diff --git a/libwvdrmengine/oemcrypto/ref/src/oemcrypto_auth_ref.cpp b/libwvdrmengine/oemcrypto/ref/src/oemcrypto_auth_ref.cpp
index 1473d3ea..8697860f 100644
--- a/libwvdrmengine/oemcrypto/ref/src/oemcrypto_auth_ref.cpp
+++ b/libwvdrmengine/oemcrypto/ref/src/oemcrypto_auth_ref.cpp
@@ -187,6 +187,7 @@ bool AuthenticationRoot::Initialize(OEMCrypto_ProvisioningMethod method) {
     // If provisioning method is something other than ProvisioningError
     // indicates it has already been initialized before.  Must
     // existing data.
+    rsa_key_set_ = false;
     rsa_key_.reset();
     test_rsa_key_.reset();
     keybox_.reset();
@@ -195,11 +196,8 @@ bool AuthenticationRoot::Initialize(OEMCrypto_ProvisioningMethod method) {
   prov_method_ = method;
   switch (method) {
     case OEMCrypto_DrmCertificate: {
-      std::unique_ptr<RsaPrivateKey> key =
-          RsaPrivateKey::Load(kPrivateKey, kPrivateKeySize);
-      if (key) {
-        rsa_key_ = std::move(key);
-      } else {
+      rsa_key_set_ = rsa_key_.LoadPkcs8RsaKey(kPrivateKey, kPrivateKeySize);
+      if (!rsa_key_set_) {
         // This error message is OK in unit tests which use test certificate.
         LOGE(
             "FATAL ERROR: Platform uses a baked-in certificate instead of a "
@@ -224,7 +222,7 @@ bool AuthenticationRoot::Initialize(OEMCrypto_ProvisioningMethod method) {
 bool AuthenticationRoot::IsValid() const {
   switch (prov_method_) {
     case OEMCrypto_DrmCertificate: {
-      return HasDrmCertKey() && HasDeviceKey();
+      return rsa_key_set_ && HasDeviceKey();
     }
     case OEMCrypto_Keybox: {
       return HasDeviceKey();
@@ -326,18 +324,17 @@ OEMCryptoResult AuthenticationRoot::LoadTestRsaKey() {
     LOGE("System does not support DRM certificates");
     return OEMCrypto_ERROR_NOT_IMPLEMENTED;
   }
-  if (test_rsa_key_) {
+  if (test_rsa_key_.get() != nullptr) {
     LOGE("Test RSA key is already loaded");
     return OEMCrypto_ERROR_INSUFFICIENT_RESOURCES;
   }
-  std::unique_ptr<RsaPrivateKey> key =
-      RsaPrivateKey::Load(kTestRSAPKCS8PrivateKeyInfo2_2048,
-                          sizeof(kTestRSAPKCS8PrivateKeyInfo2_2048));
-  if (!key) {
+  if (!test_rsa_key_.LoadPkcs8RsaKey(
+          kTestRSAPKCS8PrivateKeyInfo2_2048,
+          sizeof(kTestRSAPKCS8PrivateKeyInfo2_2048))) {
     LOGE("Failed to load test RSA key");
     return OEMCrypto_ERROR_UNKNOWN_FAILURE;
   }
-  test_rsa_key_ = std::move(key);
+  rsa_key_set_ = true;
   return OEMCrypto_SUCCESS;
 }
 
diff --git a/libwvdrmengine/oemcrypto/ref/src/oemcrypto_auth_ref.h b/libwvdrmengine/oemcrypto/ref/src/oemcrypto_auth_ref.h
index aa898886..3269613b 100644
--- a/libwvdrmengine/oemcrypto/ref/src/oemcrypto_auth_ref.h
+++ b/libwvdrmengine/oemcrypto/ref/src/oemcrypto_auth_ref.h
@@ -8,14 +8,17 @@
 #define OEMCRYPTO_AUTH_REF_H_
 
 #include <stdint.h>
-
 #include <memory>
 #include <vector>
 
+#include <openssl/rsa.h>
+
 #include "OEMCryptoCENC.h"  // Needed for enums only.
 #include "disallow_copy_and_assign.h"
+#include "oemcrypto_key_ref.h"
 #include "oemcrypto_keybox_ref.h"
-#include "oemcrypto_rsa_key.h"
+#include "oemcrypto_rsa_key_shared.h"
+#include "oemcrypto_types.h"
 
 namespace wvoec_ref {
 // The AuthenticationRoot class contains the OEMCrypto information
@@ -66,13 +69,13 @@ class AuthenticationRoot {
 
   // Returns the shared RSA private key from the built-in DRM
   // Certificate.
-  std::shared_ptr<RsaPrivateKey> ShareDrmCertKey() {
-    return test_rsa_key_ ? test_rsa_key_ : rsa_key_;
+  RSA_shared_ptr& SharedRsaKey() {
+    return test_rsa_key_.get() != nullptr ? test_rsa_key_ : rsa_key_;
   }
-  RsaPrivateKey* DrmCertKey() const {
-    return test_rsa_key_ ? test_rsa_key_.get() : rsa_key_.get();
+  RSA* rsa_key() {
+    return test_rsa_key_.get() != nullptr ? test_rsa_key_.get()
+                                          : rsa_key_.get();
   }
-  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
@@ -141,10 +144,11 @@ class AuthenticationRoot {
   OEMCrypto_ProvisioningMethod prov_method_ = OEMCrypto_ProvisioningError;
 
   // DRM certificate.
-  // If no keybox, this is the private key of the baked-in DRM
-  // Certificate.
-  std::shared_ptr<RsaPrivateKey> rsa_key_;
-  std::shared_ptr<RsaPrivateKey> test_rsa_key_;
+  // TODO(b/168544740): Remove |rsa_key_set_| when RSA_shared_ptr has
+  // been replaced with scoped RsaPrivateKey.
+  bool rsa_key_set_ = false;
+  RSA_shared_ptr rsa_key_;  // If no keybox, this is baked in certificate.
+  RSA_shared_ptr test_rsa_key_;
 
   // Keybox data.
   std::unique_ptr<WvKeybox> keybox_;
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 0a2fc0dc..7e3c2eb2 100644
--- a/libwvdrmengine/oemcrypto/ref/src/oemcrypto_engine_device_properties_prov30.cpp
+++ b/libwvdrmengine/oemcrypto/ref/src/oemcrypto_engine_device_properties_prov30.cpp
@@ -65,7 +65,7 @@ class Prov30CryptoEngine : public CryptoEngine {
       return OEMCrypto_ERROR_SHORT_BUFFER;
     }
     memcpy(public_cert, kOEMPublicCert, kOEMPublicCertSize);
-    if (!session->LoadRsaDrmKey(kOEMPrivateKey, kOEMPrivateKeySize)) {
+    if (!session->LoadRSAKey(kOEMPrivateKey, kOEMPrivateKeySize)) {
       LOGE("Private RSA Key did not load correctly.");
       return OEMCrypto_ERROR_INVALID_RSA_KEY;
     }
diff --git a/libwvdrmengine/oemcrypto/ref/src/oemcrypto_engine_ref.cpp b/libwvdrmengine/oemcrypto/ref/src/oemcrypto_engine_ref.cpp
index d0f5f581..d999fe6c 100644
--- a/libwvdrmengine/oemcrypto/ref/src/oemcrypto_engine_ref.cpp
+++ b/libwvdrmengine/oemcrypto/ref/src/oemcrypto_engine_ref.cpp
@@ -20,6 +20,7 @@
 #include "keys.h"
 #include "log.h"
 #include "oemcrypto_key_ref.h"
+#include "oemcrypto_rsa_key_shared.h"
 #include "string_conversions.h"
 
 namespace {
@@ -80,10 +81,7 @@ SessionId CryptoEngine::OpenSession() {
 }
 
 SessionContext* CryptoEngine::MakeSession(SessionId sid) {
-  if (root_of_trust_.HasDrmCertKey()) {
-    return new SessionContext(this, sid, root_of_trust_.ShareDrmCertKey());
-  }
-  return new SessionContext(this, sid);
+  return new SessionContext(this, sid, root_of_trust_.SharedRsaKey());
 }
 
