERROR_NOT_IMPLEMENTED;
@@ -301,7 +300,7 @@ std::vector<uint8_t> AuthenticationRoot::DeviceId() const {
   }
   if (prov_method_ == OEMCrypto_Keybox) {
     LOGE("Expected keybox to be set for a device ID");
-    return std::vector<uint8_t>();
+    return kEmptyVector;
   }
   return std::vector<uint8_t>(kFakeDeviceId.begin(), kFakeDeviceId.end());
 }
@@ -312,7 +311,7 @@ std::vector<uint8_t> AuthenticationRoot::DeviceKey() const {
     return kb->DeviceKey();
   }
   LOGE("No device key has been set");
-  return std::vector<uint8_t>();
+  return kEmptyVector;
 }
 
 bool AuthenticationRoot::HasDeviceKey() const { return keybox() != nullptr; }
@@ -327,7 +326,7 @@ OEMCryptoResult AuthenticationRoot::LoadTestRsaKey() {
     LOGE("System does not support DRM certificates");
     return OEMCrypto_ERROR_NOT_IMPLEMENTED;
   }
-  if (test_drm_cert_key_) {
+  if (test_rsa_key_) {
     LOGE("Test RSA key is already loaded");
     return OEMCrypto_ERROR_INSUFFICIENT_RESOURCES;
   }
@@ -338,7 +337,7 @@ OEMCryptoResult AuthenticationRoot::LoadTestRsaKey() {
     LOGE("Failed to load test RSA key");
     return OEMCrypto_ERROR_UNKNOWN_FAILURE;
   }
-  test_drm_cert_key_ = std::move(key);
+  test_rsa_key_ = std::move(key);
   return OEMCrypto_SUCCESS;
 }
 
@@ -400,48 +399,22 @@ OEMCryptoResult AuthenticationRoot::GetKeyData(uint8_t* key_data,
   return kb->GetKeyData(key_data, key_data_length);
 }
 
-OEMCryptoResult AuthenticationRoot::InstallOemCertificate(
-    const uint8_t* private_key, size_t private_key_size,
-    const uint8_t* public_cert, size_t public_cert_size) {
-  if (prov_method_ != OEMCrypto_OEMCertificate) {
-    LOGE("System does not support OEM certificates");
-    return OEMCrypto_ERROR_NOT_IMPLEMENTED;
-  }
-  if (oem_cert_ || oem_cert_key_) {
-    LOGE("OEM certificate is already installed");
-    return OEMCrypto_ERROR_INSUFFICIENT_RESOURCES;
-  }
-  std::unique_ptr<OemCertificate> oem_cert = OemCertificate::Create(
-      private_key, private_key_size, public_cert, public_cert_size);
-  if (!oem_cert) {
-    LOGE("Failed to install OEM certificate as root of trust");
-    return OEMCrypto_ERROR_UNKNOWN_FAILURE;
-  }
-  if (oem_cert->key_type() != OemCertificate::kRsa) {
-    LOGE("Only RSA-based OEM certificates supported");
-    return OEMCrypto_ERROR_UNKNOWN_FAILURE;
-  }
-  std::unique_ptr<RsaPrivateKey> oem_cert_key =
-      RsaPrivateKey::Load(oem_cert->GetPrivateKey());
-  if (!oem_cert_key) {
-    LOGE("Failed to parse OEM certificate private key");
-    return OEMCrypto_ERROR_INVALID_RSA_KEY;
-  }
-  oem_cert_ = std::move(oem_cert);
-  oem_cert_key_ = std::move(oem_cert_key);
-  return OEMCrypto_SUCCESS;
-}
-
 OEMCryptoResult AuthenticationRoot::GetOemPublicCertificate(
     uint8_t* public_cert, size_t* public_cert_length) const {
   if (prov_method_ != OEMCrypto_OEMCertificate) {
     LOGE("System does not support OEM certificates");
     return OEMCrypto_ERROR_NOT_IMPLEMENTED;
   }
-  if (!oem_cert_) {
-    LOGE("OEM certificate is not installed");
-    return OEMCrypto_ERROR_UNKNOWN_FAILURE;
+  LOGE("OEM certificates have not been implemented on auth root");
+  return OEMCrypto_ERROR_NOT_IMPLEMENTED;
+}
+
+const std::vector<uint8_t>& AuthenticationRoot::GetOemPrivateKey() const {
+  if (prov_method_ != OEMCrypto_OEMCertificate) {
+    LOGE("System does not support OEM certificates");
+    return kEmptyVector;
   }
-  return oem_cert_->GetPublicCertificate(public_cert, public_cert_length);
+  LOGE("OEM certificates have not been implemented on auth root");
+  return kEmptyVector;
 }
 }  // namespace wvoec_ref
diff --git a/libwvdrmengine/oemcrypto/ref/src/oemcrypto_auth_ref.h b/libwvdrmengine/oemcrypto/ref/src/oemcrypto_auth_ref.h
index c2a88dcd..aa898886 100644
--- a/libwvdrmengine/oemcrypto/ref/src/oemcrypto_auth_ref.h
+++ b/libwvdrmengine/oemcrypto/ref/src/oemcrypto_auth_ref.h
@@ -15,7 +15,6 @@
 #include "OEMCryptoCENC.h"  // Needed for enums only.
 #include "disallow_copy_and_assign.h"
 #include "oemcrypto_keybox_ref.h"
-#include "oemcrypto_oem_cert.h"
 #include "oemcrypto_rsa_key.h"
 