 UsageTable* CryptoEngine::MakeUsageTable() { return new UsageTable(this); }
diff --git a/libwvdrmengine/oemcrypto/ref/src/oemcrypto_engine_ref.h b/libwvdrmengine/oemcrypto/ref/src/oemcrypto_engine_ref.h
index 150fdf96..6ccf13c4 100644
--- a/libwvdrmengine/oemcrypto/ref/src/oemcrypto_engine_ref.h
+++ b/libwvdrmengine/oemcrypto/ref/src/oemcrypto_engine_ref.h
@@ -8,16 +8,19 @@
 #define REF_OEMCRYPTO_ENGINE_REF_H_
 
 #include <stdint.h>
-
+#include <time.h>
 #include <map>
 #include <memory>
 #include <mutex>
 #include <vector>
 
+#include <openssl/rsa.h>
+
 #include "OEMCryptoCENC.h"
 #include "file_store.h"
 #include "oemcrypto_auth_ref.h"
 #include "oemcrypto_key_ref.h"
+#include "oemcrypto_rsa_key_shared.h"
 #include "oemcrypto_session.h"
 #include "oemcrypto_types.h"
 #include "oemcrypto_usage_table_ref.h"
diff --git a/libwvdrmengine/oemcrypto/ref/src/oemcrypto_ref.cpp b/libwvdrmengine/oemcrypto/ref/src/oemcrypto_ref.cpp
index b2f3b63c..aeca0675 100644
--- a/libwvdrmengine/oemcrypto/ref/src/oemcrypto_ref.cpp
+++ b/libwvdrmengine/oemcrypto/ref/src/oemcrypto_ref.cpp
@@ -172,8 +172,11 @@ OEMCRYPTO_API OEMCryptoResult OEMCrypto_GenerateDerivedKeys(
       enc_key_context, enc_key_context + enc_key_context_length);
 
   // Generate mac and encryption keys for current session context
-  return session_ctx->DeriveKeys(crypto_engine->DeviceRootKey(), mac_ctx_str,
-                                 enc_ctx_str);
+  if (!session_ctx->DeriveKeys(crypto_engine->DeviceRootKey(), mac_ctx_str,
+                               enc_ctx_str)) {
+    return OEMCrypto_ERROR_UNKNOWN_FAILURE;
+  }
+  return OEMCrypto_SUCCESS;
 }
 
 OEMCRYPTO_API OEMCryptoResult OEMCrypto_GenerateNonce(OEMCrypto_SESSION session,
@@ -890,10 +893,8 @@ static OEMCryptoResult OEMCrypto_RewrapDeviceRSAKey30(
     return OEMCrypto_ERROR_INVALID_NONCE;
   }
 
-  const std::vector<uint8_t> enc_encryption_key(
-      encrypted_message_key,
-      encrypted_message_key + encrypted_message_key_length);
-  if (!session_ctx->InstallRSAEncryptedKey(enc_encryption_key)) {
+  if (!session_ctx->InstallRSAEncryptedKey(encrypted_message_key,
+                                           encrypted_message_key_length)) {
     LOGE(
         "OEMCrypto_RewrapDeviceRSAKey30: "
         "Error loading encrypted_message_key.");
@@ -903,11 +904,11 @@ static OEMCryptoResult OEMCrypto_RewrapDeviceRSAKey30(
   // Decrypt RSA key.
   std::vector<uint8_t> pkcs8_rsa_key(enc_rsa_key_length);
   if (!session_ctx->DecryptRSAKey(enc_rsa_key, enc_rsa_key_length,
-                                  enc_rsa_key_iv, pkcs8_rsa_key.data())) {
+                                  enc_rsa_key_iv, &pkcs8_rsa_key[0])) {
     return OEMCrypto_ERROR_INVALID_RSA_KEY;
   }
-  if (!session_ctx->LoadRsaDrmKey(pkcs8_rsa_key.data(), enc_rsa_key_length)) {
-    LOGE("Failed to load RSA DRM key");
+  if (!session_ctx->LoadRSAKey(&pkcs8_rsa_key[0], enc_rsa_key_length)) {
+    LOGE("[OEMCrypto_RewrapDeviceRSAKey30(): Failed to LoadRSAKey.");
     return OEMCrypto_ERROR_INVALID_RSA_KEY;
   }
 
@@ -925,24 +926,23 @@ static OEMCryptoResult OEMCrypto_RewrapDeviceRSAKey30(
   const std::vector<uint8_t> context(
       wrapped->context, wrapped->context + sizeof(wrapped->context));
   // Generate mac and encryption keys for encrypting the signature.
-  const OEMCryptoResult derive_key_result =
-      session_ctx->DeriveKeys(crypto_engine->DeviceRootKey(), context, context);
-  if (derive_key_result != OEMCrypto_SUCCESS) {
+  if (!session_ctx->DeriveKeys(crypto_engine->DeviceRootKey(), context,
+                               context)) {
     LOGE("[_RewrapDeviceRSAKey30(): DeriveKeys failed.");
-    return derive_key_result;
+    return OEMCrypto_ERROR_UNKNOWN_FAILURE;
   }
 
   // Encrypt rsa key with keybox.
-  if (!session_ctx->EncryptRSAKey(pkcs8_rsa_key.data(), enc_rsa_key_length,
+  if (!session_ctx->EncryptRSAKey(&pkcs8_rsa_key[0], enc_rsa_key_length,
                                   wrapped->iv, wrapped->enc_rsa_key)) {
     LOGE("[_RewrapDeviceRSAKey30(): EncrypteRSAKey failed.");
     return OEMCrypto_ERROR_UNKNOWN_FAILURE;
   }
   const size_t buffer_size = enc_rsa_key_length + sizeof(WrappedRSAKey);
-  // The wrapped keybox must be signed with the same key we verify with.
-  // Reference implementation uses the server key.
+  // The wrapped keybox must be signed with the same key we verify with. I'll
+  // pick the server key, so I don't have to modify LoadRSAKey.
   unsigned int sig_length = sizeof(wrapped->signature);
-  if (!HMAC(EVP_sha256(), session_ctx->mac_key_server().data(),
+  if (!HMAC(EVP_sha256(), &session_ctx->mac_key_server()[0],
             session_ctx->mac_key_server().size(), wrapped->context,
             buffer_size - sizeof(wrapped->signature), wrapped->signature,
             &sig_length)) {
@@ -1006,10 +1006,10 @@ static OEMCryptoResult OEMCrypto_RewrapDeviceRSAKey(
   // Decrypt RSA key and verify it.
   std::vector<uint8_t> pkcs8_rsa_key(enc_rsa_key_length);
   if (!session_ctx->DecryptRSAKey(enc_rsa_key, enc_rsa_key_length,
-                                  enc_rsa_key_iv, pkcs8_rsa_key.data())) {
+                                  enc_rsa_key_iv, &pkcs8_rsa_key[0])) {
     return OEMCrypto_ERROR_INVALID_RSA_KEY;
   }
-  if (!session_ctx->LoadRsaDrmKey(pkcs8_rsa_key.data(), enc_rsa_key_length)) {
+  if (!session_ctx->LoadRSAKey(&pkcs8_rsa_key[0], enc_rsa_key_length)) {
     return OEMCrypto_ERROR_INVALID_RSA_KEY;
   }
 
@@ -1025,22 +1025,21 @@ static OEMCryptoResult OEMCrypto_RewrapDeviceRSAKey(
   const std::vector<uint8_t> context(
       wrapped->context, wrapped->context + sizeof(wrapped->context));
   // Generate mac and encryption keys for encrypting the signature.
-  const OEMCryptoResult derive_key_result =
-      session_ctx->DeriveKeys(crypto_engine->DeviceRootKey(), context, context);
-  if (derive_key_result != OEMCrypto_SUCCESS) {
-    return derive_key_result;
+  if (!session_ctx->DeriveKeys(crypto_engine->DeviceRootKey(), context,
+                               context)) {
+    return OEMCrypto_ERROR_UNKNOWN_FAILURE;
   }
 
   // Encrypt rsa key with keybox.
-  if (!session_ctx->EncryptRSAKey(pkcs8_rsa_key.data(), enc_rsa_key_length,
+  if (!session_ctx->EncryptRSAKey(&pkcs8_rsa_key[0], enc_rsa_key_length,
                                   wrapped->iv, wrapped->enc_rsa_key)) {
     return OEMCrypto_ERROR_UNKNOWN_FAILURE;
   }
   const size_t buffer_size = enc_rsa_key_length + sizeof(WrappedRSAKey);
-  // The wrapped keybox must be signed with the same key we verify with.
-  // Reference implementation uses the server key.
+  // The wrapped keybox must be signed with the same key we verify with. I'll
+  // pick the server key, so I don't have to modify LoadRSAKey.
   unsigned int sig_length = sizeof(wrapped->signature);
-  if (!HMAC(EVP_sha256(), session_ctx->mac_key_server().data(),
+  if (!HMAC(EVP_sha256(), &session_ctx->mac_key_server()[0],
             session_ctx->mac_key_server().size(), wrapped->context,
             buffer_size - sizeof(wrapped->signature), wrapped->signature,
             &sig_length)) {
@@ -1174,10 +1173,9 @@ OEMCRYPTO_API OEMCryptoResult OEMCrypto_LoadDRMPrivateKey(
   const std::vector<uint8_t> context(
       wrapped->context, wrapped->context + sizeof(wrapped->context));
   // Generate mac and encryption keys for encrypting the signature.
-  const OEMCryptoResult derive_key_result =
-      session_ctx->DeriveKeys(crypto_engine->DeviceRootKey(), context, context);
-  if (derive_key_result != OEMCrypto_SUCCESS) {
-    return derive_key_result;
+  if (!session_ctx->DeriveKeys(crypto_engine->DeviceRootKey(), context,
+                               context)) {
+    return OEMCrypto_ERROR_UNKNOWN_FAILURE;
   }
   // verify signature.
   if (!session_ctx->ValidateMessage(
@@ -1191,7 +1189,7 @@ OEMCRYPTO_API OEMCryptoResult OEMCrypto_LoadDRMPrivateKey(
                                      sizeof(wrapped->signature));
   size_t enc_rsa_key_length = wrapped_rsa_key_length - sizeof(WrappedRSAKey);
   if (!session_ctx->DecryptRSAKey(wrapped->enc_rsa_key, enc_rsa_key_length,
-                                  wrapped->iv, pkcs8_rsa_key.data())) {
+                                  wrapped->iv, &pkcs8_rsa_key[0])) {
     return OEMCrypto_ERROR_INVALID_RSA_KEY;
   }
   size_t padding = pkcs8_rsa_key[enc_rsa_key_length - 1];
@@ -1200,7 +1198,7 @@ OEMCRYPTO_API OEMCryptoResult OEMCrypto_LoadDRMPrivateKey(
     padding = 0;
   }
   size_t rsa_key_length = enc_rsa_key_length - padding;
-  if (!session_ctx->LoadRsaDrmKey(pkcs8_rsa_key.data(), rsa_key_length)) {
+  if (!session_ctx->LoadRSAKey(&pkcs8_rsa_key[0], rsa_key_length)) {
     return OEMCrypto_ERROR_INVALID_RSA_KEY;
   }
   return OEMCrypto_SUCCESS;
@@ -1233,8 +1231,22 @@ OEMCRYPTO_API OEMCryptoResult OEMCrypto_GenerateRSASignature(
     LOGE("[OEMCrypto_GenerateRSASignature(): ERROR_INVALID_SESSION]");
     return OEMCrypto_ERROR_INVALID_SESSION;
   }
-  return session_ctx->GenerateRSASignature(message, message_length, signature,
-                                           signature_length, padding_scheme);
+
+  size_t required_size = session_ctx->RSASignatureSize();
+  if (*signature_length < required_size) {
+    *signature_length = required_size;
+    return OEMCrypto_ERROR_SHORT_BUFFER;
+  }
+
+  if (message == nullptr || message_length == 0 || signature == nullptr ||
+      signature_length == 0) {
+    LOGE("[OEMCrypto_GenerateRSASignature(): OEMCrypto_ERROR_INVALID_CONTEXT]");
+    return OEMCrypto_ERROR_INVALID_CONTEXT;
+  }
+
+  OEMCryptoResult sts = session_ctx->GenerateRSASignature(
+      message, message_length, signature, signature_length, padding_scheme);
+  return sts;
 }
 
 OEMCRYPTO_API OEMCryptoResult OEMCrypto_DeriveKeysFromSessionKey(
@@ -1247,22 +1259,27 @@ OEMCRYPTO_API OEMCryptoResult OEMCrypto_DeriveKeysFromSessionKey(
     return OEMCrypto_ERROR_UNKNOWN_FAILURE;
   }
   if (!crypto_engine->ValidRootOfTrust()) {
-    LOGE("[OEMCrypto_DeriveKeysFromSessionKey(): ERROR_KEYBOX_INVALID]");
+    LOGE("[OEMCrypto_GenerateDerivedKeys(): ERROR_KEYBOX_INVALID]");
     return OEMCrypto_ERROR_KEYBOX_INVALID;
   }
   if (mac_key_context_length > kMaxContextKeyLength ||
       enc_key_context_length > kMaxContextKeyLength ||
       enc_session_key_length > kMaxContextKeyLength) {
-    LOGE("[OEMCrypto_DeriveKeysFromSessionKey(): ERROR_BUFFER_TOO_LARGE]");
+    LOGE("[OEMCrypto_GenerateDerivedKeys(): ERROR_BUFFER_TOO_LARGE]");
     return OEMCrypto_ERROR_BUFFER_TOO_LARGE;
   }
 