 namespace wvoec_ref {
@@ -68,12 +67,12 @@ class AuthenticationRoot {
   // Returns the shared RSA private key from the built-in DRM
   // Certificate.
   std::shared_ptr<RsaPrivateKey> ShareDrmCertKey() {
-    return test_drm_cert_key_ ? test_drm_cert_key_ : drm_cert_key_;
+    return test_rsa_key_ ? test_rsa_key_ : rsa_key_;
   }
   RsaPrivateKey* DrmCertKey() const {
-    return test_drm_cert_key_ ? test_drm_cert_key_.get() : drm_cert_key_.get();
+    return test_rsa_key_ ? test_rsa_key_.get() : rsa_key_.get();
   }
-  bool HasDrmCertKey() const { return test_drm_cert_key_ || drm_cert_key_; }
+  bool HasDrmCertKey() const { return test_rsa_key_ || rsa_key_; }
 
   // Loads the system's built-in RSA key.  Only implemented for
   // devices that are that pre-provisioned with a built-in DRM
@@ -83,7 +82,7 @@ class AuthenticationRoot {
   OEMCryptoResult LoadTestRsaKey();
 
   // Removes any installed test RSA key.
-  void RemoveTestRsaKey() { test_drm_cert_key_.reset(); }
+  void RemoveTestRsaKey() { test_rsa_key_.reset(); }
 
   // Keybox-based root of trust API.
 
@@ -125,14 +124,6 @@ class AuthenticationRoot {
 
   // OEM Certificate-base root of trust API.
 
-  // Installs an OEM certificate as the root of trust.  The provided
-  // private key and public cert are parsed, but not validated. The
-  // private key will be made available for sessions to load.
-  OEMCryptoResult InstallOemCertificate(const uint8_t* private_key,
-                                        size_t private_key_size,
-                                        const uint8_t* public_cert,
-                                        size_t public_cert_size);
-
   // For OEM Cert-based devices, returns the OEM Public Certificate
   // component of the OEM Certificate.
   // This method implements the expected behavior of
@@ -144,9 +135,7 @@ class AuthenticationRoot {
   // the OEM private key into a session.
   // Should only be called for devices that use OEM Certificates
   // for provisioning.
-  std::shared_ptr<RsaPrivateKey> ShareOemCertKey() { return oem_cert_key_; }
-  RsaPrivateKey* OemCertKey() const { return oem_cert_key_.get(); }
-  bool HasOemCertKey() const { return static_cast<bool>(oem_cert_key_); }
+  const std::vector<uint8_t>& GetOemPrivateKey() const;
 
  private:
   OEMCrypto_ProvisioningMethod prov_method_ = OEMCrypto_ProvisioningError;
@@ -154,17 +143,13 @@ class AuthenticationRoot {
   // DRM certificate.
   // If no keybox, this is the private key of the baked-in DRM
   // Certificate.
-  std::shared_ptr<RsaPrivateKey> drm_cert_key_;
-  std::shared_ptr<RsaPrivateKey> test_drm_cert_key_;
+  std::shared_ptr<RsaPrivateKey> rsa_key_;
+  std::shared_ptr<RsaPrivateKey> test_rsa_key_;
 
   // Keybox data.
   std::unique_ptr<WvKeybox> keybox_;
   std::unique_ptr<WvKeybox> test_keybox_;
 
-  // OEM certificate.
-  std::unique_ptr<OemCertificate> oem_cert_;
-  std::shared_ptr<RsaPrivateKey> oem_cert_key_;
-
   CORE_DISALLOW_COPY_AND_ASSIGN(AuthenticationRoot);
 };
 }  // namespace wvoec_ref
diff --git a/libwvdrmengine/oemcrypto/ref/src/oemcrypto_engine_device_properties_prov30.cpp b/libwvdrmengine/oemcrypto/ref/src/oemcrypto_engine_device_properties_prov30.cpp
index d2115ca1..0a2fc0dc 100644
--- a/libwvdrmengine/oemcrypto/ref/src/oemcrypto_engine_device_properties_prov30.cpp
+++ b/libwvdrmengine/oemcrypto/ref/src/oemcrypto_engine_device_properties_prov30.cpp
@@ -24,15 +24,6 @@ class Prov30CryptoEngine : public CryptoEngine {
   explicit Prov30CryptoEngine(std::unique_ptr<wvcdm::FileSystem>&& file_system)
       : CryptoEngine(std::move(file_system)) {}
 
-  bool Initialize() override {
-    if (!CryptoEngine::Initialize()) {
-      return false;
-    }
-    const OEMCryptoResult result = InstallOemCertificate(
-        kOEMPrivateKey, kOEMPrivateKeySize, kOEMPublicCert, kOEMPublicCertSize);
-    return result == OEMCrypto_SUCCESS;
-  }
-
   bool config_local_display_only() { return true; }
 
   // Returns the max HDCP version supported.
@@ -56,6 +47,31 @@ class Prov30CryptoEngine : public CryptoEngine {
     return OEMCrypto_OEMCertificate;
   }
 
+  OEMCryptoResult get_oem_certificate(SessionContext* session,
+                                      uint8_t* public_cert,
+                                      size_t* public_cert_length) {
+    if (kOEMPublicCertSize == 0) {
+      return OEMCrypto_ERROR_NOT_IMPLEMENTED;
+    }
+    if (public_cert_length == nullptr) {
+      return OEMCrypto_ERROR_UNKNOWN_FAILURE;
+    }
+    if (*public_cert_length < kOEMPublicCertSize) {
+      *public_cert_length = kOEMPublicCertSize;
+      return OEMCrypto_ERROR_SHORT_BUFFER;
+    }
+    *public_cert_length = kOEMPublicCertSize;
+    if (public_cert == nullptr) {
+      return OEMCrypto_ERROR_SHORT_BUFFER;
+    }
+    memcpy(public_cert, kOEMPublicCert, kOEMPublicCertSize);
+    if (!session->LoadRsaDrmKey(kOEMPrivateKey, kOEMPrivateKeySize)) {
+      LOGE("Private RSA Key did not load correctly.");
+      return OEMCrypto_ERROR_INVALID_RSA_KEY;
+    }
+    return OEMCrypto_SUCCESS;
+  }
+
   // Returns "L3" for a software only library.  L1 is for hardware protected
   // keys and data paths.  L2 is for hardware protected keys but no data path
   // protection.
diff --git a/libwvdrmengine/oemcrypto/ref/src/oemcrypto_engine_ref.h b/libwvdrmengine/oemcrypto/ref/src/oemcrypto_engine_ref.h
index f7f92c14..150fdf96 100644
--- a/libwvdrmengine/oemcrypto/ref/src/oemcrypto_engine_ref.h
+++ b/libwvdrmengine/oemcrypto/ref/src/oemcrypto_engine_ref.h
@@ -75,8 +75,8 @@ class CryptoEngine {
 
   OEMCryptoResult LoadTestRsaKey() { return root_of_trust_.LoadTestRsaKey(); }
 
-  OEMCryptoResult IsKeyboxOrOemCertValid() const {
-    return root_of_trust_.IsKeyboxOrOemCertValid();
+  OEMCryptoResult IsKeyboxValid() const {
+    return root_of_trust_.IsKeyboxValid();
   }
 
   std::vector<uint8_t> DeviceRootKey() const {
@@ -97,26 +97,6 @@ class CryptoEngine {
     return root_of_trust_.GetKeyData(key_data, key_data_length);
   }
 