   SessionContext* session_ctx = crypto_engine->FindSession(session);
   if (session_ctx == nullptr || !session_ctx->isValid()) {
-    LOGE("[OEMCrypto_DeriveKeysFromSessionKey(): ERROR_INVALID_SESSION]");
+    LOGE("[OEMCrypto_GenerateDerivedKeys(): ERROR_INVALID_SESSION]");
     return OEMCrypto_ERROR_INVALID_SESSION;
   }
 
+  if (session_ctx->allowed_schemes() != kSign_RSASSA_PSS) {
+    LOGE("[OEMCrypto_GenerateDerivedKeys(): x509 key used to derive keys]");
+    return OEMCrypto_ERROR_INVALID_RSA_KEY;
+  }
+
   const std::vector<uint8_t> ssn_key_str(
       enc_session_key, enc_session_key + enc_session_key_length);
   const std::vector<uint8_t> mac_ctx_str(
@@ -1271,7 +1288,10 @@ OEMCRYPTO_API OEMCryptoResult OEMCrypto_DeriveKeysFromSessionKey(
       enc_key_context, enc_key_context + enc_key_context_length);
 
   // Generate mac and encryption keys for current session context
-  return session_ctx->RSADeriveKeys(ssn_key_str, mac_ctx_str, enc_ctx_str);
+  if (!session_ctx->RSADeriveKeys(ssn_key_str, mac_ctx_str, enc_ctx_str)) {
+    return OEMCrypto_ERROR_UNKNOWN_FAILURE;
+  }
+  return OEMCrypto_SUCCESS;
 }
 
 OEMCRYPTO_API uint32_t OEMCrypto_APIVersion() {
diff --git a/libwvdrmengine/oemcrypto/ref/src/oemcrypto_rsa_key.cpp b/libwvdrmengine/oemcrypto/ref/src/oemcrypto_rsa_key.cpp
index 6a9c2af2..71aea9b4 100644
--- a/libwvdrmengine/oemcrypto/ref/src/oemcrypto_rsa_key.cpp
+++ b/libwvdrmengine/oemcrypto/ref/src/oemcrypto_rsa_key.cpp
@@ -993,6 +993,7 @@ bool RsaPrivateKey::InitFromBuffer(const uint8_t* buffer, size_t length) {
   }
   // Step 3: Verify field width.
   const int bits = RSA_bits(key.get());
+  LOGD("Loaded RSA private key size: bits = %d", bits);
   field_size_ = RealBitSizeToFieldSize(bits);
   if (field_size_ == kRsaFieldUnknown) {
     LOGE("Unsupported RSA key size: bits = %d", bits);
diff --git a/libwvdrmengine/oemcrypto/ref/src/oemcrypto_rsa_key_shared.cpp b/libwvdrmengine/oemcrypto/ref/src/oemcrypto_rsa_key_shared.cpp
new file mode 100644
index 00000000..6c73ad81
--- /dev/null
+++ b/libwvdrmengine/oemcrypto/ref/src/oemcrypto_rsa_key_shared.cpp
@@ -0,0 +1,101 @@
+// Copyright 2018 Google LLC. All Rights Reserved. This file and proprietary
+// source code may only be used and distributed under the Widevine Master
+// License Agreement.
+//
+//  Reference implementation of OEMCrypto APIs
+//
+#include "oemcrypto_rsa_key_shared.h"
+
+#include <assert.h>
+
+#include <openssl/bio.h>
+#include <openssl/err.h>
+#include <openssl/rsa.h>
+#include <openssl/sha.h>
+#include <openssl/x509.h>
+
+#include "log.h"
+
+namespace wvoec_ref {
+
+void dump_boringssl_error() {
+  int count = 0;
+  while (unsigned long err = ERR_get_error()) {
+    count++;
+    char buffer[120];
+    ERR_error_string_n(err, buffer, sizeof(buffer));
+    LOGE("BoringSSL Error %d -- %lu -- %s", count, err, buffer);
+  }
+  LOGE("Reported %d BoringSSL Errors", count);
+}
+
+void RSA_shared_ptr::reset() {
+  if (rsa_key_ && key_owned_) {
+    RSA_free(rsa_key_);
+  }
+  key_owned_ = false;
+  rsa_key_ = nullptr;
+}
+
+bool RSA_shared_ptr::LoadPkcs8RsaKey(const uint8_t* buffer, size_t length) {
+  assert(buffer != nullptr);
+  reset();
+  uint8_t* pkcs8_rsa_key = const_cast<uint8_t*>(buffer);
+  BIO* bio = BIO_new_mem_buf(pkcs8_rsa_key, length);
+  if (bio == nullptr) {
+    LOGE("[LoadPkcs8RsaKey(): Could not allocate bio buffer]");
+    return false;
+  }
+  bool success = true;
+  PKCS8_PRIV_KEY_INFO* pkcs8_pki = d2i_PKCS8_PRIV_KEY_INFO_bio(bio, nullptr);
+  if (pkcs8_pki == nullptr) {
+    BIO_reset(bio);
+    pkcs8_pki = d2i_PKCS8_PRIV_KEY_INFO_bio(bio, nullptr);
+    if (pkcs8_pki == nullptr) {
+      LOGE("[LoadPkcs8RsaKey(): d2i_PKCS8_PRIV_KEY_INFO_bio returned nullptr]");
+      dump_boringssl_error();
+      success = false;
+    }
+  }
+  EVP_PKEY* evp = nullptr;
+  if (success) {
+    evp = EVP_PKCS82PKEY(pkcs8_pki);
+    if (evp == nullptr) {
+      LOGE("[LoadPkcs8RsaKey(): EVP_PKCS82PKEY returned nullptr]");
+      dump_boringssl_error();
+      success = false;
+    }
+  }
+  if (success) {
+    rsa_key_ = EVP_PKEY_get1_RSA(evp);
+    if (rsa_key_ == nullptr) {
+      LOGE("[LoadPkcs8RsaKey(): PrivateKeyInfo did not contain an RSA key]");
+      success = false;
+    }
+    key_owned_ = true;
+  }
+  if (evp != nullptr) {
+    EVP_PKEY_free(evp);
+  }
+  if (pkcs8_pki != nullptr) {
+    PKCS8_PRIV_KEY_INFO_free(pkcs8_pki);
+  }
+  BIO_free(bio);
+  if (!success) {
+    return false;
+  }
+  switch (RSA_check_key(rsa_key_)) {
+    case 1:  // valid.
+      return true;
+    case 0:  // not valid.
+      LOGE("[LoadPkcs8RsaKey(): rsa key not valid]");
+      dump_boringssl_error();
+      return false;
+    default:  // -1 == check failed.
+      LOGE("[LoadPkcs8RsaKey(): error checking rsa key]");
+      dump_boringssl_error();
+      return false;
+  }
+}
+
+}  // namespace wvoec_ref
diff --git a/libwvdrmengine/oemcrypto/ref/src/oemcrypto_rsa_key_shared.h b/libwvdrmengine/oemcrypto/ref/src/oemcrypto_rsa_key_shared.h
new file mode 100644
index 00000000..98ea154e
--- /dev/null
+++ b/libwvdrmengine/oemcrypto/ref/src/oemcrypto_rsa_key_shared.h
@@ -0,0 +1,42 @@
+// Copyright 2018 Google LLC. All Rights Reserved. This file and proprietary
+// source code may only be used and distributed under the Widevine Master
+// License Agreement.
+//
+//  Reference implementation of OEMCrypto APIs
+//
+#ifndef OEMCRYPTO_RSA_KEY_SHARED_H_
+#define OEMCRYPTO_RSA_KEY_SHARED_H_
+
+#include <stdint.h>
+
+#include <openssl/rsa.h>
+
+namespace wvoec_ref {
+
+// Shared pointer with specialized destructor.  This pointer is only shared
+// from a CryptoEngine to a Session -- so we don't have to use full reference
+// counting.
+class RSA_shared_ptr {
+ public:
+  RSA_shared_ptr() : rsa_key_(nullptr), key_owned_(false) {}
+  ~RSA_shared_ptr() { reset(); };
+  // Explicitly allow copy as share.
+  explicit RSA_shared_ptr(const RSA_shared_ptr& other) :
+      rsa_key_(other.rsa_key_), key_owned_(false) {}
+  RSA* get() { return rsa_key_; }
+  void reset();
+  bool LoadPkcs8RsaKey(const uint8_t* buffer, size_t length);
+
+ private:
+  void operator=(const RSA_shared_ptr);  // disallow assign.
+
+  RSA* rsa_key_;
+  bool key_owned_;
+};
+
+// Log errors from BoringSSL.
+void dump_boringssl_error();
+
+}  // namespace wvoec_ref
+
+#endif  // OEMCRYPTO_RSA_KEY_SHARED_H_
diff --git a/libwvdrmengine/oemcrypto/ref/src/oemcrypto_session.cpp b/libwvdrmengine/oemcrypto/ref/src/oemcrypto_session.cpp
index 4ca614b9..51bf560e 100644
--- a/libwvdrmengine/oemcrypto/ref/src/oemcrypto_session.cpp
+++ b/libwvdrmengine/oemcrypto/ref/src/oemcrypto_session.cpp
@@ -25,17 +25,20 @@
 #include <openssl/x509.h>
 