-  OEMCryptoResult InstallOemCertificate(const uint8_t* private_key,
-                                        size_t private_key_size,
-                                        const uint8_t* public_cert,
-                                        size_t public_cert_size) {
-    return root_of_trust_.InstallOemCertificate(private_key, private_key_size,
-                                                public_cert, public_cert_size);
-  }
-
-  OEMCryptoResult GetOemPublicCertificate(uint8_t* public_cert,
-                                          size_t* public_cert_length) const {
-    return root_of_trust_.GetOemPublicCertificate(public_cert,
-                                                  public_cert_length);
-  }
-
-  std::shared_ptr<RsaPrivateKey> ShareOemPrivateKey() {
-    return root_of_trust_.ShareOemCertKey();
-  }
-
-  bool HasOemPrivateKey() const { return root_of_trust_.HasOemCertKey(); }
-
   virtual void Terminate();
 
   virtual SessionId OpenSession();
@@ -175,6 +155,15 @@ class CryptoEngine {
     return OEMCrypto_Keybox;
   }
 
+  virtual OEMCryptoResult get_oem_certificate(uint8_t* public_cert,
+                                              size_t* public_cert_length) {
+    return OEMCrypto_ERROR_NOT_IMPLEMENTED;
+  }
+
+  virtual OEMCryptoResult load_oem_private_key(SessionContext* session) {
+    return OEMCrypto_ERROR_NOT_IMPLEMENTED;
+  }
+
   // Used for OEMCrypto_IsAntiRollbackHwPresent.
   virtual bool config_is_anti_rollback_hw_present() { return false; }
 
diff --git a/libwvdrmengine/oemcrypto/ref/src/oemcrypto_ref.cpp b/libwvdrmengine/oemcrypto/ref/src/oemcrypto_ref.cpp
index 6aa2f19e..b2f3b63c 100644
--- a/libwvdrmengine/oemcrypto/ref/src/oemcrypto_ref.cpp
+++ b/libwvdrmengine/oemcrypto/ref/src/oemcrypto_ref.cpp
@@ -762,8 +762,10 @@ OEMCRYPTO_API OEMCryptoResult OEMCrypto_IsKeyboxOrOEMCertValid(void) {
     case OEMCrypto_DrmCertificate:
       return OEMCrypto_SUCCESS;
     case OEMCrypto_Keybox:
+      return crypto_engine->IsKeyboxValid();
     case OEMCrypto_OEMCertificate:
-      return crypto_engine->IsKeyboxOrOemCertValid();
+      // TODO(sigquit): verify that the certificate exists and is valid.
+      return OEMCrypto_SUCCESS;
     default:
       LOGE("Invalid provisioning method: %d.",
            crypto_engine->config_provisioning_method());
@@ -795,7 +797,7 @@ OEMCrypto_LoadOEMPrivateKey(OEMCrypto_SESSION session) {
     LOGE("OEMCrypto_ERROR_INVALID_SESSION");
     return OEMCrypto_ERROR_INVALID_SESSION;
   }
-  return session_ctx->LoadOemPrivateKey();
+  return crypto_engine->load_oem_private_key(session_ctx);
 }
 
 OEMCRYPTO_API OEMCryptoResult OEMCrypto_GetOEMPublicCertificate(
@@ -809,8 +811,7 @@ OEMCRYPTO_API OEMCryptoResult OEMCrypto_GetOEMPublicCertificate(
          crypto_engine->config_provisioning_method());
     return OEMCrypto_ERROR_NOT_IMPLEMENTED;
   }
-  return crypto_engine->GetOemPublicCertificate(public_cert,
-                                                public_cert_length);
+  return crypto_engine->get_oem_certificate(public_cert, public_cert_length);
 }
 
 OEMCRYPTO_API OEMCryptoResult OEMCrypto_GetDeviceID(uint8_t* device_id,
diff --git a/libwvdrmengine/oemcrypto/ref/src/oemcrypto_session.cpp b/libwvdrmengine/oemcrypto/ref/src/oemcrypto_session.cpp
index 657867aa..4ca614b9 100644
--- a/libwvdrmengine/oemcrypto/ref/src/oemcrypto_session.cpp
+++ b/libwvdrmengine/oemcrypto/ref/src/oemcrypto_session.cpp
@@ -296,15 +296,6 @@ OEMCryptoResult SessionContext::RSADeriveKeys(
   return DeriveKeys(session_key_, mac_key_context, enc_key_context);
 }
 