 #include "advance_iv_ctr.h"
+#include "disallow_copy_and_assign.h"
 #include "keys.h"
 #include "log.h"
 #include "odk.h"
 #include "oemcrypto_engine_ref.h"
 #include "oemcrypto_key_ref.h"
+#include "oemcrypto_rsa_key_shared.h"
 #include "oemcrypto_types.h"
 #include "platform.h"
 #include "string_conversions.h"
 #include "wvcrc32.h"
 
-namespace wvoec_ref {
+static const int kPssSaltLength = 20;
+
 namespace {
 
 // Increment counter for AES-CTR.  The CENC spec specifies we increment only
@@ -63,8 +66,11 @@ void advance_dest_buffer(OEMCrypto_DestBufferDesc* dest_buffer, size_t bytes) {
       break;
   }
 }
+
 }  // namespace
 
+namespace wvoec_ref {
+
 /***************************************/
 
 class ContentKeysContext : public SessionContextKeys {
@@ -175,17 +181,31 @@ EntitlementKey* EntitlementKeysContext::GetEntitlementKey(
 
 /***************************************/
 
-SessionContext::SessionContext(CryptoEngine* ce, SessionId sid)
-    : valid_(ce != nullptr), ce_(ce), id_(sid) {
+SessionContext::SessionContext(CryptoEngine* ce, SessionId sid,
+                               const RSA_shared_ptr& rsa_key)
+    : valid_(true),
+      ce_(ce),
+      id_(sid),
+      current_content_key_(nullptr),
+      session_keys_(nullptr),
+      license_request_hash_(),
+      rsa_key_(rsa_key),
+      allowed_schemes_(kSign_RSASSA_PSS),
+      decrypt_started_(false),
+      timer_limits_(),
+      clock_values_(),
+      usage_entry_(nullptr),
+      srm_requirements_status_(NoSRMVersion),
+      usage_entry_status_(kNoUsageEntry),
+      compute_hash_(false),
+      current_hash_(0),
+      bad_frame_number_(0),
+      hash_error_(OEMCrypto_SUCCESS),
+      state_nonce_created_(false),
+      state_request_signed_(false),
+      state_response_loaded_(false) {
   ODK_InitializeSessionValues(&timer_limits_, &clock_values_, &nonce_values_,
                               CryptoEngine::kApiVersion, sid);
-  memset(license_request_hash_, 0, sizeof(license_request_hash_));
-}
-
-SessionContext::SessionContext(CryptoEngine* ce, SessionId sid,
-                               std::shared_ptr<RsaPrivateKey>&& rsa_key)
-    : SessionContext(ce, sid) {
-  rsa_key_ = std::move(rsa_key);
 }
 
 SessionContext::~SessionContext() {}
@@ -238,28 +258,27 @@ bool SessionContext::DeriveKey(const std::vector<uint8_t>& key,
   return true;
 }
 
-OEMCryptoResult SessionContext::DeriveKeys(
-    const std::vector<uint8_t>& master_key,
-    const std::vector<uint8_t>& mac_key_context,
-    const std::vector<uint8_t>& enc_key_context) {
+bool SessionContext::DeriveKeys(const std::vector<uint8_t>& master_key,
+                                const std::vector<uint8_t>& mac_key_context,
+                                const std::vector<uint8_t>& enc_key_context) {
   // Generate derived key for mac key
   std::vector<uint8_t> mac_key_server;
   std::vector<uint8_t> mac_key_client;
   std::vector<uint8_t> mac_key_part2;
   if (!DeriveKey(master_key, mac_key_context, 1, &mac_key_server)) {
-    return OEMCrypto_ERROR_UNKNOWN_FAILURE;
+    return false;
   }
   if (!DeriveKey(master_key, mac_key_context, 2, &mac_key_part2)) {
-    return OEMCrypto_ERROR_UNKNOWN_FAILURE;
+    return false;
   }
   mac_key_server.insert(mac_key_server.end(), mac_key_part2.begin(),
                         mac_key_part2.end());
 
   if (!DeriveKey(master_key, mac_key_context, 3, &mac_key_client)) {
-    return OEMCrypto_ERROR_UNKNOWN_FAILURE;
+    return false;
   }
   if (!DeriveKey(master_key, mac_key_context, 4, &mac_key_part2)) {
-    return OEMCrypto_ERROR_UNKNOWN_FAILURE;
+    return false;
   }
   mac_key_client.insert(mac_key_client.end(), mac_key_part2.begin(),
                         mac_key_part2.end());
@@ -267,31 +286,48 @@ OEMCryptoResult SessionContext::DeriveKeys(
   // Generate derived key for encryption key
   std::vector<uint8_t> enc_key;
   if (!DeriveKey(master_key, enc_key_context, 1, &enc_key)) {
-    return OEMCrypto_ERROR_UNKNOWN_FAILURE;
+    return false;
   }
 
   set_mac_key_server(mac_key_server);
   set_mac_key_client(mac_key_client);
   set_encryption_key(enc_key);
-  return OEMCrypto_SUCCESS;
+  return true;
 }
 
-OEMCryptoResult SessionContext::RSADeriveKeys(
+bool SessionContext::RSADeriveKeys(
     const std::vector<uint8_t>& enc_session_key,
     const std::vector<uint8_t>& mac_key_context,
     const std::vector<uint8_t>& enc_key_context) {
-  if (!rsa_key_) {
-    LOGE("No RSA key set");
-    return OEMCrypto_ERROR_DEVICE_NOT_RSA_PROVISIONED;
+  if (!rsa_key()) {
+    LOGE("[RSADeriveKeys(): no RSA key set]");
+    return false;
   }
-  if (!(rsa_key_->allowed_schemes() & kSign_RSASSA_PSS)) {
-    LOGE("Key cannot be used for session key decryption");
-    return OEMCrypto_ERROR_INVALID_RSA_KEY;
+  const size_t actual_key_size = static_cast<size_t>(RSA_size(rsa_key()));
+  if (enc_session_key.size() != actual_key_size) {
+    LOGE(
+        "[RSADeriveKeys(): encrypted session key wrong size: %zu, expected "
+        "%zu]",
+        enc_session_key.size(), actual_key_size);
+    dump_boringssl_error();
+    return false;
   }
-  session_key_ = rsa_key_->DecryptSessionKey(enc_session_key);
-  if (session_key_.empty()) {
-    LOGE("Failed decrypt session key");
-    return OEMCrypto_ERROR_UNKNOWN_FAILURE;
+  session_key_.resize(RSA_size(rsa_key()));
+  const int decrypted_size =
+      RSA_private_decrypt(enc_session_key.size(), &enc_session_key[0],
+                          &session_key_[0], rsa_key(), RSA_PKCS1_OAEP_PADDING);
+  if (-1 == decrypted_size) {
+    LOGE("[RSADeriveKeys(): error decrypting session key.]");
+    dump_boringssl_error();
+    return false;
+  }
+  session_key_.resize(decrypted_size);
+  if (decrypted_size != static_cast<int>(wvoec::KEY_SIZE)) {
+    LOGE("[RSADeriveKeys(): error. Session key is wrong size: %d.]",
+         decrypted_size);
+    dump_boringssl_error();
+    session_key_.clear();
+    return false;
   }
   return DeriveKeys(session_key_, mac_key_context, enc_key_context);
 }
@@ -300,13 +336,8 @@ OEMCryptoResult SessionContext::PrepAndSignLicenseRequest(
     uint8_t* message, size_t message_length, size_t* core_message_length,
     uint8_t* signature, size_t* signature_length) {
   if (signature_length == nullptr || core_message_length == nullptr) {
-    LOGE("Output length parameters are null");
     return OEMCrypto_ERROR_INVALID_CONTEXT;
   }
-  if (!rsa_key_) {
-    LOGE("No DRM key available for signature");
-    return OEMCrypto_ERROR_UNKNOWN_FAILURE;
-  }
   const size_t required_signature_size = CertSignatureSize();
   OEMCryptoResult result = ODK_PrepareCoreLicenseRequest(
       message, message_length, core_message_length, &nonce_values_);
@@ -393,10 +424,6 @@ OEMCryptoResult SessionContext::PrepAndSignProvisioningRequest(
   if (signature_length == nullptr || core_message_length == nullptr) {
     return OEMCrypto_ERROR_INVALID_CONTEXT;
   }
-  if (!rsa_key_ && mac_key_client_.empty()) {
-    LOGE("Session cannot sign request");
-    return OEMCrypto_ERROR_UNKNOWN_FAILURE;
-  }
   if (state_request_signed_) {
     LOGE("Attempt to sign prov request after license request");
     return OEMCrypto_ERROR_UNKNOWN_FAILURE;
@@ -461,20 +488,29 @@ OEMCryptoResult SessionContext::GenerateSignature(const uint8_t* message,
   return OEMCrypto_ERROR_UNKNOWN_FAILURE;
 }
 
-size_t SessionContext::CertSignatureSize() const {
-  if (!rsa_key_) {
-    LOGE("No RSA key set");
+// This is ussd when the device is a cast receiver.
+size_t SessionContext::RSASignatureSize() {
+  if (!rsa_key()) {
+    LOGE("no RSA key set");
     return 0;
   }
-  return rsa_key_->SignatureSize();
+  return static_cast<size_t>(RSA_size(rsa_key()));
 }
 
-size_t SessionContext::ROTSignatureSize() const {
+size_t SessionContext::CertSignatureSize() {
+  // TODO(b/67735947): Add ECC cert support.
+  if (!rsa_key()) {
+    LOGE("No private key set");
+    return 0;
+  }
+  return static_cast<size_t>(RSA_size(rsa_key()));
+}
+
+size_t SessionContext::ROTSignatureSize() {
   if (ce_->config_provisioning_method() == OEMCrypto_Keybox)
     return SHA256_DIGEST_LENGTH;
-  if (ce_->config_provisioning_method() == OEMCrypto_OEMCertificate) {
+  if (ce_->config_provisioning_method() == OEMCrypto_OEMCertificate)
     return CertSignatureSize();
-  }
   LOGE("Bad prov method = %d",
        static_cast<int>(ce_->config_provisioning_method()));
   return 0;
@@ -483,27 +519,92 @@ size_t SessionContext::ROTSignatureSize() const {
 OEMCryptoResult SessionContext::GenerateCertSignature(
     const uint8_t* message, size_t message_length, uint8_t* signature,
     size_t* signature_length) {
-  if (!rsa_key_) {
+  // TODO(b/67735947): Add ECC cert support.
+  if (message == nullptr || message_length == 0 || signature == nullptr ||
+      signature_length == 0) {
+    LOGE("OEMCrypto_ERROR_INVALID_CONTEXT");
+    return OEMCrypto_ERROR_INVALID_CONTEXT;
+  }
+  if (!rsa_key()) {
     LOGE("No RSA key set");
     return OEMCrypto_ERROR_INVALID_RSA_KEY;
   }
-  return rsa_key_->GenerateSignature(message, message_length, kRsaPssDefault,
-                                     signature, signature_length);
+  if (*signature_length < static_cast<size_t>(RSA_size(rsa_key()))) {
+    *signature_length = CertSignatureSize();
+    return OEMCrypto_ERROR_SHORT_BUFFER;
+  }
+  if (allowed_schemes_ != kSign_RSASSA_PSS) {
+    LOGE("Message signing not allowed");
+    return OEMCrypto_ERROR_INVALID_RSA_KEY;
+  }
+
+  // Hash the message using SHA1.
+  uint8_t hash[SHA_DIGEST_LENGTH];
+  if (!SHA1(message, message_length, hash)) {
+    LOGE("Error creating signature hash");
+    dump_boringssl_error();
+    return OEMCrypto_ERROR_UNKNOWN_FAILURE;
+  }
+
+  // Add PSS padding.
+  std::vector<uint8_t> padded_digest(*signature_length);
+  int status = RSA_padding_add_PKCS1_PSS_mgf1(
+      rsa_key(), &padded_digest[0], hash, EVP_sha1(), nullptr, kPssSaltLength);
+  if (status == -1) {
+    LOGE("Error padding hash");
+    dump_boringssl_error();
+    return OEMCrypto_ERROR_UNKNOWN_FAILURE;
+  }
+
+  // Encrypt PSS padded digest.
+  status = RSA_private_encrypt(*signature_length, &padded_digest[0], signature,
+                               rsa_key(), RSA_NO_PADDING);
+  if (status == -1) {
+    LOGE("Error in private encrypt");
+    dump_boringssl_error();
+    return OEMCrypto_ERROR_UNKNOWN_FAILURE;
+  }
+  return OEMCrypto_SUCCESS;
 }
 