-OEMCryptoResult SessionContext::LoadOemPrivateKey() {
-  if (!ce_->HasOemPrivateKey()) {
-    LOGE("No OEM private key");
-    return OEMCrypto_ERROR_UNKNOWN_FAILURE;
-  }
-  rsa_key_ = ce_->ShareOemPrivateKey();
-  return OEMCrypto_SUCCESS;
-}
-
 OEMCryptoResult SessionContext::PrepAndSignLicenseRequest(
     uint8_t* message, size_t message_length, size_t* core_message_length,
     uint8_t* signature, size_t* signature_length) {
diff --git a/libwvdrmengine/oemcrypto/ref/src/oemcrypto_session.h b/libwvdrmengine/oemcrypto/ref/src/oemcrypto_session.h
index 8811b9eb..4ed6846e 100644
--- a/libwvdrmengine/oemcrypto/ref/src/oemcrypto_session.h
+++ b/libwvdrmengine/oemcrypto/ref/src/oemcrypto_session.h
@@ -75,9 +75,6 @@ class SessionContext {
       const std::vector<uint8_t>& enc_session_key,
       const std::vector<uint8_t>& mac_context,
       const std::vector<uint8_t>& enc_context);
-
-  virtual OEMCryptoResult LoadOemPrivateKey();
-
   virtual OEMCryptoResult PrepAndSignLicenseRequest(uint8_t* message,
                                                     size_t message_length,
                                                     size_t* core_message_length,
diff --git a/libwvdrmengine/oemcrypto/test/oec_session_util.cpp b/libwvdrmengine/oemcrypto/test/oec_session_util.cpp
index 243c7984..6a3b85cd 100644
--- a/libwvdrmengine/oemcrypto/test/oec_session_util.cpp
+++ b/libwvdrmengine/oemcrypto/test/oec_session_util.cpp
@@ -51,12 +51,67 @@ void PrintTo(const vector<uint8_t>& value, ostream* os) {
 }
 }  // namespace std
 
-namespace {
-constexpr size_t kTestSubsampleSectionSize = 256;
-}  // namespace
-
 namespace wvoec {
 
+namespace {
+
+constexpr size_t kTestSubsampleSectionSize = 256;
+
+// Encrypt a block of data using CTR mode.
+void EncryptCTR(const vector<uint8_t>& in_buffer, const uint8_t* key,
+                const uint8_t* starting_iv, vector<uint8_t>* out_buffer) {
+  ASSERT_NE(nullptr, key);
+  ASSERT_NE(nullptr, starting_iv);
+  ASSERT_NE(nullptr, out_buffer);
+  AES_KEY aes_key;
+  AES_set_encrypt_key(key, AES_BLOCK_SIZE * 8, &aes_key);
+  out_buffer->resize(in_buffer.size());
+
+  uint8_t iv[AES_BLOCK_SIZE];  // Current iv.
+
+  memcpy(iv, &starting_iv[0], AES_BLOCK_SIZE);
+  size_t l = 0;  // byte index into encrypted subsample.
+  while (l < in_buffer.size()) {
+    uint8_t aes_output[AES_BLOCK_SIZE];
+    AES_encrypt(iv, aes_output, &aes_key);
+    for (size_t n = 0; n < AES_BLOCK_SIZE && l < in_buffer.size(); n++, l++) {
+      (*out_buffer)[l] = aes_output[n] ^ in_buffer[l];
+    }
+    ctr128_inc64(1, iv);
+  }
+}
+
+// Uses OEMCrypto to decrypt some random data in 'cenc' mode. This function
+// assumes that the correct key is already selected in the session. It requires
+// the plaintext of that key so that it can encrypt the test data. It resizes
+// the provided vectors and fills them with the expected and actual decrypt
+// results. Returns the result of OEMCrypto_DecryptCENC().
+OEMCryptoResult DecryptCTR(OEMCrypto_SESSION session_id, const uint8_t* key,
+                           vector<uint8_t>* expected_data,
+                           vector<uint8_t>* actual_data) {
+  vector<uint8_t> encrypted_data(kTestSubsampleSectionSize);
+  expected_data->resize(encrypted_data.size());
+  actual_data->resize(encrypted_data.size());
+
+  // Create test sample description
+  OEMCrypto_SampleDescription sample_description;
+  OEMCrypto_SubSampleDescription subsample_description;
+  GenerateSimpleSampleDescription(encrypted_data, *actual_data,
+                                  &sample_description, &subsample_description);
+
+  // Generate test data
+  EXPECT_EQ(GetRandBytes(expected_data->data(), expected_data->size()), 1);
+  EncryptCTR(*expected_data, key, &sample_description.iv[0], &encrypted_data);
+
+  // Create the pattern description (always 0,0 for 'cenc')
+  OEMCrypto_CENCEncryptPatternDesc pattern = {0, 0};
+
+  // Decrypt the data
+  return OEMCrypto_DecryptCENC(session_id, &sample_description, 1, &pattern);
+}
+
+}  // namespace
+
 int GetRandBytes(unsigned char* buf, int num) {
   // returns 1 on success, -1 if not supported, or 0 if other failure.
   return RAND_bytes(buf, num);
@@ -70,9 +125,6 @@ void GenerateSimpleSampleDescription(
     const std::vector<uint8_t>& in, std::vector<uint8_t>& out,
     OEMCrypto_SampleDescription* sample,
     OEMCrypto_SubSampleDescription* subsample) {
-  ASSERT_NE(sample, nullptr);
-  ASSERT_NE(subsample, nullptr);
-
   // Generate test data
   EXPECT_EQ(GetRandBytes(&sample->iv[0], KEY_IV_SIZE), 1);
 
@@ -950,7 +1002,8 @@ void EntitledMessage::LoadKeys(OEMCryptoResult expected_sts) {
   if (expected_sts != OEMCrypto_SUCCESS) {
     return;
   }
-  VerifyEntitlementTestKeys();
+  VerifyKCBs();
+  VerifyDecrypt();
 }
 
 OEMCryptoResult EntitledMessage::LoadKeys(const vector<uint8_t>& message) {
@@ -997,11 +1050,11 @@ void EntitledMessage::EncryptContentKey() {
   }
 }
 
-// This function verifies that the key control block reported by OEMCrypto agree
-// with the truth key control block.  Failures in this function probably
+// This function verifies that the key control blocks reported by OEMCrypto
+// agree with the truth key control block.  Failures in this function probably
 // indicate the OEMCrypto_LoadEntitledKeys did not correctly process the key
 // control block.
-void EntitledMessage::VerifyEntitlementTestKeys() {
+void EntitledMessage::VerifyKCBs() {
   for (unsigned int i = 0; i < num_keys_; i++) {
     EntitledContentKeyData* key_data = &entitled_key_data_[i];
     const size_t entitlement_key_index = key_data->key_index;
@@ -1028,6 +1081,28 @@ void EntitledMessage::VerifyEntitlementTestKeys() {
   }
 }
 
+void EntitledMessage::VerifyDecrypt() {
+  const OEMCrypto_SESSION session_id =
+      license_messages_->session()->session_id();
+
+  // Loop through all the keys and try decrypt with each one.
+  for (unsigned int i = 0; i < num_keys_; i++) {
+    const EntitledContentKeyData* const key_data = &entitled_key_data_[i];
+
+    OEMCryptoResult result = OEMCrypto_SelectKey(
+        session_id, key_data->content_key_id, key_data->content_key_id_length,
+        OEMCrypto_CipherMode_CTR);
+    ASSERT_EQ(result, OEMCrypto_SUCCESS) << "For key " << i;
+
+    vector<uint8_t> expected_data;
+    vector<uint8_t> actual_data;
+    result = DecryptCTR(session_id, key_data->content_key_data, &expected_data,
+                        &actual_data);
+    EXPECT_EQ(result, OEMCrypto_SUCCESS) << "For key " << i;
+    EXPECT_EQ(actual_data, expected_data) << "For key " << i;
+  }
+}
+
 void RenewalRoundTrip::VerifyRequestSignature(
     const vector<uint8_t>& data, const vector<uint8_t>& generated_signature,
     size_t core_message_length) {
@@ -1297,30 +1372,6 @@ void Session::GenerateDerivedKeysFromSessionKey() {
   key_deriver_.DeriveKeys(session_key.data(), mac_context, enc_context);
 }
 