 OEMCryptoResult SessionContext::GenerateRSASignature(
     const uint8_t* message, size_t message_length, uint8_t* signature,
     size_t* signature_length, RSA_Padding_Scheme padding_scheme) {
-  if (padding_scheme != kSign_PKCS1_Block1) {
-    LOGE("Only PKCS1 block1 padding scheme allowed");
+  if (message == nullptr || message_length == 0 || signature == nullptr ||
+      signature_length == 0) {
+    LOGE("OEMCrypto_ERROR_INVALID_CONTEXT");
     return OEMCrypto_ERROR_INVALID_CONTEXT;
   }
-  if (!rsa_key_) {
+  if (!rsa_key()) {
     LOGE("No RSA key set");
     return OEMCrypto_ERROR_INVALID_RSA_KEY;
   }
-  return rsa_key_->GenerateSignature(message, message_length, kRsaPkcs1Cast,
-                                     signature, signature_length);
+  if (*signature_length < static_cast<size_t>(RSA_size(rsa_key()))) {
+    *signature_length = RSA_size(rsa_key());
+    return OEMCrypto_ERROR_SHORT_BUFFER;
+  }
+  if (((padding_scheme & allowed_schemes_) != padding_scheme) ||
+      (padding_scheme != kSign_PKCS1_Block1)) {
+    LOGE("padding_scheme not allowed");
+    return OEMCrypto_ERROR_INVALID_RSA_KEY;
+  }
+  // This is the maximum digest size possible for PKCS1 block type 1,
+  // as used for a CAST receiver.
+  const size_t max_digest_size = 83u;
+  if (message_length > max_digest_size) {
+    LOGE("RSA digest too large");
+    return OEMCrypto_ERROR_SIGNATURE_FAILURE;
+  }
+  // Pad the message with PKCS1 padding, and then encrypt.
+  const int status = RSA_private_encrypt(message_length, message, signature,
+                                         rsa_key(), RSA_PKCS1_PADDING);
+  if (status < 0) {
+    LOGE("Error in RSA private encrypt. status = %d", status);
+    dump_boringssl_error();
+    return OEMCrypto_ERROR_UNKNOWN_FAILURE;
+  }
+  *signature_length = static_cast<size_t>(RSA_size(rsa_key()));
+  return OEMCrypto_SUCCESS;
 }
 
 // Validate message signature
@@ -933,19 +1034,24 @@ OEMCryptoResult SessionContext::InstallKey(
 }
 
 bool SessionContext::InstallRSAEncryptedKey(
-    const std::vector<uint8_t>& enc_encryption_key) {
-  if (!rsa_key_) {
-    LOGE("Session does not have an OEM cert key");
+    const uint8_t* encrypted_message_key, size_t encrypted_message_key_length) {
+  encryption_key_.resize(RSA_size(rsa_key()));
+  const int decrypted_size = RSA_private_decrypt(
+      encrypted_message_key_length, encrypted_message_key, &encryption_key_[0],
+      rsa_key(), RSA_PKCS1_OAEP_PADDING);
+  if (-1 == decrypted_size) {
+    LOGE("[RSADeriveKeys(): error decrypting session key.]");
+    dump_boringssl_error();
     return false;
   }
-
-  std::vector<uint8_t> encryption_key =
-      rsa_key_->DecryptEncryptionKey(enc_encryption_key);
-  if (encryption_key.empty()) {
-    LOGE("Failed to decrypt session encryption key");
+  encryption_key_.resize(decrypted_size);
+  if (decrypted_size != static_cast<int>(wvoec::KEY_SIZE)) {
+    LOGE("[RSADeriveKeys(): error. Session key is wrong size: %d.]",
+         decrypted_size);
+    dump_boringssl_error();
+    encryption_key_.clear();
     return false;
   }
-  encryption_key_ = std::move(encryption_key);
   return true;
 }
 
@@ -1056,23 +1162,23 @@ bool SessionContext::EncryptRSAKey(const uint8_t* pkcs8_rsa_key,
   return true;
 }
 
-bool SessionContext::LoadRsaDrmKey(const uint8_t* pkcs8_rsa_key,
-                                   size_t rsa_key_length) {
-  std::unique_ptr<RsaPrivateKey> key =
-      RsaPrivateKey::Load(pkcs8_rsa_key, rsa_key_length);
-  if (!key) {
-    LOGE("Failed to parse RSA key");
+bool SessionContext::LoadRSAKey(const uint8_t* pkcs8_rsa_key,
+                                size_t rsa_key_length) {
+  rsa_key_.reset();
+  if (rsa_key_length < 8) {
+    LOGE("[LoadRSAKey(): Very Short Buffer]");
     return false;
   }
-  constexpr uint8_t kAllSchemes = kSign_RSASSA_PSS | kSign_PKCS1_Block1;
-  if (key->allowed_schemes() == 0 ||
-      (key->allowed_schemes() & kAllSchemes) == kAllSchemes) {
-    LOGE("RSA DRM key has an invalid set of schemes: allowed_schemes = 0x%08x",
-         key->allowed_schemes());
-    return false;
+  if ((memcmp(pkcs8_rsa_key, "SIGN", 4) == 0)) {
+    uint32_t schemes_n;
+    memcpy((uint8_t*)&schemes_n, pkcs8_rsa_key + 4, sizeof(uint32_t));
+    allowed_schemes_ = htonl(schemes_n);
+    pkcs8_rsa_key += 8;
+    rsa_key_length -= 8;
+  } else {
+    allowed_schemes_ = kSign_RSASSA_PSS;
   }
-  rsa_key_ = std::move(key);
-  return true;
+  return rsa_key_.LoadPkcs8RsaKey(pkcs8_rsa_key, rsa_key_length);
 }
 
 OEMCryptoResult SessionContext::CheckKeyUse(const std::string& log_string,
@@ -1255,6 +1361,7 @@ OEMCryptoResult SessionContext::Generic_Sign(const uint8_t* in_buffer,
     return OEMCrypto_SUCCESS;
   }
   LOGE("[Generic_Sign(): hmac failed");
+  dump_boringssl_error();
   return OEMCrypto_ERROR_UNKNOWN_FAILURE;
 }
 
@@ -1295,6 +1402,7 @@ OEMCryptoResult SessionContext::Generic_Verify(const uint8_t* in_buffer,
     }
   }
   LOGE("[Generic_Verify(): HMAC failed");
+  dump_boringssl_error();
   return OEMCrypto_ERROR_UNKNOWN_FAILURE;
 }
 
diff --git a/libwvdrmengine/oemcrypto/ref/src/oemcrypto_session.h b/libwvdrmengine/oemcrypto/ref/src/oemcrypto_session.h
index 4ed6846e..cd768b96 100644
--- a/libwvdrmengine/oemcrypto/ref/src/oemcrypto_session.h
+++ b/libwvdrmengine/oemcrypto/ref/src/oemcrypto_session.h
@@ -18,7 +18,7 @@
 #include "odk_structs.h"
 #include "oemcrypto_auth_ref.h"
 #include "oemcrypto_key_ref.h"
-#include "oemcrypto_rsa_key.h"
+#include "oemcrypto_rsa_key_shared.h"
 #include "oemcrypto_session_key_table.h"
 #include "oemcrypto_types.h"
 #include "oemcrypto_usage_table_ref.h"
@@ -59,22 +59,21 @@ class SessionContextKeys {
 };
 
 class SessionContext {
+
  public:
-  SessionContext(CryptoEngine* ce, SessionId sid);
   SessionContext(CryptoEngine* ce, SessionId sid,
-                 std::shared_ptr<RsaPrivateKey>&& rsa_key);
+                 const RSA_shared_ptr& rsa_key);
   SessionContext() = delete;
   virtual ~SessionContext();
 