-void Session::EncryptCTR(const vector<uint8_t>& in_buffer, const uint8_t* key,
-                         const uint8_t* starting_iv,
-                         vector<uint8_t>* out_buffer) {
-  ASSERT_NE(nullptr, key);
-  ASSERT_NE(nullptr, starting_iv);
-  ASSERT_NE(nullptr, out_buffer);
-  AES_KEY aes_key;
-  AES_set_encrypt_key(key, AES_BLOCK_SIZE * 8, &aes_key);
-  out_buffer->resize(in_buffer.size());
-
-  uint8_t iv[AES_BLOCK_SIZE];  // Current iv.
-
-  memcpy(iv, &starting_iv[0], AES_BLOCK_SIZE);
-  size_t l = 0;  // byte index into encrypted subsample.
-  while (l < in_buffer.size()) {
-    uint8_t aes_output[AES_BLOCK_SIZE];
-    AES_encrypt(iv, aes_output, &aes_key);
-    for (size_t n = 0; n < AES_BLOCK_SIZE && l < in_buffer.size(); n++, l++) {
-      (*out_buffer)[l] = aes_output[n] ^ in_buffer[l];
-    }
-    ctr128_inc64(1, iv);
-  }
-}
-
 void Session::TestDecryptCTR(bool select_key_first,
                              OEMCryptoResult expected_result, int key_index) {
   OEMCryptoResult select_result = OEMCrypto_SUCCESS;
@@ -1331,28 +1382,12 @@ void Session::TestDecryptCTR(bool select_key_first,
         license_.keys[key_index].key_id_length, OEMCrypto_CipherMode_CTR);
   }
 
-  // Create test sample description
-  vector<uint8_t> unencrypted_data(kTestSubsampleSectionSize);
-  vector<uint8_t> encrypted_data(unencrypted_data.size());
-  vector<uint8_t> output_buffer(unencrypted_data.size());
-  OEMCrypto_SampleDescription sample_description;
-  OEMCrypto_SubSampleDescription subsample_description;
-
-  ASSERT_NO_FATAL_FAILURE(GenerateSimpleSampleDescription(
-      encrypted_data, output_buffer, &sample_description,
-      &subsample_description));
-
-  // Generate test data
-  EXPECT_EQ(GetRandBytes(unencrypted_data.data(), unencrypted_data.size()), 1);
-  EncryptCTR(unencrypted_data, license_.keys[key_index].key_data,
-             &sample_description.iv[0], &encrypted_data);
-
-  // Create the pattern description (always 0,0 for CTR)
-  OEMCrypto_CENCEncryptPatternDesc pattern = {0, 0};
-
-  // Decrypt the data
+  vector<uint8_t> unencrypted_data;
+  vector<uint8_t> output_buffer;
   const OEMCryptoResult decrypt_result =
-      OEMCrypto_DecryptCENC(session_id(), &sample_description, 1, &pattern);
+      DecryptCTR(session_id(), license_.keys[key_index].key_data,
+                 &unencrypted_data, &output_buffer);
+
   // We only have a few errors that we test are reported.
   ASSERT_NO_FATAL_FAILURE(
       TestDecryptResult(expected_result, select_result, decrypt_result))
diff --git a/libwvdrmengine/oemcrypto/test/oec_session_util.h b/libwvdrmengine/oemcrypto/test/oec_session_util.h
index 272e85e1..d2bde5e8 100644
--- a/libwvdrmengine/oemcrypto/test/oec_session_util.h
+++ b/libwvdrmengine/oemcrypto/test/oec_session_util.h
@@ -476,8 +476,6 @@ class EntitledMessage {
   void set_num_keys(uint32_t num_keys) { num_keys_ = num_keys; }
   uint32_t num_keys() const { return num_keys_; }
   void SetEntitlementKeyId(unsigned int index, const std::string& key_id);
-  // Verify that key control blocks of the loaded keys.
-  void VerifyEntitlementTestKeys();
   OEMCrypto_EntitledContentKeyObject* entitled_key_array();
   // Returns entitled_key_data_ which is used as input message buffer to
   // load entitled content keys API.
@@ -487,6 +485,11 @@ class EntitledMessage {
  private:
   // Find the offset of the give pointer, relative to |entitled_key_data_|.
   OEMCrypto_Substring FindSubstring(const void* ptr, size_t size);
+  // Verify that key control blocks of the loaded keys matches their entitlement
+  // key.
+  void VerifyKCBs();
+  // Verify that decryption with the entitled keys works.
+  void VerifyDecrypt();
 