-  bool isValid() const { return valid_; }
+  bool isValid() { return valid_; }
 
-  virtual OEMCryptoResult DeriveKeys(const std::vector<uint8_t>& master_key,
-                                     const std::vector<uint8_t>& mac_context,
-                                     const std::vector<uint8_t>& enc_context);
-  virtual OEMCryptoResult RSADeriveKeys(
-      const std::vector<uint8_t>& enc_session_key,
-      const std::vector<uint8_t>& mac_context,
-      const std::vector<uint8_t>& enc_context);
+  virtual bool DeriveKeys(const std::vector<uint8_t>& master_key,
+                          const std::vector<uint8_t>& mac_context,
+                          const std::vector<uint8_t>& enc_context);
+  virtual bool RSADeriveKeys(const std::vector<uint8_t>& enc_session_key,
+                             const std::vector<uint8_t>& mac_context,
+                             const std::vector<uint8_t>& enc_context);
   virtual OEMCryptoResult PrepAndSignLicenseRequest(uint8_t* message,
                                                     size_t message_length,
                                                     size_t* core_message_length,
@@ -88,7 +87,9 @@ class SessionContext {
   virtual OEMCryptoResult PrepAndSignProvisioningRequest(
       uint8_t* message, size_t message_length, size_t* core_message_length,
       uint8_t* signature, size_t* signature_length);
-  // Restricted to CAST receivers using PKCS1 block padding only.
+  // The size of an RSA signature.  This is used when signing as a CAST
+  // receiver.
+  size_t RSASignatureSize();
   virtual OEMCryptoResult GenerateRSASignature(
       const uint8_t* message, size_t message_length, uint8_t* signature,
       size_t* signature_length, RSA_Padding_Scheme padding_scheme);
@@ -140,12 +141,13 @@ class SessionContext {
       const std::vector<uint8_t>& key_data_iv,
       const std::vector<uint8_t>& key_control,
       const std::vector<uint8_t>& key_control_iv);
-  bool InstallRSAEncryptedKey(const std::vector<uint8_t>& enc_encryption_key);
+  bool InstallRSAEncryptedKey(const uint8_t* encrypted_message_key,
+                              size_t encrypted_message_key_length);
   bool DecryptRSAKey(const uint8_t* enc_rsa_key, size_t enc_rsa_key_length,
                      const uint8_t* wrapped_rsa_key_iv, uint8_t* pkcs8_rsa_key);
   bool EncryptRSAKey(const uint8_t* pkcs8_rsa_key, size_t enc_rsa_key_length,
                      const uint8_t* enc_rsa_key_iv, uint8_t* enc_rsa_key);
-  bool LoadRsaDrmKey(const uint8_t* pkcs8_rsa_key, size_t rsa_key_length);
+  bool LoadRSAKey(const uint8_t* pkcs8_rsa_key, size_t rsa_key_length);
   virtual OEMCryptoResult LoadRenewal(const uint8_t* message,
                                       size_t message_length,
                                       size_t core_message_length,
@@ -177,6 +179,7 @@ class SessionContext {
     encryption_key_ = enc_key;
   }
   const std::vector<uint8_t>& encryption_key() { return encryption_key_; }
+  uint32_t allowed_schemes() const { return allowed_schemes_; }
 
   // Return true if nonce was set.
   bool set_nonce(uint32_t nonce);
@@ -202,9 +205,9 @@ class SessionContext {
 
  protected:
   // Signature size of the currently loaded private key.
-  size_t CertSignatureSize() const;
+  size_t CertSignatureSize();
   // Signature size when using a keybox or OEM Cert's private key.
-  size_t ROTSignatureSize() const;
+  size_t ROTSignatureSize();
   virtual OEMCryptoResult GenerateCertSignature(const uint8_t* message,
                                                 size_t message_length,
                                                 uint8_t* signature,
@@ -254,52 +257,46 @@ class SessionContext {
   // entry, it also checks the usage entry.
   OEMCryptoResult CheckKeyUse(const std::string& log_string, uint32_t use_type,
                               OEMCryptoBufferType buffer_type);
+  RSA* rsa_key() { return rsa_key_.get(); }
 
-  bool valid_ = false;
-  CryptoEngine* ce_ = nullptr;
+  bool valid_;
+  CryptoEngine* ce_;
   SessionId id_;
-
-  // Message keys.
-  std::shared_ptr<RsaPrivateKey> rsa_key_;
   std::vector<uint8_t> mac_key_server_;
   std::vector<uint8_t> mac_key_client_;
   std::vector<uint8_t> encryption_key_;
   std::vector<uint8_t> session_key_;
-
+  const Key* current_content_key_;
+  std::unique_ptr<SessionContextKeys> session_keys_;
   ODK_NonceValues nonce_values_;
   uint8_t license_request_hash_[ODK_SHA256_HASH_SIZE];
-
-  // Content/entitlement keys.
-  const Key* current_content_key_ = nullptr;
-  std::unique_ptr<SessionContextKeys> session_keys_;
-
-  bool decrypt_started_ =
-      false;  // If the license has been used in this session.
+  RSA_shared_ptr rsa_key_;
+  uint32_t allowed_schemes_;  // for RSA signatures.
+  bool decrypt_started_;      // If the license has been used in this session.
   ODK_TimerLimits timer_limits_;
   ODK_ClockValues clock_values_;
   std::unique_ptr<UsageTableEntry> usage_entry_;
-  SRMVersionStatus srm_requirements_status_ = NoSRMVersion;
+  SRMVersionStatus srm_requirements_status_;
   enum UsageEntryStatus {
     kNoUsageEntry,      // No entry loaded for this session.
     kUsageEntryNew,     // After entry was created.
     kUsageEntryLoaded,  // After loading entry or loading keys.
   };
-  UsageEntryStatus usage_entry_status_ = kNoUsageEntry;
+  UsageEntryStatus usage_entry_status_;
 
   // These are used when doing full decrypt path testing.
-  bool compute_hash_ = false;  // True if the current frame needs a hash.
-  uint32_t current_hash_ = 0;  // Running CRC hash of frame.
-  uint32_t given_hash_ = 0;    // True CRC hash of frame.
-  uint32_t current_frame_number_ = 0;  // Current frame for CRC hash.
-  uint32_t bad_frame_number_ = 0;      // Frame number with bad hash.
-  OEMCryptoResult hash_error_ =
-      OEMCrypto_SUCCESS;  // Error code for first bad frame.
+  bool compute_hash_;  // True if the current frame needs a hash.
+  uint32_t current_hash_;  // Running CRC hash of frame.
+  uint32_t given_hash_;    // True CRC hash of frame.
+  uint32_t current_frame_number_;  // Current frame for CRC hash.
+  uint32_t bad_frame_number_;  // Frame number with bad hash.
+  OEMCryptoResult hash_error_;  // Error code for first bad frame.
 
   // The bare minimum state machine is to only call each of these function
   // categories at most once.
-  bool state_nonce_created_ = false;
-  bool state_request_signed_ = false;
-  bool state_response_loaded_ = false;
+  bool state_nonce_created_;
+  bool state_request_signed_;
+  bool state_response_loaded_;
 
   CORE_DISALLOW_COPY_AND_ASSIGN(SessionContext);
 };