   LicenseRoundTrip* license_messages_;
   uint32_t num_keys_;
@@ -528,9 +531,6 @@ class Session {
   // Generate known mac and enc keys using OEMCrypto_DeriveKeysFromSessionKey
   // and also fill out enc_key_, mac_key_server_, and mac_key_client_.
   void GenerateDerivedKeysFromSessionKey();
-  // Encrypt a block of data using CTR mode.
-  void EncryptCTR(const vector<uint8_t>& in_buffer, const uint8_t* key,
-                  const uint8_t* starting_iv, vector<uint8_t>* out_buffer);
   // Encrypt some data and pass to OEMCrypto_DecryptCENC to verify decryption.
   void TestDecryptCTR(bool select_key_first = true,
                       OEMCryptoResult expected_result = OEMCrypto_SUCCESS,
diff --git a/libwvdrmengine/oemcrypto/test/oemcrypto_test.cpp b/libwvdrmengine/oemcrypto/test/oemcrypto_test.cpp
index 07d2a1e7..8612bdae 100644
--- a/libwvdrmengine/oemcrypto/test/oemcrypto_test.cpp
+++ b/libwvdrmengine/oemcrypto/test/oemcrypto_test.cpp
@@ -2516,8 +2516,8 @@ TEST_P(OEMCryptoLicenseTest, SelectKeyNotThereAPI16) {
     OEMCrypto_SampleDescription sample_description;
     OEMCrypto_SubSampleDescription subsample_description;
 
-    ASSERT_NO_FATAL_FAILURE(GenerateSimpleSampleDescription(
-        in_buffer, out_buffer, &sample_description, &subsample_description));
+    GenerateSimpleSampleDescription(in_buffer, out_buffer, &sample_description,
+                                    &subsample_description);
 
     // Generate test data
     for (size_t i = 0; i < in_buffer.size(); i++) in_buffer[i] = i % 256;
@@ -2551,8 +2551,8 @@ TEST_P(OEMCryptoLicenseTest, RejectCensAPI16) {
   OEMCrypto_SampleDescription sample_description;
   OEMCrypto_SubSampleDescription subsample_description;
 
-  ASSERT_NO_FATAL_FAILURE(GenerateSimpleSampleDescription(
-      in_buffer, out_buffer, &sample_description, &subsample_description));
+  GenerateSimpleSampleDescription(in_buffer, out_buffer, &sample_description,
+                                  &subsample_description);
 
   // Create a non-zero pattern to indicate this is 'cens'
   OEMCrypto_CENCEncryptPatternDesc pattern = {1, 9};
@@ -2582,8 +2582,8 @@ TEST_P(OEMCryptoLicenseTest, RejectCbc1API16) {
   OEMCrypto_SampleDescription sample_description;
   OEMCrypto_SubSampleDescription subsample_description;
 
-  ASSERT_NO_FATAL_FAILURE(GenerateSimpleSampleDescription(
-      in_buffer, out_buffer, &sample_description, &subsample_description));
+  GenerateSimpleSampleDescription(in_buffer, out_buffer, &sample_description,
+                                  &subsample_description);
 
   // Create a zero pattern to indicate this is 'cbc1'
   OEMCrypto_CENCEncryptPatternDesc pattern = {0, 0};
@@ -2612,8 +2612,8 @@ TEST_P(OEMCryptoLicenseTest, RejectCbcsWithBlockOffset) {
   OEMCrypto_SampleDescription sample_description;
   OEMCrypto_SubSampleDescription subsample_description;
 
-  ASSERT_NO_FATAL_FAILURE(GenerateSimpleSampleDescription(
-      in_buffer, out_buffer, &sample_description, &subsample_description));
+  GenerateSimpleSampleDescription(in_buffer, out_buffer, &sample_description,
+                                  &subsample_description);
   subsample_description.block_offset = 5;  // Any value 1-15 will do.
 
   // Create a non-zero pattern to indicate this is 'cbcs'.
@@ -2643,8 +2643,8 @@ TEST_P(OEMCryptoLicenseTest, RejectOversizedBlockOffset) {
   OEMCrypto_SampleDescription sample_description;
   OEMCrypto_SubSampleDescription subsample_description;
 
-  ASSERT_NO_FATAL_FAILURE(GenerateSimpleSampleDescription(
-      in_buffer, out_buffer, &sample_description, &subsample_description));
+  GenerateSimpleSampleDescription(in_buffer, out_buffer, &sample_description,
+                                  &subsample_description);
   subsample_description.block_offset = 0xFF;  // Anything 16+
 
   // Create a zero pattern to indicate this is 'cenc'.